https://www.sba.org.br/open_journal_systems/index.php/cba en-US grace@fem.unicamp.br (Grace S. Deaecto) Wed, 19 Oct 2022 00:00:00 -0300 OJS 3.1.2.1 http://blogs.law.harvard.edu/tech/rss 60 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3175 This work describes a control scheme proposed for guiding a leader-follower formation of mobile robots. In our approach, there is no information sharing, emphasizing a decentralized approach. The follower robot uses a laser scanner mounted on it to get and estimate information of its leader, such as its location and velocities. The proposed strategy can be applied in scenarios with several agents, in the possibility of having several leaders and also several followers. To validate this proposal, four robots are used, first in a diamond-shaped formation with one leader and three followers; then in a line-shaped formation, containing three leaders and three followers. The system stability can be verified through the asymptotic convergence of the formation variables to the desired values during the experiments, which is in accordance with the theoretical analysis performed in the controller design. Leonardo A. Fagundes-Junior, Denise Cristina H. de Freitas, Mário Sarcinelli-Filho, Alexandre S. Brandão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3175 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3176 In electrical planning and operation of an interconnected network, accurate infor- mation about the dynamic behaviour of a system is essential for its effective control and reliable operation. Specifically, in small-signal stability analysis, an accurate measurement of synchronous machine dynamic states, such as its rotor speed, is very important to mitigate the detrimental effects of poorly damped electromechanical oscillations in electric power systems. With the development of smart grids and an environment rich in information, it becomes possible to develop new methods to monitor and estimate the behavior of this variable from remote signals and apply it in stability studies. In this context, this paper proposes a decentralized approach based on Kalman Filter to estimate the rotor speed of synchronous generators. The proposed method uses only signals that can be easily sampled by measuring equipment, such as current and voltage transformers at the high voltage side of the step-up transformer of the power plant. The results obtained in the 68-bus system show an efficiency of the technique in estimating the speed of the generator under analysis even with the presence of noise in the sampled signals. Lucas de Paula F. D. Cardoso, Thales Pedro S. Esperança, Edson Luis Geraldi Junior, Tatiane Cristina C. Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3176 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3177 The rail system is essential for commercial activities and transport of people in several countries, playing an important role in improving economic indicators. In order to ensure the reliability and safety of rail transport, it is becoming increasingly important to monitor the conditions of the railway and to execute planned maintenance. The defect in the sleepers can cause an overload on adjacent sleepers, accelerating the structure fatigue of such components, contributing to the occurrence of new defects and finally affecting the track gauge. In this context, one proposes a new method for detecting defects in steel sleepers from the permanent way geometric signals, based on signal processing and machine learning. Three classifiers with different learning characteristics were trained: Artificial Neural Networks (ANN), Suport Vertor Machines (SVM) and AdaBoost. In addition, a multiple classifier system was implemented to improve system accuracy. Leonardo Pessoa Freitas e Silva, Glauco Ferreira Gazel Yared, Agnaldo José da Rocha Reis Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3177 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3178 This paper proposes the design of an adaptive virtual actuator for linear discrete- time systems subject to actuator faults. By means of new conditions based on Linear Matrix Inequalities (LMIs) and the virtual actuator adaptation law, the control reconfiguration without requiring the use of a Fault Detection and Isolation module (FDI) to compensate the different actuator faults becomes possible. Thus, in the presence of faults, the reconfigured system behaves asymptotically as the nominal system (without faults), not being subject to loss of performance and stability due to possible errors in the FDI module. Computer simulations for an open- loop stable and an unstable system are performed to verify the performance of the proposed methodology for different scenarios of actuator faults. From the analysis of the time responses obtained, it is possible to observe that the reconfigured system is able to compensate the faults and continue tracking the reference signal, with similar behavior to that of the nominal system. Mariella Maia Quadros, Víctor Costa da Silva Campos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3178 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3179 This article addresses the problem of vision-based robot control where the equilibrium is defined via a reference image. Specifically, this work considers the class of general direct solutions that diagonally decouple the control error dynamics also in the general case. Hence, those solutions provide for high versatility and accuracy, whilst the decouplings reduce analysis complexity and can improve system performance. In such a demanding context, the existing general diagonal direct visual servoing technique can present a stability problem arising from its parametrization. This study proposes a new parametrization and its new nonlinear estimator to solve such problem. Theoretical analysis of local stability, convergence, diffeomorphism and of that decoupling property are provided. Experimental results are also obtained using a camera- mounted 6-DoF robotic arm in a challenging scenario. Geraldo Silveira, Luiz Mirisola, Pascal Morin Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3179 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3180 The high insertion of Distributed Generation (DG) in the distribution networks can cause overvoltage in the feeders, in the low load condition and when there is high energy production by the Photovoltaic (PV) plants. Thus, resulting in the transgression of the voltage limits imposed by the regulatory agency. Other effect in energy quality are the harmonic distortions caused by frequency inverter. The objective of this paper is to present a case study in a low voltage system where there are photovoltaic plants of the self-consumption type remote, in order to verify the energy quality levels at the connection point. 1008 measurements were made in a period of seven days, where voltage and harmonics data were collected. It was found that in terms of the quality of voltage, there were transgressions in the periods of high generation, where the maximum voltage in the reading was 1.08 pu. There were no harmonic voltage violations according to the standard values. On the other hand, it was verified levels of current harmonics. Eleandro Luis Marques da Silva, Renata Mota Martins, Gustavo Marchesan, Ghendy Cardoso Junior, Leonardo Audalio Ferreira do Nascimento, Enoque Dutra Garcia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3180 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3181 This article presents the design and practical implementation of a dual-axis solar tracker using low-cost components and recyclable materials. The prototype has an open and circular structure, offering a natural cooling. The tilting of the photovoltaic panel is performed using two servomotors to obtain highest intensity of sunlight captured by 4 LDR sensors, placed to the left of the panel and separated by two opaque barriers, generating the shadow caused by the sun movement. For the system supervision and control, a Scada was developed using the ScadaBR. The prototype was tested and results compared, considering a system with fixed panel, one and dual-axis tracker. Results showed that the dual-axis tracker system proved to be more efficient, considering a generated voltage, around a 12, 45% compared to the single-axis tracker. Rodrigues da Silva M.B. Lorena, Jeronimo dos Santos Marcos P., De Sousa S. Thalyta, Beltrán A. Reinel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3181 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3182 The contribution of variable-speed generators in modern electrical systems has grown, mainly due to the installation of wind turbines. These generators use different configurations of electrical machines and electronic converters, one of the main ones being the combination of synchronous generators and three-level bi-directional voltage source inverters. One of the points that must be evaluated is their operation during the occurrence of electrical faults. Within this context, this article aims to present an analysis of electrical faults in salient- pole synchronous generators controlled by back-to-back three-level Neutral Point Clamped converters. A simulation performed on the Simulink software, in which electrical faults were defined on a variable-speed setup, was used as case study. It was noted that faults directly affect the behavior of the variable-speed generator and that differences in measured variables can be used to distinguish between faults occurring on the grid or generator side. Rodolfo V. Rocha, Renato M. Monaro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3182 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3183 In Brazil, there is a high rate of irregular dams, including places that are not even cataloged. These dams have a high potential for socio-environmental damage and a possible rupture would be capable of destroying rivers and villages. This paper proposes an ensemble method composed of hybrid models, based on Convolutional Neural Network (CNN) and Support Vector Machine (SVM) for detecting tailings dams in satellite imagery. The database used was BrazilDAM, considering 1924 multispectral images, where some combinations were evaluated using 13 different bands. The proposed method achieved 96.1% accuracy, 96.8% F1- score, and 98.7% AUC. The application of the proposed method shows better results than the traditional methods proposed in the literature. Diego A. B. Cardoso, Matheus R. Guimarães, Roberta B. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3183 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3184 In order to increase the generation of solar energy in a smaller installation area, that is, to maximize the captured irradiation, a solar tree project was developed. There are several parameters used in its construction and, among them, the divergence angle, angle between two consecutive photovoltaic modules, is a variable that helps in the efficiency of light capture. Studies in plants involving mathematical models show that divergent angles equal to the Fibonacci angle (or golden angle), whose value is 137, 5◦ and equal to the Lucas angle, whose value is 99, 5◦, provide better results in irradiation because they decrease the shading of the leaves in the spiral model. Thus, in order to obtain a mathematical model of the tree and verify the divergent angle relationship with irradiation and, thus, study the maximum points of this curve, a system identification process was used to model a tree. The objective is to verify which are the angles that provide the maximum irradiation. The model used was static model, using the least-squares method (MMQ), through data collected by simulation via software Rhinoceros. Larissa B. Grassi, Daniela P. A. Marins, Lohane B. Palaoro, Jussara F. Fardin, José L.F. Salles, Marcelo E. V. Segatto, Marcia H.M. Paiva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3184 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3185 In an electric power system, the assessment and prediction of dynamic security are essential to avoid interruptions in the supply of electricity to consumers, in addition to ensuring that the system operates reliably. Regarding the transient safety assessment, predicting the behavior of the electrical power system in the post-fault period within a short time interval is essential so that preventive and, if necessary, corrective actions are taken. In view of this, the present work proposes to develop an approach based on artificial neural networks, multilayer perceptron, for the prediction of transient stability in an electrical power system through measurements that can be easily acquired by phasor measurement units, such as magnitude and voltage angle of the buses. In the proposed structure, the smallest number of measurement cycles necessary to accurately assess the state of the grid was investigated. The results obtained in the IEEE 68 bus system show the efficiency of the predictor that obtains an accuracy of 97.5% in the classification from 6 consecutive measurement cycles of the system response. When only 1 measurement cycle was provided to the predictor, a high accuracy was also achieved (96.1%) by the proposed methodology. Gabriel Mancini, Guilherme L. da Cunha, Ricardo A. Souza Fernandes, Tatiane C. da Costa Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3185 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3186 The advances on deep learning techniques made computer vision tasks more accurate and faster by relying on convolutional neural networks and more powerful hardware. In the industry, automatic inspection supported by these methods may ensure constant maintenance and avoid railway acidentes. Thereby, this work proposes the application of deep learning and image processing methods for automatic inspection of train wagons wheelsets. More specifically, the size of wheels and the thickness of bandage are measured, in addition to locating the bearing fixing screws. The neural network built performs semantic segmentation on photographs provided by the mining company Vale. Using a U-Net architecture with ResNet50 as backbone, the network was able to reach 92.50% in mIoU and 97.52% in mPA, which are the adopted metrics for evaluating this proposal. The post-processing step retrieved the screws and improved evaluation metrics, indicating the success of the proposed inspection. Bruna Reis Lyra, Clebeson Canuto, Raquel Frizera Vassallo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3186 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3187 With the advent of new sources of power generation, among them the renewable ones,there has been a significant change in the power grid profile, especially for the distribution sectors. Thus, substations (SEs) with obsolete equipment find it difficult to meet the growing and diversified demands for energy, and a reflection of this problem is the significant increase in the levels of short-circuit currents. The short-circuit current limiter (SCCL) appears in this scenario as a protection equipment that can help, along with other components, in limiting the short circuit and minimize this problem. Among the several existing SCCL topologies, there is the saturated core current limiter (SCCL-SC) with its operation based on the dynamic characteristics of the ferromagnetic materials that compose its cores. This paper describes the extension of a single-phase modeling, in MATLAB software, of the LCCC-NS to simulations on three-phase electrical networks. The results prove the influence of the DC magnetic flux in the initial instants of a single-phase short circuit, due to the approximations considered for the three-phase model. However, when compared with measurements performed in the laboratory, the three types of DC current tested in the three-phase model of the limiter responded satisfactorily in the moments after the short circuit. Mariana Moraes Oliveira Rocha, Felipe Sass, Guilherme Gonçalves Sotelo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3187 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3188 The intensity of waste generation has become one of the biggest problems in today’s society, as it is a virtually impossible problem to be eliminated, where one of the possible solutions would be to take advantage of the benefits that waste can bring, which is the generation of electric energy through the use of biogas generated in landfills. Thus, this theme was thought to provide a general understanding of landfill, solid waste, biogas production and the electric energy generation through the use of biogas. In order to take advantage of this generation potential, it will be important to identify ways of treating waste, mechanisms for obtaining biogas and converting biogas into electrical energy. Aiming to study the potential of energy generation from waste from a sanitary landfill in Foz do Iguaçu/PR, aiming to develop the use of biogas as an alternative source of renewable energy and to estimate the potential for generating electricity derived from methane gas from waste of landfill. With the calculation of the estimate of biogas generation, it was possible to verify that the sanitary landfill of Foz do Iguaçu has an average production capacity to generate enough biogas to feed approximately 964 homes by the year 2030. Adão Ednei Vieira, Ali Mohamad Kanso, Oswaldo Hideo Ando Junior, Fernando Marcos de Oliveira, Marcelo Henrique Manzke Brandt Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3188 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3189 In this paper, a fuzzy descent method applied to adaptive filtering algorithms in the hypercomplex domain is proposed. The adopted methodology consists of Mamdani fuzzy inference system design, in the hypercomplex domain, applied to the computation of adaptation step size to be adopted for the convergence of the adaptive filtering algorithm. The partitioning of the universe of discourse regarding to the components of input and output hypercomplex variables of fuzzy inference system, to define the rule base, is performed by the expert’s knowledge about the application. For validation purposes, the proposed methodology was applied to a Normalized Least Mean Square (NLMS) filter variation, which is based on the minimization of cost function of the Recursive Least Square (RLS) algorithm. Computational results and comparative analysis illustrates the efficiency and applicability of the proposed methodology, providing lower computational cost and lower final misfit for estimating the optimal weights of the adaptive filter. Daiana Caroline dos Santos Gomes, Ginalber Luiz de Oliveira Serra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3189 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3190 Agriculture combined with robotics and automation uses methods and tools from the fourth industrial revolution to carry out processes that were previously done manually. It is aimed through this, the construction of a prototype for automatic irrigation. The system has mobility through the coordinate axes of a Cartesian robot, XYZ, being able to locate each plant, verify the need for irrigation according to its data and carry out the action, if necessary, efficiently and effectively. Isa Paula Ferreira Silva, Kennya Resende Mendonça Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3190 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3191 The power generated by PV arrays is directly associated with climatic conditions of the site of installation, through incident solar irradiance, ambient temperature and wind speed being the parameters that most affect their power generation. Therefore, it is evident that carrying out studies to better understand the influence of these parameters on generation is extremely important. It is known that the greater the incident solar irradiance, the greater PV module output power. High ambient temperatures causes an increase in module temperature, resulting in a decrease in power generation. The PV module temperature depends on numerous factors, which makes its estimation a very complex task. With the objective of increasing the quality and precision of this estimation, several authors have developed mathematical models that relate the cell operating temperature with the meteorological parameters. To evaluate the key characteristics that affect PV module temperature, this paper proposes a survey and comparison of the main mathematical models for estimating the operating temperature of PV arrays, found in literature. A model based on the average values of the evaluated methods is also proposed. Sofia S. F. Spanghero, Paula S. Vicente, Eduardo M. Vicente Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3191 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3192 This article presents an industrial inspection cell that utilizes a six degrees of freedom robotic manipulator to automate the inspection of vehicle parts with complex geometry. An inspection is defined as a sequence of poses that must be visited in sequence, allowing an end- effector mounted camera to capture images of the part from various angles. The two most utilized types of movement by industrial robots are implemented and compared in an inspection task. The first type is kinematic control for linear trajectory tracking in Cartesian space, and the second type uses fifth degree polynomials to generate joint space trajectories. The two movements were tested in a simulation environment that faithfully reproduces the real inspection cell. Experimental results show that the joint space movement results in smoother control signals when compared to the linear movement, although producing unpredictable Cartesian space trajectories. Lucca Garcia Leão, Gustavo Medeiros Freitas, Luiz Fernando Etrusco Moreira, Antônio Otávio Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3192 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3193 In the study of control systems, a piece of equipment used in the literature is the Aeropendulum. This system consists of a pendulum-motor-propeller set coupled to a rotational axis, where the angular displacement of the pendulum happens due to the thrust force of the propeller. So, the motor-propeller set must be activated according to the desired angle for the pendulum. This work presents the construction of a didactic Aeropendulum prototype, which was developed at the Automation Laboratory of the Federal Institute of Paraná (IFPR) – Jacarezinho. After the building of the prototype, a linear model for the system was obtained by carrying out tests in open-loop configuration around an operating point and using the 'ident' tool of the Matlab® software. A tracking controller based on LQR was designed to stabilize the system and make the pendulum angle follow a step-like trajectory. Simulations and experiments with the prototype showed the effectiveness of the proposed strategy. Hugo Fernando Yamanaka, Carlos Alexandre de Souza Bispo, Ricardo Breganon, Fernando Sabino Fonteque Ribeiro, João Paulo Lima Silva de Almeida, Uiliam Nelson Lendzion Tomaz Alves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3193 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3194 The present paper addresses the problem of stability analysis and robust stabilization of switched linear systems with time-delay in the state function. The uncertainty class considered is of discrete-time varying polytopic type. Conditions are proposed, in the form of linear matrix inequalities, via time-varying uncertain parameter-dependent switched Lyapunov functions, to ensure the positivity, stability and robust stabilization of the dynamic system. Polytopic uncertainties are considered in the state matrix and in the matrix that weights the time-delay state function. Two example systems are employedd to verify the effectiveness of the proposed conditions. Rodrigo Possidônio Noronha, Ginalber Luiz de Oliveira Serra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3194 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3195 The increase in the world population has generated the need for greater energy supplies. However, its growth was not accompanied, in numbers, by the supply of energy. In this context, environmental factors also prove to be a reducing agent for energy security, since the occurrence of long periods of drought affect the production of electricity. In view of this fact, energy independence is sought through renewable sources, of which wind energy has been standing out in the sector. Thus, this article enables an analysis of the hourly fluctuation of wind speed in some cities in Brazil, focusing on the Northeast region with the purpose of determining a possible implementation of wind farms under the determination of the wind regime. As a result, the highest wind intensities occur in periods with low rainfall. Therefore, it proves the possibility of using wind resources as a source capable of reducing water energy dependence in months of drought. To produce the results, databases from the Instituto Nacional de Meteorologia were used, verifying hourly data from automatic stations over a period of ten years, between 2012 and 2022. Vanessa Cristina Pereira Miranda, Stefânia de Oliveira Silva, Manoel Messias Silva Junior, Kleymilson do Nascimento Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3195 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3196 The paper presents an experimental study carried out using the regenerative grid simulator NHR 9410, in order to carry out studies on the integration of distributed generation systems to the electrical grids, mainly from the point of view of voltage variations. The process is carried out by implementing a virtual impedance, which emulates the impedance values of lines, where the tests are performed with the network simulator subjected to different conditions of active and reactive power. The experiment is validated by connecting a battery energy storage system (BESS) to the grid simulator. Chrystiano Alves Galdino, Victor Flores Mendes, Pedro de Oliveira Coelho, Arthur Miranda do Vale Ribeiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3196 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3197 Environment perception is one of the most complex tasks to be performed au- tonomously. Besides depending on expensive sensors, many applications require high compu- tational power, limiting the applicability of such solutions. This paper presents a solution for environment perception with monocular cameras, focusing on low processing costs for embedded systems or modern smartphone applications. The solution uses classical image analysis tech- niques (such as disparity maps and their U/V variants) with modern techniques (deep artificial neural networks) to detect and estimate the distance of objects in space. Experimental results show good accuracy in distance estimation, significant improvements in object detection, and a runtime close to that of algorithms using only classical methods. Samuel Henrique Guimarães Braga, Danilo Alves de Lima, Felipe Oliveira e Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3197 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3198 The entire industry has been striving to transition to a low carbon economy, and among these efforts are initiatives to reduce release of gas to the flare system. In order to achieve this reduction, it is necessary to measure and identify the sources of gas being released in the process. Due to the involved costs and technical difficulties, usually only the main flare lines have theirs flow measured in those systems. This article presents a flow inference system for major elements that release gas into the flare system, including safety relief valves (PSVs), control valves, and restriction orifices. In addition to estimating the flow, the proposed system groups gas delivery sources, making it possible to evaluate process units, areas and industrial plants, in addition to estimating the cost of this mass of gas burned in the flare system, considering even the type of involved gas. As a pilot application, the described solution comprises the monitoring of oil and gas refineries. Júlia Guardiani, Celi Lopes, Diego Medeiros, Lucas Marques, Danilo Curvelo, Diego Cabral, Gustavo Leitão, Ivanovitch Silva, Luiz Affonso Guedes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3198 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3199 Distribution systems, due to their complex topologies and configurations, present the challenge of maintaining the reliability and continuity of the energy supply. In this sense, one of the main faults in the electrical network is the emergence of multi-stage faults, which represent 20% of fault occurrences. Aiming at the context of smart grids, and considering electricity meters that will be optimally allocated, this work proposes a methodology for classifying multistage faults in primary radial and overhead distribution feeders, based on decision trees (DA), whose Input parameters are the currents of the primary distribution feeder under study, measured only at the substation. The current oscillographs were obtained from simulations with the software MATLAB/SIMULINK and the signal processing method adopted was the RMS (Root Mean Square). Therefore, the obtained results represent an accurate classification, superior to 97%, indicating efficiency of the proposed method for the classification of such defects. Marcelo Estevão da Silva, Joaquim Osterwald Frota Moura Filho, Juan Carlos Peqquenã Suni, Márcio André Baima Amora Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3199 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3200 Microgrids are basically composed of dispatchable and distributed generation, storage system and loads. They must be able to guarantee a stable supply of energy to the loads, being able to operate in connected or islanded mode in relation to the energy utility. Studies to evaluate the Electric Power Quality indices must be carried out for different operating conditions. In this paper, a modeling of the distribution grid of the CAMPUSGRID microgrid using PSCAD/EMTDC software are presented. Simulation results of diferent load profiles, load connection/disconnection scenarios and intermittent generation integration are presented. Anna D. E. F. Rocha, Amiron W. dos S. Serra, Patrícia de S. Santos, Lucas de M. C. França, Silvangela L. da S. L. Barcelos, Osvaldo R. Saavedra, Rafael G. Bento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3200 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3201 Screening is a process that classifies particles by size. The mining industry uses this process by employing vibrating screens, mainly in crushing circuits. The objective is to separate a material stream into two fractions: coarse material (retained) and thin material (through). The coarse material fraction is fed to crushers to be comminuted (reduced particle size). When screening is inefficient, fine particles are carried along with the coarse particles, which overloads the crushing stage, causing productivity losses and even equipment damage. In the literature, it is common to find control works to increase the efficiency of crushers, but there is little about control systems to increase the efficiency of screens. This work presents a fuzzy control solution applied in a screening process formed by ten parallel lines, in a Vale iron ore beneficiation plant, in Canaã dos Carajás, PA. The results indicate an increase of 15.87% in the time in which the screens operate at greater efficiency. Alexandre G. Fonseca, Thomás V. B. Pinto, Kaike S. Albuquerque, Robson A. Duarte, Thiago A. M. Euzébio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3201 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3202 This work aimed to develop a strategy for driving a three-phase induction machine using indirect field-oriented control and Space Vector pulse width modulation, aiming to control the speed and shaft currents in order to maintain a constant speed for variations in rotor load. Among the results obtained, it can highlight the slip of less than 1% after applying a load 50% higher than the nominal one supported by the machine. The SVPWM provided a maximum utilization of 104.58% of the converter’s DC bus in the overmodulation region and 100% in the linear region. Judson P. da Silva, Igor L. Araujo, Rodrigo P. de Medeiros, Cecílio M. de Sousa Neto, Tania L. Laura Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3202 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3203 The wide use of three-phase induction motors (TIM) in various industry sectors encourages the search for techniques for monitoring and diagnosing defects in these machines to avoid production stops and unforeseen maintenance. Bearing fault detection is performed by analyzing the behavior of some motor variables, such as vibration and stator current, and their classification using artificial intelligence and machine learning. However, few studies on the modeling and simulation of these faults present a viable resource to cover several engines and specific operating conditions, such as different loads and speeds. Therefore, this work aims to implement a model for TIM’s bearing failure simulations in dq0 reference that provides current data of a stator phase to analyze this frequency spectrum. From information extracted from this spectrum, 200 samples representing different TIM situations with bearing failures are submitted to two pattern classifiers, Multilayer Perceptron network and Kohonen network, to validate the proposed diagnostic method. Carolina A. Bianchini, Marcelo Favoretto Castoldi, Alessandro Goedtel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3203 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3204 This paper describes the project of a brushed DC motor controller for the locomotion system of a combat robot with the aim of developing the national technology, since similar controllers are only available in the international market. Also is presented in detail the thermal dissipation study developed and the calculation of track width in printed circuit boards so that the controller supports currents of up to 80 A. The project also counts with peripherals such as datalogger, telemetry and a sensors network capable of monitoring voltage, current and temperature. Currently the device is fully working, with printed circuit board already assembled and tested in laboratory. Thiago H. Soares Santos, Listz Simões de Araújo, Elias José de Rezende Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3204 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3205 The concept of Industry 4.0 is being widely implemented in all phases of industry and brings the proposal of possible solutions for more complex applications such as data flow, modelling, simulation of physical systems, safety, and security. Among the technologies related to Industry 4.0, we have the digital twin that is based on the physical models generated and synchronized by the execution of the process life cycle. Thus, the main goal of Digital Twin is to provide information about the physical system to build its representation on a virtual twin. We also have the maturity analysis proposed by RAMI to evaluate in which context of Industry 4.0 the system is. Rafael S Mendonca, Marcelo A. Oliveira, Florindo A. C. Ayres Jr, Renan L. P. Medeiros, Vicente F. Lucena Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3205 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3206 The main objective of this work is to evaluate the factors that cause an increase in the error in current transformers used in measurement and protection, as pointed out in the specialized literature, and to propose a new connection topology and treatment of the measured data using computational compensation methods with the purpose of optimizing the accuracy of current transformers. In this way, it is possible to reduce billing losses in the system and enable protection relays to perform power quality measurements with the greatest possible reliability. The experimental results present in this work validate the proposed theory and suggest that this measurement methodology has the potential for an important innovation in this topic. Rodrigo C. Ciarlini, Francisco Kleber de A. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3206 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3207 The growing demand for traditional mathematics through electrical quality and the change of generated electrical systems to smart grids, the development of computer systems, which is possible from the modeling of distribution systems. In the present work, a study and analysis of the influence of line models on the voltage profile of primary electrical energy distribution feeders is carried out. The mathematical modeling of the IEEE 13 primary feeder was made in Matlab®/Simulink® software as the original and a modification to active grid with the insertion of a wind turbine as distributed generation, being the primary implementation and the primary implementation of the distributed distribution line models and concentrated. The results obtained allowed the validity of the models, and the comparative analysis in the test profiles regarding accuracy and computational performance. Pedro Fellipe Lima Brandão, Ângelo Marcílio Marques dos Santos, Hugo de Magalhães Moura, Juan Carlos Peqqueña Suni Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3207 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3208 Applications based on gestures or actions are increasingly common in everyday life. This is because it allows the user to activate the equipment without the need to touch it, besides being possible to activate it remotely. Thus, this work proposes a gesture recognition method using Principal Component Analysis (PCA) as a dimensionality reducer of variables, and the Euclidean distance as a classifier. The objective here is o interact with an environment through the actions of a user. To do this, a own database with 14 classes of actions were created. The classifier is validated through an online operation and confusion matrix are used to analize the results. The classifier achieved a hit rate higher than 80% for 6 of the 14 classes. This shows that the present work can be improved. However, it is worth noting that the main contribution was the formalization of a simplistic classifier, which makes use of a small database. Werikson F. de O. Alves, Ketia S. Moreira, Alexandre S. Brandão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3208 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3209 This work presents the development of an extremum seeking controller (ESC) based on periodic perturbation for tracking the resonance frequency in HRG gyros. For controller validation, a simulation model based on gyro motion equations is developed in Simulink environment. The behavior is analyzed for systems with one or two resonance peaks and for time-varying resonance frequencies. Felipe Augusto Rizzi, Bruno Augusto Angelico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3209 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3210 Testing with robots and especially with large agricultural robots is a task that requires high costs, risks and depends on weather conditions. Although there is a gap between simulation environments and real environments, simulation environments offer the advantages of being totally safe, making it possible to verify the performance of the control algorithm and even have the possibility of simulating sensors and actuators that have not yet been physically implemented. In addition, simulation enable risk-free assessment and adjustment of new control methods before implementation in real systems. In this work, we propose an approach to run experiments with Deep Reinforcement Learning (DRL) algorithms using Robot Operating System (ROS) and Gazebo robotics simulator. For this purpose, we use the robo-gym framework to interface between the DRL algorithm and the simulation using an OpenAI Gym environment, and augmented the capacity of Gazebo using the gazebo-fmi-actuator plugin that allows co- simulation with Functional Mock-up Unit (FMU). It is also presented an application of the simulation and control of the hydraulic steering system of a large agricultural robot using a Deep Deterministic Policy Gradient (DDPG), Soft Actor Critic (SAC), and Twin Delayed DDPG (TD3) DRL algorithms and comparing they with a PID controller. Gabriel A.B. Arias, Arthur J.V. Porto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3210 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3211 The state estimation process is fundamental for the real-time operation of electric power systems (EPSs), since the estimated values of the state variables are the basis for the execution of functions related to real-time monitoring of EPSs. In the traditional modeling of the state estimation process in EPSs, it is assumed the hypothesis that the measurements available for estimation have independent random errors. However, because the measurements are the result of processing signals from several sensors, and several measurements may share signals from the same sensors, that hypothesis is not valid. Given the above, this paper has two objectives: (i) to analyze the procedure for obtaining measurements from sensor signals; and (ii) to investigate the influence of the sharing of sensor signals in the traditional process of state estimation in EPSs. For this, this study uses the weighted least squares state estimator, associated with the largest normalized residual test, as they are the estimator and the technique for gross errors processing most used in practice and most studied in academia.The influence of the hypothesis that the measurement errors are independent was evaluated from the perspective of the accuracy of the estimates obtained and the handling of gross errors. Lais C. Oliveira, Vitor H. P. Melo, Renato Oliveira, João Bosco A. London Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3211 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3212 This article deals with the design and control of a new rotational series elastic actuator (SEAr) to drive the hip joint of the Exo-TAO exoskeleton. The proposed actuator consists of a flat DC motor, a Harmonic Drive gear and a customized torsion spring. Torque control is implemented to ensure secure and compliant interaction with the user. Experiments with the Exo-TAO, configured with zero impedance, showed that a healthy individual can walk wearing the exoskeleton with reasonable comfort and a near-natural gait pattern. Wilian M. dos Santos, Felix M. Escalante Ortega, Adriano A. G. Siqueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3212 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3213 Robotics is a tool that encompasses concepts of automation, control, electronics, and pro- gramming, widely used in teaching through modules and didactic plants. In order to develop a low-cost system for teaching robotics, this work presents the construction of a holonomic robot with three omnidirectional wheels. For this construction, a mathematical analysis of the system is described, in addition to physical, mechanical, electronic, and programming solutions. The prototype developed allows applications of classical control, sensing and remote control, planning, and navigation, among others in the robotics area. Kayke A. T. Martins, Nathan A. Z. Xavier, Lucas V. R. Alves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3213 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3214 The objective of this paper is to size the power required by the main powertrain components used to electrify a backhoe loader in order to meet the requirements demanded by an operating cycle called backfill. The backhoe loader is modelled based on the external forces acting on itself. The power sizing approach was inspired in a technique applicable to the on-road vehicle electrification. This technique was adapted to electrify a backhoe loader. The backhoe loader modelling and the power sizing were implemented in a script developed in MATLAB. The simulation results showed backhoe loader is not able to recover braking kinetic energy along the backfill. The results also showed that power minimization of the engine-generator set maximizes the capacities of power and energy of the electrical energy storage source. Pedro H. A. de Oliveira, Igor A. Pires, Braz de J. C. Filho, Anderson do Nascimento, Thales A. C. Maia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3214 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3215 Skin cancer is the main type of cancer that affects people all over the world, being melanoma the most feared, due to its rapid spread throughout the body. If it is detected in the early stages, the chances of cures are above 96%. Due to this, approaches to help the clinicians in the correct diagnosis, as well as that focused on the explanations, have been largely explored. In this context, this paper aims to build a binary classification of skin moles model using the ResNet50 and explain its prediction by comparing two known explainer tools LIME and Decision Trees (DT). The ResNet50 architecture achieved results of about 92% in terms of accuracy and up to 91% in sensibility and specificity. When LIME and DT were compared, both showed no fidelity error. However, in terms of stability, measured by the Jaccard index, LIME presented an stability of 0.497 ± 0.473 and DT of 1.0 ± 0.0, showing stability only for the latter. These results were obtained from 30 runs of images randomly chosen from the test base. Through a visual analysis, LIME varied in two of the 5 images from the benign and in one from the malignant lesion. As important as generating good classification models is providing clinicians with good explanation models that are intuitive and consistent. Samara S. Santos, Tamires M. Rezende, Marcos A. Alves, Frederico G. Guimarães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3215 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3216 Currently, with greater awareness about environmental impacts arising from electricity generation, there is a growing demand for forms of energy generation through renewable sources, such as solar and wind energy, to the detriment of known harmful impacts forms of energy, such as the burning of fossils fuels. In addition, the increase in the use of non-linear loads in recent decades has resulted in greater disturbances in the electrical network, such as harmonics, for example. Thus, this study aims to carry out an analysis and development of an integrated topology based on the DC-DC Zeta converter, which, in addition to operating as an interface converter when connected to a photovoltaic (PV) system, is responsible for injecting current into the electrical grid, can act as an parallel power active filter (FAPP) mitigating problems related to harmonics generated by non-linear loads, it is should be noted that this operation will be done through computer mathematical modeling and simulations. André L. B. Ferreira, Anderson A. Dionizio, Leonardo P. Sampaio, Sérgio A. O. da Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3216 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3217 The advent of the IEC 61850 standard and its extensions has caused a tremendous impact on the substation automation protection and control (PAC) systems. New breakthroughs are taking place supported by the IEC 61850 that consider the virtualization of the Intelligent Electronic Devices (IEDs). In view of these technological advances, a modern PAC laboratory is essential for education and training of professionals and students of engineering and technology. This paper presents a PAC platform, implemented in the Electrical Engineering Department of the Federal University of Ceara, Brazil, to promote the understanding, technical knowledge, and tools in power system digital protection. The PAC platform aims to offer a hands-on and interactive training environment to facilitate the learning and foster analytical skills, critical thinking, and self-confidence on power system protection. The learning platform includes physical and virtual IEDs, notebooks and a relay test set connected to a Local Area Network (LAN). The design of a Virtual IED (VIED) is presented, and validation tests of the instantaneous overcurrent function are performed. Test results have shown horizontal GOOSE communication between physical IED and VIED. Thus, VIEDs were used instead of physical IEDs to build a PAC learning platform. The VIEDs provide a new effective means for training qualified personnel in the state-of-the-art in power system protection and for application on smart substation. Claudivan D. Freitas, Ruth P.S. Leão, Raimundo F. Sampaio, Lucas S. Melo, Giovanni C. Barroso, Luís L.P. Martins, Alice S. Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3217 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3218 In this work, we study the applications of constructive heuristic and job positioning algorithms for a long-term maintenance scheduling problem. This problem is complex, where it is necessary to schedule preventive maintenance orders for the available work teams for a time horizon. Up to date, constructive heuristic and job positioning algorithms have not been explored in the literature for this problem. This study proposes a method that can generate a set of constructive algorithms based on several construction rules and returns the best of them for each instance. We use large instances to evaluate the proposed method. In addition, we compare its results with those of meta-heuristic algorithms from the literature. The proposed method demanded much less computational time. Moreover, it found the best result in 49% of the instances, including the largest with more than 33,000 jobs. Diego Gomes Coelho, Luciano Perdigão Cota, Marcone Jamilson Freitas Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3218 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3219 According to the 2029 Ten Year Energy Expansion Plan, there are a trend in applying battery energy storage system (BESS) in photovoltaic (PV) plants. In this context, this work presents an elaboration of an optimal energy management system (EMS) for a joint operation of BESS in centralized PV plants (PV/BESS). This article aims to determine an objective function to optimize it, maximizing the profit concentration of a PV/BESS system applied to the simulated centralized PV plant of Coremas. For the system model the considered variables are, energy pricing model, batteries degradation and losses model and a penalty due to power limit violation. The operation optimization was achieved through the use of genetics algorithm. System simulations performed in MATLAB obtained positive results for the proposed EMS, obtaining an average profit gain of 2.11% for 2021. Liane M. Oliveira, Micael P. Lucena, Lucas Haas, Sidneia L. Cavalcante, Camila S. Gehrke, Lucas V. Hartmann, Flávio S. V. Gomes, Italo R. F. M. P. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3219 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3220 This work proposes a new method to use virtual reconfigurable stabilizers for stabilization and oscillation damping in DC-DC converters with constant power loads. This concept, inspired by reconfiguration blocks for fault hiding, is used in this paper for dealing with negative impedance effects while maintaining the operation with a controller previously designed. Thus, design conditions based on linear matrix inequalities are presented to obtain the parameters of the stabilizer for guaranteeing the exponential stability of the converter’s operation point. Numerical simulations indicate that the stabilizer is able to improve the system’s damping and to guarantee the stability in scenarios where the nominal controller is unable to stabilize it. Iury Bessa, Pedro H. S. Coutinho, Isaías V. de Bessa, Renan L. P. Medeiros, Reinaldo M. Palhares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3220 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3221 In this work, the optimal power flow problem is formulated based on the implicitly coupled method (CRIC - Calcul de Reseaux Implicitement Couples) with the objective of optimizing energy generation costs and the voltage level of the electrical power system while satisfying the main operational and network security constraints. The characteristics and implementation processes used in the development of the implicitment coupling method are presented and discussed in detail. The proposed method was implemented in the AMPL language, solved using the solver KNITRO, and applied to IEEE 118-, ACTIVSg200-, and ACTIVSg500-bus systems. The obtained results demonstrate that, compared to the traditional coupled method, the proposed method for solving the optimal power flow problem determines solutions of comparable quality, if not superior. This presents the implicitly coupled method as a novel and promising alternative for the large-scale electrical system optimization. Lucas C. Yamaguti, Juan M. Home-Ortiz, José R. S. Mantovani Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3221 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3222 This paper presents the impacts evaluation of power quality disturbances through simulations carried out using MATLAB and Simulink. In this regard, a transmission line with series compensation is modeled and subjected to short-circuit in several scenarios analyzed. The performance of the parameterized protection relay with distance function, ANSI 21, as well as the power quality impacts on the system are investigated. Research related to this topic is increasingly significant, due to the high penetration of solar and wind sources into the energy system. Verification of the protection devices’ operation, when exposed to power quality disturbances, is necessary, since they lack monitoring systems capable of measuring such impacts in real-time. These disturbances can considerably affect the protection system operation, and consequently impact the electrical system as a whole, causing huge losses to network users. Industrial and commercial consumers, who need availability, quality, and reliability of energy supply to maintain their electro-intensive industrial processes are the most affected. Vinícius C. de Moraes, Igor D. Melo, Jeanderson S. Mingorança, Camile A. Moraes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3222 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3223 Renewable energy sources such as solar photovoltaic have grown every year. Although beneficial, the integration of photovoltaic solar generation systems can cause problems due to meteorological variations that lead to uncertainties in energy production. In this sense, this work evaluated three artificial neural networks topologies to improve the forecasting of photovoltaic power and energy. The results show that the topology with 5 neurons in the hidden layer was able to predict the photovoltaic energy with an error of less than 1.3% in relation to the measured energy. Gustavo Henrique de Paula Santos, Paul Junior Zapana Vargas, Elmer Pablo Tito Cari, Moisés Carlos Tanca Villanueva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3223 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3224 In this article, a Feed Forward Artificial Neural Network is applied to the RLS-LMS adaptive algorithm, with the objective of tuning the weight parameters, calculating the ideal or optimal weights used in the signal input of the linear filters that adapt the pattern of uniform linear array antenna radiation, directing multiple narrow beams to desired users and nullifying interference or unwanted users. The application of this neural network provides the ability to increase the efficiency and optimize the use of smart antennas. The results obtained are presented. This article is based on the work of (Ribeiro et al, 2019) taking the results obtained in the use of the combination of two adaptive filters LMS (Least mean- square) and RLS (recursive least-square) combined to obtain an adaptive algorithm RLS- LMS that surpassed classical algorithms in terms of convergence speed and stability. ANTÔNIO HENRIQUE DOS SANTOS RIBEIRO, JOÃO VIANA DA FONSECA NETO, FRANCISCO DAS CHAGAS DE SOUZA Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3224 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3225 Social robotics is an increasing area that has boosted the integration of robots and people in common environments. Thus, new Human-Robot Interaction (HRI) techniques have emerged to make robots behave in an acceptable and social ways. interaction is one of these new techniques, that dictate the distance between robots and humans. In this sense, robots must respect the proxemic zones of people around them, while navigating in the shared spaces. In this work, we propose a social aware navigation system based on proxemic that responds to voice commands to move around in an environment shared with people. This social navigation system is integrated into GProxemic Navigation, a system that automatically provides the robots location and the proxemic zones that robots must avoid during their navigation, according to the environment characteristics. To demonstrate the functionality and suitability of the proposed proxemic navigation system, we implemented it in an autonomous wheelchair. this implementation, the wheelchair can be activated to make the most efficient path respecting the social constrains of the environment Marcelo Sampaio, Giovane Moreira, Adriel Souza, Érika Correia, Anderson Leite, João Vilasboas, José Díaz Amado, João Marques Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3225 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3226 For the purpose of defining and understanding the power phenomena in electrical circuits, two theories have been highlighted in the literature, the Current’s Physical Components (CPC) and the Conservative Power Theory (CPT). Therefore, this paper investigates the main similarities and discrepancies between CPC and CPT through computational simulations of single-phase electrical circuits under sinusoidal and non-sinusoidal voltage conditions. Although the two methods are based on different concepts and domains, the results obtained are very similar. Moreover, this paper tries to explain the causes of similarities based on the decomposition’s foundations and the resulting currents values. Matheus B. Arcadepani, Alexandre C. Moreira, Fernando P. Marafão, Helmo K. Morales-Paredes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3226 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3227 Electric motors are the most common equipment in industrial plants, and bearings are the most vulnerable components to failure. Considering the importance of electric motors operating in good conditions to maintain the continuity of the production process in industrial plants, this work investigates and compares the performance of several classification architectures when applied to the diagnosis of bearing failures. To build the models 13 statistical descriptors were extracted from the vibration signals available in the Paderborn data set. The models were built in the time domain and time-scale domain using the wavelet transform, and the k-Nearest Neigbour (k-NN), Support Vector Machine (SVM) and Decision Tree (DA) algorithms were applied. The performances of the models were evaluated using the metrics of accuracy, precision, sensitivity, specificity, and F1-score. The average result obtained in all classifier configurations was around 98%. Rodrigo Cesar Campos, Gizele Poltronieri do Nascimento, Gabriel Tozatto Zago, Luiz Alberto Pinto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3227 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3228 This work aims to generate indicators to monitor a pharmaceutical laboratory water treatment plant processes from the creation of a data analysis model, which includes stages from data collection to data visualization. The proposed methodology includes understanding the process and defining analysis objectives, collecting data from controllers, preparing them in the pre-processing stage to make them suitable for the study and then exploring and visualizing information extracted from these data. The expected result is to generate monitoring indicators that provide information to improve water treatment unit monitoring. Ítalo O. Fernandes, Heitor M. Florencio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3228 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3229 E-commerce platforms (marketplaces) receive daily thousands of products belonging to new classes that have not participated in the training process of the algorithm responsible for automating the classification of products. However, it is difficult to constantly update the system with these products, because the cost of retraining the classifiers currently in operation is high due to the large size of the databases. In this sense, the use of product classifiers that use few- shot learning algorithms is an interesting option, as they are capable of being trained using only new classes containing one or few samples per class. Therefore, the k-nearest neighbor (KNN), Matching Networks (MN) and DPGN (Distribution Propagation Graph Network) algorithms were compared in the product classification problem using a database, with 312 classes and 3120 samples, from a marketplace. The tests were performed with k-fold cross-validation, of which the matching networks presented the best result with 93.78% accuracy. Aleson G. S. Chaves, Bruno H. G. Barbosa, Danton D. Ferreira, Paulo R. Silva, Sinval T. Nascimento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3229 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3230 Over the years, electric power consumption has been increasing significantly, making it necessary to adopt measures to monitor the process up to the distribution, so that its supply is not interrupted. In that process, among the various devices that are part of the system, the proper monitoring of the operational state of the substation disconnect switches plays an important role. They are responsible for connecting the high voltage to the medium voltage, used to reconfigure the network and isolate the equipment for maintenance. In this scenario, this work developed a methodology for detecting 69kV disconnect switches and determining their operational state: opened or closed. The system applies computer vision techniques, aiming to generate a generalized model for real-time inference of the switches during the regular operation. The methodology incorporates image acquisition, data preparation, training with the tiny- YOLO algorithm, and testing of the model obtained. As a result, in face of the approached scenario, it was verified that the proposed solution can successfully detect correctly the state of the phases, achieving a mAP equals to 97.50%. Tamires M. Rezende, Bruno A. S. Oliveira, Glauco M. V. de Paula, Gustavo P. de Souza, Daniel Calvo, Eugênio L. Daher, Adriano O. da Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3230 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3231 Using the RTK technique, GNSS receivers may achieve centimeter positioning accuracy, but the high cost limits its use in many applications. This work brings assembly schemes and open-source codes of analysis and implementation of a low-cost RTK applied in an autonomous surface vehicle with an embedded sensor to survey the water conditions of hydroelectric generation reservoirs. This system has out-of-the-box compatibility with equipment and other robots that operates with GPS or GNSS receivers and its costs are less than R$10,000.00. In the tests, the system achieve an accuracy of approximately 0.12 m, a value better than 4.5 m obtained with the receiver operating with single-point positioning. Thus, the proposed system is able to improve the data collected by the embedded sensor and the vehicle navigation, without increase significantly the final cost. Guilherme Aparecido Barbosa Pereira, Leonardo de Mello Honório, Edimar José de Oliveira, Alessandro Salles Carvalho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3231 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3232 The smart inverter function Volt-Var (VV) was proposed to mitigate one of the major impacts caused by distributed generation in Distribution Systems (DSs), overvoltage. Therefore, the operation and planning of the new DSs require robust VV modeling in the load flow calculation. In this context, this work presents a comparative study of the convergence process of the load flow calculation, considering two different VV models in the literature: the model used in the OpenDSS software and one based on the linearization of the QV curve. Simulation results in the IEEE 4 and 34 nodes test feeders expose the relevance of the relationship between the VV and QV curves and the scale factor in the convergence process and find that the OpenDSS model has a lower computational cost, however with a lower efficiency. Finally, possible improvements are proposed. Miguel F. M. Sampaio P., Julio A. D. Massignan, Vitor H. P. de Melo, Benvindo R. Pereira, João Bosco A. London Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3232 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3233 This work presents the development of an Internet application that allows the tracking of agricultural products and the virtual visitation of rural properties located in the Linhares Geographical Indication (GI) of cocoa, created at the request of the Associação dos Cacauicultores do Espírito Santo (ACAU). Headquartered in Linhares, Espírito Santo, ACAU is currently working to strengthen its brand on a national and international scale and looking for ways to add value to its GI product, the cocoa bean. The methodology used in the development of the tracking technology used by Cacauicultura Capixaba is described in this manuscript, from the method used for the dissemination of laboratory information on the characteristics of the almonds to the display of aerial and panoramic images of the property where he was cultivated. As a result, a tool aligned with the Agriculture 4.0 concept is obtained, allowing the final consumer of the almond to track information that certifies the quality of the product while also virtually knowing the geographical location where it was produced. This alignment raises the profile of producers included in the Geographical Indication as well as ACAU. Vinicius de Moura Siqueira, Mateus Falcão, Edione Cirilo Pereira, Lucas Vago Santana, Geovani Alipio Nascimento Santos, Adalto dos Reis Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3233 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3234 This paper proposes the control design and analysis for a multivariable Gradient- based stochastic extremum seeking under delays. Multi-input systems with output delay and time delays in the input channels are dealt with. The phase compensation of the stochastic dither signals and a new predictor based on the estimate of the unknown Hessian are presented and incorporated in the closed-loop, allowing to achieve exponential stability and convergence to a small neighborhood of the unknown extremum point. This result is rigorously reached by using backstepping transformation and averaging in infinite dimensions. A numerical example is shown to illustrate the effectiveness of the proposed predictor-based stochastic extremum seeking for time-delay compensation. Paulo Cesar Souza da Silva, Paulo César Pellanda, Tiago Roux Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3234 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3235 This work introduces modeling and characterization of a microgrid system focused on a single-phase distributed generation (DG) for hardware-in-the-loop (HIL) real-time (RT) applications. The interconnection of key modules/blocks and their effects are discussed such a way that the presented system can be enlarged or useful for other works. The DG system is composed of a photovoltaic (PV) arrangement connected with static converters, battery energy storage system (BESS) unit, and optional output filter. An accurate system characterization for HIL applications contributes to reduce rework costs. A small scaled microgrid composed of 600 nodes distribution network is considered for preliminary tests and fault scenarios. Modeling and some preliminary simulation results are presented. Paulo G. M. Leandro, Gregory A. de Almeida Carlos, Oswaldo H. Ando Junior, Fabiano Salvadori Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3235 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3236 Applications with autonomous robots play an important role in the industry and in everyday life. Among them, the activities of manipulating and moving objects are highlighted by the wide variety of possible applications. These activities in static and known environments can be implemented through logic planned by the developer, but this is not feasible in dynamic environments. Machine learning techniques such as Reinforcement Learning (RL) algorithms have sought to replace the pre-defined programming by teaching the robot how to act. This paper presents the implementation of two RL algorithms, Deep Deterministic Policy Gradient (DDPG) and Proximal Policy Optimization (PPO), for orientation and position control of a 6-degree-of-freedom (6-DoF) robotic manipulator. The results demonstrated that the DDPG had a faster learning convergence in simpler activities, but if the complexity of the problem increases, it might not obtain a satisfactory behavior. On the other hand, PPO can solve more complex problems, however, it limits the convergence rate to the best result in order to avoid learning instability. Felipe R. Campos, Aline X. Fidêncio, Gustavo Pessin, Gustavo M. Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3236 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3237 This work presents an experimental test bench for generating representative distur- bances in a transformer. The experimental configuration uses a 1 kVA three-phase transformer with accessible taps in its windings to generate turn-to-turn and turn-to-ground faults. Further- more, external faults and transformer energizations in the presence and absence of permanent faults were also generated in this experiment. The records of the evaluated events are exported from the oscilloscopes to be evaluated in an offline way in a MATLAB® environment. The performance of the conventional differential protection unit (87T) is evaluated for these real cases. The consistent results highlight the feasibility of using the experimental setup as a valuable step for validating transformer differential protection schemes. Rodrigo P. Medeiros, Lucas D. Simões, Flavio B. Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3237 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3238 The coexistence of service robots in social media has intensified, making human- robot interaction increasingly fluid and necessary. In this context, the present work aims to apply an architecture called Erika responsible for integrating a chatbot that interacts by voice and text command with the autonomous navigation of a wheelchair, which respects social restrictions based on the proxemics zones. An Application Programming Interface is responsible for connecting the chatbot with a web application that communicates with Robot Operating System. The results found demonstrate that the wheelchair can respond to the commands provided by the chatbot, so that, finally, it can trigger autonomous or manual navigation, when necessary. Anderson Leite, Érika B. Correia, Giovane Fernandes Moreira, Marcelo Sampaio, João Vilasboas, Adriel Bastos, José Díaz-Amado, João Soares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3238 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3239 This paper presents a new limited switching frequency digital hysteresis current control method for a five-level neutral point clamped (NPC) Type G medium voltage induction motor drive. An indirect rotor field-oriented controller (RFOC) is used to speed control. The hardware topology and the controller implementation are described. The proposed method is compared to the traditional one, which is based on sampling frequency limitation. Results obtained from computer simulations are presented. It can be noted from them an improvement of the voltage and current harmonics spectra and diminution of the torque ripple amplitude. Daniel Franco Leal, Alex-Sander Amável Luiz, Marcelo Martins Stopa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3239 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3240 This work proposes different design methodologies for resonant controllers applied to static power converters focusing on an uninterrupted power supply. Three methods of resonant control are analyzed, the first is considering the internal model, the second is through state feedback and the third is applying the DQ transform. The performance of each controller is tested considering load variation, certifying the robustness against parametric uncertainties. All methods presented satisfactory results, and the internal model resonant controller obtained the best error tracking. Maicon de Miranda, Elieser P. Bastos, Fábio E. Bisogno Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3240 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3241 Non-technical losses (NTLs) or commercial losses are caused by multiple factors such as: energy theft, energy meter fraud, self-reconnection, damaged energy meter, consumer default and others. NTLs cause significant financial losses to power utilities, undue changes in the distribution network and damage to consumer units (CUs) with the increase in their energy bill. In this context, we propose a methodology based on artificial neural networks (ANNs) to detect NTLs in power distribution network. The methodology has two modules: (i) extraction of statistical attributes and (ii) module for classification based on the Fuzzy ARTMAP. The proposed methodology presents high indexes for the metrics: success rate (99.0%), reliability (93.6%), and specificity (96.7%). Therefore, it has good coverage for detecting irregular CUs and a high success rate in field inspections. Thus, costly field visits by inspection teams in regular UCs are drastically reduced. Vitor G. Silveira, Andréia S. Santos, Mara L.M. Lopes, José F. Resende da Silva, Lucas Teles Faria Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3241 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3242 In order to extract temporal characteristics, find the trend and seasonality and eliminate noise from a time series, one of the ways is to use a time series decomposition technique. In this work, two time series decomposition methods are discussed. The first performs the SSA algorithm for time series decomposition using a more usual approach, in which eigenvalues and eigenvectors are calculated in batch from the whole time series. In the second approach, the eigenvalues and eigenvectors are updated recursively. The methods were implemented in MatLab® and the computational cost between the algorithms was compared. The results illustrate that the recursive SSA approach has a lower computational cost compared to the batch method. Guilherme Santos Martins, Mateus Giesbrecht Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3242 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3243 An intelligent PID (iPID) model-free controller is applied for longitudinal control of a simulated vehicle, acting as a substitute for the driver. An efficient discrete implementation for an intelligent proportional (iP) controller is presented and discussed, especially its ability to attenuate noise. The robustness of the controller used is verified by means of a statistical analysis, focusing on vehicle braking for safety reasons. Comparisons with an equivalent Proportional Integral (PI) controller are performed to verify the advantages and disadvantages of the iP controller. Rodrigo M. França, Bruno A. Angélico, Armando A. M. Laganá Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3243 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3244 This article proposes a new method for assessing the impact of an event, such as epidemics, natural and technological disasters, in a given set of places. The proposed method uses machine learning techniques and statistical tools to investigate effects of the event, in one or more variables, through different angles. Four distinct analyses are performed, three monovariate (descriptive analysis; Resultant Vectors Graph; and statistical comparison through paired t tests) and one multivariate analysis through Fuzzy c-means clustering algorithm. The proposed method is applied in a case study: the Fund˜ao dam failure in Mariana – MG. This event is investigated with respect to “Number of dengue fever cases” and “GDP” variables. This new method managed to identify the impact, or its absence, in the observed counties after the event. The main results indicated that Mariana and Conselheiro Pena suffered an increase in dengue fever cases level in almost all analysis. Lucas L. Carneiro, Ed Wilson R. Vieira, Walmir M. Caminhas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3244 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3245 Vehicle parking maneuvers in large cities have a great influence on traffic flow, measures that minimize time and space spent on these maneuvers are of great value. As a starting point, one must plan the best way to carry out parking, a non-trivial task with regard to non-holonomic vehicles prevalent in large metropolises. Based on this scenario, this work presents a path planning algorithm to park a car based on polynomial parameterization optimized by genetic algorithm. The objective is to define a law of motion to steer the vehicle from an initial pose near a parking space to a final pose within the latter smoothly, without interruption, avoiding any obstacles on the way. Path tracking is performed via pure pursuit controller. Results are presented in a 3D physical simulation environment and compared with another approach present in the literature, demonstrating its usefulness and providing the basis for broader studies. Renan P. Vieira, Téo C. Revoredo, IEEE Member Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3245 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3246 This paper proposes the performance and robustness analysis of the positional and incremental Generalized Minimum Variance Control (GMVC), designed in adaptive and non- adaptive topology, experimentally in a Multiple-Input and Single-Output (MISO) physical process, which has aerodynamics similar to several aerospace processes, where performance and robustness indexes are evaluated, widely studied in academia and industry. In addition to evaluating the design of the didactic plant to prove the efficiency of control techniques with the use of a complementary filter together with the responses of the sensors. The model is identified with the least squares estimation algorithms, being applied recursively to the adaptive algorithms. The results shows that GMVC with incremental action in the ARIX model in the self-tuning topology proved to be more efficient. Nelson N. N. Yamaguti, Daniel A. M. da Silva, Bruno G. Dutra, Antonio S. Silveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3246 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3247 The energy currently consumed by the Federal University of Paraíba (UFPB) exceeds, in some periods, the demand limits contracted by the university, which can result in tariff fines and consequently an increase in expenses. This increase in costs could be avoided by managing energy demand through an intelligent electrical grid by adding Electric Vehicles (EVs) that compensate for excess demand by injecting power into the grid when necessary. At this juncture, this article addresses a case study on the possibility of integrating an intelligent electrical grid with Vehicle to Grid (V2G) as a demand management mechanism in view of its technical and economic feasibility. For that, it was considered the survey of the percentage of the increase of electric vehicles in Paraíba, the study of the scenarios of opportunity for charging vehicles at the university, the possibility of supplying energy from the vehicle to the UFPB network and the impact on the electric network. of the university without and with load management. The results show that EVs operating with the V2G network can reduce up to 81% of fines from load management, and this financial savings could be used as an incentive for EV owners to allow energy exchange with the company’s network. university during the period of stay at UFPB. João Soares Farias Neto, Ítalo César Araújo Ferreira, Claudio Paz da Silva Filho, Camila Maciel Andrade, Lucas Vínicius Hartmann, Marcel Ayres de Araújo, Fabiano Salvadori, Camila Seibel Gehrke Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3247 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3248 The rehabilitation potential of myoelectric prosthesis for upper-limb amputee led to its wide investigation in the last two centuries. However, its everyday use still faces several challenges, such as high cost of available commercial models and unsatisfactory functionality. Thus, the present work proposes the development of an upper-limb prosthesis, focusing on the myoelectric signal measurement system. The electromyography system was integrated to an adjustable armband with three measurement channels made with traditional disposable Ag/AgCl passive electrodes readapted as active dry electrodes. For purposes of performance evaluation and database creation, myoelectric signals were collected from 12 healthy volunteers performing daily activities using a bottle. It was verified the high influence at measurements of volunteer physical characteristics, especially those relating to physical fitness, amount of forearm skin or adipose tissue, and sweating. Furthermore, the electrodes also showed high sensitivity to positioning and movement artifacts at the electrode-skin interface. A database of myoelectric signals was created for future pattern characterization. The electromyographic armband performance was demonstrated by driving a claw-type prosthesis using direct control. Bruna S. Morais, Dr. Samuel L. Nogueira, Dr. Thiago L. Russo, Dra. Gabriela L. Santos, Luisa F. G. Salazar, Dr. Arlindo N. Montagnoli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3248 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3249 Predicting the energy consumption of a grinding mill in real-time is of great importance for a mineral processing plant. Grinding is a critical stage in mineral processing and the number one in electrical energy consumption. The mills represent more than 70% of the total energy consumed in some units. The consumption prediction enables a balance in the production demand in a way that prefers the more economically viable moments. Thus, it is an effort toward sustainable mineral processing and low-cost operation. This paper presents the initial study to model the energy consumption of a grinding mill with an artificial neural network. The industrial data are provided by a copper mine plant in the north of Brazil. Kássia Fernanda da Silva, Thomás V. B. Pinto, Thiago A. M. Euzébio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3249 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3250 The arc flash is a dangerous electrical hazard event to workers and equipment, due to the high incident energy associated with it. Yet, there are few laboratories in the world that perform experimental tests related to it, due to the complexities and high costs involved in their composition. Thereby, the Smart Grid Institute (UFSM) together with CPFL Energy developed a high-current laboratory for arc flash tests with the goal to investigate conditions of arc flash related to the national electrical context, that are not approached in the international standards, such as the guide IEEE Std 1584-2018. But, for laboratory’s validation, it is necessary that the tests produce analogue results in relation to the mathematical model of the guide IEEE Std 1584- 2018, so in the future will be possible to explore situations that are not in standard’s scope. Thus, this paper presents the main details related to the construction of the arc flash laboratory, as well as demonstrates the results obtained through an initial test. From the experiment carried out, it is possible to realize that the laboratory has a structure capable of generating a safe and high-current arc flash and measure the respective incident energy, but there are still several matters to explore and improve in the laboratory. Pedro O. Bacin, Ana Paula G. Marchesan, Rafael C. Beltrame, Daniel P. Bernardon, Marina Camponogara, Tiago B. Marchesan, Vitor C. Bender, Leonardo H. Medeiros, Lucas M. Chiara, Fernando C. Pepe, Gilnei José G. Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3250 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3251 In the last decades, distributed generation (DG) has experienced ever high growth. Most of the energy sources used in DG, notably solar and wind power, are dependent on electronic converters for integration with the main grid. The development of converters and their control structures usually applies computational simulations, which allow for fast analysis of the prototypes. However, the performance of those simulations is dependent on the model used. Grid-connected converters, like LCL-type inverters, tend to need high-order models to correctly represent most of its dynamics, which may lead to time-consuming analysis and simulations. In the literature, many works present simplified models of grid-tied inverters, being some of those unable to deal with frequency components other than the fundamental. This paper proposes a new model for an LCL filter-based grid-tied inverter with harmonics modeling flexibility, which allows the complexity to be adjusted to some extent. The considered system and its respective control scheme are firstly presented. Then, the contribution of this work is discussed for the considered study case. The main goal of this work is an approach suitable for a wide range of applications and analyses with various degrees of complexity in the field of LCL-type inverter studies. Simulation results applying the proposed model are presented and compared with results obtained via real-time domain emulations (RTDE). Marcelo Piveta, Emerson G. Carati, Jean P. da Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3251 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3252 Brazil is one of the most important producers of iron ore in the world and with the potential to grow over the years. The mining sector demands the adoption of new technologies for the development of specialized systems that increase the efficiency in the production process. Mining must embrace innovation for automation of repetitive tasks, systems integration, continuous process improvement, disaster risk reduction and adaptation to the global context. In this sense, the article proposes the use of Fuzzy Time Series(FTS) to learn a representation of the data that is more effective for the classification stage, using data originating from Plant A of the Ferro S11D Project, from Vale S.A., located in Canaã dos Carajás, Pará, Northern region of Brazil. The result demonstrated a significant improvement in failure prediction from the addition of PWFTS (Probabilistic Weighted Fuzzy Time Series) techniques to the XGBoost (Extreme Gradient Boosting) algorithm. From the proposed methodology, there was an increase in accuracy from 79,3% to 98,9%. Gabriel Vinicios M. Fernandes, Agnaldo Rocha Reis, Frederico Gadelha Guimarães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3252 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3253 The outbreak of coronavirus disease 2019 (Covid-19) accelerated the technological advancement in the context of Education 4.0, since several educational institutions had their face-to-face activities suspended, recommending distance education as a measure to contain the spread of the virus and an alternative for the continuity of their activities. In distance learning, there is a difficulty in training students skills that are only acquired with practical experimentation in laboratories. In this context, this paper presents the development of an experimental platform of complementary support for teaching basic electricity concepts to high school or technical students, with remote access and control, which, unlike most solutions found in the literature, is implemented directly in a single-board microcontroller (SBC). For this purpose, a simpler and cheaper architecture is proposed (when compared to other remote laboratories). Finally, to improve the user experience, improving the intuitiveness and reducing the need for supervision or additional support, a graphical interface is developed in the form of a digital twin of the hands-on experiment. Isaias M. Oliveira, Cecília F. Morais Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3253 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3254 The growth of the national electricity market has attracted many trading and generators agents to the sector. However, the players in the market face the challenges of high price volatility. From the generators point of view, in addition to the market price risk, there are uncertainties associated with own generation that depends on the generation technology. In this way, the portfolio optimization technique is an approach that aims to improve the management of a business and achieve strategic objectives in an environment of uncertainty. Among the various technologies and mathematical models in the literature, the ones that stand out the most are those of computational intelligence, which are widely explored in portfolio optimization applied in other segments of the industry. In this work, we investigate the application of meta-heuristics applied to electricity portfolio optimization problems in the Brazilian market. The results obtained indicate that such techniques are adequate, contributing to improve the management and the results of the trader’s companies. Ruan D. J. Anselmo, Andre A. Augusto, Julio C. S. Souza, Milton B. Do Coutto Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3254 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3255 The ARS algorithm is a reinforcement learning method that seeks to map the best actions to the process operating conditions. Initially, the algorithm has no instructions and no knowledge of the process dynamics. Thus, this technique seeks to learn while interacting with the process and the search for the best actions is guided only by a numerical reward signal. The continuous stirring tank (CSTR) process, simulated in Python, is used as an interaction environment for the ARS algorithm. The main objective of this work is to apply the ARS algorithm to tune a PI controller of the CSTR process. The states are the setpoint values applied to the process before and after its variation. Actions are the PI controller parameters for each reference set (states). The reward was defined as the inverse of the sum of the error module. The tunings proposed by the ARS are 8.3% (same operating point) better than the tuning benchmark chosen for comparison. Santino M. Bitarães, Moises T. Silva, Thiago A.M. Euzébio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3255 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3256 In this work, control structures for regulating mass flow in feeders in conveyor belt circuits are discussed, in mining processes, when the dead time is high. In this case, dead time consists of the difference between the instant of the event of change of feeder speed and the instant of the detection event of the effect of this change in the flow measurement scale of this equipment. The motivation of this work is the search to obtain an increase in operational safety, avoiding flow values above the nominal reference values of the equipment, and to achieve the optimal use of the capacity of the mass transport circuits. The following control strategies are evaluated: Proportional-Integral-Derivative (PID) controller, Internal Model Controller (IMC) and Smith predictor. It is concluded that the use of the structure with Smith predictor, with feed mass adherence of 99,26%, had the best performance. Tiago A. Moraes, Saulo N. Matos, Moisés T. da Silva, Thiago A.M. Euzebio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3256 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3257 This article proposes the development of a system for recording and monitoring biomedical signals (electrocardiogram and blood oxygenation.), based on Internet of Things (IoT) technology, allowing remote clinical monitoring of possible endemic conditions. As a benefit, the prototype developed will have a significant impact on biomedical instrumentation as a support in the clinical supervision of patients with endemic diseases, and in preventive medicine, in the early identification of possible cardiac and respiratory diseases. Combining telemedicine and automation, the results obtained demonstrate that the system is efficient in capturing, transmitting, and classifying data, in addition to providing greater convenience to the patient. João Victor Bentes Soares, Luana Ribeiro Gomes, José Ruben Sicchar Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3257 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3258 This paper presents a Binary Integer Linear Programming (BILP) formulation for the problem of optimal allocation of meters, considering two objectives: minimizing the number of meters and maximizing the number of identifiable faults. The problem was tested on a 15-bus European Medium Voltage System of CIGRÉ, considering the inclusion of a distributed generator and the possibility of operating the system as a weekly meshed network. The optimization problem was solved through the Algorithm for Bicriteria Discrete Optimization (ABCDO), to obtain an exact Pareto Front. Next, the Nondominated Sorting Genetic Algorithm (NSGA-II) was used to find different equivalent solutions for each Pareto Front point. The meter allocations obtained were used to feed a fault locating algorithm based on voltage measurements. The results presented allocations with one or two meters, reaching hit rates in the fault location close to 90%. Further, this work found optimal positions for the meters regardless of the topology variations, which is interesting for the application in modern distribution networks. Paulo E. T. Martins, Mário Oleskovicz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3258 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3259 Collaborative robots are becoming more present in various activities, inside and outside the industry. The use of these robots allows greater precision and accuracy in carrying out the tasks. However, it is important to take into account some factors to ensure the safety of the system, such as the ability to avoid obstacles that may be present in the operating environment. In this work, we propose a system for trajectory optimization of a robotic manipulator in complex environments using the algorithms Covariant Hamiltonian Optimization for Motion Planning (CHOMP) and Stochastic Trajectory Optimization for Motion Planning (STOMP), and an RGB+D sensor for obstacle detection. The entire system was implemented based on the open-source framework Robot Operating System (ROS). Performance of the algorithms was analyzed based on their success rate, planning time, and duration of the generated trajectory. Results indicate that the proposed system can generate feasible and collision-free trajectories in static environments. Miguel Felipe Nery Vieira, André Gustavo Scolari Conceição Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3259 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3260 This work presents the construction of a Ball and Beam system and the design of a nonlinear controller applied to it. This problem consists of controlling the position of a sphere that moves over a bar, keeping it at the desired set-point. Based on the system model, it was designed a Feedback Linearization controller capable of stabilizing the system and, thus, controlling the sphere in the desired position. The controller was firstly validated in simulation and then was embedded in a microcontroller to control the real system. Yan U. S. Correa, Bruno A. Angélico, Eduardo A. Tannuri Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3260 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3261 This article presents a multimodal software architecture, developed to incorporate the functionalities of an autonomous robotic system with social interactions. The architecture will be implemented in a wheelchair, making it intelligent and enabling more than one form of navigation, always considering the data obtained from the environment and people. Heli N. Silva, Emanuelle G. Paulino, José Díaz-Amado, João Erivando Soares Marques Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3261 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3262 The parameter estimation of systems that operate interconnected requires not only accuracy but also the preservation of properties intrinsic to the physical system, as passivity, in such a way that models that do not guarantee that property may incur unstable behavior in time-domain simulations. The main objective of this paper is the application of a 4SID algorithm to estimate passive state-space models, from frequency response data. To attain that purpose, passivity enforcement equations based on LMIs are formulated as constraints of the optimization problem to reach a globally optimal and passive solution. A weighting methodology, in the frequency domain, is also formulated as an LMI, and it is incorporated into the algorithm in order to improve the approximation between the response of the estimated model and the data. A case study using experimental data measured from a power transformer is presented to show and validate the proposed approach. The results reveal that the proposed algorithm solves passivity enforcement problems in a single step without interactions and is capable to estimate passive models with 4SID algorithms. Lucas F. M. Rodrigues, Wagner F. S. Souza, Gustavo H. C. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3262 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3263 This paper presents an implementation of a fault detection scheme based on the identification of neuro-fuzzy models of a photovoltaic system in the AC conversion circuit. Fast fault detection implies the ability to perform preventive rather than corrective maintenance, which represents a benefit in the economical, material and environmental fields. Therefore, a method based on fuzzy logic with fuzzy residuals is proposed for the correct and fast detection of different types of faults. A residual evaluation is performed and a decision is made to what kind of threshold for robust fault detection is better. The results obtained show the good performance of the proposed scheme, where the detection system demonstrates its robustness to different faults. The proposed method is compared with traditional methods like mathematical model based on state-space equations and detection methods like Unknown Input Observers (UIO). The methods were applied into a real solar inverter and the results obtained were similar and as good as in simulations. Raquelita Torres, Damien Olazabal, Alain Segundo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3263 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3264 This paper proposes the development of an approach for better identification of jumps in collaborative Markovian systems, aiming at a better estimation of orientation and joint angles in consecutive segments of the human body and in articulated robotic devices. The proposal consists of elaborating combined strategies to identify sensors with less dynamic acceleration and at the same time greater relation with the movement, using established strategies of strapdown and finite state machines. For application of the proposal, a Markovian Articular Spatial System was implemented using Strapdown and Gait Cycles. The results obtained were promising, and for the angles of movement in the sagittal plane we obtained a Pearson correlation of 0.80 for the trunk and above 0.996 for the other segments, with an RMSE of 2.17 for the trunk and below 1.43 for others. As for the knee joint angle, a correlation of 0.99 and with RMSE of 1.27 was obtained, which demonstrates the efficiency of the method for segments that have a reliable estimate of orientation, which does not occur with the same accuracy for hip joint, as it depends on the trunk segment. Lucca B. Castro ∗, Mateus Pereira, Edson Francelino, Roberto S. Inoue, Samuel Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3264 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3265 The risks in exploring unknown environments have attracted interest in using mobile robots. In addition, the coordinated and cooperative use of multiple robots to perform these tasks can provide better efficiency in exploration. In this context, this work presents the development of an exploration system with multiple robots for mapping, using a boundary selection method based on the exchange of information among robots. In addition, a planner based on the rapidly-exploring random tree (RRT*) determines the path to the chosen frontier point, carrying out replanning if necessary during the route, always aiming to go to strategic frontier points and avoiding obstacles that may appear along the way. Simulated experiments are presented comparing the use of only one robot for exploration to the use of more than one. Victor R. F. Miranda, Armando A. Neto, Gustavo M. Freitas, Israel Amaral, Luciano C. A. Pimenta, Leonardo A. Mozelli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3265 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3266 This work proposes a heuristic approach to reduce transgressions of collective indicators of irrigating consumers with the use of energy storage systems and photovoltaic solar generation. The approach is based on the values of indicators and consumption of the sets of consumers to determine the appropriate size of SAE and UFV to be installed at strategic points of the Electric Power System. A case study is presented that illustrates the installation of 4 SAE-UFV sets, with the respective associated costs, highlighting the payback on investment from 8th year of installation. F. G. Fabrin, D. P. Bernardon, V, J. Garcia, A. Pose, L. Reis, S. Butto, L. M. Chiara, D. W. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3266 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3267 A fast decoupled power flow algorithm is proposed in this paper to calculate the frequency and voltages in islanded microgrids. The decoupling is characterized by two subproblems: Pθω and QV. The computational cost of the proposed method is minimized through the application of a stationary Newton- Raphson method. The Newton-Raphson and Fixed-Point methods were used to validate the accuracy and the computational cost of the proposed technique. This validation was carried out in a 310 nodes microgrid through a probabilistic power flow study. Uncertainties related to load forecasting error and equipment failures were modeled in the probabilistic power flow through the Monte Carlo Simulation. The tests results revealed that the proposed fast decoupled power flow achieved solutions very close to those generated by the Newton-Raphson and Fixed-Point methods, but with expressive reductions in the computational cost regarding to Newton-Raphson method. Elson N. M. Silva, Anselmo B. Rodrigues, Maria da Guia da Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3267 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3268 In a large mining site, the equipments are operational in a vast geographic region, and some of these equipments have locomotion restrictions, such as shovels, tractors, and drills. Due to these limitations, these types of equipment need to be supplied at their places of operation using fuel trucks with supply infrastructure, called fuel convoys. In this study, we addressed the routing problem of these fuel convoys seeking to minimize the longest route. To solve the problem, we propose a mixed-integer linear programming formulation. We have validated this formulation using data from the Carajás Complex, Vale S.A, in Pará-PA. The results showed that the formulation is able to find good solutions to the problem and can be used to support decision-making. Renan Portela de Souza, Natanael Salgado Coutinho, Luiz Carlos Alves Rodrigues, Luciano Perdigão Cota Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3268 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3269 The growing integration of renewable energies and the new technologies adoption make the coupling between supply and demand a challenge. Furthermore, the allocation of distributed energy resources on the electrical grid allows islands configurations, as microgrids (MG). In a MG, when the consumption exceeds the generation capacity, it leads to an inefficient operation of the system, therefore, it is necessary to know the electrical demand patterns. However, electrical load grouping of a study area into categories is a technique that allows finding consumption relationships within and between groups. This article presents and compares two methods to identify electric load clusters in distribution networks using geographic information systems (GIS), DBSCAN and K-means methods are tested. Electric load density and electrical distance prove to be effective setting factors. The performance of the methods is evaluated in the coverage area of three distribution substations of an Ecuadorian electric utility. The results show clusters, that maximize electrical and geographical proximity, which represents a support tool in the MG planning process. Chumbi Wilson E, C. José Eduardo, Jaramillo-Leon Brian, B. Leite Jônatas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3269 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3270 The field of Algorithmic Art has been following technological advances in Artificial Intelligence and, as Generative Adversarial Networks (GANs) have become popular, applications on art generation began to emerge. For most deep neural networks, large amounts of training data are essential to achieve satisfactory model quality. But there are cases, such as in MIDI musical melodies, where it is not trivial to acquire data in such a high volume. Data augmentation strategies play an important role on these cases. This paper presents a data augmentation pipeline, composed of three strategies, with the objective of improving the quality of a GAN- based musical melody generator. The proposed data augmentation pipeline was compared with a non-augmented dataset and a replicated dataset, which had the same size of the augmented dataset, but composed only of replicas. From the statistical tests performed it can be stated that the augmented dataset outperformed the non-augmented dataset and the replicated dataset, when evaluating the Fréchet Inception distance (FID) score. Matheus Bitarães, Frederico Guimarães, Frederico Coelho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3270 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3271 Many applications require efficient, low torque ripple motors; therefore, using a switched reluctance motor (SRM) in these cases requires a control technique that takes it into account. This paper proposes a novel control strategy that uses optimal reference phase currents obtained by Genetic Algorithm (GA) that minimize torque ripple while maintaining the overall stator current. The Genetic Algorithm (GA) used a Finite Element Analysis (FEA) model to choose the ideal phase currents for a set of rotor positions and reference torques. That model took mutual inductances, cross-coupling effects, and saturation into account. Upon determination of the ideal phase currents to track, a current hysteresis control strategy was proposed to maintain a load torque of 2Nm at 300rpm. To validate the proposed technique, a comparison with a Direct Instantaneous Torque Control (DITC) strategy was performed, proving which it maintains the machine efficiency and reduces torque ripple. Israel R. Soares, Khristian M. de Andrade Jr, Allan G. de Castro, Bernardo P. de Alvarenga, Geyverson T. de Paula Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3271 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3272 This work proposes the investigation of stator short circuit fault (SSCF) in Three Phase Induction Motors (TIM) related to stray flux. The level of defect is analyzed by means of an exploratory coil inserted in the motor housing, whose function is to sample the stray flux. Obtaining the voltage signals induced in the coil, it is possible to extract characteristics that can help in the automated identification of SSCF in TIM’s. In this way, considering the need to identify these faults in an incipient, automatic way and considering the importance of finding relevant attributes for the adequate characterization of these faults, this article presents an attribute engineering method aimed at fault identification, presenting the process of data acquisition, extraction, selection, reduction and evaluation of statistical attributes to obtain an accurate diagnosis. The objective is to choose only potentially relevant attributes based on statistical information for the identification of SSCF, allowing the implementation in embedded systems with small computational capacity. The results show a reduction of 57 attributes initially extracted to 8, guaranteeing an accuracy of 86% in the identification of failures. Ailton de Oliveira Louzada, Wesley Angelino de Souza, Marcelo Favoretto Castoldi, Alessandro Goedtel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3272 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3273 O projeto de veículos fora de estrada possui conceitos diferenciados em relação aos veículos rodoviários. As retroescavadeiras, por exemplo, tem como quesito de análise o fornecimento de potência para a operação de seus implementos. O principal foco dos consumidores desse maquinário é, no entanto, a melhoria da eficiência de operação em relação ao consumo de combustível e à emissão de gases durante a operação. A eletrificação é uma melhoria que permite alcançar tais objetivos. O sistema de gerenciamento de energia (EMS - Energy Management System) é um dos que atuam diretamente nesse resultado, uma vez que ele é o responsável por determinar o instante de operação da máquina elétrica, fornecendo energia para os implementos, ou da máquina a combustão em conjunto com o gerador, fornecendo energia elétrica para recarregar as baterias. Este artigo apresenta então uma proposta de um EMS para o controle do fluxo energético de um veículo fora de estrada. M. F. Ramos, S. B. Moreira, R. A. Pires Jr, I. A. Pires, B. J. Cardoso F, A. Nascimento, T. A. C. Maia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3273 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3274 This paper explores the problem of position and speed estimation of a target using satellite-based measurements in a Lie Group Kalman-like filter. The filter employs an intrinsic formulation of a nearly constant velocity model based on the Frenet-Serret frame, embedded in a Lie Group structure. It stands as a more suitable model for the kinematics of a target in space than the usual Euclidean model since it induces a banana-shaped distribution instead of the typical ellipsoidal provided by Gaussian schemes. The paper presents numeric experiments using a real application dataset to evaluate the proposed filtering scheme’s performance against the standard Euclidean representation approach. A differential GNSS solution provided by commercial software furnishes the ground truth. The results indicate a better performance of the proposed Lie Groups filtering scheme. Marcos R. Fernandes, Giorgio M. Magalhães, Yusef Cáceres, João B. R. do Val Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3274 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3275 Brazil has great potential for generating energy through renewable resources, es- pecially from sunlight. By providing a substantial profit, both for their sellers and users, photovoltaic generators are increasingly present in low voltage distribution networks. However, its excessive incorporation into the electrical system may cause problems related to the electrical power quality, such as voltage deviation, phase unbalance and increased technical losses. Consid- ering the continuous expansion of small photovoltaic generators presence on the grid, this paper aims to avoid possible disturbances, without compromising the integration of this technology into the electrical system, making it possible to take advantage of distributed generation’s full potential. Therefore, the use of energy storage systems is proposed. For comparison purposes, simulations were carried out considering storage devices connected in a distributed way, together with the PV systems or just a concentrated unit in the first bus of the studied network. Both configurations presented improvements in voltage levels, reduced losses and increased the grid’s ability to consume the generated energy locally, reducing the power exported to the medium voltage primary grid. However, it is observed that, due to its characteristic operation, the concentrated storage may worsen the unbalance percentage level. Rafael Martins Leite, Jonas Villela de Souza, Eduardo Nobuhiro Asada, Mário Oleskovicz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3275 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3276 This paper presents the multiple input multiple output (MIMO) average model of a DC microgrid (DC MG) of an electric vehicle (EV) composed by two coupled DC-DC converters sharing power on the same bus. The model inputs are the battery voltage and the EV load profile, which represents the current required during accelerations and recharges on breaking process for driving on a specific lane.The four outputs of the model are obtained as linear combinations of the inputs through a gain matrix, whose elements are functions of the electrical parameters of the MG. The influence of parasitic resistances on the model response was also analyzed through the representation of gains in three-dimensional curves. The model is validated through simulations for three load profiles, including a driving cycle for EV Formula SAE (FSAE) on the Piracicaba-SP track. For all cycles, the average model presented errors of lesser than 5% in relation to the switched circuit of the MG. In this context, the parasitic resistances have a low level of influence on the model, showing small variations in the gain matrix as their values were varied. The developed model allows a more reliable analysis of the dynamic behavior of the MG state variables, which allows the design of control systems and sizing of the converters. Márcio V. R. Campos, Lucas Jonys R. Silva, Thales A. Fagundes, Rodolpho V. A. Neves, Joseph J. Kalil, Ricardo Q. Machado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3276 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3277 This paper proposes a control system to autonomously guide a formation of a differential-drive wheeled platform and an unmanned aerial vehicle to track a given trajectory in an environment containing static obstacles. Such an environment could be, for instance, an automated warehouse. The controller embeds two partial controllers, a formation controller to move the formation accordingly and a controller to deviate the formation when an obstacle appears in its route. The formation controller is designed considering the paradigm of virtual structure, in this case the tridimensional straight line linking the two robots. As for the obstacle avoidance controller, it should make the robot to navigate through regions of low potential, where the potential is a function associated to the obstacles. When the wheeled robot enters a region whose potential is higher than a predefined threshold the controller should modify the route of the formation to avoid the obstacle. These two controllers are then integrated, using the null space-based behavioral control approach. The use of such an approach allows giving higher priority to the subtask of avoiding the obstacle, leaving the subtask of moving the formation with a lower priority, thus generating a way to move around an obstacle following a path of low potential. Mauro Sérgio M. Moreira, Mário Sarcinelli Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3277 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3278 This paper presents the performance of a trapped flux superconducting machine in 2G tapes stacked on the rotor when submitted to liquid nitrogen (LN2) temperature at 77 K. Its most relevant characteristics were obtained for comparison by a squirrel-cage induction motor of the same dimensions. In this context, the methodology of the experimental analysis and all the results obtained with the developed machine and with the induction motor at room temperature and at the temperature of liquid nitrogen will be presented. Torque results with load variation, mechanical power, electrical power, efficiency, losses, and the harmonics of the superconducting machine and the induction motor were investigated and discussed. The concept of the superconducting machine presented in this project can be applied in the future in wind energy, ship propulsion, and electric aircraft because, as will be shown, the superconducting machines achieve higher power densities than the conventional ones. Fernando Jorge Monteiro Dias, Guilherme Gonçalves Sotelo, Rubens de Andrade Júnior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3278 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3279 The demand for the development of technologies associated to the urban airspace has grown considerably. Unmanned Aerial Vehicles (UAVs) have been used in several activities, such as load transportation in emergency situations, package delivery, recreation, among others. In order to obtain safe regions for navigation of UAVs in an urban scenario, from a starting point to an arrival point, in this paper we use reachability analysis which is characterized by ensuring safety constraints in systems with bounded uncertainties. These uncertainties can be operation constraints, disturbances, among others. In order to use this technique, it is necessary to choose the most adequate representation of sets, which in this work is the constrained zonotope one. Since this representation deals with convex sets and, in the urban scenario, the admissible region for UAV navigation can be non-convex, the technique of partitioning non-convex sets into convex parts is applied. The application of the proposed methodology brought satisfactory results regarding the fulfillment of safety constraints and computational efficiency to obtain safe regions. Helen F. Oliveira, Brenner S. Rego, Guilherme V. Raffo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3279 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3280 Considering the modernization of the power systems in oil and gas (O&G) platforms, energy efficiency improvements and the integration of renewable energy sources have pointed to new technologies and applications. Thus, the integration of frequency converters for the operation of high- power machines, electronic energy converters for coupling alternative sources and energy storage systems provide challenges in the scope of energy balance control and power quality. However, they also generate novel opportunities to be exploited under the platforms energy management systems. In this scenario, this article aims to evaluate a typical power system of O&G production platforms, especially in the perspective of the applying frequency converters as active elements in the cooperative control of power quality. Felipe Leite Paes, James Blayne Oliveira Reis, Marcus Vinícius Maia Rodrigues, Luis De Oro Arenas, Flavio Alessandro Serrão Gonçalves, Helmo Kelis Morales Paredes, Fernando Pinhabel Marafão 1 Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3280 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3281 Machine learning models are used in numerous applications and, for some of them, it is desirable to be able to explain the output of the models. The search for model explainability lead to the development of Tree SHAP : a framework for tree-based models that calculates the contribution of each input feature to the predictions. In this paper, we train a regression model that predicts the yield value of seamless steel tubes at the end of the heat treatment process. We then perform a model explainability analysis to highlight the gains of such analysis in industrial applications. Ramon Gomes Durães, Turíbio Tanus Salis, Frederico Gualberto Ferreira Coelho, Antônio de Pádua Braga Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3281 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3282 This paper presents a compilation of the dielectric failure mechanisms of medium and high voltage cables. As well as, the various diagnostic methods found in the literature and used in the field, highlighting their advantages and limitations. The methods that use partial discharges to evaluate the insulation condition are emphasized and the main analysis parameter chosen is the magnitude of the apparent charge. In this context, the effectiveness and limitations of the aforementioned methods are discussed, as well as other characteristics extracted from the measurements of partial discharges to complement and, consequently, improve the quality of the results of existing diagnostic techniques. Regarding these complementary attributes, their behavior over time is presented. It is also suggested to include these values in order to obtain more substantiated and effective methodologies for the evaluation of insulation degradation. The use of more effective techniques for monitoring the condition of the cable carries some direct benefits. Which include the better planning of predictive and preventive maintenance, thus raising the level of system reliability. This improvement favors the proposition of management policies for this important asset, widely present both in industries and in power utility companies. Guilherme Fernandes Ribeiro, Hélder de Paula Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3282 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3283 This paper proposes an electronic security system of significant robustness, applying techniques of facial biometry. These systems are recurrent in the literature, and therefore have provided the advancement of artificial intelligence and computer vision techniques. Three techniques for facial attribute extraction and classification of images, both static and dynamic, with focus of the facial detection and recognition process were evaluated. The presented results demonstrate the relevance of the studied techniques, with accuracy above 98%. For field testing, a low-cost prototype was developed to suggest a functional and commercial solution. Açucena de Gois Parente, Iago Magalhães de Mesquita, Sarah Frota Alves, Francisco Aldinei Pereira Aragão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3283 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3284 Due to the three-phase induction machines (TIM) operation principle, the position control of this kind of motor is not trivial. Advances in power electronics, microprocessors technological improvements, and new control strategies have favored TIM control applications, increasingly more precise results. Position control allows the application of TIM in robotic manipulators, for example, replacing the more expensive DC machine. Thus, a Three-phase induction machine position control by indirect field-oriented strategy based on a back-to-back topology converter and Digital Signal Processor (DSP) is presented in this paper. An incremental encoder was used to obtain the angular position of the machine’s rotor. Proportional-Integral controllers were used in the position and speed control loops. Due to the high sampling frequency achieved (200 kHz), a hysteresis current controller was used. The experimental results obtained validated the adopted strategies. Paulo R. M. Costa, Marcus R. de Castro, Isaac R. Machado, Tárcio A. d. S. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3284 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3285 Electric vehicles (EV), renewable generation sources and battery storage systems are important energy resources with great potential to impact the demand profile of electrical distribution networks. In this work, a new concept of residential electrical energy management system is presented, which in addition to managing the distributed energy resources present in the residence, also manages the EV charging, integrating three important concepts: mobile storage, V2G and energy transaction. For this, a management algorithm based on mixed integer linear program for real-time operation is developed. From the analyses carried out, the important contribution that the presented management concept can offer to the EV owner in relation to the profitability of its assets is observed. In addition, the presented approach has great potential to contribute to mitigating the negative impacts caused by the uncontrolled operation of intermittent renewable energy generation and uncontrolled charging of the electric vehicle over the electrical distribution network. Aérton MEDEIROS, Luciane CANHA, Vinícius GARCIA, Juliano MOREIRA, Rodrigo MOTTA, Rodrigo DOS SANTOS Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3285 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3286 Open-circuit or short-circuit faults, as well as faults in discrete parameters are the most used models in the simulation method before testing. As the response of an analog circuit to an input signal is continuous, failures in any specific circuit element may not characterize all possible component failures. There are three important features in diagnosing analog circuit faults: faulty component identification, faulty element value determination, and circuit tolerance restrictions. To solve this problem, a fault diagnosis method is proposed in this work using a Particle Swarm Optimization (PSO), where the nonlinear equations of the circuit under test are used to calculate the circuit parameters. The objective is to identify which circuit component has the potential to present the failure by comparing the responses obtained in the real circuit and the response obtained by the optimization process. The Tow-Thomas Biquad Filter was used to evaluate the proposed implementation. The proposed methodology was able to identify the defective components in 5 out 8 cases with 100% accuracy. However, for the remaining 3 cases, a lower accuracy rate of 75% was possible. Jalber D. L. Galindo, Nadia Nedjah, Luiza de M. Mourelle Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3286 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3287 This work aimed at the development (study, design and construction) of a bench for axial axis hydrokinetic turbines, with its power train developed by the motor-generator, the motor responsible for emulating the torque of the hydro turbine rotor and the generator with converter function the rotation movement of the shaft into power. Through this workbench, it was possible to make the studies more flexible for different hydrokinetic projects, from its mechanical design or operation, separate from its mechanical design or operation, to obtain an optimal operating point for maximum efficiency in energy conversion. This study is intended for turbines aimed at isolated communities and riverside communities located on the banks of the Guamá-PA river, places of high density of difficult systems systems, or that make the installation of photovoltaic and photovoltaic systems difficult; therefore, hydrokinetic studies have very significant importance as an alternative for energy production, as there is a great potential for a renewable energy source not only in the Amazon but in all parts of the world that propose energy sources in their rivers and oceans, for through currents and tides. The bench is composed of a microcontrolled system by means of an electrical control flow, which sends the rotor of the machine's power train to the electrical generator to the actuator (servomotor), emulating the conversion of current flows into energy, for efficiency studies. in the use of machines in different scenarios. Luciano L. Pompeu, Wellington S. Fonseca, Allan R. A. Manito, Edson O. de Matos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3287 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3288 This work aims to optimize the design of a Surface-Mounted Permanent Magnet Synchronous Machine and uses a single-objective algorithm where a composite objective function has been applied. The particle swarm algorithm was used in the optimization process, where a Finite-Element Analysis (FEA) software was also adopted to perform electromagnetic analysis in the development of the algorithm. Among the possibilities of design variables in the adopted machine, the magnet thickness, polar pitch and slot width ratio (which alters the slot proportionally) were considered. As a final objective, a cost function was developed, which must be minimized and is composed of optimization objectives. The optimization objectives are torque ripple and power density. Next, the results found are presented, where it was possible to obtain a reduction of 81.3% in torque ripple and an increase of 12.5% in power density. Eduardo M. C. S. de Oliveira, Stefan T. C. A. dos Santos, Allan G. de Castro, Geyverson T. de Paula, Jose R. B. de Almeida Monteiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3288 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3289 Estimated Losses on Doubtful Accounts (ELDA) in companies is an attractive field for investigation due to the percentage of profits it represents. The objective of this work is to find a machine learning model to predict on which day the customer will pay the energy bill in order to maximize the company’s profit. To evaluate the proposed methodology, experiments were carried out using real data from customer invoices. The results of the models were compared with each other and statistical analysis was performed to verify if there is a significant difference between them. The results achieved indicate that the application of the proposed modeling is promising. Jelson André Cordeiro, Marcelo de Oliveira Rosa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3289 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3290 Applying artificial intelligence to e-commerce is a trend, however, algorithms that deal with small databases are lacking. This work proposes a model with Siamese neural network in a few shot learning context to classify new samples from an online store. In order to choose the best representative sample to be used in the Siamese network, the random choice and centroid calculation approaches were tested. In addition, an ensemble structure of Siamese network considering 3 and 5 representants was also proposed. Finally, the k-Means algorithm was used to calculate the centroids of the clusters of each class and use them as representative samples in the ensemble. The best result was with the centroid, improving performance from 93% to over 98% accuracy. Different structures were also proposed for the internal network, the best being with three hidden layers and applying the DropOut technique. In addition, it is possible to develop other alternatives to choose representatives and improve feature extractors, improving data quality, being useful to reduce the size of the analyzed data to reduce the complexity of the network in order to reduce costs with the use of servers and data storage in the cloud. Fernanda C. e Silva, Danton D. Ferreira, Bruno H. G. Barbosa, Paulo R. Silva, Sinval T. Nascimento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3290 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3291 This work presents new contributions to the computation of a bound to the ℓ1 norm and to the synthesis of dynamic output feedback controllers assuring a bound to the ℓ1 norm for discrete- time linear systems through linear matrix inequalities. Starting from sufficient stability conditions for an auxiliary system, a locally convergent iterative method is proposed for the computation of a bound to the ℓ1 norm of the impulse response of the original system, with direct extension to deal with uncertain parameters and for the synthesis of output feedback dynamic controllers of a given order. Differently from the existent techniques for ℓ1 analysis and control, the proposed method dispenses the usual one- dimensional search and considers as optimization variables the parameters of the controller, handling structural constraints without additional conservatism. Numerical examples illustrate the performance of the proposed approach. Ariádne L. J. Bertolin, Ricardo C. L. F. Oliveira, Pedro L. D. Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3291 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3292 Among the documents that make up the Procel Reluz Public Calls street lighting projects, it is essential to include the electronic file, From the data entered, there is the possibility of forming street standardized models, merging streets with the same characteristics, decreasing the number of lighting projects. Although the streets rarely have the same characteristics, they are very similar, which implies the designer’s manual work to match these characteristics. Thereby, from the criteria definition in order to match similar streets according to the requirements of Procel Reluz, this work aims to present the development of a Python script that performs the optimization of street patterns generation, and consolidate its functionality from a case study of a neighborhood in the city of Rio Branco - AC. Information was collected from 28 streets, whose data from which street were used as input to the script. After running the code, 11 street models were obtained, which represents a 60% reduction in the number of street lighting projects required to complete the retrofit. The optimized standardized street models were validated by executing all their corresponding lighting projects and their respective streets using the same luminaire series, obtaining little difference between the luminaire powers on the original scenario and the scenario with number of projects decreased by the script. Gustavo M. O. de Castro, Aline S. Gallina, Joshua B. Martins, Lucas Matheus de S. Lima, Nadine da F. A. dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3292 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3293 This work proposes a relaxation that results in better stability analysis and controller synthesis for discrete-time Takagi-Sugeno (T-S) fuzzy systems subject to partially matched assumptions. This case, in which the controller and system have the same number of rules but differ in the parameters, is a frequent case in control applications, which has a great practical interest. The proposed approach is based on representing the error between two membership functions (MFs) through a second-order polynomial. The conditions are proposed as convex optimization procedures formulated as linear matrix inequalities (LMIs), guaranteeing efficient numerical solutions. Two examples illustrate the proposal; where the first one compares the proposed analysis condition with one found in the literature. The second example uses the synthesis condition to guarantee the stability of the closed-loop system, and the T-S fuzzy controller has membership functions different from the T-S fuzzy system. The results achieved suggest the superiority of the proposed method. I. H. da Cunha, C. P. Castro, L. F. P. Silva, V. J. S. Leite Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3293 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3294 Now a days, more and more the companies need to invest in new information and control technologies to ensure operation, management and performance. This text presents a research and development project that demonstrated the strategic advantage in the use of innovative techniques of Artificial Intelligence, Machine Learning and Robotic Process Automation (RPA-software robots) in administrative and regulatory activities in an energy distribution utility. The combination of these cutting- edge technologies was implemented in two company processes, the application cases reported in the following text. These cases demonstrate how these technologies can be used to add value to companies in short-, medium- and long-term benefits. Clayton H. da Costa, Flavio L. Grando, Bruna M. Mulinari, Pedro Henrique M. Lisboa, Luis Roberto O. Santos, Fabio A. Guerra, Milton P. Ramos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3294 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3295 Many controller tuning techniques are model-based. For multivariable processes, the model identification is a difficult task. On the other hand, these processes are often found in the industry. Thus, data-driven control techniques have been developed. In this article, the VRFT and OCI tuning techniques for the multivariable PI controller are reviewed. Two strategies for designing controllers with centralized and decentralized structures are also presented. In addition, a thermoelectric process is used to evaluate the performance of the techniques and strategies considered. Victor Marinho Espínola Freire, Anna Paula V. de A. Aguiar, George Acioli Júnior, Péricles Rezende Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3295 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3296 The teaching of control engineering is a a challenging undertaking due to the concept of mathematical formalism and the complex processes. This paper describes the development of a virtual laboratory for teaching control theory, approaching the structures and the tuning of Proportional, Integral, Derivative (PID) controllers specifically applied in simulations. LABVCON (Virtual Laboratory for Teaching Control Engineering), an application developed for desktop, enables the simulation of various types of plants in a closed loop, allowing users who do not have access to costly simulation tools to integrate theoretical information in a clearer and quicker manner. Antonio Moises Nascimento Araujo, Nélio Dias Santos Júnior, Rejane de Barros Araújo, Caio César Silva de Carvalho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3296 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3297 In this paper, an iterative procedure is proposed to design decentralized robust controllers for multivariable systems, based on the effective transfer function (ETF). The uncertainties in the process are taken into account using the multiplicative model, represented by a weight transfer function matrix. An H∞ optimization is applied to the ETF of each loop in order to obtain decentralized controllers that achieve robust stability and nominal performance. In the iterative procedure, the ETF is calculated and a weight is adjust to improve the performance of the system, in order to achieve better results. The procedure was validate with simulation studies and an experiment performed on a temperature process. Egydio Tadeu Gomes Ramos, George Acioli Júnior, Péricles Rezende Barros, José Sérgio da Rocha Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3297 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3298 Mission-critical microgrids present themselves as an opportunity to add resilience and reliability to critical processes, characterized by strict requirements for energy continuity, achieving a strategic connotation for different civil and military sectors. In this context, this article reviews the concepts, classifications, modes of operation, and management of a microgrid, emphasizing critical microgrids. The work also includes cases focused on this application, including the conceptual scope of the circuit and management strategies of a microgrid under implementation in a Brazilian aerospace launch center. Based on this experience and on what has been reported from other microgrids already implemented, the main challenges and particularities involved in the installation and operation of microgrids are addressed, especially those related to the aspects of selectivity, coordination, and resilience of the electrical protection system of the microgrid, also observing criteria of economic and energy optimality. Fabricio P. Moraes, Hércules A. Oliveira, Clóvis B. Mendonça Oliveira, Jóse G. de Matos, Osvaldo R. Saavedra, Luiz Antonio De S. Ribeiro, Alexandre C. Oliveira, Pedro B. L. Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3298 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3299 Artificial Intelligence techniques, mainly machine and deep learning ones, are becom- ing the most common approach for data prediction. In this context, using these techniques instead of approaches based on classical statistics has shown interesting and important contri- butions to weather prediction. The present paper discusses the prediction of rainfall and clouds direction based on a sequence of 10 and 14 frames of radar images with a loss inferior to 0.06. Two different Convolutional Long-Short Term Memory Networks configurations were tested and this work presents the estimated frames resulting from these algorithms and presents comparisons between them, real data, and with the performance of other works. The results show that these algorithms can be suitable for short-term weather forecasting. Nícolas de Araújo Moreira, Rubem Vasconcelos Pacelli, Yuri Carvalho Barbosa Silva, Tarcísio Ferreira Maciel, Ingrid Simões, João César Moura Mota, Cerine Hamida, Rodrigo Zambrana Prado, Emilie Caillault, Modeste Kacou, Marielle Gosset Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3299 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3300 This work presents a proposal for current control using sliding mode controller plus PI (SMC+PI), applied to a single-phase inverter on H bridge connected to the grid using the LC filter at the output. For this purpose, the mathematical modeling of the single-phase inverter was done with the LC filter, the controller was designed by sliding mode plus PI, then the results of the simulations obtained for the proposal validation were shown, and finally, the conclusion itself. This control technique is used to control the current to be injected into the grid and was applied to a single-phase inverter model with LC filter developed in the Matlab/Simulink® simulation tool, results obtained experimentally validate the proposal. Richelly D. F. Pontes, Lucas D. Augusto, José A. T. Altuna, Alfeu J. S. Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3300 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3301 Inertial Navigation Systems (INSs) are extremely important for land, air, space, marine, and underwater vehicular applications. They provide a complete navigation solution (position, velocity and orientation) for the vehicle, at high sampling rate and high bandwidth, being also independent of external signals. Nevertheless, INSs have the disadvantage of accumulating errors in the long term, due to the numerical integrations carried out internally. One solution to mitigate this error accumulation is to aid the INS with auxiliary sensors, usually via Kalman filters. An alternative approach is to use vehicle’s Motion Constraints (MCs) and/or Zero Updates (ZUPTs), as “virtual sensors” in order to aid the INS. This paper investigates the aforementioned problem and shows that the proposed aiding approach is able to greatly reduce INS error accumulation over time. As main contribuition one demonstrates that individually MC and ZUPTs may not be effective in solving the problem of divergence of the terrestrial vehicular INS solution, but that, when combined, they allow a non-divergent navigation with metric level acuracy. Results from real experiments confirm the adequacy of the outlined verifications. Alisson Magno Dominghetti, Felipe Oliveira e Silva, Danilo Alves de Lima, Marcos Tadeu Xavier Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3301 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3302 This paper proposes a Path Planning with Collision Avoidance based on a Radial Basis Function (RBF) trained with random points generated by a Probabilistic Roadmap algorithm. Experiments were performed on a computational model of a SCARA manipulator. The trajectory achieved was evaluated using computational cost, R2 (multiple correlation coefficient) and root mean square error (RMSE). The results of the trajectory generated by the algorithms in the Cartesian space and also the trajectories of each joint of the manipulator, calculated from the inverse kinematics, show that RBF proved to be an efficient path estimator. The result was compared with Artificial Neural Networks Multilayer Perceptron (MLP) algorithm, where the RBF proved to be more efficient. Emerson V. A. Dias, Josias G. Batista, Catarina G. B. P. Silva, Geraldo L. B. Ramalho, Darielson A. Souza, José Leonardo N. Silva, André P. Moreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3302 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3303 Gantry crane systems are widely applied in the industry for cargo transportation. Aiming to provide a system model for the application of control techniques, this work performs the estimation of parameters of gantry crane system’s 3D models. Estimators based on the linearized model and the non-linear model of the system are proposed. The impact of the adopted discretization method is also analyzed, comparing Euler and Runge-Kutta methods. With the results obtained, smaller estimation errors were observed in the estimators with discretization using Runge-Kutta method, and no significant differences were observed when using the linearized or non-linear model. Carlos Eduardo Pedroso de Oliveira, Renato Ventura Bayan Henriques, Lucíola Campestrini Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3303 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3304 The absence of the human hand causes difficulties for the patient to perform simple daily tasks. However, anthropomorphic hand prostheses can help users regain object manipulation and grab functions. For underactuated prostheses, which are generally lighter and have a lower cost of production, precision in controlling movements is a crucial factor. In this context, this paper proposes and computationally investigates the control strategy with a complete command vector for the flexion and extension movement of the index finger of an underactuated hand prosthesis. Compared to conventional PI and PID controllers, this control topology allowed for better system responses, producing considerably lower position errors than the classical controllers. Bruno Neves de Sa, Jose Antonio Toledo, Rina Mariane Alves Dutra, Guilherme Gomes da Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3304 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3305 In recent decades, the increased use of robotic manipulators in the industrial environment has increasingly impacted the human-robot interaction and the safety performance during this interaction. Consequently, control methods that can predict contact, control force, or trajectory to avoid damage during collision become required. This paper considers mode and state estimation for detecting contact in a single-link flexible joint manipulator using the moving horizon estimation (MHE) approach. This method was addressed by employing a least-squares optimization problem, solved for each instant of time to select the best estimation of the system behavior. First, the main aspects of the method have been presented, then the effectiveness of the proposed approach was demonstrated through simulation results, comparing the solution for the real system and the estimate. Lara Candido Alvim, Leonardo Dias Pereira, Elias Dias Rossi Lopes, Helon Vicente Hultmann Ayala Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3305 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3306 In port operations, one of the activities that most demand control and monitoring is the process of loading and unloading a ship. Safety in loading and/or unloading cargo on ships is a crucial element in port activities, and for this purpose there are a series of rules and regulations that determine how these procedures must be carried out. One of the main procedures is the mooring of vessels to berths. Aiming at monitoring the berthing of ships, this work aims to implement a prototype using distance sensors attached to the pier connected to the iMCP-HT32SX, which will continuously process information regarding the distance of the ship from the pier and send alert notifications via the Sigfox network to the operating teams. Gabriel Dutra, Daniel Sampaio, Paulo Guedes, Thiago Cavalcanti, João Marcelo Teixeira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3306 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3307 This work proposes a new tuning method for the simplified filtered Smith predictor (SFSP). Based on the stable implementation structure and an auxiliary filter, it is possible to simply and directly tune the controller for first-order models with time delay. To demonstrate the effectiveness of the method and its good performance, an evaluation of the proposed method is carried out against another controller from the recent literature through simulations and performance indices. José R. de Oliveira Jr., Gabriel F. Machado, José N. do Nascimento Jr., René D. O. Pereira, Bismark C. Torrico, Fabrício G. Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3307 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3308 This work aims to present a proposal for optimized initialization of parameters of a Robust Model Reference Adaptive Controller (RMRAC). Since adaptive controllers need their initialization of gains and constants for proper tuning of the controller, and this choice of gains is related to the designer’s experience, the use of optimization algorithms to choose a suitable set of parameters for the controller is viable, because in addition to presenting optimized performance for the application, it becomes independent of the designer’s experience in tuning the parameters. For optimal tuning of the RMRAC, a Particle Swarm Optimization (PSO) is used, and the controller is applied to the current regulation of a power converter connected to the grid with an LCL filter. Simulation results are presented in Hardware-in-the-Loop, which shows the effectiveness of the proposal and better results compared to an RMRAC initialized by trial and error. Guilherme V. Hollweg, Everson Mattos, Lucas C. Borin, Gustavo G. Koch, Rodrigo Varella Tambara, Vinícius F. Montagner Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3308 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3309 This paper is entirely devoted to the design of the H2 optimal filter applied to systems with sampled-data measured outputs. Like the system, the proposed filter structure also has a hybrid dynamic. In this sense, a natural way of dealing with this problem is to use the hybrid approach. From the analysis of known optimality conditions for the H2 norm calculation, convex constraints based on differential linear matrix inequalities (DLMIs) are derived for the design of the optimal filter. An immediate consequence of the results presented here is that the filter design optimality condition falls in the particular case of the observer structure. Two examples illustrate the obtained results. Henrique W. R. Pereira, Gabriela W. Gabriel, André M. de Oliveira, José C. Geromel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3309 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3310 The real-time digital simulation (RTDS) of electrical networks is an important analysis tool, with applications in the operation, design, planning and expansion of electrical systems. To make RTDS viable, it is necessary to perform a computational modeling of the electrical network components and their characteristics, from energy generation and distribution and transmission circuits, to loads. This modeling represents a major obstacle for RTDS, since it consists of solving systems of large linear equations. In this work, five array storage methods are compared: Compressed Sparse Row (CSR), Compressed Sparse Column (CSC), Compressed Sparse Vector (CSV), Skyline and DFA2, which were used in association with the iterative methods of Jacobi and Gauss-Seidel to obtain the solutions of the system of equations that describe the behavior of the electrical network. The results obtained showed that the use of CSR storage techniques with the iterative methods will contribute to improve the performance of RTDS. Raphael Dantas Pinho, Pedro A. de Alcântara, Luciano Sales Barros, Camila Mara Vital Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3310 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3311 In this work, a binary version of the Water Flow Optimizer (WFO) algorithm, called Binary Water Flow Optimizer (BWFO), is introduced addressing the feature selection problem. WFO is an evolutionary algorithm inspired by the way water flows in nature. In this new approach, the BWFO uses the laminar flow and turbulent flow operators in a binary version, using the accuracy of the Optimum-Path Forest (OPF) classifier as an objective function. The proposed approach is evaluated through a comparative analysis made with classical methods of dimensionality reduction, more specifically with the Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), as well as the metaheuristics Binary Water Wave Optimization (BWWO) and Binary Bat Algorithm (BBA). The computational results demonstrate that the approach is a valid and effective alternative for feature selection problems. Fagner J. Matos Macêdo, Ajalmar R. da Rocha Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3311 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3312 The law of thermal conduction or Fourier’s law describes that the heat flow through a material depends on the temperature difference between two points on the material and also on its thermal conductivity, which provides an indication of the rate at which energy is transferred by the diffusion process. The estimation of this, in turn, is applied in several fields, such as in civil construction, among others. This article presents a prototype of a low cost didactic thermal plant to estimate the thermal conductivity of materials. The proposal is based on Fourier’s law and the protected hot plate principle. As a case study, the pine chip was used, due to its use in the generation of electric energy, whose accuracy in the estimation of thermal conductivity was 97,1 %, showing the effectiveness of both the method used and the proposed prototype. Marques da Luz. Luigi F., Lussón C. Ania, Beltrán A. Reinel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3312 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3313 Identifying COVID-19 on chest radiographic images (CXR) remains an essential task in patient tracking and follow-up. Several initiatives have worked on this task, and although the results presented so far are encouraging, few are reflected in applications adopted in clinical environments. Thus, understanding that there is still a field of research in this area, this work presents a method based on feature extraction by using Binary Patterns of Phase Congruency (BPPC) on segmented CXR images. The objective of this work is to be a mild and fast alternative for the automatic detection of COVID-19 and its severity levels while requiring few computational resources. To do this, radiomic features are extracted from CXR images, a selection process based on SVM is used, and two models of shallow Feedforward networks are built. The results presented far surpasses previous works, with an average accuracy for COVID- 19 detection of 98.24%, and 94.74% in identifying PCR+ images taken from people without any infections marks and Normal diagnosis. A second model is also presented, in which the task is to classify CXR images of COVID-19 in different severity levels, and the presented AUC is 98.05%. The solution’s high performance makes it a viable option as a computer-aided diagnostic tool, which can represent a significant gain in the speed and accuracy of COVID-19 diagnosis and in identifying the severity of the disease. Afonso U. Fonseca, Juliana P. Felix, Gabriel S. Vieira, Deborah S. A. Fernandes, Fabrizzio Soares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3313 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3314 This article presents an analysis of the directional and distance protection functions, based on incremental quantities, applied in the protection of transmission lines. These techniques have gained prominence in research and practical implementations, allowing time gain in fault elimination and enabling improvement in the stability margins of the electrical system. In evaluating the performance of these techniques, the software was used Alternative Transient Program(AtpDraw) to model the protection functions and the test system, where several simulations were performed in order to verify the response of these algorithms in the face of different scenarios. To complement the analysis, the algorithms were tested in two real fault. Sobreira O. Danillo, Araújo G. Cléia, Romão O. K. Polyana, Almeida R. Aryfrance, Junior F. S. Bartolomeu Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3314 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3315 This work presents the development and identification tests of a reverse osmosis (RO) desalination pilot plant. The devices that compose the system are: two hydraulic diaphragm pumps, a pre-filtration assembly, pressure and flow sensors, human machine interface (HMI), data acquisition system, and a pair of RO desalination membranes positioned in series. Given the several parametric uncertainties of the system, the experimental identification of dynamic models was performed. Considering one of the pumps as model input, and the pressure at the inlet of the membranes as output. For data acquisition the input and output were correlated with the application of a square wave excitation signal, with the system operating at around 50 psi. There were four different models, 1st order showed performance of 68.92%, 2nd order 72.8%, 3rd order 74.6%, and 4th order 73.3%. The models were also validated through residual analysis Queiroz D. M. B, Carvalho P. C. M, Nogueira F. G, Torrico B. C. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3315 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3316 Processes with multiple inputs and a single output are usual in industries. These processes present more than one actuator driving a single process variable. Analyzing a Two- Input Single-Output (TISO) process that is composed of two actuators to achieve a single process variable. Recent literature presents a Single-Input Two-Output (SITO) controller strategy, based on the Proportional (P) and Integral (I) control actions separated and paired individually, thus changing the nature of a PI-SISO (Single-Input Single-Output) to a PI-SITO. However, in the literature, it was not justified the choice of the pairing of the control actions, it was possible to observe the literature it was adopted a bias for the Proportional action, but it was not demonstrated how to choose the value of the bias. In this sense, the present study explains the matching of control actions and proposes a systematic methodology for bias selection. This adopted analyses utilizing mathematical deductions and experiments, employing computer simulations. The present study delivers the justification for the pairing of control actions proposed in the literature and a precept of the bias choice enabling an achievable implementation of the PI-SITO controller. Rafael Oliveira Pedrisch, Gustavo Catusso Balbinot, Sérgio Paulo Neves dos Santos, Kariston Dias Alves, José Diogo Forte de Oliveira Luna Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3316 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3317 The calculation of equivalents of electrical circuits is a circuit analysis strategy of simplification with theoretical importance since the most primary developments of circuits theory up to the more elaborated theories which support fault analysis, power flux analysis, system protection and electromagnetic transients. In this document it is proposed a new methodology, via graph theory, for obtaining equivalent networks to be used on power flow studies with ANAREDE. The graph of the National Interconnected System (SIN), with its four electrical islands is presented alongside the graph of a real equivalent network with 120 buses on the vicinities of Joairam 230/69 kV substation, in Recife-PE. William C. Lima, Vicente R. Simoni, Augusto César C. de Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3317 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3318 This paper analyzes the impact of the communication system latency on the stability of a centralized microgrid. For comparison purposes, wireless communication technologies LoRaWAN (Long Range Wide Area Network), Zigbee and LTE (Long Term Evolution) have been analyzed. The microgrid considered herein is a low-voltage microgrid composed of photovoltaic generation systems and energy storage systems (i.e., DER – Distributed Energy Resources) and dispersed loads. The microgrid control is centralized to steer power through the microgrid point of common coupling, named power-based control (PBC). The results have showed that the latency of the communication system and the step processing of the central controller significantly interfere with the positions of the poles within the unit circle of the Z- plane, which may interfere with the stability of the operation of the centralized microgrid. Lucas S. Chaves, Adriano J. Masi, Wanderson F. de Souza, Thiago de Oliveira, Braz de Jesus Cardoso Filho, Danilo I. Brandao Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3318 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3319 Nesta pesquisa foi desenvolvido um sistema inteligente em Lógica Fuzzy capaz de definir a prioridade das demandas de manutenção industrial com base em diretrizes previstas na política de manutenção de uma empresa do ramo petrolífero atuante no território brasileiro. Tal sistema serve como ferramenta de apoio a estes Programadores de Manutenção. O Estudo de Caso foi realizado sobre a carteira de programação de Piúma/ES, Vitória/ES, Aracruz/ES e Linhares/ES, e os principais resultados obtidos foram: a facilitação da sistemática de priorização aos Programadores de Manutenção; a previsibilidade de demandas de longa duração com alto potencial de vencimento; a otimização de recursos humanos na execução das tarefas de Programação de Manutenção com reduções de custos; o aumento da qualidade e padronização da sistemática de priorização e; maior governança para os gestores. Renan O. Souza, Raphael M. Sepulcri, Prof. Dr. Daniel C. Cavalieri Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3319 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3320 This paper presents the creation and development of a device to comply with the Normative Resolution n° 871/2020 of the Agência Nacional de Energia Elétrica, as well as a platform for collecting data from these devices and generating an XML file by the Normative Resolution. The device performs readings of the energy quality indicators in Group B’s residential consumers. The paper also presents the main changes caused by this resolution, in the short and long terms, how this impacts the energy utilities and what must be done to meet the regulations. There is also a review on the Advanced Metering Infrastructure, electronic energy meters found on the market that meet the regulations’ requirements, the network that was used, and the developed platform. In the end, in addition to the device itself, the results that were obtained from the implementation of a network composed of 168 devices in the cities of Tapejara (RS) and Ibiaçá (RS). Flávio Garlet Reck, Leonardo Adam, Fernando Vedoin Garcia, Filipe Gabriel Carloto, Lucas Maziero, Carlos Henrique Barriquello, Daniel Pinheiro Bernardon, Tiago Bandeira Marchesan, Paulo Ricardo Marin, Everton Nascimento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3320 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3321 Problem-based learning (PBL) is one of the most innovative pedagogies and is currently one of the most widespread in the world. It uses an instructional approach centered on the student, which is responsible for, from the investigation of ill-structured problems, self-directing and self- regulating their learning, with the teacher playing the role of a learning facilitator. This work proposes a methodology for the application of PBL in the teaching of digital electronics content for undergraduate courses. The proposed methodology fits PBL to the new required competence in Brazilian engineering courses, expanding the students’ skills. Finally, we present the results of evaluation forms of two disciplines using the proposed methodology. Samaherni Dias, Kurios Queiroz, Anfranserai Dias Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3321 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3322 This paper presents a comparison method of passive devices which is applied to buck-boost- type converters with LC filters in order to ascertain the topology for the compact design of such devices in continuous conduction mode (CCM). Design engineers can use the proposed method of size comparison to achieve an efficient and compact buck-boost converter, since volume of the passive devices generally defines converter size. Furthermore, this paper confirms that there is no an unique converter for any specifications instead of that there is a certain topology for a given specifications. This work considers the following buck-boost-type converters: the classical, the interleaved and the three-state switching cell topology. The three-state switching cell is included to show its greater capability to reduce the filter sizes, especially for design with duty cycles of around 1/2. This paper shows also that the filter arrangement is an option to reduce the volume of passive devices and, additionally to provide non-dissipative clamping of the switching devices. In this study idealized mathematical analysis was performed to compare the buck-boost-type converters. Hugo R. Estofanero Larico, Milton Evangelista de Oliveira Filho, Valdir Pedrinho de Tomin Junior, Roberto Santiago Alarcon Meza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3322 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3323 We propose new convex conditions, formulated in terms of linear matrix inequalities, allowing the design of robust state feedback controllers for time-varying discrete-time systems under saturating actuators. We consider the case where the actuators can be saturated on both magnitude and rate, which leads to more complex but realistic conditions. Because of the nonlinearities, the regional input-to-state stability is employed, handling energy-bounded disturbance signals. The feasibility of the proposed conditions allows computing safe estimates of the initial conditions sets depending on the disturbance energy. Two numerical examples illustrate the proposal’s application and serve to establish numerical comparisons with other approaches from the literature. Lucas A. L. Oliveira, Valter J. S. Leite, Luís F. P. Silva, Kevin Guelton Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3323 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3324 The measurement of wind speed is of interest in several applications, such as wind power generation, mainly for the optimal determination of locations for the installation of wind farms. In the current scenario, the ways of measuring this quantity are diverse, however, when the design restrictions point to a measurement with sufficient accuracy, instruments based on ultrasonic sensors stand out, as they present a low uncertainty compared to conventional mechanical instruments. In this sense, its measurement principle requires the estimation of the Time of Flight (ToF), which is the travel time of the ultrasonic signal from the transmitting transducer to its detection in the receiving transducer. Therefore, the conventional techniques for estimating the ToF are those based on time intervals and digital signal processing, but there are, on the other hand, those based on artificial intelligence. In this article, an artificial intelligence model based on Artificial Neural Networks capable of estimating the wind speed is presented. Furthermore, the construction process is described, as well as its experimental results commented. Lucas D. de Oliveira, José H. B. da Silva, Juan M. M. Villanueva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3324 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3325 The electrical arc is an electrical hazard with the likelihood of occurrence, to a greater or lesser degree, in energized systems, thus becoming an electrical hazard. This phenomenon causes the release of a large amount of energy, and its thermal effects are quite expressive. From the quantification of this energy, individual protection strategies applicable to the worker who will intervene in this type of scenario are chosen. This paper exposes the definition of these strategies for a hypothetical situation of intervention in an overhead distribution grid with the occurrence of an electrical arc caused by a three- phase fault. This choice is made from the incident energy estimation, using the IEEE Std 1584-2018 method and, the use of NFPA 70E-2021 standard to direct the applicable individual protection strategies. Marina Camponogara, Pedro O. Bacin, Daniel P. Bernardon, Tiago B. Marchesan, Fernando C. Pepe, Gilnei J. G. dos Santos, Lucas M. de Chiara Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3325 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3326 Greenhouses are used to maintain an environment of productive and healthy growth of agricultural crops, which can be obtained by an automatic control system with the objective of modifying the various parameters of the dynamic behavior and optimizing the production of grow crops. Among one the aspects of developing control strategies are those based on mathematical models considering the various physical interactions. This article presents the analysis and simulation of a simplified dynamic model of an agricultural greenhouse. The main purpose is to obtain the dynamic behavior of the internal, greenhouse, and soil temperatures, comparing them with the external temperature. The simulation results indicate that the model presented is capable of representing the dynamics of different temperatures that affect an agricultural greenhouse. Emanuel Thiago de Andrade da Silva, Moisés Tavares da Silva, Lincoln Machado de Araujo, Ademar Gonçalves da Costa Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3326 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3327 The electrical submersible pumping (ESP) system is an important artificial lifting method of crude oil in the world oil production process. The three-phase induction motor that drives the pump has accentuated geometric restrictions and operates in hostile conditions of temperature and pressure in the production environment, so it has some design improvement points that must be explored for better machine performance, such as increased efficiency and higher power density. This work presents a development methodology for the electromagnetic design of a permanent magnet ESP motor using opensource software. The objective is to demonstrate that the appropriate and coordinated tools usage allows the design and optimization of systems with high technological challenges. In addition, there are advantages such as software transparency, no need for license costs and the possibility of parallel computing. Key design requirements and basic procedures are discussed in this paper. Jose Antonio Toledo, Thales Alexandre Carvalho Maia, Leonardo Adolpho Rodrigues da Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3327 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3328 This paper presents a linear robust control strategy for DC-DC Boost converters operating on continuous current mode (CCM), aiming for output regulation. Besides the standard uncertainties on load resistance and duty cycle, the proposed modeling also considers uncertainties on the main inductor parameters, which are the Equivalent Series Resistance (ESR) and the inductance. Variations on temperature, frequency and current might cause parameter deviation, often disregarded in control design. A new uncertain model based on polytopic covering is proposed to include the inductor uncertainties. Although the modeling complexity is higher, the simplicity of linear state feedback controller is preserved, providing a low cost solution for output regulation. The H∞ controller synthesis is performed by an offline algorithm that solves a LMI-based optimization problem. A study of case is presented and simulation results suggest the effectiveness of the proposed concept. Caio dos S. Magalhães, Bernardo Ordoñez, Humberto X. Araújo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3328 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3329 This work aims to present two approaches for busbar protection of Distribution substations using the IEC 61850 standard. At the station bus level, the first one uses a decentralized methodology through logic between IEDs with function 50 and the GOOSE message. The second, the more challenging methodology, makes use of the process bus, in which it centralizes the Sampled Values from the Merging Units to perform the busbar protection. The simulations of faults internal and external to the distribution substation bus, in addition to overload conditions, were implemented in the real-time software HYPERSIM – OPAL-RT. Through the simulations, the functioning of the two promising methodologies regarding the digitization of substations is analyzed. Ângelo Felipe Sartori, Adriano Peres de Morais, Diomar Adonis Copetti Lima, Ulisses Chemin Netto, Daniel Pinheiro Bernardon, Wagner Seizo Hokama, Júlia Beatriz Ramos da Conceição Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3329 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3330 This work investigates the problem of estimating the flue gas flow signal in a heat exchanger using the Kalman filter. The methodology of this work comprises two steps: the mathematical modeling step and the state estimation step. In the first step, the Autoregressive models with Exogenous Inputs (ARX) are obtained, which describe the dynamics of the HE-3 heat exchanger system. In the second step, the estimation of the flue gas flow signal is obtained using the Kalman filter from the identified ARX model and a set of measurements. The results obtained suggest that the Kalman filter is a promising method for the estimation of signals involved in the reduction step in steelmaking, making it a useful tool for applications in steelmaking processes. Felipe M. Majuste, Seleme M. B. Dias, Wendy Y. Eras-Herrera Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3330 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3331 Despite its advantages and the continuous growth of photovoltaic energy in the market, photovoltaic modules still have low efficiency in the generation of electric energy, which, in fixed module systems, is aggravated by the fact that the solar rays do not fall perpendicularly on the modules, causing their potential not to be used to its fullest. Seeking to solve this problem, optimization strategies have been created to maximize the power generation capacity of these modules. to analyze the efficiency and technical feasibility of implementing mobile mirrors coupled to photovoltaic modules to increase the use of solar rays in photovoltaic generation and reduce the shading effect. For the development of this research, two prototypes were assembled: the first one is a physical model simulating a residence with the system of movable mirrors, automatically controlled, using an Arduino development board, and the second one was built with a kit of photovoltaic modules with a nominal power of 345 W and, coupled to it, a mirror that remains mobile, allowing the rotation and desirable inclination. From the data collected, an average optimization of 19.1% was obtained in the generation and reduction of 31.12% of the shading effect through the redirection of sunlight with the mirror. Lissandra Souza Silva, Marcos Borges Conceição, Flávio Couvo Teixeira Maia, Márcio da Silva Pereira Bove, Reginaldo Barnabé Gonzales Grimaldi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3331 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3332 High performance inverters are key components in electrical applications. The operating capacity, efficiency and life cycle of inverters can be limited by the magnitude of losses and external factors such as ambient temperature and humidity. To attenuate high levels of temperature, the use of heat exchange systems with liquid cooling is recurrent to reduce the temperature level and increase the full efficiency of the system. This papper presents the thermal study of losses in power modules and liquid cooling sinks that are performed and implemented in ANSYS to obtain thermal parameters, using Finite Elements Analysis (FEA). From the thermal impedance of the system and implementation of the Foster thermal network, the heatsink is validated in the software Typhoon Hil, making it possible to obtain the heatsink’s cooling profile for different loads connected to a three-phase inverter. In the validation step, a 50 kW RL load was connected to the three-phase inverter to evaluate the heatsink cooling capacity for different inverter operating conditions. Paulo Henrique Alves Silva e Silva, Eduardo Cattani Silva, Lucas Rossato Rocha, Paulo R.Eckert, Rodrigo Padilha Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3332 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3333 Alzheimer’s is a neurodegenerative disease that is related not only to memory, but to impairment of other important mental functions. From this perspective, the health care sector has shown one of the largest increases in the amount of digital data, which has led to the emergence of different techniques for exploring and treating them. These technologies are of fundamental importance for the health professional to ensure more accurate diagnoses, in addition to optimizing time, reducing costs and choosing the best interventions in the clinical decision-making process. In addition to contributing to a broader understanding of information and detection of hidden patterns. Therefore, a machine learning model was proposed to identify the best functional biomarkers of cognitive response to Transcranial Direct Current Stimulation (tDCS) capable of differentiating responders and non-responders to treatment. Fernanda Maria Lima Fernandes, Larissa Pereira Costa, Suellen Mary Marinho dos Santos Andrade, José Maurício Ramos de Souza Neto, José Hélio Bento da Silva, Juan Moises Maurício Villanueva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3333 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3334 This paper presents a methodology for probabilistic assessment of the combined hosting capacity (HC) of photovoltaic (PV) microgenerators and electric vehicles (EV) in low- voltage (LV) distribution networks considering local Volt-VAr control of both PV inverters and EV charging. The proposed methodology is based on the Monte Carlo method considering uncertainties associated with PV generation and EV charging. The used stochastic variables are PV location, EV user behavior, residential load profile, PV rated capacity, and regulatory aspects. Tests and simulations have been performed in a real LV distribution network using Python and OpenDSS via DLL interface. The simulation results have been statistically analyzed by boxplots. The following operational variables have been monitored simultaneously: voltage magnitude, voltage unbalance, transformer loading. In addition, a complementary study on the real losses in the LV network is presented. Finally, the simulation results show that the local Volt- VAr control is effective to increase the combined HC of PV and EV charging in LV distribution networks. Fernando Duarte Brito, Luiz Eduardo Sales e Silva, João Paulo Abreu Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3334 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3335 Over the years, the robot grasping area has received considerable attention. Several techniques were developed to increase the efficiency and autonomy of robot manipulators. This work presents a brief review and analysis of different techniques applied to deep learning-based robot grasping generation models, in addition to some of the challenges that need to be overcome in the area. Kleber L. S. Filho, Leizer Schnitman, Sérgio R. X. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3335 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3336 Resonant controllers, whether Resonant Proportional (PR) or Vectorial Proportional Integral (VPI), are increasingly used in power electronics converters. Since they are most often embedded in digital microcontrollers, the discretization effects of their mathematical models directly impact the dynamics of the final system. This paper proposes a new discretization for the PR and VPI resonant controllers. Allied to this proposition, a design algorithm focused on optimizing the closed-loop stability of the system via inverse Nyquist diagrams and harmonic current compensation is also proposed. Simulation results prove the validity of the proposed discretization as well as the design algorithm. Fábio A. L. Alves, André R. de Castro, Thiago C. Tricarico, Marcello S. Neves, Maurício Aredes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3336 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3337 Distillation columns constitute one of the most important processes in the Chemical Industry, in which the implementation of advanced control techniques is an indispensable effort. Dynamic models of distillation columns are among the most complex found in process control systems. This requires the identification of suitable models, then, many difficulties arise due to the complexity of these processes. This work presents a parametric identification of a debutanizer column by a multivariable model, with two inputs and two outputs, using a NARMAX polynomial model, which serves for application in control. Manoel O. S. Sobrinho, Adhemar B. Fontes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3337 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3338 In this paper, we propose an event-triggered control strategy based on a dynamic output-feedback controller for stabilizing discrete-time linear parameter-varying (LPV) sys- tems. Such a controller has an anti-windup term and is partially dependent on time-varying parameters. To economize the limited network resources, two event generators are introduced on the sensor-to-controller and controller-to-actuator channels. They decide whether the current output measurement and control input should be sent through the network or not. Sufficient conditions in terms of linear matrix inequalities (LMIs) are provided to ensure the regional asymptotic stability of the closed-loop system and estimate its domain of attraction. The transmission activity is indirectly reduced thanks to appropriate optimization procedures. A numerical example testifies the efficiency of the proposed methodology. Carla de Souza, Valter J. S. Leite, Eugênio B. Castelan Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3338 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3339 A estimativa de harmônicas e inter-harmônicas é uma tarefa essencial para analisar a Qualidade da Energia Elétrica (QEE). Essas componentes podem interferir na funcionalidade do dispositivo, levando ao aquecimento de motores e ineficiência no consumo de energia. Normalmente, a estimação dessas componentes é realizada pela Transformada de Fourier, no entanto, a precisão da estimativa pode diminuir em cenários adversos. Sendo assim, este trabalho propõe um método de três pontos da Transformada Discreta de Fourier Interpolada (IpDFT) para aumentar o desempenho da estimação de harmônicas e inter-harmônicas, considerando componentes de alta frequência com baixa amplitude em cenários de desvio de frequência. Os resultados mostram que o método proposto possui boa acurácia, robustez e baixa complexidade computacional. Portanto, este método é adequado para aplicações reais em Sistemas Elétricos de Potência, considerando diferentes cenários, como a presença de ruídos e desvio de frequência. Luiz F. A. Rodrigues, Henrique L. M. Monteiro, Danton D. Ferreira, Thales W. Cabral, Felipe M. Dias, Mateus O. Mostaro, Leandro R. M. Silva, Renato A. Ribeiro, Marcelo A. A. Lima, Carlos A. Duque Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3339 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3340 Accurate and robust acquisition of angular position and stator currents is critical for developing high-performance three-phase motor drives. Resolver sensor is widely used to measure the motor shaft angular position in harsh conditions. On the other hand, frequency division multiplexing (FDM) is a powerful alternative to send the motor stator current signals and the resolver outputs to the data acquisition system (DAQ) used in three-phase motor drives. In most approaches, the frequency of the resolver excitation voltage is less than the switching frequency of the PWM technique used to control the motor. Hence, the distance between the spectra of the resolver signals and the current signals, which depends on the resolver excitation frequency, is small, increasing the interference of the current signals in the angle estimation (crosstalk). This paper proposes an improved multiplexing approach to reduce the effect of crosstalk in angle estimation. The resolver excitation frequency is 1.5 times the inverter switching frequency so that the resolver outputs are zero when the PWM carrier reaches its valley. Thus, synchronous current sampling can be applied to get the stator current signals, and the effect of crosstalk is reduced in the angle estimation. Simulation results prove that the proposed approach reduces the crosstalk effect in the angle estimation and allows recovering the current signals. Igor Ono, Thyago Estrabis, Gabriel Gentil, Raymundo Cordero, Julio C. O. de S. Lescano Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3340 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3341 Smugglers use a variety of tactics to bring goods into a country without paying taxes. These bandits usually operate at night, when the weather and lack of light make it easier for them to move goods. Smugglers' entry points are typically rural areas with a vast distance between them and the city. Thermal cameras and drones are the most effective tools for detecting smugglers because they can identify items that are unaffected by weather, lighting, or body posture, and they can cover enormous amounts of terrain quickly. This research proposes a new thermal model that uses transfer learning from a small hand-labeled database and another model created from a public thermal database to recognize 49 objects with 524,700 thermal images, as well as define and propose a final model of pedestrian recognition in thermal images captured with a drone that has a 94% accuracy. Santiago Felipe Luna Romero, Charles Roberto Stempniak, Mauren Abreu de Souza, Gilberto Reynoso-Meza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3341 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3342 This paper considers the trajectory tracking control of a robotic system for Wire Arc Additive Manufacturing (WAAM) of complex geometry parts. The considered (redundant) robotic system is composed by a robotic manipulator and a positioning table. In order to use the system redundancy, a task-priority based kinematic control scheme to control a manipulator and a positioning table coordinately is proposed. The manipulator and positioning table are considered as a single kinematic chain, defining the primary task as the trajectory tracking of the welding torch defined in the positioning table deposition frame and setting a secondary task to align the welding torch with a desired direction defined in the inertial frame (e.g., gravity direction). A complete Lyapunov stability analysis is performed considering unmodelled dynamics in the kinematic control loop. The effectiveness of the proposed method is shown experimentally on a WAAM robotic system composed of a six-axis industrial manipulator, a two-axis positioning table and a Cold Metal Transfer (CMT) power source. Nicolas Lizarralde, Fernando Coutinho, Fernando Lizarralde Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3342 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3343 Process modeling is a way of identifying and predicting possible failures in various systems, thus seeking to eliminate production waste. The use of mathematical models makes it possible to represent a given system in several different ways, depending on the perspective to be considered when choosing the system. This paper aims to model the data obtained from the battery discharge of a quad-rotor drone, Parrot Rolling Spider, in which two new Shoot Li-Po batteries, model XT-412, were used. For each battery, 5 tests were performed, and for each one, the battery discharge profile was recorded, ranging from 3.30V to 4.10V, at intervals of 50(mV). Such data were analyzed with the MATLAB program platform, system identification toolbox, which is used to build mathematical models of dynamic systems from measured input and output data. Within the tool, it was possible to model four mathematical models: ARX, OE, NARX and Hammerstein-Wiener, where the correctness values of these models can be seen in this work.As results it can be highlighted that the non-linear Hammerstein-Wiener model presented the highest accuracy, but presented the highest Computational Execution Time. Batista D. Catumba, José A. Monteiro Sobrinho, Adriel de O. Freitas, Vandilberto P. Pinto, Leonardo R. Rodrigues Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3343 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3344 The use of a Genetic Algorithm (GA) as a tool for the solution to engineering optimization problems has been proven to be effective and easy to implement. This paper presents a Genetic Algorithm- based optimization of the firing angles of a 2.2 kW 8/6 Switched Reluctance Machine aiming to reduce a well-known disadvantage of the SRMs: the torque ripple. Initially, the machine was modeled in Matlab/Simulink® by means of lookup tables obtained via finite element simulation. Thus, based on a co- simulation model also implemented in Matlab/Simulink®, the algorithm returned the optimized commutation angles of the phase excitation that minimize the SRM torque ripple for a chosen operation point. The results confirm that the torque performance of the SRM is sensitive to the commutation angles and, therefore, it was possible to define switching commands that improved the torque performance of the SRM drive up to 53% when comparing non-optimized and optimized angles for four different operating points. Renata Rezende Reis, Marcio L. M. Kimpara, Raymundo C. Garcia, Gabriel Gentil, Thyago Estrabis, João Onofre Pereira Pinto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3344 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3345 This paper presents a method of calibration of a 2D laser sensor (Profilometer) used in a robotic system of Additive Manufacturing. The proposed iterative method is based on Hand-Eye calibration and uses only information from data obtained with a single plane, without information of the plane localization. The calibration of the location of the profilometer with respect to the manipulator end-effector to which it is coupled is essential to extract geometric characteristics from parts manufactured by Additive Manufacturing. Simulations and experiments in a robotic Additive Manufacturing system show the effectiveness of the proposed method to determine the sensor pose with respect to the end-effector coordinate system. Gilmar P. Cruz Júnior, Nicolas Lizarralde, Fernando Coutinho, Gustavo M. Freitas, Fernando Lizarralde Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3345 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3346 This work demonstrates the positioning of different energy sources in relation to access requests and indicates the potential of other energy sources, with the development and improvement of technologies, for urban centers. In this case, the work explains about natural gas cogeneration in places where the offer of roofs and areas for the implementation of solar systems are not possible or interesting, due to shading, positioning, area limitation, inadequate geometry, area costs or others types of interference. As part of the work, a case study and financial analysis are presented to demonstrate its feasibility. The future growth of this type of access must be considered in the planning and operation of distribution networks, as it will have a considerable participation in the constitution of the electric system in urban centers. Élio Vicentini, Ricardo Caneloi dos Santos, Ricardo da Silva Benedito Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3346 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3347 The main advantage of using the Doubly-fed Induction Generator - DFIG, in wind power generation systems with variable speed, is that the power electronics used correspond only to a fraction of the generator’s nominal power, considering that only the slip power it is processed by the static converter connected to the rotor circuit. This paper covers details from the steps of mathematical modeling of the converters and design of the controllers, to the characterization of the prototype commissioned to carry out the study. Experimental results obtained in a 13kVA DFIG are shown, and transient analyzes under different conditions preceding the stator connection with the electrical grid are discussed to validate the effectiveness of the control strategies used. Such conditions involve the parallelism with differences between the voltage amplitudes of the grid and the stator, and the parallelism with speed different from the synchronous one. André Lage Almeida Dias, Clodualdo Venicio de Sousa, Guilherme Monteiro de Rezende, João Lucas da Silva, Yasmine Neves Maia, Gabriel Azevedo Fogli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3347 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3348 This article presents the application of Higher Order Statistics for the extraction of characteristics of the inrush current phenomenon, together with Fisher's Linear Discriminant for the selection of characteristics with the greatest potential for distinction, in relation to steady-state and short- term events. circuit, as well as the application of the Neural Networks technique for the classification of these types of events. The modeling process of these events was carried out in the software APTDraw (Alternative Transient Program), having as an initial step the process of validating the simulation data, in relation to the real data measured in a 69/13.8kV Substation. The application of the techniques together resulted in a satisfactory distinction and classification of events, giving credibility to the efficiency of the application. Romão O. K. Polyana, Almeida R. Aryfrance, Carvalho S. G. José, Araújo G. Cléia, Sobreira O. Danillo, Junior F. S. Bartolomeu Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3348 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3349 The solution to the restoration problem consists of minimizing the network switching looking for a new configuration, respecting all operational restrictions, and reconnecting the most significant number of consumers who were left without service due to a permanent fault. Many techniques that deal with this problem present solutions with a low computational time and consider the practical characteristics of real large networks. However, few papers in the literature consider the protection functions and restrictions in service restoration problems. From this perspective, this paper proposes to incorporate the protection functions of the phase and neutral overcurrent relay in the base methodology of a Multiobjective Evolutionary Algorithm in Tables (AEMT). However, the paper will not treat the protection system as a constraint of the problem, preventing reasonable solutions from being selected. Thus an adaptive approach is considered in this paper, that is, adapting the protection system to the new network configurations when they violate the protection restrictions of the system. The observed results were promising, and the importance of incorporating the protection functions into the problem was observed considering the adaptive approach. Jullian C. Zan, Etiane O. P. de Carvalho, Denis V. Coury, Mário Oleskovicz, João Bosco A. London Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3349 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3350 This work presents the design of an output feedback dynamic controller applied in a generation system connected to the infinite bus. This controller aims to allocate the system poles in a desired region of the complex plane and minimize the relationship of norm-H2 and norm-H∞ to perform the damping of electromechanical oscillations. The proposed power system stabilizer (PSS) is compared with a PSS designed using the conventional technique using frequency analysis to damp electromechanical oscillations and with the system operating without the presence of an ESP regulator. To perform the comparison between the systems, the dynamic response was used, in the form of accommodation time, maximum oscillation peak, control effort, and ISE, ITAE, ISC, and ITAC indices. Finally, the proposed controller obtained superior performance to the conventional one, and the system worked without the presence of a PSS, This is because that controller has the lowest performance, signal overshoot and settling time. Nei Junior Da Silva Farias, Renan Landau Paiva de Medeiros, Florindo Antônio de Carvalho Ayres Júnior, João Edgar Chaves Filho, Iury Valente de Bessa, Vicente Ferreira de Lucena Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3350 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3351 The present work aims at the development of a didactic tool that serves as support to the academics of the discipline of Electric Power Substations. The application will provide the user with demonstrations of maneuvers in the most common busbar arrangements, facilitating and providing an understanding of the different equipment that make up a substation. It was decided to use the Tkinter package, which comes with the official distribution of the Python free license interpreter, being responsible for the graphical user interface. It is intended to carry out a quality assessment of the application with the students of the discipline. The application will be made available for download, for personal and/or academic use, through the GitHub.com hosting platform, where it provides access control and various collaboration features. Laís Brum Menezes, Cristiane Cauduro Gastaldini, Laura Lisiane Callai dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3351 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3352 In this paper, a new switched static output feedback controller design for uncertain linear time-invariant (LTI) systems is proposed. The approach chosen for the design of static output feedback gains is based on the two-stage method, which consists in first obtaining a state feedback gain matrix that is then used as an input parameter for the design of the desired static output feedback controller at the second stage. The proposed strategy considers performance improvement regarding the specification of a minimum closed-loop rate. The solution for the investigated problem is presented in terms of linear matrix inequalities (LMIs) obtained using the Finsler’s Lemma. The obtained results are compared with a robust static output feedback method, in a controller design and practical implementation for a real active suspension system. Leandro Campos Vargas, Bruno Sereni, Edvaldo Assunção, Marcelo Carvalho Minhoto Teixeira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3352 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3353 Mechanical transmission systems are often used to convert the torque-speed ratio and transmit power for movements of different natures. In transmission by spur gears, non- entrapment clearances can cause effects that impair the description of the system dynamics as a linear model (non-linearities) that, in some cases, must be identified and compensated. This work aims to identify a non-linearity caused by gaps between a spur gears pair in a mechanical transmission system using NARMAX polynomial models, the proposed approach uses the similarities between a system with hysteresis and one with backlash. The results present that the established techniques for the identification of systems with hysteresis can also be applied to systems with backlash. Jonathan Guimarães Ribeiro, Matheus Delgado de Azevedo, Samir Angelo Milani Martins, Erivelton G. Nepomuceno Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3353 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3354 Nowadays, the generation of renewable solar energy is developing on a large scale. Nonetheless, acquiring a photovoltaic system implies a high cost due to its components such as modules and high-power inverters. Taking it into consideration, only part of the population has financial access to invest in this system. A possible solution to this problem is the use of solar tiles which have become popular and enables the consumer to buy it gradually, according to his financial availability. Since plenty of this technology cannot be found in the market, there are some studies using protypes which associate mini solar panels to traditional roof tiles. In this paper, we present the economic feasibility analysis of a prototype based on mini solar panels associated to an ecological tile. Through this work, we demonstrate that this system is economically feasible, meeting the power demand and enabling its acquisition by low-income families. Ana Cecília Fernandez dos Santos, Eduardo José de Araújo, Kimberlly da Silva Neves, Lorena Araújo dos Santos, Marlon Lucas Gomes Salmento, Tamires Cristina Rodrigues Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3354 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3355 The transport of object by groups of robots can be advantageous when an object is too large or too heavy to be effectively handled by a single robot alone. It requires the coordination and synchronization of pushing forces to be exercised by the robots. In this paper, we propose a new algorithm called Cooperative Transport of Object (CTO). The algorithm has four stages. The first one implements the search for object. The second stage of the algorithm start when a robot finds the object. It then recruits the other robots. During the third stage each robot first computes then goes to the position it must be located at to execute the pushing actions. When the positioning of all robots around the circular object is completed, the fourth stage commences. Therein, the robots start alternating between pushing and positioning actions to maintain the object within the expected transport trajectory. This is performed until the object is homed. The algorithm is implemented in GRITSBot swarm robots, using Robotarium. The algorithm is effective to carry out the stages and the corresponding performance is promising. Gustavo Bueno Ferreira, Nadia Nedjah, Luiza de Macedo Mourelle Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3355 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3356 This paper proposes a framework for applying model checking in industrial control design based on the GRAFCET language. The aim of this research was to develop a step- by-step to help create a digital twin with a cyberphysical aspect of a system composed of a control program and a plant to be controlled. For this, it is proposed, through manual inspection, the creation of templates of the most common modules that compose the internal and external environment of the control. The creation of models in state machine was used for the environments and for the control itself. The application of model checking is done through the NuSMV tool, which has its own language based on state evolution with property verification in Computation Tree Logic - CTL. For illustration purposes, a example of a valve with all the components found in more recent real projects in the oil and gas industry is introduced. The result was a model capable of experimenting with execution paths and analyzing them by verifying the security and operating properties of the system. Additionally, a validation of the initially designed control program was successfully carried out, being able to serve, in a real application, as a complement to a factory acceptance test before its implementation in an embedded PLC. Thiago G. R. Cruz, Antonio E. C. da Cunha Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3356 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3357 This paper presents the modelling of a DC microgrid powered by ion-lithium batteries and a bank of ultracapacitors (UCs), and used as power source in electric vehicles of the Formula SAE competition. The control strategy is implemented for the proper management between the energy sources, to reduce battery degradation and to explore the characteristics of the UCs, which have a high energy gradient to support the power peaks during the acceleration and braking regenerative energy while driving the vehicle. Additionally, computational tools were used to model the power plant, collect electrical data and apply particle swarm optimization (PSO). Finally, the simulations showed a reduction of the battery energy consumption (greater than 10%) with a lesser level of current stress (current peaks) on the Piracicaba-SP track, where the SAE competitions take place. Márcio V. R. Campos, Lucas Jonys R. Silva, Thales A. Fagundes, Rodolpho V. A. Neves, Joseph J. Kalil, Ricardo Q. Machado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3357 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3358 The outage scheduling in transmission networks is one of the most complex tasks performed by the independent system operator (ISO), that is responsible for accepting, denying or rescheduling the outage requests planned by the equipment owners. Such requests, if approved, may cause operative problems, which have to be anticipated by the ISO by performing several analyses. If necessary, the ISO must define an outage scheduling in which all outages take place within a given time window, being also desirable to preserve system operation security as most as possible. The problem complexity resides in its combinatorial nature, as the number of combinations of possible time instants to perform the outages may be extremely high. This work proposes a methodology for the optimal scheduling of transmission equipment outages that seeks to identify an outage scheduling that, in a given time window, optimizes system operation security. Leonardo Gonzaga da Silva, Rainer Zanghi, Julio Cesar Stacchini de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3358 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3359 Neurodegenerative disease is a general term to describe various diseases that affect the neurons, causing motor and physiological symptoms, such as involuntary movements, weakness, and gait problems. Neurodegenerative diseases do not have cure, and diagnosing them, especially in early cases, is a hard task, due to the lack of definitive tests for many of them. In this paper, we investigate the problem of identifying subjects with Parkinson’s Disease (PD), Huntington’s Disease (HD), Amyotrophic Lateral Sclerosis (ALS), and healthy control subjects using gait dynamics. This multiclassification problem is tackled with a multilayer feedforward neural network fed with statistical and signal features extracted from time series obtained from the left and right foot using force-sensitive resistors. In contrast to other approaches, we have used only one minute of gait signal, focusing on minimizing the patients’ effort, who may already have difficulties walking continuously and without aid, even for short periods of time, including those in the initial stages of the neural disease. Our results show that 96.88% of accuracy may be achieved for this multiclassification problem, surpassing other results in the literature, and pointing to a step close to aid the diagnosis of neurodegenerative diseases. Juliana P. Felix, Afonso U. da Fonseca, Hugo A. D. do Nascimento, Nilza N. Guimarães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3359 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3360 This paper presents an emulation-based design condition for event-triggered control systems under denial-of-service (DoS) attacks. Considering a deterministic model that constrains the duration of DoS attacks only in an average sense, the proposed condition ensures the exponential stability of the closed-loop system and provides a maximal percentage of time at which information can be lost without leading to instability. A multi-objective optimization problem is proposed to establish the relation between the reduction of transmission attempts and the tolerance to DoS attacks. The commitment between these two objectives is illustrated by means of numerical simulations, as well as the effectiveness of the proposed ETC scheme in reducing the network resources usage even in the presence of DoS attacks. Pedro H. S. Coutinho, Iury Bessa, Márcia L. C. Peixoto, Paulo S. P. Pessim, Pedro O. F. Pires, Reinaldo M. Palhares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3360 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3361 This work evaluates uplink scalability of industrial wireless networks regarding central- ity concepts. It applies simulations of centralized mesh-topology networks, taking WirelessHART networks as case study, in scenarios of high node density and varied quantities and distribution of access points. Performance criteria such as refresh rates, node buffer size and reliability are evaluated as varied project specifications. The study infers that the lowest end-to-end communication success rates are concentrated on chains which top nodes present higher degree and betweeness centrality, and the most faulty packages tend to be those generated on devices with lower proximity centrality. Dylan M Timm, Max Feldman, Leandro B Becker, Ivan Muller Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3361 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3362 In this article, we present a teaching proposal regarding the basic elements of process control, without the need for any advanced mathematical framework. The methodology addresses conceptually the majority of the steps required for the analysis and design of simple control systems. The programatic content of this educational guideline is presented, as well as tools that can be used in the classroom. Furthermore, a test-bench kit is proposed in order to carry out experiments regarding different subjects. Julio Elias Normey-Rico, Marcelo M. Morato Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3362 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3363 In this work we present the design of a fractional order PI control and a PLC based implementation for an industrial scale level control bench. The system is a first order plus deadtime, with dead zone until it reaches the operating regime, the pump presented saturation power. The controller design used a constrained optimization and took into account the reduction of settling time, null steady state error and robustness specifications. For the implementation, an adaptation of the approximation method of a long memory discrete time PID controller (LDPID) was used. The programming was developed in Ladder logic. Simulations and experimental tests of regulation, tracking and robustness were carried out. The FOPI controller presented the better performance compared to the classic PI both in simulations and in experimental tests. Nikolas M. L. Santos, Paulo R. O. Martins, Gustavo C. Silva Neto, Florindo A. C. Ayres Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3363 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3364 The expansion of distributed generation in the context of microgrids has allowed the emergence of increasingly larger and more complex structures, with different amounts of converters and control techniques, different operating modes, presence of local loads, among others. In this context, the development of models to analyze the stability of microgrids provides an important tool for greater assurance of a safe and efficient operation. Thus, the objective of this paper is to propose a modular small-signal model, capable to represent different configurations of microgrids, for system stability analysis. As a case study is presented a microgrid with two converters, using two different control techniques: droop and synchronverter, with local loads and operating in connected mode. The paper validates the developed small- signal model, through the comparison with the behavior of a dynamic model simulated in MATLAB/Simulink, and presents stability analysis in relation to the controllers gains. Gustavo C. M. Oliveira, Reginaldo V. Ferreira, Sidelmo M. Silva, Leandro Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3364 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3365 This work presents an architecture proposal for dam safety monitoring systems. It includes modules for data collection, processing, storage, analysis and availability. It seeks to reduce the design, development and application challenges of dam safety monitoring systems. A monitoring system was developed based on this proposal and applied at UHE Dona Francisca. Murilo L. Fonseca, Santiago D. Piovesan, Giancarlo Marchesini, Marcelo C. Nunes, Gustavo Y. C. P. Coelho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3365 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3366 The article deals with the development of a magnetic torquer based on the axiomatic design theory to define the constructive characteristics of the device to be applied in the attitude control of small- size satellites. The physical principles of this actuator, the modeling of the characteristics to be manipulated by the theory, the proposal of a prototype and the initial experimental tests for the design strategy validation are presented. For the core of the coil that constitutes a torquer rod, an innovative material with nanocrystalline composition was chosen, the FINEMET®, aiming to take advantage of its magnetic permeability properties and reduced hysteresis phenomenon to generate a more linear signal, a requirement of the control system. Preliminary results show that the project proposal is promising as a contribution to the improvement of fundamental devices for the continuous and accelerated growth of the use of Cubesats. Matheus A. Soares, Luiz S. Martins-Filho, Eduardo Gueron, Eduardo S. Ferreira, Hérlon O. Morsch Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3366 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3367 The deployment of DGs, especially micro and mini distributed photovoltaic (PV) power system on large scale in the low-voltage distribution power system is currently a concern for utilities, in terms of Power Quality (PQ) in their grids. This paper proposes a computational tool using MATLAB/Simulink platform capable of estimating the hosting capacity (HC) in low-voltage electrical grid. In other words, the platform estimates the maximum amount of distributed generation that the electrical grid can support without deteriorating the performance of its operation and PQ criteria. To estimate the grid hosting capacity, the computational tool performs iterative simulation and analyses. There are several simulations changing the location of DGs into the grid and increases the DGs power capacity. Thiago M. Braga, Hélio Marcos André Antunes, Hugo R. Torquato, Danilo I. Brandão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3367 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3368 The work presents the development of a low cost Computerized Numerical Control (CNC) didactic module to aid in teaching and learning methods in engineering. This stems from the need to train graduates with competent and socially responsible technical capacity, linked to the teaching proposals stipulated by the new National Curriculum Guidelines (DCNs) to be implemented in engineering courses. A low-cost CNC Laser engraving machine was developed, with the aim of applying methods and strategies of active methodologies to activate the learning of the proposed content in the Numerical Command and Machine Tools course at the Federal Institute of Rondônia. For the development it was used research tools, such as an online academic platform, and methodology for the development of mechatronics products, the V Model. The research results presents the closure of the machine assembly and active methodology strategies for student-centered learning. The machine confection made a multidisciplinary character possible, through the sharing of the 3D printer archives it is possible to replicate the machine by others teachers in other teaching centers and laboratories. André Marinho, Rafael Pedrisch, João Magalhães, Ariadny Milena, Artur Vitório Andrade Santos, José Diogo Forte de Oliveira Luna Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3368 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3369 This work investigates the hybrid active damping for grid-tied LCL inverters. This method uses, besides the capacitor current feedback, the point of common coupling voltage. Mathematical modelling is carried out and the analysis of the impact of the choice of damping gains in the system stability is presented by verifying the poles positions in the unit circle. For choosing the gains for both active damping and current controller, a particle swarm optimization (PSO) algorithm is used, considering robustness for grid inductance variation. Real-time simulations are provided to verify the effectiveness of the proposed method. A. Braga Jr., G. X. Prestes, P. H. A. S. E Silva, R. P. Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3369 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3370 The insertion of renewable energy sources (RES) in power systems causes a decrease in the system’s equivalent inertia, which may result in the instability of the power system. On the other hand, energy storage systems have proven to be an effective tool to increase the flexibility in the operation of energy systems, which may favor integrating RES. In this way, plug-in electric vehicle (PEVs) batteries can be used as storages when such vehicles are parked and connected to the grid. In this work, the contribution of PEVs to primary frequency response (PFR) is analyzed in systems dominated by RES. A day-ahead scheduling model is developed considering PEVs groups can actively participate in electricity markets, supporting day-ahead reserve capacity and providing PFR. The proposed model is implemented in the distribution system of the Federal University of Amapá. Amanda T. R. Fernandes, Miguel C. R. Peinado, Maria R. D. Martin, Rodrigo A. Ramos, Ahda P. G. Pavani, Natali V. C. Gonçalves, Werbeston D. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3370 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3371 This paper proposes the use of consecutive inertial sensors to estimate joint angles in the human body, as well as in rigid devices such as exoskeletons and articulated robots, consid- ering the occurrence of possible online misalignments and automatic adaptation, promoting the system’s robustness to such uncertainties. The proposal consists of modeling the problem as a spherical joint with projection of movements in the plane of greater angular amplitude, defining a minimization problem for the automatic virtual alignment of the inertial sensors. In the study, two filtering systems based on Kalman were developed to achieve the proposal, the first being used as a tool for online optimization and adjustment of the virtual alignment parameters of the sensors, while the second was responsible for the fusion of the signals in order to estimate the joint angle of the molded joint. The results obtained were promising, with a Pearson correlation of around 0.99 and RMSE close to 1o when compared with measurements from an encoder, and the system adaptation to sudden changes in orientation took a few seconds after the occurrence, this being dependent on the size of the fitting data window. Mateus Pereira, Edson Francelino, Lucca B. Castro, Roberto S. Inoue, Samuel Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3371 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3372 In recent years, there has been a growing demand for energy solutions considered clean, especially wind energy, which in 2018 was responsible for 8.3% of the national energy matrix. Wind energy has numerous advantages, such as the fact that it is inexhaustible, clean, and contributes to local economic development, among others. However, it is surrounded by numerous challenges regarding availability, which is related to the possibility of occurrence of ramp events. In this sense, models capable of accurately predicting the output power of wind farms are increasingly being investigated. This paper aims to understand the basic characteristics of ramp events and analyze the effects on the electrical power systems, seeking to point out predictive proposals to contribute to the development of a model capable of making an accurate prediction of ramp events. Josélio C. Cruz, Denisson Q. Oliveira, Osvaldo R. Saavedra, Clovis Bosco Oliveira, Leiliane Trindade de A. do Monte Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3372 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3373 The integration of machines and devices is highlighted in current industrial processes, especially in those where robotic manipulation is present. Manipulators are versatile automation solutions, capable of perform a wide range of tasks just by changing their tool and programming. In the robotics laboratory of CEFET-MG Divinópolis, a Comau Smart5 SiX® robot is available and was used as a basis for a simulation application in a previous academic work. To provide continuity, it was proposed the development of a manipulation tool to validate the results of a cube stacking task. With that in mind, this paper aimed to complement a robotic cell, through the design, construction, programming and testing of a two-finger parallel gripper, compatible with the mentioned manipulator. This was done through a theoretical study to design the parts, followed by 3D modeling, manufacture and assembly processes. Electronic drive circuits were produced, in addition to control and communication algorithms. Thus, it was obtained a versatile and low-cost tool, capable of meeting the defined specifications. Alysson A. A. Pereira, Renato S. Dâmaso, Cláudio P. Lopes, Henrique A. Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3373 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3374 As conventional hydroelectric power plants are reaching physical and environmental constraints, hydrokinetic turbines, which use only a natural flow from the rivers analogous to wind generation, may become a growing solution to overcome these limits. There is still an unexplored hydropower potential, which is more ecologically correct to take advantage of in a distributed and not dammed way. This paper describes a power converter topology and a control system for a hydraulic turbine to inject power into the grid proportional to the river flow rate. The control system is composed of: an MPPT (Maximum Power Point Tracking), which measures the voltage and current in the DC bus and generates a voltage reference of the DC link for the maximum power of the turbine-generator system; by the DC link voltage controller, which provides a reference for the control of electric current injection into the network; and by the single-phase instantaneous current control of the grid-connected voltage source inverter. One of the contributions consists of identifying the operating conditions and limits of the whole system, composed of the hydraulic turbine, the electric generator, and the power converter. The same methodology may be applied to design specific sets of a turbine-generator-converter system for each application. Julio C. O. de S. Lescano, Luigi G. Junior, Hugo C. S. Souza, Thyago Estrabis, Gabriel Gentil, Raymundo Cordero Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3374 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3375 In recent years, the number and capacity of solar photovoltaic (PV) installations connected to the power system are growing at a rapid pace worldwide. Therefore, power quality issues related to voltage regulation and grid stability are becoming relevant problems for distribution networks and PV owners. To mitigate these impacts, interconnection standards have been amended to add smart features to solar PV inverters as “Smart Inverters”, such as Low Voltage Ride-Through (LVRT) and dynamic voltage support. This paper explores the Volt-VAr control as a dynamic voltage support during faults in smart inverters with LVRT capacity. Furthermore, this work also develops different strategies to deal with DC link voltage level and converter capacity limitation. The simulation results show the reactive power injected to the system, the behavior of the inverter terminal voltage, and the DC link voltage level for different current priority techniques. Rafaella A. F. Santos, R. Reginatto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3375 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3376 Dynamic Security Regions (DSR) are tridimensional graphics that evaluate power system security. For this purpose, the system is divided into three-generation groups. They allow the evaluation of different generation scenarios considering the security limits for the damping ratios associated with electromechanical oscillation modes. The literature shows that Power System Stabilizers (PSS) optimal tuning increases the damping ratios in closed-loop operation, and this paper investigates the PSS tuning on the DSR shape. The DSR is built using a Particle Swarm Optimization based approach, and the results are obtained for the New England test system. Victor F. Carvalho, Wesley Peres, Raphael P. B. Poubel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3376 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3377 This article presents the didactic plant Sallen-Key-Duino, built for the study of digital controllers. In addition, the theoretical and experimental results of the construction of a discrete controller with compensator, conceived based on the frequency analysis of the didactic plant, are presented. The practical and analytical results of the study are compared in the MATLAB software, in order to show the effectiveness of the plant and the chosen control method. Raimundo S. R. Neto, Luiz D. S. Bezerra, Guilherme de A. Barreto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3377 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3378 Recent advances in algorithms and embedded systems have created possibilities to meet the demand for advanced controllers in processes with fast dynamics. In general, advanced controllers are very costly from a computational point of view and end up being used in processes with slow dynamics or need to be implemented in sophisticated computers. The implementation of advanced controllers in low-cost embedded systems, such as microcontrollers, can contribute to the use of these techniques in a greater number of processes. This paper provides a proposal of implementation of a generalized predictive control algorithm of fast computation with constraints in a microcontroller platform. Issues of automatic code generation and the improvement of the control signal computation time and required memory space are evaluated. The implemented controller was experimentally simulated and tested in a case study of a multivariable system with first order transfer functions. The computation time obtained was about 1,2 ms. João Pedro Brunoni, Vinícius Berndsen Peccin, Rodolfo César Costa Flesch, Julio Elias Normey-Rico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3378 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3379 With the growing trend in demand for electricity and the increase in the penetration of intermittent sources in the Brazilian energy matrix, such as solar and wind, there is a need for studies of new technologies capable of contributing to the quality of energy in this new scenario. Thus, it is observed that the use of batteries can bring several advantages such as voltage regulation and loss reduction. However, for this allocation to be made in an advantageous way, characteristics such as lifespan, costs, and the influence of temperature on battery capacity must be considered. To do this, this work proposes a method based on a genetic algorithm. Maria Elisa F. Octaviano, Eduardo M. Loureiro, Leandro R. de Araujo, Débora R. R. P. Araujo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3379 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3380 This work carries out a study that aims to obtain a residential energy consumption management solution based on industry 4.0 concepts and technologies, such as augmented reality and IoT, and the modeling of Digital Twins. This system enables the storage, monitoring and visualization of energy consumption data from an energy meter, having an energy meter device located in a residence in the city of Curitiba-PR. The proposed architecture was divided into three layers: hardware, cloud, and software, resulting from the combination of IoT and Digital Twins architecture modeling. The results are satisfactory, because with the solution obtained it became possible to manage the energy consumption of the residence in question, providing the consumer with the monitoring of their consumption online, enabling decision-making and insights (indications) for actions aiming at efficient consumption in the context of energy efficiency. Francisco Borges Carreiro, Júlia Ferreira Nascimento, Guilherme Mateus Lopes Sousa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3380 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3381 This paper presents an Optimal Power Flow (OPF) to minimize the load shedding in the steady- state operation of unbalanced three-phase islanded microgrids. The droop characteristic of Distributed Generators (DG) connected to the grid through Voltage Source Inverters is appropriately modeled. The limits of voltage, generated power, and frequency are also considered. Besides, the frequency dependence of loads and line parameters are taken into account. The methodology is evaluated using a 25-bus unbalanced islanded microgrid, and the results point out that considering load variation reduces the total amount of load shed. Wesley Peres, Raphael P. B. Poubel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3381 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3382 This work addresses the problem of regional stability analysis of discrete-time linear systems subject to asymmetric control saturation. Conditions to assess the exponential stability of the origin using piecewise quadratic functions as Lyapunov candidates are proposed. Estimates of the region of attraction of the origin are obtained as level sets of those functions and additional conditions to obtain better estimates considering some size criteria are discussed. A numerical example shows the applicability of the proposed method. Leonardo Cabral, Giorgio Valmorbida, João Manoel Gomes da Silva Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3382 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3383 Recent works in the literature deal with efficient numerical conditions to robustly stabilize state-delayed discrete-time systems under saturating actuators. However, practical issues such as the rejection of exogenous signals and their effects on the region of safe initial conditions have not been thoroughly investigated. This work extends a previous controller design condition to handle the ℓ2 gain between the exogenous signals and the measured output. Moreover, the notion of input-to-state stability is applied, allowing to consider the effects of the disturbance signals over the estimates of the safe initial conditions region. Furthermore, a recent optimization procedure formulated in an augmented space is applied, allowing better estimates of the region of safe initial conditions while maintaining the numerical complexity acceptable. A numerical example illustrate the methods proposed and compare the achievements with the concerned literature. Romulo J. Silva Jr., Valter J. S. Leite, Luís F. P. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3383 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3384 In the work routine, accidents cause several losses, both for the contractor and the people hired. At the same time, profit and materials are lost in the companies, the work capacity and, in the worst cases, the worker’s life is affected. From 2002 to 2020, a rate of 6 deaths was recorded for every 100 thousand formal jobs in Brazil. The present work resulted in the evaluation of a computational model using machine learning to prevent serious accidents. Through the use of sliding window algorithms for data standardization, satisfactory results were achieved, in which it was possible to predict the occurrence of severe accidents for periods of up to seven days. Additionally, a prototype of an intelligent web system was proposed, using cloud microservices, using the prediction model created. Davi A. Leão, Carlos Wilker N. Santana, Iago S. Rodrigues, Carlos Henrique L. Cavalcante, Asley A. Batista Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3384 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3385 This paper presents an application of a model-free control for a quadruple tank system. Such a system is multivariable and has characteristics of its multivariable zero depending on the opening of the valves. The control is based on an ultra-local model determined by algebraic estimators in a short time window. The control scheme is tested in simulations considering three different cases. Satisfactory results were obtained even for a time-varying case. Gustavo Junqueira, Gabriel Pereira das Neves, Bruno Augusto Angélico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3385 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3386 The design and simulation of a fuzzy controller to a multilevel static compensator (STATCOM) connected to a low-voltage grid is presented, operating in order to maintain the power factor always close to unity. An H-bridge with a T cell in one of the legs is used as a DC- AC converter in the compensator. It is described the operation principle of the STATCOM and details of the controller’s design, such as fuzzy sets and rules created. Operations with loads of several natures and intensities were simulated and in all of them, the controller presented a good performance, confirming its applicability along with the STATCOM in power factor control. Laila S. Ribeiro, Domingos Sávio L. Simonetti Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3386 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3387 This work presents a modeling method for linear parameter-varying (LPV) system of a fuel oil injection plant of a 360 MW thermal power generation unit. The modeling of this system receives little attention from the literature and can be a relevant contribution for a more economical and sustainable operation of the boiler start-up procedure. The LPV model uses as inputs the opening of the fuel valve and the number of open burners, the outputs are the fuel pressure inside the pipeline and its consumption. The scheduling variable adopted is the number of open burners, considering its influence on the pressure and fuel oil consumption dynamics. The model was obtained through batch data collected from a real plant during its start-up operation. The model acquired in this article can help the design of more advanced control strategies to improve the overall plant operation. Adriano Rodrigues de Paula, Nickson Ramon Tomé de Sousa, Fabrício Gonzalez Nogueira, Bismark Claure Torrico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3387 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3388 This paper proposes the application of a switched robust predictive control applied to output voltage control of a three-state switching cell boost converter considering the average space-state equivalent boost model. The proposed technique follows the switched quadratic performance index minimization principle modeled via linear matrix inequalities (LMIs) to closed-loop stabilization problem of a boost converter. The simulation results evidence the closed-loop stabilization of the presented converter using the switched predictive control demonstrated through the time response analysis and the closed-loop boundary ellipsoids procedure. This study demonstrated that the proposed control technique is suitable to output voltage control of boost converter. As future works are the validation test in the experimental setup. Roberta R. T. Alves, Luís Carvalho, Marcus V. S. Costa, Francisco E. U. Reis Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3388 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3389 This article proposes the implementation of a naturally saturated reactor of nine cores in software with a graphical interface, namely ATPDraw, MATLAB/Simulink and PSCAD. The different methodologies for representing the equipment in each of the programs are pointed out. The mathematical model is presented, based on the theory of coupled circuits, which serves as a reference for the simulations of this equipment in various digital environments. The validation of the developed models will be made from the comparison between the results obtained in the software under study, with the original implementation, carried out in the EMTP-ATP. To justify the proposal, the advantages of implementing the model in the considered programs are presented, in detriment to the original. Augusto César C. de Oliveira, Carlos Augusto C. Santiago, Matheus Vinícius F. de Oliveira, William C. Lima, Luiz Antônio M. da Fonte, Manoel Afonso C. Jr., Vicente R. Simoni, Fernando Edier F. Freitas, Marcelo José A. Maia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3389 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3390 In this paper, we address the problem of supervisory control of Networked Discrete Event Systems, where the transmission of event occurrences from the plant to the supervisor and the transmission of control decisions from the supervisor to the plant are carried out through a network with several communication channels subject to bounded delays, with different maximum delay upper bounds for each channel. Due to the multichannel structure, there may occur changes in the order of observations and there may also occur situations where the same control decision reaches different locations in the plant with different delays. To deal with such effects, we propose a new automaton model and, based on this model, we formulate a networked supervisory control problem, present a necessary and sufficient condition for the existence of a solution, and a test to verify the proposed existence condition. Marcos Vinícius Silva Alves, Lilian Kawakami Carvalho, João Carlos dos Santos Basilio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3390 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3391 In this paper we propose a strategy to detect covert attacks on cyber-physical systems by extending the original plant with an auxiliary system. This auxiliary system is designed as a Markovian jump system. A detection system composed by a Kalman filter is presented. The efficacy of the proposed method is illustrated by a simulation example. Alexsandra C. Ribeiro, Diego S. Carneiro, Eduardo F. Costa, Vilma A. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3391 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3392 The three-phase four-wire voltage source converters are the equipment used in the connection of alternative sources to the distribution system where the loads are predominantly single-phase. Three-phase unbalanced neutral distribution system has unwanted components of negative and zero sequence. Under these conditions, the synchronism between the VSC and the electrical grid that is done using the PLL (Phase Locked Loop) is affected. Traditional PLLs such as SRF-PLL (Synchronous Reference Frame-PLL) is widely used, however they do not guarantee synchronism in unbalanced conditions. The PLLs DSOGI-PLL (Dual Second Order Generalized Integrator-PLL) and DTOGI-PLL (Dual Third Order Generalized Integrator-PLL) ensure accurate synchronization between the VSC and the mains under unsafe conditions. ideals. Thus, the objective of this article is to evaluate the effect of voltage unbalance and voltage harmonics on the ac currents of the VSC using DSOGI-PLL and DTOGI-PLL. Alex F. Silva, Paulo F. Silva, Claudionor F. Nascimento, Alfeu J. Sguarezi Filho, Fernando Lino, Patricia R. Albuquerque, José O. Domingues Júnior, Lucas D. Augusto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3392 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3393 The main target of this paper is to present the development steps of a Visible Light Communication (VLC) system applied to Solid-State Lighting (SSL) with frequency suitable to an Universal Software Radio Peripheral (USRP). The goal here is to establish a testbed prototype according to the frequency response limits of the hardware used, to make possible studies of VLC applications with real-time evaluation of the performance metrics. Rodrigo F. Miranda, Carlos H. Barriquello, Vitalio A. Reguera, Lucas Teixeira, Marco A. D. Costa, Djeisson H. Thomas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3393 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3394 The dosage of chemicals products represents one of the main benefits that automation systems can bring to water treatment processes. However, the investments required can discourage the use of these systems and, in some cases, make the project unfeasible, especially for small treatment plants. So, the search for less costly solutions is a point of great interest, once the purification of natural waters is increasingly necessary. In the present work, a turbidimeter based on image processing was developed in order to provide results for a small Programmable- Logic Controller (PLC), in which a coagulant product dosing system can be implemented. The system’s performance was evaluated through a pilot plant and the results were satisfactory in all repetitions of the experimental procedure adopted, indicating the feasibility of the proposed method. Dimitri C. Viana, Roberto A. Braga, Bruno Henrique G. Barbosa, Alessandra Rose C. R. Campos, Danton D. Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3394 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3395 This paper addresses the polyquadratic stabilization of switched linear systems with polytopic uncertainties. Time-varying uncertain parameter-dependent switched Lyapunov functions are used to obtain conditions, in the form of linear matrix inequalities, that guarantee the polyquadratic stabilization and positivity of the dynamical system. The present work considers the case of discrete time-varying polytopic uncertainties in the switched state matrix, switched input matrix, and state feedback switched gain matrix. In addition, polyquadratic stabilization is performed with the eigenvalues placement in a circular region in the complex plane. Two example systems are employed to verify the effectiveness of the proposed conditions. Rodrigo Possidônio Noronha, Ginalber Luiz de Oliveira Serra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3395 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3396 This paper presents the development of an inertial navigation system using the Extended Kalman Filter (EKF) algorithm with sensor fusion. For this purpose, the proposed algorithm was applied to a flight simulation of rocket RD-08, which was designed by student from the ITA Rocket Design team (ITA-RD) to participate at the international competition SpacePort America Cup, that took place in the USA, an event belonging to the IREC (Intercollegiate Rocket Engineering Competition). Since the acquisition of sensor data was not possible during the competition, in this paper sensor data were modeled based on technical information obtained from sensor datasheets. Measurements from accelerometers, gyrometers, and GPS were simulated. Finally, the EKF algorithm was implemented with GPS sensor fusion to estimate the velocity, geographic position, attitude, and inertial sensors biases of the vehicle to minimize the modeling and measurement errors. Nathália M. da Silva Mesquita, Carlos A. P. Carvalho, Leonardo R. Rodrigues Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3396 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3397 In this work, a tool for the study, teaching, and simulation of three-phase induction motors is presented, in which the representation of the rotating magnetic field is obtained, an essential topic for understanding the dynamic operation of the equipment. For this, we use new educational technologies as didactic tools in the teaching and learning process. We use the software Matlab@ as a tool, where we develop a simulation algorithm and a dynamic interface, which allow the adjustment of the motor’s parameters and operating conditions to obtain the respective rotating magnetic field. The results are presented, demonstrating the simulation and its contribution to the understanding and learning of the physical phenomenon. Ruhan Pontes Policarpo de Souza, Jackson Nunes Alves, Paulo Henrique Camacho, Marcelo Favoretto Castoldi, Cristiano Marcos Agulhari, Wagner Endo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3397 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3398 An optical fiber-based surface plasmon resonance sensor for hepatocellular carcinoma diagnosis is presented here. Conventional, tip-based, and D-shaped configurations are used to construct the sensor. The sensing region length, the bimetallic layer, full width at half maximum (FWHM), figure of merit (FOM), sensitivity, and signal-to-noise ratio (SNR) have been used to analyze the sensor performance. The sensor setup uses three layers: a ZBLAN fluoride optical fiber core (optical substrate), a 40 nm-gold or 40 nm-silver films (plasmonic metal), and healthy and pathological samples (analyte). Moreover, a bimetallic layer has been also investigated, where the thicknesses ranged from 10 nm to 40 nm. Also, the sensing region varied from 5 mm to 60 mm. The results obtained for the sensitivity of the simulated sensors were: 3, 903.4 nm/RIU for gold, 3, 821.5 nm/RIU for silver, and 3, 415.1 nm/RIU for silver-gold layer. Renata Charlene Barbosa Xavier, Jessica Neiva Alpino, Cleumar da Silva Moreira, Rossana Moreno Santa Cruz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3398 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3399 As part of the activities developed in the scope of a R&D+I, the present work visits the concepts of modeling and control of the current loop of a grid-connected voltage source inverter with LC filter. Using the equations of the power processing system in the synchronous reference, the block diagrams of the subsystems and their interconnections are developed, providing a correct understanding of the interactions between the control loops, the decoupling processes, as well as the system simplification steps. Employing classical control concepts, the tuning procedures for the current loop controllers are presented and discussed. Using parameters and configurations of the voltage source inverter present in one of the electrocenters of the Petrolina Reference Center in Solar Energy, computational simulations were conducted, being presented and analyzed results of current injected into the grid, voltages at the connection point, harmonic distortions, active and reactive powers and power factor. Eubis P. Machado, Adeon C. Pinto, Jadsonlee S. Sá, Ricardo M. Prates, Rodrigo P. Ramos, Wedson P. Silva, Justino E. L. Araújo, Renato Ribeiro Jr., José B. de Melo Filho, Alex C. Pereira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3399 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3400 With the severe shortage of electrical energy in the world and the rising demand, we will become more and more dependent on energy and pay more and more for it. Unfortunately, when available energies become expensive and scarce, they end up being used regardless of environmental needs and prices. However, it is necessary to invest in solutions that can provide cheaper energy with less impact on the environment, and one of the ways to do this is research in the area of photovoltaics, which makes the process of extracting energy from photovoltaic panels cheaper and more efficient. Faced with this path that solves the problem, it is important to study photovoltaic panel architectures to verify how they work, what their limitations are, and how they behave in the face of these limitations. One architecture that is becoming popular is the architecture of full power optimizers connected in series with the inverter. Thus, in this article this architecture will be studied with the objective of understanding its limitations and behavior. At the end, it will be possible to better understand how this architecture works and what its limitations are. Fernando Rafael Arnhold da Silva, Valdemar Moreira Cavalcante Junior, Tiago Alves Fernandes, Márcio Evaristo da Cruz Brito, Fabrício Bradaschia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3400 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3401 Distributed generation using renewable energies is a solution to meet the growing demand for energy around the world. In grid-connected photovoltaic systems, transformerless inverters play an important role as they are lighter, cheaper and more efficient than conventional ones. This paper proposes a transformerless inverter topology with AC-decoupling and DC-link midpoint clamping for photovoltaic systems, with the objective of solving the leakage current issue by eliminating common mode voltage fluctuation. A comparison with two other existing transformerless inverter topologies is performed. The proposed topology exhibits a reduction in leakage current, in addition to fewer devices in the current path and, consequently, lower losses. Simulation results are presented in order to demonstrate the best performance of the new topology. Arnaldo O. Cunha Junior, Filipe A. da C. Bahia, Joao P. R. A. Mello, Fabiano F. Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3401 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3402 This paper addresses the development and results of an attitude control system designed for an experimental rocket, built to have its rotational axes stabilized during the entire rocket’s ascent flight operation. To achieve this, its nonlinear equations of motion were developed, not considering aerodynamics coefficients and mass variation. Therefore, the control law was designed using the sliding mode control for the nonlinear equations, since it is a well- known robust control method. Simulations of the whole system were performed and the results were analyzed taking into account the expected results for the control system. Thus, all the results and knowledge obtained during this project offer an alternative to the most used control systems in real aerospace applications. Paula Reis da Silva, Tiago Roux Oliveira, Davi A. Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3402 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3403 The use of computer simulations allowed some of the research carried out by the PET group in the robotics laboratory of CEFET-MG in Divinópolis to continue during the pandemic period. As a way of recommending the use of simulators in academic activities, this article deals with some details of realistic simulators such as CoppeliaSim and the Webots. It is also shown as an example the accomplishment of a research, the development of a game of pick up and throw boxes in the Webots. The use of this simulator also allowed the continuity of both the Seeds Project and the Internal Robotics Competition. Getúlio A. da Silva, Erick Nathan M. Alves, Miguel L. Rodrigues, Renato S. Dâmaso Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3403 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3404 In this paper, a novel Multivariable Adaptive Super-Twisting Algorithm is proposed. Considering a multilayered structure, the proposed adaptive scheme does not require the knowledge of upper bounds for the matched disturbances and their derivatives. Extracting information from the equivalent control, a second-order sliding mode is achieved by adapting both gains in a non-conservative way, potentially reducing the undesirable effects of chattering. Jair L. de Azevedo Filho, Eduardo Vieira L. Nunes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3404 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3405 The United Nations created the 17 Sustainable Development Goals (SDGs) to promote environmental protection, economic growth, and social justice. In this scenario, science is crucial to solving the challenges addressed by the SDGs. SciVal, for example, is a tool that tracks scientific publications related to the SDGs with the support of a team of experts. Aiming to reduce the need for specialized knowledge and to provide a more autonomous tool, this study proposes a multi-label classification model based on natural language processing and recurrent neural networks to map scientific publications to the SDGs. The proposed model is tested with the articles of the Brazilian Congress of Automatics (CBA) 2020. The data used to train the model comprises manuscript titles acquired from the Scopus database using the SciVal analytics tool, and they are related to 16 out of the 17 SDGs. Results have shown that the papers published in the CBA 2020 focused on SDGs 7, and 9, which are related to clean energy and industry innovation. Furthermore, all SDGs were associated with at least one publication, indicating that intelligent automation can contribute in a interdisciplinary way to the SDGs implementation. Alexandre Dias, Gisliany Alves, Germano Lima, Ariel Alsina, Ivanovitch Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3405 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3406 State estimators (SEs) are among the most important tools for power system real- time modeling. With the advent of Wide-Area Measurement Systems (WAMSs), combinations of measurements from Phasor Measurement Units (PMUs) and Remote Terminal Units enabled the development of highly accurate SEs. However, although the PMUs provide much more information about the system state, typical issues faced by real-time state estimation applications still remain, such as the ones related to observability of the measurement sets. Within this context, this paper proposes (as its main contribution) a modified state estimation process to monitor the voltage stability margin of buses that are not directly monitored by meters. To achieve this goal, a well-known method based on the H∆ matrix was extended to perform redundancy and observability analysis of metering systems containing only PMU measurements, using rectangular coordinates for the phasor measurements and state variables. A linear Weighted Least Squares SE is implemented to estimate the complex voltage of observable buses, regardless of the presence of PMUs in them. Based on all estimated state variables, the voltage stability margin of the whole system is also estimated. Simulation results carried out in the IEEE test systems of 14, and 118 buses validate the effectiveness of the proposed scheme. Maiara C. Oliveira, Murilo E. C. Bento, Joao B. A. London Jr, Rodrigo A. Ramos, Ahda P. Grilo-Pavani Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3406 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3407 This paper presents the application of the Extended Prediction Self-Adaptive Control (EPSAC) to the path tracking problem of wheeled mobile robots (WMRs). The main complexity of the control problem is that a WMR is a MIMO (multiple-input and multiple-output) system, being also nonsquare, nonlinear, and with input constraints. EPSAC, which belongs to the class of Model-based Predictive Controllers (MPC), is an interesting option to overcome such difficulties because its main properties are: (i) the control performance can be improved when the future reference trajectory is previously known as in the case of WMR, (ii) it has the ability to deal with constraints during the calculation of the control law in a fairly straightforward way, and (iii) with proper tuning in nonlinear models, a sub-optimal solution closer to nonlinear MPC can be obtained if compared to the conventional linear MPC. Simulations and experiments on a real robot have shown improved performance regarding trajectory tracking associated with reduced computational cost if compared to other MPCs applied to WMR proposed in literature. Italo J. L. Batista, Bismark C. Torrico, Fabricio G. Nogueira, Julio E. Normey-Rico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3407 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3408 This work presents an analysis of different models to represent renewable generation in the study of electromagnetic transients using the ATP program. Simulations were carried out in a real system analyzing the qualitative performance of the system in the face of defect applications. Thiago F. S. Costa, Antonio C. S. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3408 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3409 Devices that resemble biological recognition systems, that is, inspired by the function- ing of human organs, have made important advances in recent decades. Therefore, interest in the concept of electronic tongues has increased considerably in recent years. This study uses this type of device in order to identify different samples of flavor enhancers (Glutamate, Guanylate and Inosinate). The applied methodology employs different computational techniques for the identification such as Principal Curves and three types of Artificial Neural Networks. The best results reached 95,4% accuracy through models implemented with Self Organization Maps. L. P. O. Sousa, D. D. Ferreira, D. S. Correa, J. E. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3409 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3410 In this work, we study the design of L2 − L∞ filters for Markov jump linear systems with hidden states. In this context, the Markov chain cannot be perfectly measured and the only available information to the filter are the measured output and a random variable, called detector, which is related to the mode of the system. In order to model this variable, we consider that the joint process of the Markov chain and the detector follows an exponential hidden Markov model. The results are given in terms of Linear Matrix Inequalities and are illustrated by means of a numerical simulation. André M. de Oliveira, Oswaldo L. V. Costa, Gabriela W. Gabriel, Sérgio R. Barros dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3410 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3411 This paper presents the study and development of a bidirectional DC-DC converter powered by current through coupled inductors using phase-shift technique to control the power flow. The original topology, from which this version was conceived, uses pulse-width modulation as the switching technique, but in this work the phase-shift technique is adopted. The proposed modification has the advantage of making the power flow control simpler, and guarantees the operation of part of the switches with soft switching of the ZVS type. The working principle and mathematical analysis of the power characteristic of the converter, as well as its dynamic model are presented. A project example with input voltage, output voltage and power, respectively, of 28V, 180V and 500W is proposed. Simulation results are presented in order to prove the theoretical analysis developed. Moisés de O. Magalhães, Gustavo A. de Lima Henn, Herminio M. de Oliveira Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3411 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3412 This paper presents a two-module DC-DC converter topology based on the macro/micro strategy aiming to obtain a fast response with low voltage ripple. The steady-state design of converter is presented, as well as the development of a decoupled control strategy for each module. The converter design was validated using simulations in the PSIM software. Renan C. Viero, Jefesron V. Flores, Aurélio T. Salton, Eduardo R. Rohr Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3412 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3413 This study proposes an approach to identify a ground fault motor in a low voltage three phase electrical system with a High Resistance Grounding (HRG) through the application of deep learning techniques. Electrical systems grounded by high value resistors have the advantage of limiting the leakage current to earth. However, the identification of the equipment that presented the fault is not simple, as such currents can be confused with eddy currents, which may eventually occur in the installation. The proposed method consists of using the zero sequence currents of the equipment in normal operating condition and in the ground fault condition, in order to classify these signals by their characteristics and create a model capable of separating these classes. This approach differs from existing techniques because it uses the fault current signature and not the RMS value. For the elaboration of classification models, raw signals were used for direct input into a one dimensional convolutional neural network. The best result (f1-score of 100.00%) demonstrates the feasibility of implementing the technique in industrial systems for detecting earth leakage equipment in this type of installation. Lucas de Oliveira Soares, Rodrigo Cesar Campos, Marco Antonio de Souza Leite Cuadros, Luiz Alberto Pinto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3413 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3414 Robotic devices capable of interacting with the environment are increasingly common, with autonomous robots as an example of this. However, it is necessary for these devices to be able to extract as much information as possible from the environments that they are envolved. To this, computer vision techniques are used to process images of the environment. So, the objective of this work is to propose a strategy that uses computer vision techniques to identify objects to count and estimate their position, from an RGB-D camera coupled to an autonomous mobile robot. This strategy was validated through testing in 3 different scenarios, which explore the robot’s autonomous navigation capability and camera image capture. The results of all scenarios presented a relevant object count and a average error less than 0.19 meters in the pose estimate. Matheus Loureiro, Fabiana S. V. Machado, Ricardo Mello, Anselmo Frizera Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3414 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3415 This work presents the design of RST controllers for elbow flexion and extension movements through simulation. Mathematical models for the movements were identified and the RST parameters of two controllers were obtained. The operation of the controllers was evaluated operating individually and, later, in parallel. At the end, new studies are proposed to adapt the controller obtained in the simulation to be used in tests with real arm. Renata R. Lima, Eugênio P. Júnior, Aparecida F. de Andrade, Bruno L. Faustino, Fabrício G. Nogueira, Bismark C. Torrico, Victor Hugo C. de Albuquerque Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3415 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3416 This work proposes new stability conditions for the master-slave synchronization of nonlinear discrete-time Lur’e systems subject to input saturation via event-triggered control techniques. From the Lyapunov Theory arguments, Finsler’s Lemma and properties of the closed- loop system nonlinearity, sufficient conditions are derived to ensure the regional asymptotic stabilization of the origin of the synchronization error, i.e., to guarantee that the slave trajectories converge to those of the master. Following an emulation-based design, the objective is to determine an appropriate event generator for the closed-loop system. In order to systematically compute the event-triggering mechanism parameters, an optimization problem aiming to reduce the number of events with respect to a time-triggered implementation is proposed. A numerical example is performed to show the effectiveness of the proposed methodology. C. Lisbôa, J. V. Flores, L. G. Moreira, J. M. Gomes da Silva Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3416 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3417 The time-optimal control of Time-Weighted Systems (TWS) is an approach that can be used to makespan reduction of Computer-Integrated Manufacturing (CIM) Systems. Unfortunately, the complexity of the TWS algorithms turns even suboptimal solutions com- putationally intractable when dealing with realistic CIM systems with multiple components, stations, and different productions batches. In this paper, we propose some strategies to alleviate the complexity cost of makespan reduction computations using TWS. The strategies consist of: relaxing the need of symmetric imposed mutual exclusions relations between events; using a hashtable algorithm for makespan computations instead of a heap of pieces algorithm; avoiding computation of batch supervisors using a scalable synthesis method; and applying a Clonal Search heuristic for makespan reduction. With this, we obtain the reduction of the computational cost while maintaining the advantages of the TWS approach regarding the reduction of models by representing one task by only one event. The performance of the proposed algorithm is compared with some of the known efficient approaches by means of a realistic CIM example. Gabriel Laport Vargas, Antonio Eduardo Carrilho da Cunha Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3417 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3418 This work proposes a selective estimator of harmonic current components based on a deep neural network (DNN), which is able to provide the amplitudes and phase shifts of these components through a quarter cycle of the current fundamental waveform. A sufficiently optimal configuration was reached for application in the harmonic estimation proposal from an exhaustive search for DNN parameters. The DNN training was performed from a set of current samples in the time domain. The evaluation test indicated that the DNN presents an average of approx. 99% of amplitude errors smaller than 0.0036 pu and, in relation to the phase shifts, the average errors are smaller than 0.0041 rad. Furthermore, a case study targeting selective harmonic compensation by means of an active power filter is presented considering reference currents generated from the DNN estimations. The results show that there was a 59.3% reduction in total harmonic distortion (THD) by using the proposed strategy, reducing from 29.88% to 12.16% which is still a high value, while individual (selected) harmonic components were attenuated into values between 80 and 94%, indicating the viability of DNN in this type of application. Luiz G. R. Bernardino, Claudionor F. Nascimento, Wesley A. Souza, Augusto M. S. Alonso, Fernando P. Marafão, Edson H. Watanabe Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3418 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3419 Recently, fusion architectures have presented great notoriety in the context of hybrid power system state estimation. By employing a two-stage model, those architectures allow the inclusion of new data sources such as synchronized phasor measurements, without requiring the exclusion of well-established estimators. According to the conventional fusion paradigm, in case gross measurements pass unnoticed through first stage estimators, final fusion results will inevitably be also contaminated, as there is no second layer of defense against spurious data. This paper presents an alternative formulation based on the Maximum Correntropy Criterion (MCC) to constitute a novel fusion framework. In the absence of gross errors, the fusion via MCC approach is completely equivalent to the classical one. In addition to that, however, the proposed strategy equips the fusion module with an extra functionality as an active layer of protection against inconsistent data, whenever gross errors are not properly filtered by the first- stage estimators. The proposed approach is evaluated through several experiments conducted on the 14-bus IEEE test system. Larah Brüning Ascari, Antonio Simões Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3419 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3420 This article proposes a computational approach applied to the classification of Electric Power Quality Disturbances (PQD), which are based on the Variational Mode Decomposition (VMD) and the Random Forest (RF) classifier algorithms. Firstly, nine parametric equations- based different signals were generated. Variational mode decomposition (VMD) has been used to decompose the signals into various intrinsic mode functions (IMFs). Seven statistical characteristics were extracted from the instantaneous amplitude (AI) of the decomposed IMFs. The RF model is then developed to classify PQD based on these characteristics. The proposed approach is validated by analytical results, where the classifier accuracy was 99,71%. It confirms that the proposed analysis is capable of providing necessary and accurate information for PQD. Maísa L. F. Santos, Suzete E. N. Correia, Cleumar S. Moreira, Álvaro de M. Maciel, Edgard L. L. Fabricio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3420 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3421 In microgrids based on photovoltaic/battery generation, uncertainties during islanded operation can cause voltage and frequency fluctuations, making the control systems involved in the microgrid more difficult to action. From the photovoltaic maximum power point tracking (MPPT) point of view, to reduce the effects of uncertainties it is necessary to use a more robust method that guarantees correct supplying. In this paper, a comparison between two MPPTs based on the conventional Perturb & Observe algorithm is proposed, in the first one MPPT directly returns the duty-cycle for the DC-DC boost converter, being denominated of open- loop, and in the second one, the MPPT output voltage signal passes through internal cascaded proportional-integral loops before being converted in duty-cyle signal, being denominated of closed-loop. The objective is to evaluate the robustness provided by the closed-loop method, especially during the islanded operation. Both algorithms were simulated in MATLAB/Simulink with a 1,725W photovoltaic array (RISEM RMS 72-6-345P). The comparison analysis is based on the power quality delivered to the load through the observation of total harmonic distortion (THD), ripple level, settling time, and steady-state error. Results suggest that the closed-loop method provides a better and more reliable MPPT. Lindemberg R. de Lima, Luana C. S. Soares, Pedro A. de Alcântara, Camila M. V. Barros, Luciano S. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3421 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3422 In this paper, a new automatic control technique based on fractional-order systems is investi- gated to improve the performance of the Power Systems Stabilizer (PSS), making the Electric Power System (EPS) most efficient. For this, we used the dynamic model of the 10 kVA scaled-down generation system. Initially, two power system stabilizers are tuned and then, a methodology for the design of stabilizers is proposed, based on the fractional-order pole placement (FOPP). The behavior of the lead-lag compensators is performed through simulations, using MATLAB/Simulink. Therefore, we sought to compare the performance of conventional and fractional PSS and, analyzing the results obtained, the system with PSS via fractional pole placement was the one that best dampened the electromechanical oscillations and presented the lowest control effort. Claudia Sabrina M. da Silva, Florindo A. de C. Ayres Junior, Renan L. P. de Medeiros, João Edgar Chaves Filho, Vicente F. de Lucena Junior, Jerônimo X. do Prado Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3422 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3423 Traditionally, the dynamic response of distribution networks is modeled in stability simulations by an equivalent representing the load behavior. In networks with distributed generation (DG), it is common for generation to be represented as a negative load. However, with the significant increase of DG units, there is a need to represent these distribution systems considering the generation connected to them. This article presents a methodology for obtaining a dynamic equivalent of microgrids, which has models for representing static and dynamic loads and DG connected via converters and synchronous generators. The method is based on the gray-box approach, in which it is assumed an equivalent model composed of known physical components. Additionally, an advantage of this approach is the fact that the parameters of the equivalent model are calculated based on measurements taken at the point of common coupling (PCC) and, as a result, it is not necessary to know the parameters of the different components connected to the distribution system. The methodology is validated using computer simulations with a medium voltage test distribution network. The results confirm that the equivalent can be used to represent distribution systems with DG. Edson A. Abreu, Vinicius P. Suppioni, Ahda. P. Grilo-Pavani, Rodrigo A. Ramos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3423 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3424 This paper aim the study and sign Libras cataloging for further search for the MINDS- Libras dataset. Although there is progress in the availability of sign bases in Libras for use by the scientific community, as is the case with MINDS-Libras, it is still a challenge for a Libras sign recognition area to have access to a sample of signs for training computer systems that can recognize signals automatically. It intends to expand to a MINDS-Libras base of two: evaluating the generation of synthetic data and analyzing the large mass of data publicly formed during the remote activities that take place in the period of the Covid-19 pandemic. The initiative for this work is in the contribution that they intend to force for the Computational vision of recognition that impacts directly in the social and cultural areas for the emerged community. Arthur Cesar da Silva Almeida, Tamires Martins Rezende, Sílvia Grasiella Moreira Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3424 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3425 Over recent decades, power distribution systems have been required to handle extreme events that are increasing in both frequency and intensity. In addition, there are novel technologies, planning strategies, and operational approaches. In this context, topological flexibility is a key aspect to allow distribution systems to accommodate all the simultaneous emerging changes and requirements. Topological flexibility is the capability of a system to rearrange its structure and is directly related to sectionalizing and tie switches operation. In this paper, metrics calculated from a bipartite multigraph representation aiming to describe the topological flexibility of distribution systems are presented. Different distribution systems are used to illustrate the bipartite graph representation and the derived metrics. Our approach is directly applicable to distribution systems characterization and enables future development of metrics to fully describe the topological flexibility of such systems. Michel Bessani, Lucas de S. Batista, Felipe Campelo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3425 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3426 This paper presents a study of modular multilevel converter (MMC) to link a photovoltaic plant to medium voltage. The topology is based in multistrings where a PV array are connected on submodules (SM’s) of the converter. The methodology was use arm average model to represent arm dynamics of the converter. The loop output currents and virtual DC bus voltage control are performed using classical control techniques based on frequency response and PI controllers. Furthermore, the behavior of the MMC was analyzed and discussed during unbalance in power generation (power mismatch) whose compensation is made through the differential currents. Computational simulations are performed to show system operation under standard conditions and evaluate performance of the control strategy in relations to disturbances. The results proved the effectiveness of the control techniques used as well as ability of differential currents to handle with internal power mismatches of the MMC Samelius S. Oliveira, Isaac R. Machado, Joham L. D. S. Albuquerque, Alan R. S. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3426 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3427 This work presents the first robust model predictive control approach for controlling an Electric Submersible Pump (ESP) lifted oil well system considering its benefits and operational envelope constraints. The proposed scheme is based on a robust infinite horizon model predictive controller (RIHMPC) with multi-model formulation as the uncertainty description and zone control scheme to explicitly consider the time-varying ESP (downthrust and upthrust) envelope constraints. The proposed control strategy is tested through simulation for the disturbances commonly found in the oil wells with ESP installations and (nonlinear) plant/model mismatch scenarios. Results show an applicable formulation capable of accommodating nonlinearities in the form of uncertainties and a low computational cost, with characteristics suitable for real- time applications. Bruno A. Santana, Victor S. Matos, Daniel D. Santana, Márcio A. F. Martins Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3427 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3428 In this article, the H∞ model reference problem in two degrees of freedom control methodology using dynamic output feedback for continuous-time linear systems is presented. The controller design is formulated in terms of Linear Matrix Inequalities (LMIs). An illustrative example is presented to demonstrate the utility of the proposed synthesis procedure. Ariany C. de Oliveira, Víctor C. S. Campos, Leonardo A. Mozelli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3428 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3429 With the evolution of the Industry 4.0, automation in the industry has intensified and has carried out automation processes for activities that demand repetition and are performed by humans, reducing the activities that have physical effort and positioning them in monitoring and solving unexpected problems to make decisions when required (Moura,2019). This project aimed a solution for an air-conditioning factory in the Manaus Industrial Pole, where there is a production line in which a subpart of the product, called the control box, is manufactured. At one of this line's workstations, the operator performs the following activities: takes the product off the line, scans the product model's bar code, and visually inspects the components. After the inspections, the operator judges the speed of this line in relation to the final assembly line and decides whether the product will continue in the production process or should be stored in a buffer. In this context, there arose the motivation to research and develop a functional prototype for the automation of the described process highlighting the implementation of an automated buffer to evaluate the current production rhythm of the final assembly line before making this transfer. Alan Jr. Lopes Gomes, Nelson A. Gouvea, Paulo V. P. Ibernon, Racy Jr. S. Dias, Ângela T. P. Lima, Caio César de A. Gomes, Carla Oran F. de Souza, Josiane de Jesus Bezerra, Leonardo Morgado dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3429 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3430 This paper addresses the problem of language opacity for a class of discrete-event systems whose transitions occur within some known time interval after the event becomes enabled. For this purpose, a new class of timed automata is proposed, the so-called time-interval automata, in which a time interval is associated with each event that labels a transition. For such automata, the operations of complement, projection and product are redefined without using refinement by partition, as usually used in the literature. The usual language-based definition of opacity is extended to this class of automata and an algorithm for its verification is proposed. Mariana Guimarães Marques, João Carlos Basilio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3430 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3431 Linear matrix inequalities are a powerful tool in the field of analysis and synthesis of robust control systems. Robust control by static or dynamic output-feedback are more com- plicated to be formulated as convex optimization problems based on linear matrix inequalities. One strategy to obtain formulations for static output-feedback control synthesis is to transform a state-feedback control synthesis formulation through change of variables that requires a choice of a matrix. The choice of this matrix affects the performance of the resulting controller or even the existence of a feasible solution to the problem. We propose in this work to apply an evolutionary optimization algorithm to determine the optimal value of this matrix, and other parameters of the original formulation, to obtain the optimal ∞ robust control system. We present a case study to demonstrate the advantage of the proposed method. Pauliana Rufino de Almeida Lima Oliveira, Eduardo Nunes Gonçalves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3431 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3432 Water distribution networks (WDNs) require proactive maintenance methods in order to ensure its correct functioning. Failures, such as leakages and pipe deterioration, lead consumers to bad experiences such as having water supply services interrupted. In this paper, the focus is to improve a WDN. First, we set a pattern curve and the objective function will achieve a pre-established value of minimum pressure to all nodes in the system. Three options are available: pipe replacement, pipe cleaning and leakage fixing. Thus, by considering a limited budget, the most economic solution must be determinated to attend the operational pressure and, at the same time, lead to the minimum mean pressure during 24 hours of operation. In this development, we used the Particle Swarm Optimization (PSO) method. The results point to a tool with huge potential of implementation in WDNs rehabilitation. Tames F. Mariano, Gustavo M. Lima, Bruno M. Brentan, Brenner S. Rego, Guillherme V. Raffo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3432 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3433 Given the growing of solar photovoltaic (PV) power in the Brazilian power mix, and considering that PV generation is intermittent, there is great need of PV generation forecasting models for better operational planning of both the PV power plant itself and the power grid. Thus, this paper proposes the application of Machine Learning models to forecast the power generation of a 160 MW PV plant located in the state of Ceará (Brazil). The aim is to forecast the daily power output of the power plant over 365 days based on the historical power data and the weather data of the PV power plant. To accomplish the task, distinct prediction models were tested, such as: sequences recognition, Artificial Neural Networks (ANN), XGBoost and hybrid approaches. The performance of the implemented models was evaluated using error metrics, and the XGBoost model achieved the most accurate results as regard to the prediction error and the execution time followed by the ANN. The Pattern Sequence-based Forecast (PSF), which is more transparent than an ANN or even XGBoost, has proved competitive, having the best performance among the models trained only with historical data of power generation. Lucas T. da Silva, Ruth P. S. Leão, André W. B. Silva, Danielle B. Cavalcante, Raimundo F. Sampaio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3433 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3434 In this work, the design of an optimal closed-loop control of an inverted pendulum is performed using a deep neural network (DNN). A training database is created by solving several optimal control problems, resulting in an optimal open loop control, using the MATLAB platform. The DNN is then trained in this database and, after, used to calculate the optimal control given the plant states, effectively closing the loop. Simulations are performed and presented to demonstrate the optimal controller performance when applied to the system. Róger Mateus Sehnem, Alexandre Sanfelici Bazanella Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3434 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3435 This paper addresses the problem of distributed control design for nonlinear inter- connected systems with time-varying delays in the interconnections. A new sufficient condition for the stabilization of interconnected systems based on the Lyapunov theory and considering that the nonlinear interconnections are sector bounded in the polytopic domain is presented. Numerical simulations illustrate the efficiency of the proposed approach in guaranteeing the asymptotic stability of the overall interconnected system. Paulo S. P. Pessim, Pedro H. S. Coutinho, Iury Bessa, Márcia L. C. Peixoto, Márcio J. Lacerda, Reinaldo M. Palhares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3435 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3436 Series compensators regulate and keep acceptable voltage levels in power transmission lines that will reflect positive power quality indexes. However, depending on the kind of compensator to be used, it can add complex parameters to the line modelling due to its non- linear operation and, consequently, in the responses of the current methods utilized for fault location in transmission lines. In this context, this work aims to present an efficient way to determine which section of the two terminals compensated transmission line a single phase to ground fault occurred. The methodology used consists of obtaining voltage and current signals of transmission line terminals. Considering the signs, applying the Discrete S Transform for a pre-processing and, by the calculated coefficients, feeding an Artificial Neural Network so that the determination of in what section the fault occurred, in the left or the right side of the compensator. The obtained results were promising and presented the potentiality of the utilized methodology. Matheus do V. Oliveira, Leonardo da S. Lessa, Mário Oleskovicz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3436 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3437 The protection against earth faults in the stator of generators is one of the main topics evaluated during the protection studies. In this context, several methods of protection against this type of defect have been developed over the years, however, none of the traditional methods is able to guarantee the selectivity of the protection system in scenarios that consider the operation of multiple generators in parallel, grounded by high impedance. Therefore, this paper proposes a test platform through a real-time simulation scope and evaluates a selective protection scheme against ground faults in the stator of synchronous generators. The results obtained allow us to conclude that the coverage and efficiency of the evaluated method is conditioned to the harmonic level present in each one of the generators that share the same busbar. Leonardo P. R. Maciel, Paulo M. da Silveira, Carlos A. V. Guerrero, Brian K. Johnson, Romulo G. Bainy, Hari P. Challa, Paulo S. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3437 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3438 This article analyzes the influence of the tilt angle of phase conductors in three-phase transmission lines (TLs). In this study, ground-return impedance and admittance are calculated by the Nakagawa’s approach, considering soils with conductivity of 0.01 and 0.001 S/m. The modal attenuation constant and the modal propagation velocity are calculated between 100 Hz to 10 MHz, for 5 different angles (0°, 30°, 45°, 60° and 90°). The transient voltages were calculated for two disturbances (energization and lightning strike) applied to one of the phases while the receiving terminal is left open. The results show that the voltages generated in the excited phases are not significantly affected by the tilt angle. However, the induced voltages in the non excited phases show significant variation as a function of this angle. Tainá Fernanda Garbelim Pascoalato, Sérgio Kurokawa, Anderson Ricardo Justo de Araújo, José Pissolato Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3438 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3439 Hydrogen production plants (HPP) are infrastructures that require automation technologies, for the continuous monitoring of the status and execution of the devices, in order to improve plant availability, process safety and constant product quality. This article proposes the formal modeling of discrete behavior and the design of closed- loop control structures of the PPH of the Itaipu Technological Park (PTI). The Supervisory Control Theory (TCS) is used to control individual PPH subsystems, while the overall functioning is implemented through the sequential control of its operation. For modeling the free behavior of the subsystems and the respective interlocking and safety specifications, regular language in the form of automata was used. The control structures, called supervisors, are obtained by the TCS synthesis process. The sequential production control of the H2 is based on experimental knowledge translated into a flowchart. Both control approaches are implemented in programmable logic controllers (PLC's), following a TCS implementation methodology, and tested on a laboratory bench, which represents, from the point of view of the PPH discrete dynamics, to all its equipment. The results obtained demonstrate the systematization, flexibility and efficiency to carry out the project of the control system of a PPH, in addition to allowing the structuring and verification in a laboratory bench. Angel A. Quispe, Sandro Battistella, Ricardo Ferracin, Romeu Reginatto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3439 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3440 Currently, the energy matrix has undergone numerous modifications in order to meet the new demands of this scenario in constant transformation. The technological improvement has provided an important advance in the use of renewable sources for energy production that aims to guarantee the environmentally correct consumption. However, the insertion of numerous photovoltaic systems, in the form of distributed generators, presented in recent years may cause impacts on the distribution network, because this initially was not conceptualized for this context. Thus, the present study seeks to analyze the insertion of distributed photovoltaic generation in a real distribution grid located in the city of Sinop, in the state of Mato Grosso. For the modeling of the distribution electric system the OpenDSS program was chosen and the data obtained from the local utility was considered, which was organized into 178 georeferenced bars. Matheus Holzbach, Samilly T. F. Ferreira, Carla C. S. Carvalho, Adriana S. Resende, John F. Franco Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3440 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3441 Considering the smart grids (SGs) establishment scenario, where the presence of non-linear loads and new power generation forms become increasingly expressive, there is a potential for the emergence of new disturbances. Furthermore, considering the huge amount of data coming from smart meters, it is necessary to use novelty detection methods in voltage and current waveform signals, in order to preserve the relevant information and promote efficient storage of the data. The Stockwell Transform (ST) is a time-frequency distribution that has shown great ability to detect novelties related to stationarity changes in signals. Therefore, the present work describes the use of ST for the purpose of detecting novelties in Power Quality (PQ) signals. The implementation of this transform in FPGA is proposed through the use of a Soft- Core processor to optimize the hardware resources of the FPGA. In addition, a voice selection strategy is proposed in order to reduce the complexity of the algorithm, as well as reduce the processing time, while maintaining the detection capability. Victor Mendes Ribeiro, Naiara da Silva Maia dos Santos, Eder Barboza Kapisch, Leandro Rodrigues Manso Silva, Carlos Augusto Duque Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3441 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3442 This study seeks to assess and mitigate the installation impact of electric vehicle charging stations in distributed systems in terms of voltage level. The methodology applies the Monte Carlo simulation to obtain the possible critical cases of the system, given the installation of the recharging station, during a year of operation. A meta heuristic method, called Evolutionary Particle Swarm Optimization (EPSO), is used to schedule the electric vehicles recharges at the recharging station. The EPSO method uses as the objective function the ratio between the peak power and the mean power of the system (PAPR) in order to reduce the peak load seen by the grid. The case study was developed in a 33-bus test system. The load curves of the system are related to a distributed system from Canada and the electric vehicles recharge data used came from an UK project. The results showed that the insertion of the recharge station can lead to the appearance of critical cases in the system. However, with the use of the scheduling process it is possible to mitigate them, thus emphasizing the importance of this study. Héricles E. O. Farias, Camilo S. Rangel, Bernardo Z. Franciscatto, Luciane N. Canha, Zeno I. Nadal, Rodrigo B. dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3442 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3443 This paper presents a dual-stage three-port microinverter for three-phase grid- connected PV applications with a battery connected in the third port. The battery operates as a backup power source to compensate for the power mismatch between the source and the grid and to store excess power generated by the PV panel. A DAB converter is used to provide galvanic isolation and maximum power point tracking of the PV panel. To verify the theoretical analysis of the proposed topology, a 400 W three-port microinverter was designed and simulated. Felipe C. Brandão, Deyvid V. Souza, Bartolomeu F. dos Santos, Walbermark M. dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3443 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3444 Inspection in photovoltaic generation systems is of utmost importance for maintenance and corresponding generation efficiency. The combined use of unmanned aerial vehicles and deep learning computational algorithms can be considered a potentially strong technique for the automatic inspection of non-conformities present in photovoltaic panels. In this work, a methodology was developed for inspecting a ground-based solar power plant by capturing video collected by drones and analyzing and classifying the resulting images using convolutional neural network models. Subimages cropped from the extracted images were processed and classified into one of four classes: intact panel and with mild, medium and severe non-conformities. Accuracies of up to 96.42% in the classification of non-conformities were obtained. Rodrigo P. Ramos, Ricardo M. Prates, Jadsonlee da S. Sá, Adeon C. Pinto, Eubis P. Machado, Wêdson P. da Silva, José Bione M. Filho, Alcides Codeceira Neto, Alex C. Pereira, Eduardo B. Jatobá Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3444 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3445 This paper presents the design and analysis of the extremum seeking for static maps with input governed by a parabolic partial differential equation (PDE) of the diffusion type defined on a time varying spatial domain described by an ordinary differential equation (ODE). This is the first effort to pursue an extension of extremum seeking from the heat PDE to the Stefan PDE. We compensate the average-based actuation dynamics by a controller via backstepping transformation for the moving boundary, which is utilized to transform the original coupled PDE-ODE into a target system whose exponential stability is proved. The local exponential convergence to a small neighborhood of the optimal point is proven by means of backstepping methodology, Lyapunov functional and averaging in infinite dimensions. Maurício Linhares Galvão, Tiago Roux Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3445 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3446 Machine Learning techniques for fault location and diagnosis in phase shift power transformers have been proposed in the literature. However, most of them adopt loss functions that consider a few moments of the error distribution, not adequately extracting the information stored in data available for diagnosis. Information theoretic criteria can overcome this limitation, resulting in better training and inference, and consequently, enhancing the fault analysis. This work presents an information theoretic learning approach to fault analysis in indirect symmetrical phase-shift transformers. The methodology consists of training an artificial neural network for fault detection using information theoretic cost functions. A comparative study with the traditional mean square error cost function will also be present. Felipe Munaro Lima, Andre Abel Augusto, Vitor Hugo Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3446 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3447 The aim of this paper is to investigate the reluctance torque and to propose a novel control strategies to reduce the steady-state torque ripples in Interior Permanent Magnet Synchronous Machine (IPMSM). Despite the conventional vector control strategy applied to the PMSM use zero dx-axis current to reduce the effect of the reluctance torque, this is unsuitable when it comes to the IPMSM due to the cross-coupling effect between the qx- and dx-axis. At first, a novel modeling of reluctance torque is proposes, which allows elaborating control strategy by means of injecting current in dx-axis to null the reluctance torque together with the cogging torque. For this purpose, it is necessary the machine parameters and pre-made lookup table. The results demonstrate the effectiveness of the proposed strategy and that the torque ripple can be totally reduced. Célio L. Filho, Israel R. Soares, Khristian M. de Andrade Jr, Bernardo P. de Alvarenga, Geyverson T. de Paula Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3447 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3448 In the present study, a drive scheme for IPMSM is proposed to obtain high dynamic performance and system efficiency with reduced computational cost. To achieve these objectives, a discontinuous modulation technique was used in the converter and an MTPA strategy was developed in the IPMSM. It is based on Lagrange interpolation with the Briot-Ruffini-Horner technique, which makes it possible to obtain interpolators with reduced interpolation error. Simulation results validated the accuracy and processing time of the obtained MTPA interpolation and a simulation based on a nonlinear machine model demonstrated the effectiveness of the proposed scheme. Eduardo Cattani Silva, Lucas Rossato Rocha, Paulo Henrique Alves Silva e Silva, Rodrigo Padilha Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3448 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3449 This work details the study and application of a fuzzy expert system for the specific dosage control of starch on the flotation process of iron ore beneficiation. This advanced control manipulates the setpoint of the classic controller PID (proportional, integral, derivative), that controls the starch flow rate. The purpose of this aplication is to improve the specific starch dosing and reduce the content of iron in the tailing, contributing to increasing the mass yield of iron ore. The results with the active system show the achievement of the aforementioned objectives, with emphasis on the reduction of starch consumption, which is an expensive input used in the iron ore beneficiation process. Lucas A. Reis, Paula R. Gonçalves, Tiago C. Nunes, Luiz R. F. Junior, Felipe N. Caldas, Marcílio C. Silva, Wanderlei S. Sales, Guilherme A. S. Franco, Cezar G. Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3449 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3450 This paper proposes a dynamic event-triggered scheme for scalar extremum seeking control. Integrating Lyapunov and averaging theories for dis- continuous systems, a systematic design procedure and stability analysis are developed. Ultimately, the resulting closed-loop dynamics proves the advantages of integrating both approaches, dynamic event-triggered and extremum seeking. The Zeno behavior is precluded and the local exponential stability of the closed-loop system are guaranteed. An illustration of the benefits of the new control method is presented using consistent simulation results. Victor Hugo Pereira Rodrigues, Liu Hsu, Tiago Roux Oliveira, Mamadou Diagne, Pedro Vieira Martins dos Anjos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3450 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3451 Hybrid Active Power Filters (HAPF) have attracted great interest due to their ability to compensate for harmonics and reactive power. For reactive compensation purposes, the Finite Control Set Model Predictive Control (FCS-MPC) has shown to be very efficient in the HAPF used in this work. To accomplish this task, a mathematical model of the equipment is deduced aiming to perform prediction steps and calculate the control references. The parameters of this model are dependent on the values of its passive components. However, these components may change due to failure conditions or time degradation. The proposal of this paper is to analyze the influence of the variation of the HAPF parameters on the voltage and currents used as control references. As a contribution, it is proposed to estimate these parameters using an Adaptive Notch Filter with Least Mean Square algorithm. Simulations results with MATLAB/Simulink show that there is a high influence of capacitor bank impedance mismatch in the FCS-MPC and that the proposed algorithm is able to estimate this parameter properly. Fabiane Souza, Sílvia C. Ferreira, Robson B. Gonzatti, Rondineli R. Pereira, João Gabriel L. Foster, Joselino S. Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3451 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3452 In this paper, a zero-attracted proportionate normalized LMS adaptive algorithm (ZA-PNLMS) is proposed, which combines individual activation factors with upper limited gains. The proposal presented here upper limits the gains of the algorithm coefficients for identifying plants with a high degree of sparseness, leading to better distribution of the adaptation energy between the coefficients. Computer simulations, considering sparse systems with disturbance and tracking, attest to the effectiveness of the proposed algorithm. Alzeneide Dutra Pessoa, Francisco das Chagas de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3452 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3453 Industrial alarms are a way to maintain a proper and secure operation of industrial processes avoiding productive and quality losses, accidents, and possible environmental disasters. However, most alarm systems suffer from the high incidence of chattering alarms, which are alarms that rapidly transit from active and inactive states. To minimize this problem, alarm systems use dead-band techniques to alarm thresholds. However, the alarm dead- band parameters must be well tuned to be effective. In this context, this work proposes a method to improve the quality in specifying alarm dead-bands. The method is based on optimization of performance metrics of alarm systems considering the actual alarm threshold. This method provides effective alarm dead-band values that reduce chattering alarms without being excessively large. To validate our approach, a case study was used to determine the efficiency of the proposed method in comparison with common standards. The data for the case study was generated using Tennessee Eastman Process, which is a well-known simulator in literature. Yuri T. P. Nunes, Rute Souza de Abreu, Gustavo Leitão, Luiz Affonso Guedes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3453 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3454 This study proposes the categorization of consumers according to their priority index in order to assist maintenance crews during emergency dispatch activities. The priority index is evaluated based on operational and behavioral parameters that characterize each consumer through the improvement of two multi-criteria decision methods, AHP and SMART. After the computational analysis of the priorities of each consumer, the evaluation by feeder in case of interruption at multiple points is also offered and the results are presented in a visual way in order to facilitate the operators' decision-making process. Gabriela B. Silva, Helmo K. Morales-Paredes, Juan Carlos Cebrian Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3454 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3455 Animals have the ability to move in unstructured terrain. Robotics researchers study this ability to perform tasks in industrial, mining, oil and gas, and disaster environments. However, for a robot to perform this locomotion efficiently in different environments, it is necessary to plan the steps as well as the synchronized control of its legs. This article considers a quadruped robot with legs modeled using the Euler-Lagrange equations. Each leg has an impedance control that receives reference trajectories from gait patterns through 6th degree Bézier curves. Leg control and gait patterns were implemented in Matlab and simulated in CoopeliaSim using the Vortex realistic physics engine. The results obtained in the simulation demonstrate that the proposed controller is able to track the Bézier curve used as a reference, making the robot move with static walking and trotting gait patterns, presenting a compliance to forces applied to the feet. Gabriel Duarte Gonçalves Pedro, Gustavo Medeiros Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3455 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3456 In this article, strategies to control knee flexion and hip flexion are presented based on the excitation of the muscles responsible for such movements, in view of the widespread use of functional electrical stimulation (FES) for treatment of neurological diseases, accidents, among others. Currently, the application of the stimulus does not guarantee a desired response in relation to the intended excitation, since the technique applied to the muscle is characteristic of a system that is non-linear in nature. For this, step applications and pseudo-random binary signals (PRBS) were used to identify Autoregressive Model with Exogenous inputs (ARX) models. The integration between OpenSim© and MATLAB© software was also explored for the visualization of a three-dimensional model of a human leg under the chosen conditions. The answers were obtained through the application of RST controllers, designed by allocation of auxiliary poles, acting separately, where each controller acts independently, and with both acting simultaneously. Finally, in order to identify a region of stability of the controllers, movement for hip flexion above 38° was explored, where unstable regions were reached. Bruno L. Faustino, Aparecida F. de Andrade, Renata R. Lima, Eugênio P. Júnior, Fabrício G. Nogueira, Bismark C. Torrico, Victor Hugo C. de Albuquerque Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3456 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3457 In the last few years, the application of robotics in environments common to human beings has been increasing. There exists several proposals of socially aware navigation frameworks for mobile robots, however all of them generally focused in a specific aspect of social relantionships between humans and robots; so, there exist a lack of approaches that integrate all the aspects related to social navigation. This work aims to propose an autonomous navigation framework based on the integration of social perception elements (from a robocentric perspective) with proxemics modelling, considering the presence of human beings and the perception of their needs, feelings or intentions. We verified the feasibility of our approach by implementing it in ROS and Gazebo, and making a qualitative evaluation of its performance in two simulated scenarios where we included people with different fellings about robot presence, that triggered changes in the path planned by the robot in real time. So, it was concluded that this framework is feasible for implementing social navigation in mobile robots. Fábio Leite, Manoel Andrade, Gabriel Alves, Daniel, José Díaz-Amado, Raphaell Sousa, Dennis Barrios-Aranibar Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3457 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3458 The measurement of wind speed is a key issue for the optimization of energy generation in wind farms. Currently, there are numerous ways to perform its estimation, however, the usual mechanical anemometers are rudimentary. and have a considerable margin of error due to friction between parts and the inertia of the system. In this way, it is observed in the current scenario a greater trend towards the use of ultrasonic anemometers , which are based on the calculation of the time of flight of the ultrasonic wave, a variable that consists of the time interval required for a wave emitted from a transducer ultrasonic transmitter to reach a receiving transducer. Thus, one of the techniques to estimate the time of flight of the ultrasonic wave is Threshold Detection, however, this method is profoundly affected by noisy signals. In this paper, in order to make this method more robust, an application of the Wavelet Transform integrated to the Threshold Detection method is presented. José H. B. da Silva, Lucas D. de Oliveira, Juan M. M. Villanueva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3458 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3459 Didactic modules are important to consolidate fundamental concepts as well as to prepare and to develop key abilities required to design and implement closed-loop control techniques. From experimental tests, practical aspects such as noise attenuation, constraints effect mitigation, robustness and non-linearities can be characterized. In this work, the NTC (Negative Coefficient Temperature) temperature control is presented from a low cost perspective in the context of control engineering education. This kind of didactic module can be highlighted due to the combination of low cost and portability with an expressive non-linearity. Hence a brief systematic discussion is presented based on the phenomenological model, the materials and methods, and some experimental results for providing emphasis on ingredients such as the portability, low-cost requirement, and on the non-linear property. Victor Coutinho Vieira Santos, Tito Luís Maia Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3459 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3460 DC microgrid systems can be represented by cascade converter systems. These types of systems are composed of constant power loads that can lead the system to instability. In this context, several stability criteria based on the forbidden region that evaluate the smallest mesh gain are used to assess the stability of the system. This work proposes to evaluate the stability of a cascade converter system against changes in the controller’s design. This evaluation was performed using the Nyquist diagram of the lowest loop gain of the system through Middlebrook stability criteria, gain margin and phase margin, and opposite argument. Marenice M. de Carvalho, Isaías V. de Bessa, Renan Landau P. de Medeiros, Florindo A. C. Ayres Júnior, Iury V. Bessa, Luiz E. Sales e Silva, Vicente F. de Lucena Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3460 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3461 In three-phase active filtering, the voltage inverter is the key for successful mitigation of harmonic components. Dealing with medium and high voltage applications, multilevel inverters are more suitable. The presented proposal allows to analyse the performance of three-phase active filters composed by single-phase 5-Level H-bridge voltage Modular Mutilevel Inverters and comparate them with those that use single-phase 5-Level H-bridge voltage Neutral Point Clamped inverters. Furthermore, the developed control system includes a strategy to balance the twelve capacitors voltages of the three single-phase modular multilevel inverters. The results show the effectiveness of this strategy, as well as its filtering capacity, with the possibility of adjusting the control parameters to obtain a similar quality to that obtained with neutral point clamped filters. Felipe Gomes da Silva Souza, Guilherme Baumann Corrêa, José Andrés Santisteban Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3461 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3462 Hyperspectral Imaging Systems (HSI) collect spectral data and spatial images simultaneously and continuously in hundreds of narrow spectral bands to generate a data cube. Specifically in mineralogy, remote sensing techniques using hyperspectral images are becoming increasingly popular on remote mapping of mineral formations. Datasets containing hyperspectral images from sensors such as Hyperion installed on the NASA’s Earth Observing satellite 1 (EO-1) can be found online. Considering these facts, we propose in this work the use of analysis and pattern recognition techniques in data cubes from HSI systems, more specifically from EO-1 Hyperion satellite. The hyperspectral image analysed includes the Carajás mine (Pará, BR) for the purpose of reconnaissance and identification of iron ore deposits using unsupervised learning and K-Means clustering method. The results show that about 6.72% of the analysed area is composed of iron ore, which corresponds to approximately 51km2. Érica S. Pinto, Gustavo Pessin, Alan K. Rêgo Segundo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3462 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3463 Water supply companies are always being modernized with the implementation of new technologies, such as supervisory control systems and data acquisition. With the arrival of Industry 4.0 concept, the next step is the development of Digital Twins (DT) in order to find solutions in the lowest possible time and support operators training. The studies related to DT are recent and have few applications in water supply network systems, where most part of the research are related to concepts and how it can be improved with its implementation. This article describes the steps to develop a DT in order to support decision-making process, detect anomalies and assist in the training of operators of a hydraulic plant. The study was divided into two parts, the first consists of the develop of a Digital Model, and the second of a Digital Shadow. Artificial Neural Networks were used for the Digital Model implementation, in which two different activation functions were considered, the sigmoid and ReLU, thus looking for the best result of the mean square error between the two activation functions. The best model was used in parallel with the real hydraulic plant, thus observing its performance in relation to the real data. Among the developed models, the ReLU activation function presented the best performance , being in the sequence used in Digital Shadow implementation, which even having a result with a greater error than that observed in its training and validation step, but presenting a good behavior in relation to the actual plant data. The results obtained in the Digital Model and Digital Shadow stages are relevant for the development of DT. Caio M. Nascimento, Ademar V. Silva Netto, Juan M. M. Villanueva, Euler C. T. Macêdo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3463 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3464 This paper presents an approach to incorporate the uncertainty of wind power generation in the design of Wide-Area Damping Controllers (WADCs). The approach is based on the Cross-Entropy method and allows obtaining deviations from the predicted output power that result in violations of the small-signal stability margin. The Cross-Entropy based algorithm allows accelerating the convergence of the sampling generation by making adaptive changes to the probability density function, minimizing the variance. As a result, the worst scenarios are identified and, consequently, the Wide-Area Damping Controllers can be designed to enhance the damping factors of the system for critical conditions. The proposed approach procedure was applied to a modified version of the IEEE Benchmark 68-bus NETS-NYPS System, with significant penetration of wind power generation. The results show that the WADC designed is effective to damp low-frequency electromechanical oscillations even in critical conditions of power injections from wind power sources. Natali V. C.Gonçalves, André M Kernbichler, Tatiane C. C. Fernandes, Ahda P.Grilo-Pavani, Rodrigo Andrade Ramos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3464 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3465 This article investigates the influence of overhead ground wires (OGWs) on transient responses in power transmission lines (TLs). For this study, several simulations were performed considering two three-phase TLs, one of 138 kV and the other of 230 kV, both towers situated on the soil of 1000 Ω.m. The ground-return impedance and admittance are calculated by Nakagawa’s formulation and the frequency-dependent soil electrical parameters are represented by the Alípio and Visacro’s formulation. The line parameters (resistance, inductance, and capacitance) were calculated for a frequency range from 10 Hz to 10 MHz, for the TLs with and without OWGs. Then, the transient voltages developed for energizing (switching maneuver at one phase) the TLs for these same conditions were studied. The results showed that a significant variation is obtained for the self and mutual resistances and inductances when the effect of the OGWs is reflected on the impedance and admittance matrices of the line. However, this variation is negligible for the capacitance. As a consequence, the voltages generated in the open-receiving end of the TLs presented variations that are more expressive for the induced voltages on the non-energized phases. Tainá Fernanda Garbelim Pascoalato, Anderson Ricardo Justo de Araújo, Sérgio Kurokawa, José Pissolato Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3465 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3466 This work presents the partial results obtained on the development of applied research. Nowadays, in the agricultural process there is a growing need on automating the productive process with technological support. One of the jobs is the data collection about the soil’s hydric condition that is done manually and, on large properties, may become tricky and longstanding. Once dealing with a manual conference, it may generate mistakes on reading. With these problems in mind, the authors look for creating automated systems for irrigation using Agriculture 4.0 (Agro 4.0) concepts. This part of the manuscript presents the materials and methods applied to the building of a prototype made to digitalize, send and store data about the soil’s hydric tension in a single cloud database. Furthermore, there are shown details of the interface created to view the data from the internet. Such features line up the presented system with the Internet of Things (IoT) and provide evidence that it may be used as a tool for monitoring useful sensorial information on the automated irrigation process. Mateus Falcão, Vinicius de Moura Siqueira, Henrique de Sá Paye, Lucas Vago Santana, Erlon Cavazzana Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3466 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3467 This paper presents an open-circuit semiconductor fault detection strategy for modular converters. It is proposed a specific technique for filtering the harmonic signals of the output voltage, with a faster identification capacity than the Fast Fourier Transform (FFT), the most used method until then. The technique proposed uses the Generalized Delayed Signal Cancellation operation (GDSC), a method capable of cancelling groups of harmonics, similar to a bandpass filter, but with a faster response. Henrique F. de Souza, Alessandro L. Batschauer, Felipe J. Zimann Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3467 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3468 The allocation of wind turbines in a wind farm is a really important task, due to the fact that the positioning of wind turbines affects the power produced by the generator unit and consequently in the power converted into energy. In this sense, the present work proposes to find the best location of wind turbines in a wind farm considering different wind directions using the Grey Wolf Optimizer (GWO). The study considers the wake effect, different wind directions and their probability density functions. A case study present in the literature is used to evaluate the proposed methodology. Arthur E. S. Ribeiro, Cristiane Geralda Tarôco, Wesley Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3468 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3469 One of the most effective methods for reducing overfitting in deep learning models for audio classification is data augmentation. The range of techniques available, as well as a lack of understanding of the most efficient ones, can result in severe time and processing power costs. This survey covers numerous techniques, tools, and datasets for offline data augmentation to assist in the selection and implementation of data augmentation strategies to improve audio classification models in Environmental Sound Classification, Music Information Retrieval, and Automatic Speech Recognition. Finally, we present a short review of papers that apply data augmentation in Environmental Sound Classification which indicates that the use of spectrogram and audio augmentation has considerable potential for improving the performance of convolutional models, especially for small datasets with increases in accuracy of up to 30%. However, the accuracy gains achieved may be insufficient to justify the additional computer burden depending on the application. Furthermore, the usage of image data augmentation is unsuitable for audio data. Lucas Ferreira-Paiva, Elizabeth Alfaro-Espinoza, Vinicius M. Almeida, Leonardo B. Felix, Rodolpho V. A. Neves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3469 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3470 Diabetic foot is a condition caused by diabetes mellitus (DM) that can cause irreversible damage, such as amputation and other complications. This article aims to classify patients diagnosed with DM in high or low risk of developing diabetic foot using the Confident Learning (CL) method. CL enables the removal of noisy data and, consequently, provides a more reliable classification. The available database is composed of 54 known risk factors of 250 patients diagnosed with DM. The development of the method was divided into: (i) feature selection; and (ii) application of the CL technique. The results showed that there is a gain of 6% in sensitivity, 14% in specificity and 9% in accuracy when removing noise from the diabetic foot ulcer risk classifier database. In addition, when comparing the competitive neural layer- based method with the proposed one, the CL-based method presented a sensitivity 26% and an accuracy 4% higher than the competitive neural layer-based method, but it has a specificity 13% lower. Lucas Alexandre Alvarenga Cardoso, Giovanna Gouvêa Spuri de Miranda, Danilo Piveta Alvarenga, Arthur Phillipe Marcondes Souza, Ana Cláudia Barbosa Honório Ferreira, Maria Helena Baena de Moraes Lopes, Danton Diego Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3470 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3471 In electricity distribution networks, one of the challenges is to identify non-technical losses. The challenge is even greater in rural distribution networks. These have large extensions and the costs for on-site inspection are higher. Irrigated rice crops have particular characteristics in terms of consumption, due to the seasonality of the crop, different irrigation modes and processes, and climatic characteristics. This article presents a methodology that aggregates the consumption recorded by the concessionaires with more relevant information to analyze how much a given consumer presents risks of non-technical losses, as well as its neighbors. This work presents the use of Artificial Intelligence in the identification of non-technical losses in rural areas with integrated irrigation systems. The technique considers robust sub-methodologies, which evaluate: meteorological data, satellite images of the region, technological mapping of crops and the calculation of the energy balance for the estimation of non-technical loss by distribution feeder. The methodology was applied in consumer units located on the western border of RS. These consumer units use the flood irrigation system for rice planting, so they have a high monthly consumption. This high consumption significantly impacts the energy utility, in the event of a PNT. The results were obtained and validated with real information from rice harvests between 2018 and 2021. Vanessa Gindri Vieira, Roberta Razzolini Biazzi, Daniel Pinheiro Bernardon, Natalia Bastos de Sousa, Henrique Silveira Eichkoff, Paulo Ricardo da Silva Pereira, Daniel Lima Lemes, Rodrigo Marques de Figueiredo, Matheus Mello Jacques, Carlos Henrique Barriquello, Vinícius Jacques Garcia, Lucas Melo de Chiara, Juliano Andrade Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3471 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3472 This article discusses the use of an external rotor reluctance machine, operating at high speed (up to 50 krpm), in a Kinetic Energy Storage System (flywheel). The outer rotor acts as a flywheel. This device stores kinetic energy during machine operation as a motor, where it is connected to a DC source. If the primary power supply (DC source) fails, it converts the kinetic energy of the flywheel, allowing the normal operation of a load. Reluctance machine rotation and DC link voltage control techniques are investigated and analyzed through real-time hardware- in-the-loop (HIL) simulations using the Typhoon HIL platform. The choice of how to obtain the angular position occurred after evaluating different techniques present in the literature, having converged to the use of optical sensors. The optimization of commutation angles was applied in the control of operations such as motor and generator. For the purpose of analysis and validation, the results of the HIL are presented, and demonstrate the ability to operate as a generator of the machine, the functioning of the developed system and its applicability. Janito dos Santos Ramos, Luís Guilherme Barbosa Rolim Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3472 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3473 In this work, we employ the recent envelope estimation method to fit a multiple linear regression model in order to make predictions of solar irradiance at horizons of 10, 20 and 30 min ahead. The advantage of using this method lies in the fact that there is a reduction in the variance of the estimated coefficients. Such a reduction is obtained by enveloping the material part, while excluding the variation of the immaterial part, which also contributes to a reduction in dimensionality, since there is a decrease in the estimation variance without an increase in the number of observations. The model was used in a dataset formed by LDR luminosity signals and statistical attributes extracted from images of the sky. The integration of the LDRs and the camera was done using a Raspberry Pi 3. Its performance was compared to that of linear (LASSO and Ridge) and non-linear (Multi-Layer Perceptron) models, being evaluated by the metrics Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Root Mean Square Error Relative (rRMSE). Felipe P. Marinho, Ajalmar R. R. Neto, Paulo A. C. Rocha Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3473 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3474 This work presents a multi-objective formulation for the co-design of controller and event-triggered transmission mechanisms, with sampling period optimization, for networked control systems in order to obtain different tradeoffs between the control system performance and the communication network usage. Random transmission delays and packet loss are considered for each independent communication link. An improved version of the multi-objective differential evolution optimization algorithm is applied to obtain a set of efficient solutions that simultaneously determine the gains of the multivariable proportional-integral controller, the sampling period, and the individual parameters of the decentralized event-triggered transmission mechanisms of each sensor and actuator. The proposed co-design methodology is evaluated through an example of a multivariable control system with two sensors and two actuators. Based on the achieved results, it is evident that the proposed synthesis methodology is quite efficient with considerable reduction in the number of transmissions with equivalent control system performance. Marcelo Ferreira Godinho, Mateus Alves Ribeiro Belo, Ana Paula Batista, Eduardo Nunes Gonçalves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3474 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3475 Offshore oil extraction presents several challenging scenarios from exploration to operation. Limitations in physical space impose restrictions on the construction of vessels that have sufficient capacitance to absorb the accentuated load variations to which this process is subject. This factor, allied to the turbulent nature of the flow into the risers, which causes occasional slugs, brings high complexity to treatment and separation vessels level control, upon which the quality of the final products depends. The present work takes advantage of recent advances in process identification techniques to develop a NARX-type neural network to carry out a Digital Twin implementation of a three-phase separator of an offshore unit, located in the Campos basin, Brazil. The Digital Twin allows simulations of different control techniques to be tested in a realistic simulation environment, as it uses heuristics and machine learning techniques capable of inferring even nonlinear relationships between variables, mirroring the physical twin behavior. The main goal is to enable these simulations to be run and achieve enhanced process control. The results obtained in the present work show that it is possible to obtain a Digital Twin using NARX-type neural networks with Mean Absolute Percentage Error marks below 1% in test situations to predict main chamber and oil chamber levels, which can be used to simulate and benchmark advanced level control strategies. Daniel P. Scardini, Leonardo A. Scardua, Gustavo M. de Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3475 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3476 Many practical industrial applications performed by robotic manipulators demand movement limitation in order to avoid any structural damage and/or colisions. This paper presents a kinematic control scheme for end-effector motion of a redundant mobile manipulator with a constrained robotic chain. The proposed kinematic control is based on the Constrained Jacobian. The main advantage of the proposed approach is that it provides full task space motion while guarantees that a point of the kinematic chain avoids any lateral motion using a conventional operational space control scheme. Experimental results are presented considering a redundant manipulator mounted on a mobile robot developed for industrial plant inspections. These results show the viability of the proposed planning and control schemes. Igor Novais, Fernando Coutinho, Fernando Lizarralde Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3476 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3477 Programmable Logic Controllers (PLCs) are central elements in industrial automation systems, with specialized control functions. Algorithms that involve complex mathematical operations are difficult to implement. However, its communication capabilities make it possible to make data available to cloud systems with a huge variety of tools for the development of monitoring systems based on machine learning. In this work, native PLC features were configured to send data to the cloud and receive the desired diagnostics. The cloud environment was developed for training models and monitoring an industrial plant, taking advantage of existing libraries. The result is a cloud environment with high computational power that provides important diagnostics to a SCADA (Supervisory Control and Data Acquisition) system in an industrial plant. Any browser screen on the local operating station allows parameterization of algorithms programmed in the cloud. In the developed application, algorithms for fault detection in the controlled plant were implemented in the cloud, using operating data for model training and monitoring. The results can be viewed both on the SCADA system graphical interface and on the cloud system dashboard. The proposed environment can be easily extended to industrial processes in general. Matheus Rangel Pimentel, Celso Jose Munaro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3477 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3478 Real-time fault detection and isolation capability has become a competitive differential for modern, complex systems due to the increasing demand for higher levels of both reliability and safety. The use of health monitoring algorithms can be considered a powerful decision tool and a key enabler for new maintenance and logistic strategies in which decisions are made based on the estimated health condition of the systems under consideration. This paper presents the study of a fault detection and isolation (FDI) algorithm for non-linear systems based on a multiple-model architecture. The Extended Kalman Filter (EKF) is used as residual generation tool while the Autonomous Multiple Models (AMM) algorithm is used for residual evaluation. Numerical experiments are conducted to assess the performance and the limitations of the algorithm. The study covers an assessment of the algorithm sensitivity to different failure intensities and also its response to failures not initially considered in the fault detection and isolation architecture. Olívia M. A. Coelho, Leonardo R. Rodrigues Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3478 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3479 This article presents the application of the Virtual Reference Feedback Tuning (VRFT) method in rotor speed regulation of wind turbines through colective pitch control. From data collected on the simulated turbine, a Proportional Integral (PI) controller is designed such that the closed-loop system exhibts a behavior as close as possible to a given reference model. Fundamental aspects for the application of the VRFT method will be analyzed, such as the choices of reference model and operating point for data collection. Simulations in the FAST software considering a 5MW turbine illustrate the method when tracking rotor speed references and rejecting disturbances in the wind speed. Maurício O. Lourencena, Jeferson Vieira Flores, Lucíola Campestrini Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3479 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3480 In this work, the orientation control problem of a pan-tilt camera for focusing on moving objects is considered. Because of being a non-linear multivariable control system with coupled control inputs, this work presents and discusses the Active Disturbance Rejection Control (ADRC) method. One of the main advantages of using the ADRC is that the control law design does not require exact knowledge of the plant parameters and the pan and tilt angles measurements. These advantages are possible by using an extended observer to estimate the non-measurable signals of the states and nonmodeled dynamics. As a contribution to state-of- the-art, it is proposed an ADRC variant approach that is implemented with a reduced-order observer. Numerical simulations and comparisons with other control techniques illustrate the efficiency of the proposed control. Indiara F. Brito, Lúcio M. Fernandes, Josiel A. Gouvêa, Milena F. Pinto, Alessandro R. L. Zachi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3480 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3481 The virtual sales market (E-commerce) has expanded a lot nowadays due to the ease and practicality provided by this way of purchase, and the fact that technologies are becoming increasingly accessible. With this, the implementation of virtual assistants by companies can add benefits for both sides of the negotiation (consumers-companies), since the use of virtual assistants can allow the automation of tasks (involving means of communication), thus accelerating solving problems and increasing productivity for customer service, in addition to being able to provide personalized experiences tailored to each customer. In this work we discuss some models and strategies that are relevant to the topic of Knowledge Base Question Answering (KB-QA), and means of developing a KB-QA model capable of answering user questions provided in natural language, based on information contained in knowledge bases (KBs) that can be implemented as part of a virtual assistant. In order to develop a superior KB-QA model via Ensemble by majority vote, the search, analysis and selection of KB-QA models are carried out for the Ensemble’s composition. For the analysis of the KB-QA models, the WebQuestionsSP question bank is used, which is developed to be answered through queries to the Freebase KB. As the main result of this work, three different Ensembles are generated, called Simple Ensemble, Ensemble with Countermeasure and Ensemble with Total Countermeasure, which are state-of-the-art for the KB-QA task considering the WebQuestionsSP database with F1-scores of 75.40%, 78.72% and 81.43% respectively. Rafael H. de Sousa, Bruno H. G. Barbosa, Danton D. Ferreira, Paulo R. Silva, Sinval T. Nascimento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3481 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3482 The expansion of offshore wind farms, the need for oil production in increasingly deeper waters and the demand for larger power transmission systems have required new levels of technology and performance of submarine power cables. The long length of these cables makes such applications more susceptible to a series of undesirable electromagnetic phenomena, including transient ones, requiring studies to be carried out for the design and commissioning of the system, as well as to assess and mitigate the consequences of such phenomena. For this type of evaluation, computer simulations are indispensable and, in the aforementioned case, they demand specific models, suitable for high frequency studies. In the case of insulated cables, the elaboration of their modeling requires, as input data, the matrices of resistances and inductances at various frequencies, from Hz to MHz. In this way, the Finite Element Method (FEM) is a powerful tool for obtaining such parameters. In this context, this paper presents a methodology composed of advanced techniques for the calculation of submarine power cables parameters through the FEM. Three different models of submarine application cables are employed in various case studies. The objective is to discuss the best way to model certain constructive characteristics of cables in the FEM, as well the impact of these characteristics on parameter values and in the associated joule losses. André M. Alzamora, José Carlos L. V. Silva, Marco Túlio A. Êvo, Hélder de Paula Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3482 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3483 The present work proposes three variations of yaw control systems and makes a comparative analysis of net generated energy gain and actuation number. The three yaw control system proposals are compared with two ideal controls. One in which the actuator is assumed to operate following the wind direction instantaneously without any limitation and the other with speed limitation. Controls were modeled and compared using one second field measurement data. The results indicate that, among the proposed variations, the one that presented the highest net energy gain is also the one with the highest number of actuations, concluding that there is a relationship between energy gain and number of actuations. Clarissa O. Eccard Dias, Luiz A. M. Lima, Edson H. Watanabe, Robson F. S. Dias Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3483 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3484 This paper presents an analysis of the balancing voltage of a bipolar dc microgrid (±190 V) formed by a four-wire three-phase bidirectional PWM rectifier. The rectifier is responsible for guaranteeing the total dc bus voltage (380 V). The balancing of symmetrical voltages is guarranteed by a Cuk voltage-balancing converter that acts equalizing the voltages in case of unbalanced loads. DC-DC converters are connected to the dc buses and aims to adjust the voltage levels for residential or commercial applications. The simulation results show that a voltage balancer is essential to keep the voltage balance of the dc microgrid. Debora Pereira Damasceno, Mateus Pinheiro Dias, João I. Y. Ota, José Antenor Pomilio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3484 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3485 The integration of wind farms to the National Interconnected System brings with it great challenges and innovations, since the electrical power systems that contain this type of generation, present different responses from conventional generation (synchronous generators) in the face of disturbances that may occur. This article presents a study on the state of the art regarding the main methodologies used in the detection, classification, and location of faults in electric energy distribution networks and the development of a detection algorithm applied in feeders of Parks wind. The methodology used in the detection algorithm is based on the calculation of the Euclidean distance of samples of the system voltage signal to detect faults. Numerous short-circuit tests were carried out considering two wind farms, under different operating conditions. The observed results show the efficiency and robustness of the proposed method in correctly detecting faults applied even for high fault resistances. Elis C. S. Trindade, Fábio B. Leão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3485 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3486 The Industry 4.0 starts the digitalization process and for this have been using new technologies as Internet of Things, Cloud Computing, Service Oriented Architecture and Control Systems in network. The integrated use of these technologies in automation and process control applications provide advantages, such as vertical interoperability and standardization of communication through networked service sharing. In this article, the redundancy of industrial process controllers is studied and the development of a redundant controller is investigated using an automation architecture oriented to microservices. The redundant controller is based on a modification of the PIDPlus algorithm to network control for operation as a microservice. Additionally, a redundancy application (orchestrator) is responsible for orchestrating microservices and recording control variables, allowing the sharing of data from process variables among redundant controllers (replica). The experimental results obtained in a pilot plant in different scenarios demonstrated feasibility and efficacy in the redundancy implementation of process controllers as a service, as well as the advantages of this type of implementation. Lucas B. Rodrigues de Sá, Ricardo P. Pontarolli, Eduardo P. Godoy Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3486 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3487 In line with the rapid increase in the use of renewable energy sources, this work proposes the application of a three-phase multilevel frequency inverter composed of two cascade inverters in photovoltaic (PV) power generation systems. This topology was originally proposed for machine control, but its advantages in energy efficiency and the reduced number of devices compared to other topologies already consolidated in the literature, make it a viable alternative for application in energy generation systems. Luan A. C. Mendonca, Filipe A. da C. Bahia, Fabiano F. Costa, André P. N. Tahim, José R. Pinheiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3487 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3488 Friction is one of the main challenges in robotics, specifically in robot manipulators, affecting the lifetime and performance of the system. The presence of complex and non-linear aspects in this phenomenon makes its modelling challenging to conceive. We present an original experimental bench composed of an motor and a link joined by a rigid joint. We seek to find the friction model that best represents the developed servosystem through experimental measurements. Thus, the Gray Box type identification process is used to optimize the different parameters of the friction models. The parameters of the different friction models are identified using the Shooting Method through the data. Then the different models are compared. We observed that the models that consider the most significant number of friction phenomena perform better. Antonio Weiller Corrêa do Lago, Lucas Castro Sousa, Felipe Rebelo Lopes, Daniel Henrique Braz de Sousa, Helon Vicente Hultmann Ayala, Marco Antonio Meggiolaro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3488 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3489 Smart walkers were developed to assist users with residual locomotion capacities providing physical support, health monitoring, and sensorial, cognitive, and navigational assistance. Multimodal human-robot interaction strategies can enable higher levels of comfort and safety when using the smart walker. Therefore, the functioning of smart walkers must be explainable and transparent, thus reflecting on the acceptance and involvement of its users. Behaviour trees are high-level language adopted in robotics due to its modularity and inherent reactivity, since its architecture facilitates the inclusion of new behaviours seamlessly.This paper proposes the use of artificial intelligence in the core of human-robot interaction strategies with focus on smart walkers to guarantee user’s safety while providing locomotion assistance. The proposed approach was experimentally validated and the results indicate that the implemented behaviour tree correctly predicted unsafe scenarios whereas responding to user’s commands. Such results motivate further studies upon the use of behavior trees for human-robot interaction, a research field still largely unexplored. Paula Cardoso, Fabiana Machado, Raquel Pereira, Ricardo Mello, Petter Ögren, Anselmo Frizera-Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3489 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3490 This study aims to present the application of the Particle Swarm Optimization (PSO) algorithm to solve the Economic Load Dispatch (ED) problem in its classical formulation, considering losses in transmission lines, and the limits of the generating units. Two case studies were made to demonstrate the method’s applicability, for systems with three and six generating units. Also, a comparison between two different stopping criteria was performed, by the maximum number of iterations and by error. The PSO was implemented using the Python programming language, in the Jupyter Notebook environment. The results were compared against each other, and against the classic optimization solution via Lagrange multipliers present in the literature. The results showed PSO’s applicability for the considered DE problems. Another conclusion of this study is that the stopping criterion by error may return unreliable results since, during the 20 algorithm executions performed in the experiments, this criterion increased the variance of the analyzed metrics and the number of iterations. Therefore, it is concluded that the number of iterations must be known for each experiment, which guarantees the robustness and reliability of the results, considering the smaller standard deviation and percentage error in this case. Gustavo M. O. de Castro, Aline S. Gallina, Moisés Arthur P. Borges, Ronaldo Francisco R. Pereira, José Humberto A. Monteiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3490 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3491 This paper proposes a model for Lithium-Polymer batteries with diffusion dynamics through a lumped parameter approach in conjunction with an electrical model. A comparison of the performance of several optimization approaches to identify the model parameters from experimental tests is also conducted. Constant and pulsed current discharge experiments were performed on a set of three battery cells using a programmable DC load. The resulting data sets were used to obtain several model parameters using different optimization approaches. The predicted outputs of a discrete battery model using the parameters estimated by each algorithm were compared against the experimental data. The resulting models had an overall good performance, proving that the chosen modelling approach is applicable to Lithium-Polymer batteries, and that the choice of algorithm to identify the system parameters must be made with care. Augusto de Holanda B. M. Tavares, Florian vor dem Esche, Saulo O. D. Luiz, Florian Holzapfel, Antonio M. N. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3491 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3492 This work presents a stability analysis for proportional-integral (PI) controllers for processes with constant delays and time-varying delays. It is frequently reported in the literature that the time delay in the feedback loop can lead the system to instability. This problem can be made worse if the delay is time-variant with, for example, a sawtooth variation, which is reported in the literature as one of the worst types of time-delay variation due to the phenomenon known as chattering. Therefore, this study allows us to assess whether the worst case scenario for a PI controller is the constant delay or the time-variant delay, in the sawtooth format. Finally, a simulation example presents the stability analysis of a very popular PI controller tuning rule in the literature, to determine whether the worst case scenario is constant delay or time-varying delay. Roberto A. M. Braga, Gabriel F. Machado, Rene D. 0. Pereira, Bismark C. Torrico, Fabricio G. Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3492 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3493 Standard 1547 by IEEE recommends that a distributed generation device should be able to detect an island and cease to energize in no more than 2 seconds. To follow this recommendation, this work presents an island detection method based on grid impedance estimation using recursive least squares. The voltages and currents measured are converted to dq coordinates before being utilized in the island detection algorithm. MATLAB and Simulink simulation results with the performance of estimated grid and load resistances and reactances and island detection signals are presented. The presented method is robust to measurements noise, and the island detection is fast and precise, allowing the equipment to cease to energize within the recommended time. Laila S. Ribeiro, José Leandro F. Salles, Jussara F. Fardin, Domingos Sávio L. Simonetti Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3493 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3494 The communication technology based on LoRa (Long Range) modulation is a very current topic in IoT (Internet of Things) given its high applicability due to its characteristics of low power consumption and long-range transmissions. Most applications using LoRa involve arranging radio transceivers at fixed points, such as crop monitoring, home sensoring, industrial production monitoring, and so on. On the other hand, there is a lot of demand for mobile applications, such as vehicular telemetry. In this article, a prototype of an automotive telemetry system using LoRa technologies is presented. In this way, the process of construction and integration of hardware and software is described, as well as its experimental results. Lucas D. de Oliveira, Thiago B. Souza, Fernanda Maria L. Fernandes, Thyaggo L. P. de Oliveira, Cleonilson P. de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3494 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3495 Among the several topologies proposed in the literature for inertial emulation in power converters, the synchronverter technology has stood out due to the versatility of its operation in various applications. From the bibliography, this work presents different possibilities of incorporating the synchronverter strategy to grid-connected distributed energy resources, from wind turbines to electric vehicles, besides showing how the synchronverter can facilitate the dissemination of HVDC networks, DC micro-grids, and also operate as static compensators. A reflection on the parameters of the synchronverter will be carried out to deepen the understanding of the technology. William Contesini, Liciane Otremba, Renato M. Monaro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3495 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3496 This paper presents the application of the variational mode decomposition associated with the Teager energy operator to extract the characteristic data from two terminals for fault location in transmission lines using the traveling wave theory in a test system with 200 km long transmission line between two voltage sources. The simulation was performed using the MATLAB/Simulink® software, reading voltage and current signals, considering all types of faults, the variation of the occurrence location, fault inception angle and fault resistance. The numerical and graphic results proved the low dependence of the fault resistance in the estimation of the distance from the local of occurrence to the main reading terminal and showed high accuracy for the methodology used. Andressa P. Oliveira, Fernando A. Moreira, Alessandra F. Picanço Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3496 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3497 This article presents an overview of the deployment of intermittent renewable energies. It shows the importance of planning the grid according to the energy storage capacity, frequency control, and other factors to which this type of solution contributes. This kind of planning prepares the system predicting solutions to provide required ancillary services for power systems. A state-of-the-art review is carried out on storage technologies applied to the optimization of power transmission systems, management of resources, power dispatch, resources integration management, and various other applications. Thais Rosa Rey, Eduardo Lorenzetti Pellini, Eduardo C. Marques da Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3497 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3498 Two Grid-Forming (GFM) control strategies based on emulation of Synchronous Machine (SM) behavior, namely Droop Control and Synchronverter, and two Andronov-Hopf Dispatchable Virtual Oscillator Control (dVOC)-based techniques are unified into a compact yet generalized control framework for GFM inverters. In the light of the proposed framework, we reassess the control laws of the studied GFM analytically, and further validate these analyzes in silico for steady-state power sharing and transient responses. We show how the mathematical structures of the studied GFM methods differ and resemble, which has an impact on the underlying grid forming performance. These differences are attributed to intrinsic nonlinearities, which can be translated as operating point parameter dependence for each GFM technique being recast for the suggested framework. Furthermore, we show that, to a certain extent, the techniques can be parameterized to have similar steady-state and dynamic responses. This work succeed in developing a technology-agnostic metrics for steady-state power sharing and dynamic behaviors of GFM methods, an important requisite for the interoperability of grid-connected inverter units. Armando J.G. Abrantes-Ferreira, Alexandre C. Oliveira, Antonio M.N. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3498 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3499 The evolution of power electronics has added several advantages to the production of electricity. This production, although still very concentrated, has been expanding over the years. Technical regulations support the installation of mini and micro generating grids, adding advantages to consumers due to the proximity to the load. In the case of university campuses, investment in energy self-sufficiency allows for investment in research, diversification of production and cost reduction with this input. In view of this scenario, an Institutional Research and Development project was developed at the Federal University of Minas Gerais, Pampulha campus in Belo Horizonte (MG). This article has the objective of publishing containing a general evaluation of the project, considering the means of production of electric energy and the environmental structure, demonstrating the feasibility and advantages for the effective reduction of the costs with electric energy in educational institutions. Mylena C. da Silva, Lucas S. Chaves, Thales A. C. Maia, Igor A. Pires, Braz de Jesus C. Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3499 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3500 Iron ore ranks second among the highest value items exported by Brazil in 2020, with Vale S.A. being the largest exporter of this commodity in the world. At this point, estimating the future behavior of a short-term iron ore price time series is an important tool at mining projects, especially in decision-making related to operational planning. The present work evaluates, in this context, the accuracy of the fuzzy models PWFTS (Probabilistic Weighted Fuzzy Time Series) and FDT (Fuzzy Decision Trees) in iron ore price prediction, by presenting a comparative study with the predictive models: ARIMA, Multilayer Perceptron (MLP) and Xgboost. In order to ensure the variability of input patterns, the data are distributed into subsets, using the sliding windows technique. In a multivariate context, predictor variables are selected through correlational analysis with the target time series, with emphasis on the inclusion of the iron ore surplus production from Vale S.A. Results for the univariable and multivariable modeling indicate superiority of the fuzzy models, according to RMSE and MAPE metrics. Hamilton Tonidandel Jr., Frederico Gadelha Guimarães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3500 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3501 This paper presents the results of a study to implement a motion cueing algorithm for a six DOF flight simulator motion base. More specifically, getting specific forces and angular velocity from X-Plane Simulator, communication between X-Plane and dSPACE board 1104, and motion cueing parameter optimization. We evaluate the simulation realism by using an objective performance indicator. The specific forces and angular velocities at the simulator are measured by an inertial measurement unit (IMU). The experimental results revealed that the motion base is capable of producing motion simulation quality comparable to that produced by similar research simulator motion bases. Matheus Pena, Mauricio Becerra-Vargas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3501 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3502 This paper presents a study and implementation of an eolic emulator platform for a wind energy generation system (EEP-WEGS), which is based on mathematical models that describe the static and dynamic behaviors of a wind turbine, composed of a permanent magnet synchronous generator. The management of electrical power generated from the mathematical model of the wind generator (MM-WG) is performed by a back-to-back converter (rectifier/inverter), which is responsible for controlling the power drained and injected into the three-phase power grid. The first stage of this converter is composed of a controlled rectifier, that is responsible for draining sinusoidal currents from the grid whose amplitudes are defined by a reference generation system (RGS), based on the MM-WG. Inside the RGS, the maximum power point tracking (MPPT) algorithm is also present. Therefore, MPPT techniques are addressed during the paper for optimizing the performance of the wind system. A three-phase inverter is used in the last stage of the back-to-back converter, which controls the DC bus voltage and the currents injected into the grid calculated by the MM-WG. For evaluation of the proposed EEP-WGS, simulation results are shown, to demonstrate the static and dynamic behaviors of a complete wind system, as well as evaluate the performance in the search for the MPP, allowing the analysis of the MPPT algorithms employed. GABRIEL R. PREVIERO, SERGIO A. O. DA SILVA, LEONARDO P. SAMPAIO Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3502 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3503 Among the pillars of Industry 4.0 stand out the simulation and virtual reality strategies, bringing the real world closer to the virtual one and generating optimization of resources and economy with the improvement in machine configurations before the actual implementation system connected via an OPC server. This work presents a proposal of automation of a virtual factory, whose process consists of filling stages with level control of a tank, palletizing station and stock of products. The Programmable Logic Controller (PLC) program is organized into program organization units in the LADDER, Structured Text (ST) and Sequential Flow Chart (SFC), as per IEC 61131-3. An identification test and controller tuning for the filling system was carried out with the PLC and the virtual factory. Results from the simulation demonstrate the operation of the virtual plant processes through a single PLC via OPC communication. Guilherme L. V. Pereira, Willian R. B. M. Nunes, Rodrigo P. Caun Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3503 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3504 This paper presents a novel approach for networked event-triggered control for linear parameter-varying systems subject to stochastic cyberattacks and network-induced delay. The proposed networked control system is composed of a gain-scheduled controller and an event-triggering mechanism. To design them, new co-design conditions based on linear matrix inequalities are provided to guarantee the mean-square asymptotic stability and the robustness with respect to stochastic norm-bounded deceptive attacks. Numerical simulations indicate that the new conditions are less conservative than other approaches in the literature and they are also able to ensure the stabilization for higher attack occurrence probability. Márcia L. C. Peixoto, Pedro H. S. Coutinho, Paulo S. P. Pessim, Iury Bessa, Reinaldo M. Palhares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3504 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3505 When the contact between an energized conductor and a high impedance surface occurs, a High Impedance Fault (HIF) is generated. It can cause interruption of electrical power supply, bushfires, and dangers to living beings. Even being a well-known and studied problem, there is still a need to develop more effective HIF protection schemes. To test these new techniques, HIFs’ current signals are necessary. However, obtaining real measurements during the fault occurrence can be challenging. To solve this issue, tests are usually performed using computational models to represent the real HIF features as detailed as possible. However, setting the HIF models parameters can be a hard task. To solve this issue, this paper presents a methodology to extract the parameters of real HIF signals to use a complete and recently- developed HIF model and validate its use in a Distribution System (DS). Tests are carried out analyzing the harmonic and interharmonic content of the signals measured in the DS. The main goal is to help researchers use the HIF model in new scenarios, improving the quality of the tests of new and existing HIF protection schemes. Gabriela N. Lopes, Luiz H. P. C. Trondoli, Jose C. M. Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3505 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3506 PLLs are synchronism circuits used in different applications ranging from signal processing to real-time algorithms applied to active power conditioners. The PLLs used in single- phase circuits can be composed by the association of quadrature signal generating circuits, such as the second-order generalized integrator (SOGI) or the all-pass filter (APF). The association of single-phase PLLs to quadrature signal generators results in a similar performance in comparison to three-phase PLLs, with no transient double-frequency oscillation. In this context, this work exploits the digital implementation in FPGA of SOGI-PLL and APF-PLL circuits through an approach based on high level synthesis (implemented in C++). A fixed-point architecture was applied to implement the PLL algorithms in 2MHz interrupts. In this case, the developed IPs (Intellectual Property) represented each of the PLLs through the included tools in the Xilinx Software VIVADO 2020.2. In this paper, there are simulation and experimental results through the FPGA. In both cases, the proposed digital implementation tracked the input signal over a period of approximately 0.06s. Fabiano da Silva Catão, Dayane Mendonça Lessa, Cleiton Magalhães Freitas, Michel Pompeu Tcheou, Luís Fernando Corrêa Monteiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3506 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3507 The most common method for the identification of HLB infected plants is visual inspection. The present work aims to present a technique using deep convolutional neural networks to identify the presence of the disease in citrus plants using digital camera images. Two types of images are used: leaves with real background (field) and homogeneous background (studio) from two different classes: healthy and sick. Miguel N. Marques, Cristiano O. Pontelli, Ely C. de Paiva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3507 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3508 This project aims to apply easy-to-implement supervised and unsupervised learning methods to do a cluster and classification analysis of the information from a wheat seeds dataset. In addition, it intends to thoroughly evaluate, employing post-processing techniques, the efficiency of the models produced from them, proving that it is not necessary to use complex procedures in this database, since the obtained results for clustering and classification were highly similar to the dataset original labels. The decision tree was chosen as the classification algorithm. Furthermore, k-means and Kohonen neural network were selected as the clustering methods. Additionally, pre-processing and exploratory data analysis techniques were explained in detail and employed in order to maximize the final quality of the model developed. Mirella M. de O. Carneiro, Milena F. Pinto, Alessandro R. L. Zachi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3508 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3509 In Particle Physics, the aim is to probe deeper into understanding the structure of matter. For this, collider experiments are essential tools to prove theories experimentally and discover whether there is new physics beyond the Standard Model of Particle Physics. In this regard, muons are important signatures for many interesting physics processes. Thus, this work presents an enhanced approach based on Self-Organizing Fuzzy Classifiers applied to the muon classification. Experimental results are included and discussed, showing the effectiveness of Self- Organizing Fuzzy Classifiers in the solution of the problem at hand. Ualison R. F. Dias, Luciano M. A. Filho, José M. de Seixas, Eduardo P. de Aguiar Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3509 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3510 This paper aims to identify the occurrence of gross errors (EG) in the measurement system of an electrical distribution power system (SDEE). The proposed methodology uses the Extended Optimal Power Flow (E-OPF) to estimate the state of the system and the Lagrange Multipliers (ML) related with the lower and upper limit of measured variable.The ML value increases when the limits of the variables are active and with it the error indexes are calculated to process gross errors in the SDEE. A case study with the modified Taiwan Power Company (TPC) 84-Buses Distribution System is used to show the main points of the proposed methodology. Ana F.P. da Costa, Edimar J. de Oliveira, Leonardo W. de Oliveira, Julio C. Stacchini de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3510 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3511 Second-order systems constitute a mathematical model class used to represent a variety of physical processes to be controlled, such as vehicle damping systems, hydraulic pump flow and robot manipulator. Due to the practical limitation inherent to physical systems (or their mathematical representation), as well as constraints on the input variables, the control under constraints became an important research field. In this context, this work aims to develop concepts and tools to control second-order linear systems, using the positive invariance property of polyhedral sets. Positive invariance has the characteristic of keeping the trajectory of the system states inside the set. This characteristic is incorporated into the analysis and design of the control law to ensure internal stability and respect of the constraints. In this work, the control of this specific system is solved by eigenstructure assignment, ensuring that the eigenvalues are in stability regions. Jaqueline Vargas, José M. Araújo, Eugênio B. Castelan, Carlos E. T. Dórea Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3511 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3512 For humans, dancing is highly associated with musicality and the rhythm of songs, which implies that dance participants need to hear the music in order to interact with each other. However, deaf or hearing impaired people (D/HH) are often excluded from this type of social interaction environment, making it even more difficult for them to live in society. Thus, it is necessary to use techniques such as an ANN to convert sound signals into others that D/HH can perceive. This technique already exists in the literature, using the Fourier transform in part of the frequency spectrum of the music as input of an ANN to determine the base step tempo of forró music, however, it was not analyzed how the variations in the network input affect its performance. Therefore, this work proposes the variation of the number of inputs and the frequency spectrum to determine the best extraction of music characteristics. With this, an extraction of audio features was defined that reduced the error by more than 20% compared to the error of the technique existing in the literature that can be used for application in a tool capable of inserting the deaf and hearing impaired in the forró dance environment, providing a better coexistence of these individuals in the local society. Hugo G. Lopes, Lucas Ferreira-Paiva, Rodolpho V. A. Neves, Leonardo B. Felix Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3512 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3513 This work presents a comprehensive analysis of a three-bus power system regarding voltage stability concerning operational limits and their influence in the region of safe operation. Specifically, this paper describes the effect of reactive power limits both in the distance to collapse and in the occurrence of saddle-node or limit-induced bifurcations. We also describe how the bifurcation surface changes with respect to reactive power limits, as well as the effect of voltage limits. The use of static analyses to assess voltage stability is supported by dynamic simulations. The studies performed for this test system can be easily extended to analyze real power systems. Lucas Sales Neves, Luís Fernando Costa Alberto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3513 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3514 Falls tend to cause physical and psychological damage, especially for people over 65 years of age. Such damage can be aggravated if they live alone and do not get help in the right time. This is one of the motivations for investigating smart devices in homes, acting as a way of monitoring some action or incident. Machine learning techniques have been applied to increase the effectiveness of these devices by looking for patterns in audio signals and in images. When using DNN (Deep Neural Networks) the success rates increase, but these solutions usually use cloud processing, which can bring a feeling of insecurity to the user. This work investigates an environment monitoring system, capable of detecting fall incidents, without invading the user's privacy, as it is based on low resolution thermal images. Some DNN models were tested to choose a model that best fits the problem, looking for architectures with few processing layers so that they can be embedded for local processing. Images from two different sensors were used, resized to the standard size of 64x64 pixels, resulting in an average accuracy of 91.66% for the bidirectional LSTM (Long short-term memory) network, and of 97.88 % using the VGG16 network. Rebeca M. Silva, Elias T. da Silva, Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3514 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3515 A Tilt-Rotor Unmanned Aerial Vehicle (UAV) is an underactuated mechanical system with highly nonlinear and coupled dynamics, that is often subjected to parametric uncertainties, unmodeled dynamics, and external disturbances. To cope with such adversities, this work proposes a robust adaptive controller capable of handling the full flight envelope of the UAV which is composed of cruise and hover flight modes. Most importantly, this work addresses the transition between hover and cruise flight and vice versa. To do so, a multi- body nonlinear dynamic model of a Quad-tiltrotor Convertible Plane (CP) Vertical Take-Off and Landing (VTOL) UAV, here called QuadCP-VTOL, is obtained using the Lagrangian formalism which takes into account nonconservative forces and torques applied by the propellers, tilting mechanisms, canards, wings, and horizontal stabilizers. Thereafter, a Linear Parameter Varying (LPV) model that covers the full flight envelope of the aircraft is derived from the nonlinear model. Accordingly to the adaptive mixing technique, several robust H∞ state feedback controllers are designed based on a parallel distribution compensation (PDC) method alongside a pole clustering technique to ensure better closed-loop performance. Results of numerical experiments conducted on a high fidelity simulator in a Hardware in the Loop (HIL) framework are presented to corroborate the efficacy of the proposed control strategy. Jonatan M. Campos, Daniel N. Cardoso, Guilherme V. Raffo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3515 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3516 Factors such as urbanization, global warming, and increased resistance of mosquitoes to insecticides have made combating the proliferation of Aedes aegypti challenging. The manual identification of outbreaks throughout mosquito traps involves financial and time-consuming resources. In this context, solutions based on audio processing and machine learning techniques for the automatic detection of mosquitoes through the tones produced during their flight have been investigated. Solutions based on deep learning have shown promising results; however, they require a large volume of data and have a high computational cost, making their wide adoption challenging, especially when it comes to audio capture and processing devices with low computational power, such as, for example, smartphones. Therefore, this work proposes a compact descriptor capable of and effective in detecting the presence of Aedes aegypti based on Mel-Frequency Cepstral Coefficients (MFCCs). The results show that the descriptor composed of 40 MFCCs combined with the XGBoost classifier can detect the presence of Aedes aegypti with values above 95% of accuracy, Kappa and F1-score. Consequently, we believe that our findings can support the implementation of a scalable and low-cost automatic Aedes aegypti detection system. Antônio Rodrigues, Eurico Júnior, Bianca Soares, Mayra Oliveira, Ricardo Rabelo, Deborah Magalhães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3516 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3517 Proportional-Integral-Derivative (PID) is one of the most used forms of control in the industry and there are several variations of its architecture. PID 2-DOF is one of them and aims to improve the rejection of disturbances of control actions more quickly. This paper presents the identification through the non-recursive least squares (LS) mathematical method of a rotational joint of a cylindrical manipulator and the application of PID and PID 2-DOF controllers. The identification of the 1st order model of the manipulator joint is performed to apply the tuning methods Ziegler/Nichols (ZN), Chien-Hrones-Reswick (CHR), Internal Model Control (IMC) and Skogestad IMC Method (SIMC) in the proposed controllers. To compare the simulation results, the following performance criteria are used: rise time (tr), settling time (ts), and overshoot. In the end, it is concluded that the tuning methods CHR and IMC obtained better results, and the PID 2-DOF controller obtained better results after fine tuning. Francisco Heleno V. Silva, Josias G. Batista, Darielson A. Souza, Alanio F. Lima, Laurinda L. N. dos Reis, Antônio B. Souza Júnior, Emerson V. A. Dias Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3517 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3518 In this paper we describe a strategy that allows the addition of active filtering functionality to a wind energy conversion system with doubly-fed induction generator connected to a distorted voltage grid. The active filtering is performed through an algorithm that uses the mathematical formulation of the instantaneous power theory to generate control references applied to the current control loop in the grid side converter. The wind energy conversion system that uses the instantaneous power theory to mitigate harmonic currents, allows to improve the quality of electrical energy in electrical systems, where non-linear loads are connected simultaneously with the generation of electricity at different points of operation. We present the active and reactive power control of the GIRB, performed through the orientation technique of the vector magnetic flux of the stator. The simulation results confirm the possibility of adding the active filtering function in GIRB wind systems using the instantaneous power theory, reducing the THD of the electric current in the grid to less than 5% with the system connected in a bus with the distorted voltage. R. R. de Souza, A. B. Moreira, T. A. S. Barros, P. J. S., Neto, M. V., de Paula, E. Ruppert, Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3518 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3519 In this paper, the control problem of solar thermal recovery plants applied in petroleum fields is studied. In these systems, we aim to maximize the solar energy captured in the collector field and the steam production in order to meet the demand of the injection wells. The proposed control system considers these objectives through a decentralized approach: (i) a PI controller with anticipatory action is used to control the temperature of the heat transfer fluid in the solar field; and (ii) two PID controllers are used to control the liquid level and outlet steam pressure of the steam generator. Simulation results with real data of solar irradiation and ambient temperature are presented to illustrate the efficiency of the proposed strategy. Letícia C. Favero, Vinícius G. Rigon, Gustavo A. de Andrade Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3519 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3520 This study presents a system for short-circuit fault diagnosis in three-phase induction motors directly connected to the grid. The methodology is based on delayed mutual information in order to extract relevant characteristics relating electrical current signals in α−β orthogonal reference system. Those data are submitted to a multilayer perceptron artificial neural network which performs the pattern classification. Tests considering several operation conditions validate the robustness and accuracy of the proposed methodology. Erick Araujo Nunes, Bruno Augusto Angélico, Alessandro Goedtel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3520 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3521 Advanced layer-based control strategies, such as LP+DMC, have a high degree of maturity with excellent results in large industrial applications. An alternative to this approach are control strategies that solve the dynamic and economic problem in a single layer, known as economic predictive control (EMPC), which has shown promising results. However, for large industrial applications, there are few comparative studies evaluating its effectiveness, compared to traditional strategies. This work presents a comparative study of an LP-DMC layered control strategy, with an EMPC controller, in an industrial application of a natural gas processing unit. Rafael Sartori, Júlio Elias Normey-Rico Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3521 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3522 This work presents a study regarding the Fault Current Values Correspondence Method (FCVCM), which uses the Smart-Meters’s ability to report the voltage sags during a short-circuit to aid the fault’s location in Distribution Systems (DSs). The studies investigate the effect of the limited precision of the measurements, the occurrence of Gross Errors, and the uncertainty associated with the load’s estimates over the FCVCM. The work also proposes to use a State Estimator for DSs with the FCVCM to enhance the method’s reliability. Furthermore, results in a 19 bus DS illustrate the improvements achieved by using this proposal. Vítor Henrique Pereira de Melo, Mário Oleskovicz, Denis V. Coury, João B. A. London Jr Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3522 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3523 This paper investigates the influence of considering the performance of different calculation of transmission line parameters on the lightning performance of line surge arresters. The lightning performance of a surge arrester installed in a typical Brazilian 138-kV transmission line is assessed, while transmission line parameters are calculated in 3 different ways namely: i) Carson formulation, ii) Nakagawa formulation considering the electrical parameters of the ground constant with the frequency, and iii) Nakagawa formulation considering the frequency- dependent characteristics of soil. Taking as reference the results determined using the Carson formulation, it is shown that the Nakagawa formulation constant and dependent with the frequency can lead to possible incorrect prevision of insulation failure in lines partially protected by lightning surge arresters. According to the results, depending on the case, maximum differences of 6.01% and 6.42% can be found, respectively. Jaimis S. L. Colqui, Rodolfo A. R. Moura, Marco Aurélio O. Schroeder, José Pissolato Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3523 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3524 Humanity is in a status of constant evolution, with emphasis on the technological areas. According to the Institute of Applied Economic Research (IPEA), in 2020 the demand for qualified professionals in the engineering areas was already estimated at 1.15 million professionals. Given the high demand for people with mastery in engineering areas, especially with practical skills, the need for an adequate education that includes both the theoretical foundations, which are essential, and the practical foundations, is visible. Therefore, this article proposes the elaboration of a didactic module for the study of several engineering areas, such as: Programming, Microcontrollers, Electric Machine Operation, Supervisory and Control Systems, besides concepts on Basic and Power Electronics. Humberto P. V. O. de Sousa, Rhuan da S. Nunes, A. Karoline G. da Silva, F. Aldinei P. Aragão, Leonardo T. Albuquerque Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3524 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3525 Bayesian Networks are a powerful tool to assess association relationships between variables on a given observed system. Despite their usage on several areas, the task of obtaining such structure exclusively from observational data is a well-documented NP-hard problem. Physarum Learner is a method to obtain a Bayesian Network from a data set, based on the foraging behaviour of the Physarum polycephalum, a member of the Myxomycetes class. However, the original method overlook crucial characteristics of this combinatorial problem. In the work here presented, we implement three changes to the Physarum Learner original algorithm and apply this improved method on three well-known benchmark data sets. Our results indicate a faster convergence point identification, while achieving good structures from a scoring standpoint. Vitor P. Ribeiro, Benvindo R. Pereira Jr., Carlos D. Maciel, José Antônio P. Balestieri Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3525 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3526 In this paper, a mixed reality environment for navigation of multiple mobile robots is proposed. The developed environment allows the integration between virtual and real elements. To identify the real elements, ARTags markers are used, which can be obstacles, targets, robots or objectives, while the virtual ones (inserted into a virtual layer) are elements that can interact with the robots, such as virtual sensors, goals, obstacles, among others, depending on the experiment to be carried out. The Robot Operating System framework is used as a communication tool between the real and virtual layers. As a result, robots with hardware constraints acquire the skill to reach and intercept a moving goal. Three experiments are presented, highlighting the capacity of the proposed tool to provide the navigation of multiple robots in the presence of static and dynamic obstacles and targets. The obtained results validate the proposed mixed reality environment as a flexible experimental tool for the navigation of multiple robots with limited hardware. Héber Renato Fadel de Morais, João Paulo Lima Silva de Almeida, Lucia Valeria Ramos de Arruda Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3526 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3527 Small diameter pipe inspection is a frequent task in the industry. The flow of materials through the pipes can generate problems, like clogs, cracks, or discontinuities that prevent or reduce its carrying capacity. Therefore, these industrial systems must always be subject to regular inspection activities. In this sense, Instituto Tecnológico Vale (ITV) proposes a robotic platform to inspect pipes over 14 inches in diameter that can visualize anomaly situations using cameras and other sensors. The robot parts are mainly low-cost materials such as 3D-printed polymers. The platform has a track locomotion mechanism, which can be adjusted to overcome diverse piping conditions. The robot software uses ROS (Robot Operating System), which helps implement autonomous features and the possibility of anomaly identification. This work presents the robotic platform, the preliminary results of the mechanical and electronic design, and the software embedded in the robot, demonstrating the feasibility of producing low-cost alternatives for inspections of industrial pipes with reduced diameters. Alexandre Magno de S Thiago Filho, Nilton Costa Pereira de S Thiago Neto, Mario César Delunardo Torres, Jacó Dias Domingues, Luiz Guilherme Dias de Barros, Héctor Azpúrua, Gustavo Pessin, Gustavo Medeiros Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3527 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3528 In the last 10 years the wind industry has developed and intensified investments in more specialized studies. Seeking to keep up with this growth, many countries have intensified the development of technologies to meet this demand, as there is a latent market in expansion and this can be measured by the increase in the dimensions of the turbines and in the generation capacity. As it develops techniques and as application tools it is a point to use techniques and techniques as well places with plenty of important resources. Direct measurements, in general, require a high cost of installation and maintenance of the towers. This problem increases in countries with an extensive territorial area, as is the case of Brazil, which would require the installation of a large number of towers for a more complete structure. This article discusses the activities analyzed for the elaboration of a power generation and telecommunication solution, in the form of a direct current. Hellen Dianne Pereira de Souza, Mayara Martins Pereira, Aline Mayara Santos Costa Costa, Shigeaki Leite de Lima, Denisson Queiroz Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3528 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3529 Inverted pendulums are an important class of underactuated systems. This paper presents a flywheel inverted pendulum (FIP) design to evaluate the performance of Swing- up and Balance control algorithms. The Swing-up algorithms evaluated are based on Energy Control strategies. The rise time and an estimation of the energy spent on this task were used as assessment metrics. Two closed loops with PID controllers were implemented to perform the Balance control of the FIP. The analyses were carried out based on the data generated from simulations and experiments. The results showed that the Maximum Energy algorithm was able to perform the swing-up with less time and lower energy consumption. Additionally, it resulted in lower errors during the execution of the Balance control, since the system conditions provided by this swing-up strategy contributed to the robustness of the system. Victor G. Cardoso, Thiago F. F. de Souza, Pedro M. G. del Foyo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3529 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3530 The Artificial Intelligence (AI) and its techniques are a broadly used field in engineering. Especially when studied in relation to renewable energy sources. Its study is important for the continuous development of the sustainable area, both in economic and social issues. Therefore, this paper aims to address the use of AI in renewable energy sources, such as solar and wind, by developing a systematic literature review. Emphasizing on the techniques used and their applications in everyday life. The main AI techniques that are highlighted in this paper are Optimization Methods, Machine Learning, and Fuzzy Logic. In each of the articles cited in this review there is at least one of these methods. In this aspect, it enabled the study in Renewable Energies, thereby highlighting its importance for the evolution of the theme proposed here. Samara Oliveira Silva Santos, André Luiz Carvalho Ottoni, Erivelton Geraldo Nepomuceno Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3530 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3531 This work proposes a null space-based controller for a formation composed by a multi-articulated robot vehicle (MARV) in backward movement and an unmanned aerial vehicle (UAV), capable of avoiding collision with ground static obstacles during navigation. The proposed formation allows the UAV to analyze the environment from a top view, adding inspection capability to the MARV. The objective is that the virtual robot representing the formation avoids ground obstacles, mimicking real applications, such as in agriculture. Besides taking care of the control of the MARV-UAV formation, the proposed system also controls the backward movement of the MARV to avoid jackknifing, the shock between the trailers or between the first trailer and the tractor, while the multi-articulated robot follows a path. In this context, the article proposes to use the null space-based behavioral control technique to a MARV-UAV formation, to manage the conflicting tasks of following a path and avoid obstacles surrounding it. Results obtained running simulations, also shown here, validate the control system proposed to guide the MARV-UAV formation. Diego Nunes Bertolani, Vinícius Pacheco Bacheti, Mário Sarcinelli-Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3531 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3532 This paper presents the execution of tests used for the comparison of three state feedback current controllers obtained from the linear quadratic regulator applied to grid- connected converters based on the control system implementation in Hardware-in-the-loop. The paper contribution is in the detailed description of three tests for the closed-loop control system validation, using a Hardware-in-the-loop to emulate the power portion of the converter, and a digital signal processor widely used in the literature for the real-time implementation of the digital control. The first test allows to conclude about the stability under variations in the grid impedance and also in real-time operation. The second test allows to conclude on the ability to tracking grid current references with phase and amplitude variations, providing a measure of the integral squared error. The third test allows to conclude on the ability to reject harmonics in the grid voltage in steady state, providing as a measure the total harmonic distortion of the grid currents and verifying the compliance of the harmonics with the limits of the IEEE 1547 Standard. The results consider grid voltage synchronization, implementation delay in the control signal, and the effect of vector modulation, presenting the grid-injected currents for each of the controllers in comparison, and the relevant metrics for the tests, indicating the feasibility of practical implementation of these controllers. Lucas C. Borin, Everson Mattos, Caio R. D. Osório, Gustavo G. Koch, Vinicius F. Montagner Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3532 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3533 In this paper, a sliding mode control using a periodic search function strategy is used to drive a robot to the origin of a stationary sound source in an industrial inspection scenario. The robotic system is composed of a mobile base equipped with a manipulator arm. A extremum- seeking controller is designed to drive the cartesian position of the manipulator to the maximum of an unknown field that represents the source of the sound emitted by a damaged roller of a belt conveyor idler. Simulation results considering the kinematic model of the robot ROSI are presented with satisfactory results. Henrique D. Faria, Fernando Lizarralde, Ramon R. Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3533 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3534 In this paper, the feedback stabilization problem of nonlinear stochastic systems driven by Wiener processes is addressed. It is shown that the existence of a stochastic control Lyapunov function that guarantees the exponential mean square stabilization of the zero solution by linear static output feedback (SOF), under certain circumstances, is equivalent to the stochastic exponential dissipativity of the plant. Quadratic supply rates are proved to be general enough to establish this equivalence. Necessary and sufficient dissipativity-based conditions for stochastic asymptotic stabilization in probability via full state feedback are also given. In general, this work extends recently published results on dissipativity-based feedback stabilization of deterministic nonlinear systems to the problem of stochastic stability analysis and control of stochastic dissipative systems, a research topic within control theory that has been attracting growing interest. An illustrative example is offered as an application of the ideas presented in the article. Diego de S. Madeira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3534 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3535 Localization of high impedance faults (HIFs) is a difficult task in power distribution systems, since the fault currents are of small magnitude, making conventional protection equipment incapable of detecting them. As a solution to the problem of locating FAIs, this work presents a method based on exhaustive search that relates system state variables with phasor measurements of network voltage and current made by PMUs (phasor measurement units). However, errors and uncertainties in the measurement data can compromise the accuracy of the data. Due to this, the algorithm that locates the approximate distance of the fault was submitted to input data with errors of different amplitudes obtained from the measurements of the PMUs and in uncertainties in the estimation of the load, in order to represent the system data with greater fidelity. The method was tested with the IEEE 34 bus system for phase-to-ground faults and proved to be robust to the influence of measurement errors. Carla F. Cavalari, João Pedro B. da Silva, Débora R. R. P. Araujo, Leandro R. Araujo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3535 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3536 In most cases, careful tuning for conventional Proportional-Integral-Derivative (PID) controllers is used to get the highest performance for the widest range of applications. However, in more complex cases, such as multiple input and multiple output (MIMO) systems, fine-tuning methods do not extract the best behavior from the system. This performance can be improved using more advanced techniques, such as Fractional Order PID (FOPID), which is based on fractional calculus. Metaheuristic optimization techniques can be used to solve the problem of optimizing a PID controller. The goal of this paper is to assess the effectiveness of FOPID when it is tweaked using metaheuristics, including the Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Harris Hawks Optimization (HHO), Marine Predators Algorithm (MPA), and Manta Ray Foraging Optimization (MRO). The ball mill pulverizing system was utilized as a test technique to evaluate tuning performance. Over 50 different runs and statistical metrics of the fitness function were applied to assess the metaheuristics’ performance. At the end of this process, it became evident that the techniques are efficient in general, and the MPA was the metaheuristic with the smallest objective function values for structured tuning in the ball mill pulverizing system, making it the most efficient technique, while both classical techniques GA and PSO were the least efficient ones. Yan Lieven Souza Lúcio, Luiza Scapinello Aquino, Viviana Cocco Mariani, Leandro dos Santos Coelho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3536 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3537 In modern power systems, transmission over long distances and offshore wind energy conversion systems increasingly use the technology of high voltage direct current transmission due to cheaper investment costs, lower power losses, and better controllability. However, effective integration of this technology drastically reduces the overall system’s inertia. This paper proposes a stability analysis of a meshed multi-terminal high voltage direct current (MTDC) system based on modular multilevel converter (MMC) with voltage margin control to connect four distinct AC grids. Simulations assessed the system performance to remain stable under abnormal operating conditions in the AC grids, such as load variations. Results suggest although a disturbance in an AC grid does not cause variations in other AC grids due to the MTDC link, it can generate variations in the DC grid. Maxwel da S. Santos, Flavio B. Costa, Luciano S. Barros, Luana C. S. Soares, Camila M. V. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3537 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3538 The world is increasingly connected through computer networks, which makes it necessary to develop techniques capable of guaranteeing the privacy and utility of the transmitted information. In this work we consider the problem of obfuscation of discrete event systems that guarantees different levels of both privacy and utility of the generated information. The system is modeled as a labeled transition system that has secret states. The first goal is to keep the information generated by the system useful so that legitimate users can use it for decision making. At the same time, the second goal is to hide critical information about the secret states of the system. However, unlike the previous approaches presented in the literature, we consider the case in which it is possible for the obfuscator to report the secret states. Thus, this approach increases the number of systems capable of being obfuscated and, since it keeps the public view of the system with the same behavior as the original system, it makes difficult to notice the presence of the obfuscator. To perform the synthesis of the obfuscator we used the software SynthSMV. João Manoel Costa Cardoso, Marcos Vicente de Brito Moreira, Lilian Kawakami Carvalho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3538 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3539 The main objective of this paper is to apply a bioinspired method, known as Twiddle algorithm, together with a numerical resolution method, to determine the equivalent resistances that compose the single diode electrical model, providing the computational simulation of photovoltaic modules. The input data has been restricted to four parameters based on manufacturer’s datasheet: maximum power voltage (Vmp), maximum power current (Imp) , short-circuit current (Isc) and open-circuit voltage (Voc). The modeling technique allows the construction of the volt-amp, I-V, and watt-volt, P-V, characteristic curves, which can be evaluated in scenarios of temperature variation as well as solar irradiation changes. To validate the results, the proposed method has been applied to the Kyocera KC200GT photovoltaic module. Data obtained from the datasheet of the module, as well as those provided by a previous known method, have been used to evaluate the performance of the method proposed here. The characteristic curves obtained showed null error at the maximum power point and discrepancies smaller than 0.1 % in the four main parameters. Elias Lopes Oliveira, Wesley Henrique Maciel, Henrique Antônio Carvalho Braga Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3539 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3540 This study investigate and test mechanical solutions of computer vision for protection of structural systems, (carbon steel), using image processing techniques to identify the appearance of the area, (carbon steel). The results obtained in validation carried out using a set of samples, prove the effectiveness of the vision system in helping to detect corrosion in carbon steel. Vinícius V. Maurente, Nicolle R. Pereira, Emanuel Estrada Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3540 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3541 In this work, connections between the areas of systems identification and deep learning are explored. A method of nonlinear systems identification is proposed based on deep neural networks and Hammerstein models. The proposed approach is formulated from the separation of the linear and non-linear parts of the models. Thus, the used network structures reflect this separation strategy and the identification is performed through the training of deep neural networks. As a reference, was adopted an identification method in which orthonormal and radial basis functions are used. In general, the proposed approach was able to provide better identification results compared to the adopted reference method. Matheus Ferreira da Silva, Péricles Rezende Barros, George Acioli Júnior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3541 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3542 This paper deals with robust control of switched affine systems with uncertain affine term, ensuring asymptotic stability of a set of pre-specified equilibrium points. In this class of switched systems, the affine term depends linearly on an uncertain vector which can be used, for instance, to model input and load variations of dc-dc power converters. The goal is to design a switching function that governs the trajectories of the closed-loop system towards an uncertain, partially unknown equilibrium point, in a framework characterized by lack of information. The control design problem is decomposed into two successive sub-problems expressed by linear matrix inequalities. An academic example with two unstable third order subsystems illustrates the theoretical results. Furthermore, the control design of a dc-dc flyback converter is used for comparison with the results available in the literature. João L. N. Brito, Grace S. Deaecto, José C. Geromel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3542 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3543 When designing a control system for an industrial process, it is desirable for it to satisfy the performance specifications, to be reliable, safe, and to have guaranteed stability. However, in the occurrence of components’ faults, such as sensors and actuators, system performance can deteriorate, resulting in loss of functionality, or even instability. Thus, it is important to design Fault Tolerant Control (FTC) systems, so that, even in the presence of faults, it is possible to guarantee the stability of the closed-loop system and ensure acceptable performance.This paper proposes a fault tolerant control approach using an adaptive hybrid PI (Proportional-Integral) controller for systems subject to actuator faults without the need to use a Fault Detection and Isolation (FDI) module. To verify the proposed methodology, computer simulations are performed considering different fault scenarios and comparisons with a classic PI and a hybrid controller without adaptation found in the literature. Orlando Vinicyus Santos Martins, Rodrigo Hiroshi Murofushi, Valter J. S. Leite, Mariella Maia Quadros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3543 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3544 In this paper, the problem of identifying dynamic modules that operate in a complex interconnect structure is discussed. This problem is presented as an extension of the classical closed-loop configuration and the goal is to consistently identify the transfer functions embedded in a dynamic network, based on the internal and external signals of the network. The objective of this paper is to provide a comparison of methods and apply them to identify modules in dynamic networks. Graph representation tools are presented to verify the network interconnection structure conditions. For a known topology, it is shown that classical prediction error methods for closed-loop identification can be generalized to provide estimates of the modulus, under certain experimental circumstances. The analysis and correction of the signals that will be used in the predictor constitute the adaptation for the case of networks and are discussed in this work. To attain that purpose, the direct method, which depends on noise models, and the two-stage method, which is independent of the noise model but depends on external excitation signals, are considered. The results show that the direct method can present bias and the two-stage method is able to reduce the variance of the parameter estimation. Therefore, the two methods presented were able to consistently estimate local modules in dynamic networks, with the two- stage method showing better indicators. The models were validated using a second set of input and output data. The results showed that the model was able to reproduce the dynamic behavior of the system with the validation data. Lucas F. M. Rodrigues, Lucas P. R. K. Ihlenfeld, Wagner F. S. Souza, Gustavo H. C. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3544 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3545 A challenge in computer vision is the aid to medical diagnosis; a standard process in these systems is the segmentation of diseases in medical images, such as computed tomography (CT) scans. Stroke stands out in several countries, being one of the leading causes of death globally. The creation of artificial intelligence systems can aid in diagnosing diseases using CT scans to segment and extract useful information. In this work, we propose a solution for the segmentation of CT images using Convolutional Neural Networks and techniques of Digital Image Processing called Geodesic Active Contour Method, aiming to improve the aid in medical diagnosis. We use Detectron2 as a neural network to perform the primary segmentation of the stroke. Then, a post-processing of the network outputs is performed using the Geodesic Active Contour method. We obtained outstanding results in segmentation with this methodology, such as accuracy reaching above 99%. Our method aims to bring a refined solution for the segmentation of medical exam images using deep learning and computer vision techniques. Calleo Belo Barroso, Alexsandro Lopes Bezerra Silveira, Julio Macedo Chaves, Luís Fabrício de Freitas Souza, Adriell Gomes Marques, Elene Firmeza Ohata, Pedro Pedrosa Rebouças Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3545 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3546 This work proposes a software tool to help plan the expansion of the primary distribution network of power distribution companies, incorporating reliability criteria. The software is based on a method that we developed to analytically assess the reliability using the information of feeders and historical data regarding occurrences of interruptions. According to this method, the data available concerning distribution systems are used to estimate reliability indices with and without expanding the network; further, the user can choose the best expansion action and assess the associated impacts as well. To demonstrate the aid in the process of decision-making for expansion planning, the software was applied to a network composed of eight distribution feeders connected to a substation. The installation and automation of normally-closed sectionalizing switches were analyzed; nevertheless, the software is flexible enough so that different types of expansion alternatives can be easily integrated. The results demonstrated that the tool is able to guide the location of installation and automation of sectionalizing switches by identifying the zones in which faults most contribute to the reliability indices. Gustavo L. Aschidamini, Gederson A. da Cruz, Lara C. de Almeida, José D. D. Garcia, Mariana Resener, Roberto C. Leborgne, Luís A. Pereira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3546 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3547 The use of electric transport is growing. This fact leads us to the implementation of new technologies related to its charging method. Currently, wireless charging, known as WPT (Wireless Power Transfer) system, is being widely studied and implemented. Thus, this work presents a bibliographic review of the main aspects and characteristics of the IPT (Inductive Power Transfer) system, that is, focusing on inductive coupling. In addition the parametrization of the coils for application in a project of 3.6 kW WPT charger operating at 85 kHz, respecting the SAE J2954 standard is presented. Finally, the inductive coupling is simulated along with the electrical circuit to validate the project methodology. Pedro Gelati Pascoal, Leonardo A. Brum Viera, Cassiano Rech, Rafael Concatto Beltrame, Vitor Cristiano Bender Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3547 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3548 Model-based predictive control (MPC) is a control design methodology based on the existence of a prediction model to solve a constraint optimal control problem with a finite receding horizon. However, in the absence of mathematical models to describe the system’s dynamical behaviour, it is necessary to use identification techniques to enable the design of predictive controllers. In this context, this work addresses the predictive control problem using an identification technique for nonlinear dynamical systems based on a non-parametric machine learning method known as Lazily Adaptive Constant Kinky Inference (LACKI). Therefore, with the prediction process being inferred from a data set describing the system input to output relations, a nonlinear predictive control strategy is presented and corroborated through a numerical example. André C. Trevas, Marcelo A. Santos, Guilherme V. Raffo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3548 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3549 This article investigates the robust stability of discrete-time uncertain linear systems with parameters belonging to intervals. Differently from the techniques available in the literature, the proposed method, formulated in terms of an iterative algorithm based on LMIs, handles the limits of the intervals as optimization variables and can be used, for example, to search for the maximum allowable variation around nominal values in order to preserve stability. Experiments involving controller fragility analysis and volume maximization of the polyhedral region centered on nominal parameters are presented to illustrate possible applications of the proposed technique. Paulo J. de Oliveira, Ricardo C. L. F. Oliveira, Pedro L. D. Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3549 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3550 The Finite Control Set Model Predictive Control (FCS-MPC) when applied for voltage control in a Boost converter presents limitations due to the non-minimum phase characteristics of this system (NMP). Therefore, setting an adequate cost function is essential for the success of the control strategy in short-time prediction horizons. In this work, the performance of the FCS- MPC applied to the Boost converter is compared among different cost-functions configurations. In a first scenario, the traditional voltage cost function is compared with two distinct proposals made by the authors: a multivariable voltage and current cost function, and a current-based function that perform indirect voltage control. In a second scenario, model corrections are made as proposed by Villarroel et al. (2019) for the delays caused by the non-minimum phase. The converter is software-simulated using Matlab/Simulink and the results obtained shows that the use of the multivariable cost function alone does not solve the optimization problem caused by the non-minimum phase characteristic. However, when the system is indirectly controlled using current control, or else when is operated with FNM corrections, the FCS-MPC demonstrated to be able to optimize the system output with low steady-state errors. Furthermore, the use of the multivariable cost function with corrections slightly improves the output voltage oscillations while maintaining a very fast transient response characteristic. Isadora N. D. S. Braga, Sílvia C. Ferreira, Bianca H. D. Kai, Camila C. Duarte, João Paulo C. Pedroso, Vinícius M. Pacheco, Daniel A. Pereira, Ricardo R. Magalhães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3550 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3551 The deployment of smart meters makes it possible to collect energy consumption readings, where it is possible to extract detailed information about individual energy usage habits. The disaggregation process composes this scenario aiming at decomposing the total energy consumption measured at the household, commercial or industrial level into the contributions of individual electrical appliances. The use of disaggregated information, on the one hand, can be used to develop predictive models capable of predicting future energy consumption behaviors; on the other hand, it can be supplied directly to customers, so that an industry’s equipment has detailed energy use. Thus, an efficient consumption optimization is expected. This article presents an innovative proposal for a cloud architecture to deal with energy disaggregation in a non-intrusive way with real industrial data, using the methods of the Combinatorial Optimization (CO) and WaveNILM literature. The performance of the methods was compared using metrics known in the literature, such as F Score, MAE and NDE. Luciana Escobar, Roosevelt Sardinha, Felipe Hollanda, Gustavo Couto, Raphael Guimarães, Eric Romani Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3551 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3552 This work presents an approach using artificial neural networks (ANN) to obtain complete P-V curves of electrical power systems subjected to contingency. The differential of this methodology is in the speed in obtaining all the P-V curves of the system, under normal operating conditions or with contingencies. The great advantage of using ANN models is that they can capture the nonlinear characteristics of the studied system to avoid iterative procedures. From the results, the ANN performed well, with mean squared error in training below the specified value. From the samples that were not part of the training, the network was able to estimate 98% of the voltage magnitude values within the established range, with residues around 10-3 and a percentage of success between the desired and obtained output of approximately 97.3%. A. Bonini Neto, C. C. de Oliveira, D. A. Alves, C. R. Minussi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3552 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3553 Generalized predictive control (GPC) has become one of the most studied and popular control approaches. The GPC control law requires the estimation of the Hessian matrix, which requires a matrix inversion procedure. However, depending on the plant model and the GPC parameters, the aforementioned procedure may be ill-conditioned: a slight variation in the parameters may generate a more significant variation in the Hessian matrix value. In that case, the noise or quantization effect reduces the GPC robustness. The process of solving ill-conditioned problems is called regularization. This paper proposes the Singular Value Decomposition (SVD) application to regularize the matrix inversion procedure used to get the Hessian matrix. SVD decomposes a matrix based on the concept of singular values. Only the most significant singular values are used in the SVD regularization technique to calculate a matrix inverse, as the smallest singular values produce ill-conditioned problems. A methodology to define the singular values used in matrix inversion is explained in this work. The proposed approach was used in a GPC- based resonant controller, using 16 bits fixed-point numbers. Simulation and experimental tests using a FPGA show that the proposed approach allows getting an accurate and robust GPC response for the tracking of sinusoidal references. Matheus Pelzl, Thyago Estrabis, Gabriel Gentil, Raymundo Cordero, Walter Suemitsu Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3553 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3554 Pulse oximetry is a non-invasive technique that allows the monitoring of physiological parameters in a very simplified way from photoplethysmographic (PPG) signals. What was possible to do only with high-cost and unwieldy biomedical equipment, has been popularized with the emergence of wearable devices. However, the way these devices are built and used directly influences the quality of the information provided to the user. PPG signals are susceptible to noise, which is largely caused by user movement during monitoring. This can cause errors in the readings and false alarms. In order to mitigate these undesirable effects, this paper proposes an algorithm called OxiTidy v.1 based on artifical neural network (ANN) capable of detecting noise in the PPG signals. These affected samples were not used to the measurements computation, instead a linear interpolation between two normal measurements of oxygen saturation (SpO2) or heart rate (HR) was performed. The algorithms proposed in this work were tested in the prototype of a Wi-Fi pulse oximeter developed at the Federal University of São Carlos (UFSCar). The results indicated that an ANN (3-3-1) based on multilayer perceptron (MLP) was able to improve SpO2 and HR estimations both at rest and in motion. OxiTidy v.1 identified the intervals where the measurements were incorrect and then interpolated new values with a good approximation to the readings performed by a pulse oximeter certified by Anvisa. Caíque Santos Lima, Rafael Vidal Aroca, André Carmona Hernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3554 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3555 Control systems with Proportional, Integral and Derivative (PID) actions are frequently used in industrial processes and in recent years techniques that simulate the implementation of optimal-adaptive controls in plants in the mining sector have been proposed as efficient tuning methods. As for the control performance embedded in Programmable Logic Controllers (PLCs), it is still under explored, which promotes the importance of discussing control implementations in PLCs. In this article, we present the simulation of a PID control system embedded in a PLC, designed in the CodeSys simulation software for application in a real plant of the operational process of unloading solids in grains by Car Dumper (CD). In the mining industry, the flow control of bulk solids in CD is done, most of the time, by varying the speed of the feeders by changing the frequency of inverters, which is manually configured with the insertion of commands in a Human Machine Interface (HMI). The use of the tuning technique of PID controllers by Internal Product is presented in order to facilitate the parameters’ configuration of the PID controller gains applied to the control of the solid flow in the unloading by CD, guaranteeing more assertiveness in the tuning process and in this way improving the speed control process of the VVs to reach the desired flow. Bianca Fontenele Lemos Veras, João Viana da Fonseca Neto, José Pinheiro de Moura Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3555 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3556 In this paper, a new design approach is proposed for state feedback robust H∞ controllers to control a DC-DC boost converter subject to state and control constraints, in the presence of parametric polytopic uncertainties. The resistances present in the inductor and in the capacitor are taken into account in the model of the converter. The results of numerical simulations demonstrate the viability of the proposed method. Luiz Carlos Cardozo Magno, Humberto Xavier Araújo, Caio dos S. Magalhães Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3556 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3557 Obtaining electrical energy from wind emerges as a solution to environmental impacts and global warming corcernments, since its environmental impact is lower when compared to other forms of energy generation. However, this new iteration presents a dynamically different behavior, making the system operation increasingly challenging. Regarding the analysis of small signal stability, it is important to identify how the increase of wind generation participation in the electrical matrix can impact on electromechanical oscillations damping ratio, which are typical of a predominantly synchronous system. For this purpose, this work evaluates the impact of increased wind penetration in the interconnected system on electromechanical oscillations from signals sampled by phasor measurement units. The Prony’s method is applied to the transient portion of the system’s response to a disturbance, allowing the assessment of the increase in wind power impact, without the need to update the mathematical model representative of the system under analysis. Simulations are performed on the 39 bus system, evaluating different load levels and wind generation participation levels. The results show that there is an increase in oscillations damping ratio as there is an increase in wind generation participation, indicating a positive impact on this interaction. André Mirandez Kernbichler, Tatiane C. da Costa Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3557 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3558 Static state estimators are still widely used for power systems monitoring and operation. This type of estimator makes use of data related only to the instant under estimation, ignoring past information. This paper proposes a measurement pre-processing method using past data and regression techniques for error detection and correction, providing improved data to static state estimators, specially under adverse situations. This approach requires no knowledge of the system dynamics, relying simply on data analysis, and is able to work with constrained datasets and high granularity. Unlike forecast aided state estimators, the proposed method operates over measurement data and does not output state variables, providing processed measurements instead. Results obtained from simulations with the 30 Bus IEEE test system indicates the proposed method can detect and correct errors in measurements, improve its accuracy and reduce effects of data losses by providing high quality pseudomeasurements. José Paulo R. Fernandes, Etiane O. P. de Carvalho, Júlio A. D. Massignan, João Bosco A. London Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3558 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3559 This article presents an application of a system for detection, isolation and identification of abnormalities and faults in an oil well simulation environment with Electric Submersible Pump (ESP) installations. The proposed method considers a linear reduced-order Unknown Input Observers (UIO) system configured in a Generalized Observer Scheme (GOS). The results were obtained from the simulation of abnormal events with component failure associated with the reservoir flow model parameter and the production choke valve that controls the column production. In both cases, plant-model mismatch scenarios were considered so as to evaluate the robustness of the proposed method, namely the response against a non-linear model and a model with noise introduction on system measurements. The proposed system proved to be capable of detecting the occurrence of abnormalities and was able to identify the abnormal modeled events. André Nascimento Vianna, Rodrigo Ribeiro Santos, Daniel D. Santana, Márcio A.F. Martins Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3559 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3560 Electric mobility is a trending topic and motivated, among other factors, by concerns about climate change. The worldwide fleet of electric vehicles (EVs) surpassed 16-million units, a 60% increase over 2020. To support this growth, a wide, robust, and sustainable charging infrastructure becomes necessary. One of the key elements to this future is the adequate deployment of charging stations (CSs) installed in places of public access. However, the planning of this infrastructure requires a balance between the capital cost (investment), the impacts on the electric grid (upgrades), and the loss of productivity by the population (longer travel times). Therefore, this paper details the development of a computational tool with integrated technic-economic holistic analyses of electric and transportation systems. By employing real- world databases, results from a case study covering the Campinas metropolitan region show that, while the capital cost increases with the number of CSs installed, the impacts on the transportation and electric grid are reduced. Consequently, the tool helps the interested CS stakeholder to identify a cost-effective solution according to his interest. José C. G. Andrade, Anderson D. Parreira, Bruno C. Souza, Bruno P. Cancian, Caio Santos, Walmir Freitas, Guilherme F. Rissi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3560 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3561 The formation control of teams of agents constitutes an important class of multiagent control systems. We combine control, graph and game theories to address a particular formation control problem – the formation tracking problem – in the context of the multiobjective noncooperative game theory. The solution concept proposed for the problem is the Pareto-Nash equilibrium, which is at the same time a Nash equilibrium (stable, self-enforcing) and, with respect to the Nash equilibrium, Pareto-optimal for each agent in the formation. A numerical example illustrates the main characteristics and contributions brought by the approach and solution concept proposed. Daniel S. Horevicz, Paulo A.V. Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3561 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3562 Brazilian HVDC transmission systems are relevant to the electricity sector due to their ability to transmit a bulck of energy over large distances. Performing equipment maintenance is the most effective way to increase the reliability of HVDCs that are critical to maintaining systemic stability. Each year, for 80 hours, each of the HVDCs in Brazil can carry out scheduled maintenance with the shutdown of the equipment that is part of the converter transmission function in the preferential period between September and November without payment of a variable portion. HVDC substations are characterized by a high number of equipment in their configuration, because of this, carrying out an optimized planning so that during the shutdown period the greatest possible amount of corrective and preventive maintenance is performed becomes a problem. In this way, the present work proposes the development of an Expert System that through the analysis of historical events and alarms of an HVDC substation, results in a simplified demonstration of the performance of the equipment to assist in the planning of the maintenance shutdown. Camila M. Andrade, João Soares Farias, Camila S. Gehrke, Fabiano Salvadori Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3562 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3563 The increased amount of monitored data allows more complex analysis and optimization techniques. As a result of the high dimensional databases, the computational cost has become a critical point. This paper proposes the application of the Principal Component Analysis (P.C.A.) to reduce high dimensional databases, applied to a hydroelectrical generation dataset, and evaluate its impacts on supervised machine learning techniques prediction. The findings of this study showed that by applying the P.C.A. the reduced dataset was able to preserve most of the data variability of original data and achieved a similar performance rate on machine learning techniques, compared to the non-reduced dataset. Gabriel de Campos, Mateus G. Santos, Pedro Paulo C. Viana, Marcelo O. Fonseca, Guilherme S. Bastos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3563 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3564 This paper presents a wind power generation system driven by a Squirrel Cage Induction Generator (SCIG), connected to the grid and which mitigates harmonics of the grid currents by means of an Active Power Filter (APF) that uses the instantaneous power (p-q) strategy. The system consists of wind turbine, gearbox, GIGE, electronic back-to-back power converter and non-linear loads. The control of the GIGE and the power delivered to the grid is carried out, in addition to performing MPPT through the method of optimal peak speed. The studied system was mathematically modeled and simulated using Matlab / Simulink software. Simulation results confirm the effectiveness of the proposed research. Ângelo Marcílio M. dos Santos, Adson Bezerra Moreira, Ricardo Parcelle Cardoso Pacífico, Nathanael Soares Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3564 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3565 The inertial response is crucial to the stable operation of the modern power systems. In this paper, an approach based on syncrophasors during ringdown and ambient operation is proposed to estimate the regional inertia. As a sub-product of the proposed procedure, the damping coefficient can be estimated. The proposed approach is based on the system identification of a ARMAX model using a selected pilot-bus, that properly reflect the frequency of the center of inertia (COI) of each region, and the power variations within at region. The approach is tested in the IEEE 68-bus system during disturbed and ambient operation. Bruno Pinheiro, Lucas Lugnani, Daniel Dotta Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3565 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3566 Vocal disorders may be present when a person’s voice fails to fulfill its basic role of communication. These disorders can be detected by the variation of perceptual parameters of the voice, such as quality, pitch, and loudness. Changes in voice parameters can be measured and classified automatically through acoustic analysis. In this study, we compare feature extraction techniques for the automatic classification of voice disorders by means of support vector machines. These techniques are based on wavelet variance, mel spectrogram, and mel frequency cepstral coefficients. The voice signals are sustained vowel “a” utterances, with neutral pitch, belonging to healthy and pathological classes, specifically nodule on the vocal folds and Reinke’s edema. These pathologies affect the vocal folds and alter acoustical parameters of voice signals. Using wavelet variance and mel spectrogram patterns the average resulting classification accuracy values were 84.4%, what was higher than the 82.2% obtained using the mel frequency cepstral coefficients. Rafael Alberto dos Santos, Paulo Rogério Scalassara, Wagner Endo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3566 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3567 The registration of 3D point clouds consists of correcting the pose of two or more partial views of objects or scenes captured in different perspectives, which finds applications in robotics and autonomous navigation. In that domain, a relevant issue involves the complexity of the alignment operation, and some methods seek to reduce it by selecting subsets of relevant points from the original clouds. In order to understand the state-of-the-art in this context, a review of the methods published between 2017 and 2021 was carried out. Eleven methods were evaluated in relation to the following questions: approach, way of selecting points of interest, type of application, technical limitations and evaluation methodology of the registration. In order to support research in this domain, the protocol adopted and the results of this evaluation were carefully documented. The review revealed that the approaches found have similar purposes, such as dense cloud alignment, recording of captures by heterogeneous sensors, merging of noisy clouds and optimization of approaches from the literature. Daniel A. C. Souza, José M. Soares, George A. P. Thé Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3567 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3568 The three-phase machine is the most used, but alternating current machines with a number of phases greater than three have advantages over three-phase machines, such as extra degrees of freedom in the drive system; increase in useful torque by effective current value; among others. Static converters used to drive the machine introduce high frequency voltage components, which find a low impedance path to ground through the stray capacitances of the machine. Among the associated problems, mechanical failures in the bearings can be mentioned; increased levels of electromagnetic emissions; among others. A reduction in these problems can be achieved by reducing the common mode voltage in the drive system, as this is the voltage that powers the parasitic circuits of the machine. Among the solutions proposed in the literature for common mode voltage reduction and eddy current circulation, one can mention the use of passive filters associated with the inverter topology and/or the use of appropriate PWM modulation strategies. In this paper a new space vector modulation PWM (SVPWM) technique is presented to reduce common mode voltage for five-phase machines. Manoel Severino de Oliveira Neto, Isaac Soares de Freitas, Paulo G. M. Leandro, Fabiano Salvadori, Gilielson Figueiredo da Paz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3568 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3569 This work addresses the daily economic optimization problem in gas-lift oil wells. The proposal uses an artificial neural network (ANN) to find the optimal solution with a lower computational cost than one produced with a phenomenological model. However, a first-principle nonlinear model of a gas-assisted oil well production system was developed to generate the experimental data. From the practical point of view, a moving horizon estimator was designed as an adequate solution for estimating hard-to-measure variables such as produced oil and gas flow rates. Thus, it was possible to train the ANN with Nonlinear Auto-regressive with Exogenous Input-type architecture. The results showed a good ANN performance in terms of prediction capability suitable to daily optimization horizon (one-step ahead) and a better computational time in the optimization problem solution compared with the standard phenomenological model. The solution approach opens possibilities for large-scale problem implementations, such as the daily optimization of the oil field production (multiple wells integrated by reservoir and manifold). Ezequias. S. Matos, Odilon S.L. Abreu, Taniel S. Franklin, Leonardo S. Souza, Márcio A. F. Martins Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3569 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3570 In this work it is proposed to improve, using the internet of things, a monitoring system based on a digital twin of a low power transformer. A new data acquisition and sending system was developed to communicate with an online database, as well as adding environmental conditions as new inputs in simulations and protection measures performed remotely. To perform the tests a sensor/actuator module was developed to send the data of ambient humidity, ambient temperature, transformer’s current and voltage. All this data was digitized, pre-processed, and forwarded to the simulator, by means of the internet of things. Thus, even though they are physically separated, they exchange information over the internet of things data that was used by the simulation’s module, in which it runs the simulation of the digital twin. In this way, thermal simulations were performed, and, from the interpretation of the results, action commands can be executed to protect the equipment from overload. To validate the results, a thermographic camera was used, measuring the temperature of the transformer in operation. Two points on the equipment were chosen for temperature analysis, one on the winding and one on the core. In the better experience, the mean absolute error between what was measured and what was calculated came 6.18% at the first point and 3.93% at the second point. The improvement of the technique to estimate the transformer temperature with the use of the internet of things, showed the feasibility of this technology with the temperature tests and the system runtime. Rodrigues L. A., Santos M, A., Rodrigues G, A, Ferreira T, V Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3570 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3571 In this paper we consider a finite horizon filtering problem for discrete-time Markov jump linear systems. We assume that only the output and the jump parameters are available to the filter and the goal is to obtain a “prediction-correction” formula which is optimal among the Markovian filters. As in the case with no jumps, we show that an optimal filter can be obtained from a set of coupled Riccati difference equations associated to the filtering problem. When there is only one mode of operation our results coincide with the traditional Kalman filter for discrete-time linear systems. Oswaldo L. V. Costa, André M. de Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3571 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3572 Applications based on Internet of Things (”Internet of Things” - IoT) devices allow consuming and monitoring data in real time and integrating different processes. This integration of data and processes is one of the main advantages of using IoT technology in Industry 4.0. The growth in the computational power of these IoT devices has enabled their use in different applications, such as the measurement of process variables by image processing. This work aims to develop an application with an IoT device, based on ESP32 with an integrated camera, to capture images from an analog manometer of a water treatment plant in a pharmaceutical industry and generate the measured pressure value. This data will be made available on the factory supervisory for real-time monitoring through the MQTT protocol. The pressure values were made available on the factory supervisory to allow the visualization of the data in real time. Gabriel Cavalheiro Francisco, Heitor Medeiros Florencio, Jefferson Doolan Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3572 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3573 One of the biggest challenges within the utilities sector is the determination of robust and low- cost methods for the massive realization of the billing of its customers. The focus of this work is the study of the LoRaWAN (Long Range Wide Area Network) protocol for the development of an advanced metering infrastructure (AMI) to perform natural gas billing for industrial customers who have a PTZ- type gas volume broker installed in their facilities. The AMI solution consists of a remote module to collect the variables of gas measurement brokers and transmit this information using LoRaWAN and an IoT platform for communication supervision and management of measurement data. Everton Camoleze de Araujo, Regis de Goes Vieira, Eduardo Paciência Godoy Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3573 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3574 The concept of autonomous microgrids has strongly increased due to the large penetration of distributed generation into the main grid, mainly photovoltaic systems. Attached to these generation units, Battery Energy Storage Systems (BESS) has been widely used to support voltage and frequency regulation since it provides a fast system response. Therefore, this microgrid configuration has extensively used a grid-forming droop control strategy in order to provide a frequency and voltage controlling interface for islanded operation mode. Although there are several studies in the literature proving that this strategy works properly, performance analyses under several load unbalances have been little addressed. This paper aims to analyze a photovoltaic/battery-based islanded microgrid architecture under the previously mentioned load scenario. The proposed work analysis has been performed through simulations using Matlab/Simulink from the modeling of all microgrid components. It was observed that in a low load power scenario, losses caused by more than 20% of unbalance degree cause BESS to not work properly, discharging instead of charging. With a high load power scenario, an unbalance degree of 45% is enough to make the system unable to control DC-Link voltage and consequently not keep AC voltage level. Pedro A. de Alcântara, Luana C. S. Soares, Lindemberg R. de Lima, Camila M. V. Barros, Luciano S. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3574 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3575 This paper describes the development of a system for myoelectric signal acquisition from a person’s forearm that also classifies finger movements from features obtained in the frequency domain. Three electromyography surface electrodes were employed, two for the signals and one for reference. They were connected to a system composed of circuits for acquisition, conditioning, digitalization, and processing of the signals. The interface with the electrodes was performed by an analog circuit based on an instrumentation amplifier in a feedback loop with the person’s body, along with a lowpass active filter composed of operational amplifiers. A commercial digital acquisition device performed the conversion from analog to digital signals. The signal processing was composed of a temporal windowing, wavelet transform decomposition, estimation of the energies and entropies of the wavelet coefficients, and classification by multilayer perceptron artificial neural networks. During the method evaluation, we tested variations of wavelet filter and time window lengths and several neural network topologies to identify the most significant parameters for signal classification. As a result, after selecting the best window and filter lengths, the tested topologies presented accuracy rates between 73% and 83% for the classification of the five types of finger movements. Ayrton Correia Guedes, Paulo Rogério Scalassara, Wagner Endo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3575 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3576 In production systems, the assembly line is widely used to manufacture products that have a set of repetitive activities and well-defined sequences. The efficiency of the assembly lines impacts the entire manufacturing process, and the optimization of resources is essential in this context. Balancing the distribution of activities to be performed by the workstations is still a design challenge, especially in the operation of mixed-product assembly lines. The difficulty occurs due to the large variation between the times of the activities of the various types of products, and short-term changes in the sequencing of these products. This paper proposes a balancing system that considers the effects of product sequencing on resource utilization, and that is based on the determination of specific sets of sequenced activities for each type of product and operator, implementing greater flexibility in workstations. This system uses balancing strategies through the application of precedence diagram and heuristic algorithm of positional weights. The modeling and simulation performed using the Colored Petri Net. To illustrate the main characteristics of this approach, a case study is presented which has as research object a truck assembly line in operation in Brazil. The simulation results indicate that it is possible: reduce the dependency on product sequencing; meet cycle time requirements; reduce by 12.5% the resources with acceptable average occupancy; and define a system for use by assembly line managers. Eduardo Bertti, Percy Javier Igei Kaneshiro, Osvaldo Luis Asato, Francisco Yastami Nakamoto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3576 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3577 Distributed Generation, Energy Storage Systems, Energy Efficiency and Demand Side Management technologies constitute Distributed Energy Resources. With the increasing pres- ence of Distributed Energy Resources technologies within Distribution Systems, management becomes necessary so that costs are minimized and system constraints are maintained. The present work presents the management problem in MicroGrids, which is solved through three different programming techniques, namely: a Non-Linear Programming model, a Linear Pro- gramming model and a Decomposed Linear Programming model. The objective is to minimize the operating costs of a MicroGrid taking into account the costs of distributed generation, the operation of controllable loads, storage systems and the purchase of energy from the main grid, considering the operating constraints of the microgrid. The Non-Linear Programming and Linear Programming models were solved via MATLAB using the fmincon and linprog functions, respectively. The Decomposed Linear Programming model was solved via Script in MATLAB, using the Danzig Wolfe decomposition technique together with the linprog function. The models were tested on a 6 bus system and the results show that the solutions of the three models are similar to each other for operation in connected mode. K. A. Falçoni, J. C. Galvis Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3577 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3578 The pandemic scenario of COVID-19 has demonstrated the importance of investments in the areas of medical research to help minimize the effects of this epidemiological crisis. Thus, some of the important items in facing the pandemic are the medical equipment for life support, where most of them are still totally dependent on electricity for their operation. In this paper, we demonstrate the evolution of an Automatic Ambu Accelerator (AAA) that uses a hybrid power system, composed of an electrical and pneumatic system, with the objective of helping the respiratory support in moments of emergency through the monitoring of pressure, heart rate, oxygen saturation (O2) in the blood and capture of carbon dioxide (CO2) concentration exhaled in the Ambu by the patient. In this way, the study shows results since the calibration of the sensors, the corrections of parts in the pneumatic system for better functioning, and even the reduction of filament consumption in the 3D printing of new housings for the sensors. Thus, showing the evolution of the robust and safe product for front-line implementation in new outbreaks. Lucas H. B. Santos, Lucas R. Morais, Jhennifer F. dos Santos, Vitor B. dos Santos, Rodrigo L. Carvalho, Antonio R. M. de Sousa, Wellington S. Fonseca, Marcelo O. e Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3578 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3579 This paper investigates the influence of the inclination angle (in relation to the vertical axis) on the harmonic grounding impedance (HGI) of four arrangements of rods and on the performance of the Ground Potential Rise (GPR) generated on those electrodes subjected to a lightning strike. A full-wave electromagnetic software FEKO using Method of Moments (MoM) is utilized for the analysis where the soil parameters (resistivity and relative permittivity) are modeled using the recommended formulas in the CIGRÈ WG. C4.33 (2019). The analysis is carried out for three soils with low-frequency resistivities (ρ0) of 100, 500 and 1,000 Ωm where the HGI is computed for a frequency range of 100 Hz to 10 MHz assuming the inclination angles of 0◦, 15◦, 30◦, 45◦ and 60◦. The transient GPR is assessed for a 1 A-0.25/100 µs lightning current. Results demonstrated that a significant reduction of the HGI is obtained when the inclination angle increases for a certain electrode arrangement. As a consequence, the transient GPR waveforms present significant mitigation for each grounding system which can be obtained only by setting distinct topology and inclination of the rods. Walter Luiz Manzi de Azevedo, José Luciano Aslan D’Annibale, Anderson Ricardo Justo de Araújo, Jaimis Sajid Leon Colqui, José Pissolato Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3579 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3580 With technological evolution, industry 4.0, and digital transformation, process simulation has become an indispensable resource nowadays. The simulation helps in the planning process of industrial plants, as well as in the academic learning of Process Control, allowing to apply the theory learned. This work aims to develop a basic library that simulates a level control plant using Node-RED as a practical laboratory, available as a platform integrated with a simple SCADA system running in the cloud, without allocation of a computing resource on the user side computer. It enables a realistic experience for students in control process class with satisfactory results and without any complex resources or significant costs to use the environment. All stages of development are presented, as well as a validation confirming that it is perfectly possible to use Node-RED to simulate small industrial plants, obtaining satisfactory results. Therefore, it is possible to use it as a didactic platform for Process Control learning, allocating e configuring compute resources and applications on demand. Ricardo L. Mariz, Rafael Emerick Z. de Oliveira, Saul da S. Munareto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3580 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3581 Traffic accidents involving the transport of ornamental stones are largely due to non-compliance with legislation. In addition, there is little inspection, which contributes to an increase in disobedience. However, recently, there has been a great advance in the field of computer vision, especially in the area of semantic analysis of objects. In this sense, this work proposes an alternative approach to the inspection of truck loading carrying ornamental stones. The approach involves a pipeline of 3D reconstruction from images, a semantic segmentation network, and a cuboid fitting algorithm. To reduce processing time, a keyframe selector algorithm is proposed. The presented pipeline has shown practical potential, although changes are still needed to bring it closer to a real-time operation. Nicolas G. Cavalcante, Clebeson Canuto, Raquel F. Vassallo, Daniel L. Cosmo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3581 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3582 The use of Switched Reluctance Machine (SRM) has increased in many applications due to its prominent advantages and the development of semiconductors and microcontrollers. The SRM control is especially complex because of its nonlinear nature and parameter variability according to the operation point. This work proposes the utilization of a Linear Quadratic Regulator for SRM speed control. LQR is an optimal control technique that provides good dynamic response and robustness to disturbances and changing parameters. The LQR design procedure for the application is detailed. The proposed controller was compared with other well-known SRM controllers, the Proportional Integral (PI) and the Hysteresis controller (HI). The simulation results demonstrated that LQR provided a compatible dynamic response, better robustness, lower torque ripple, better switching spectral frequency distribution, and less computational burden for implementation. Paulo R. M. Costa, Marcelo V. de Paula, Tárcio A. d. S. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3582 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3583 Service Desk systems have a rich information base made up of the history of calls made, which can and should be used as a reference base for subsequent calls. Standard search tools, such as keyword searches, prove to be unfeasible for searching large databases, due to the long query time and the return of results unrelated to the problem. This work aims to investigate the ability of some classical classification algorithms to find the characteristic defined here as “relevance”: the characteristic of texts with some knowledge that can be reused. The motivation is that non-relevant texts can be removed early from the dataset, allowing complex algorithms to be employed on a smaller amount of information. In the tests performed, the Naive-Bayes, Adaptive Boosting, Random Forest, Stochastic Gradient Descent, Logistic Regression, Support Vector Machine, and Light Gradient Boosting Machine classifiers were used. The classifiers showed accuracy below 0.8, indicating that, in this scenario, other more efficient approaches should be used. Marciel Mario Degasperi, Daniel Cruz Cavalieri, Fidelis Zanetti de Castro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3583 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3584 More than a third of the US population engaged in running in 2018, and the rate of lesions in inexperienced runners is higher than 80%. Often, the diagnosis of lesions in the lower limb require extensive evaluations, including gait analysis. Such analysis look for differences in pathological and normal gait, and are often conduced by health professionals which monitor myoelectric impulses and the kinematic. Yet both EMG and Kinematic are related, many challenges surround the full comprehension of this coupling. Information theoretic measures are known for discovering the dependency between variables, and have already been used for the analysis of muscle synergy and on EEG signals. This work contains a case study of the usage of Delayed and Conditional Mutual Information on healthy individuals and patellofemoral pain patients, and presents some differences found in the muscle activation patterns between both groups. Vitor Bruno de Oliveira Barth, Jordão Natal de Oliveira Junior, Victor Hugo Batista Tsukahara, Fábio Viadanna Serrão, Ana Flávia dos Santos, Carlos Dias Maciel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3584 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3585 The majority of mechanical components went through a machining process during their manufacturing. Therefore, manufacturing processes with inadequate condition tools are likely to induce unexpected operational interruptions, accidents, product quality, and economic losses. Accordingly, the ability to classify fault imminences can result in cost reduction, along with productivity and safety increase. This paper aims to discuss an autonomous model based on the Self-Organised Direction Aware Data Partitioning Algorithm (SODA) and machine learning techniques, including time series Feature Extraction based on Scalable Hypothesis tests (TSFRESH), to solve this problem. The model proposed in this work can identify the patterns that distinguish the cutting tool’s flank wear in a multi-class scenario as adequate, intermediate, and inadequate conditions, achieving satisfactory performances in all cases and allowing to prevent fault occurrences. Thiago E. Fernandes, Matheus A. M. Ferreira, Guilherme P. C. de Miranda, Marcos V. G. R. da Silva, Eduardo P. de Aguiar Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3585 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3586 This paper addresses the state-feedback control problem for state-polynomial discrete- time linear parameter varying systems. The sum of squares formulation is employed to write the conditions. Two approaches are presented, the first one makes use of the Lyapunov function to recover the gain matrices, providing state-feedback gains which may be rational in the time- varying parameter, and linear in the state variables. The second formulation allows the design of rational state-feedback control gains concerning both the time-varying parameter and the state variables. Numerical experiments borrowed from the literature are employed to illustrate the efficacy of the proposed method. Márcio J. Lacerda, Gabriel O. Ferreira, Valter J. S. Leite Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3586 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3587 Robotics was introduced in the world with the objective of automating industrial processes, that is, facilitating human work, and with this new algorithms have been emerging to increasingly improve the use of robots in an autonomous way. This paper compares the Probabilistic Road-map (PRM) and PRM-Fuzzy applied for a SCARA manipulator (Selective Compliance Assembly Robot Arm). The PRM-Fuzzy algorithm is used to optimize the path generated by the PRM, as it makes the path smoother and shorter. Are used in collision avoidance path planning and is compared by computational cost (processing time), multiple correlation coefficient, (R2), the mechanical energy consumption of the motors, and the shortest collision avoidance paths. The results show the trajectories generated by the algorithms in the Cartesian space and also the trajectories of each joint of the manipulator, calculated from the inverse kinematics. Velocities, accelerations, and torques for trajectories are also shown. Several scenarios with different obstacles were used and in all cases, the PRM-Fuzzy algorithm performed better than the conventional PRM for the comparisons performed. Emerson V. A. Dias, Josias G. Batista, Catarina G. B. P. Silva, Geraldo L. B. Ramalho, Darielson A. Souza, José Leonardo N. Silva, André P. Moreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3587 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3588 The advancement of Internet of Things (IoT) applications in the context of low-power long-distance networks today is notorious. However, some weaknesses also appeared, such as the security of the transmitted data, bandwidth and battery life of the devices. This work presents an evaluation of optimized Tiny Machine Learning (TinyML) models. The benefits of having an optimized algorithm in a sensor device are evaluated, where the data inference is performed locally. The performance of each of the techniques will be evaluated, as well as the reduction capacity they promote. A case study is presented in a LoRa network, where a dataset is used to evaluate the energy performance of the model. The result was an approximate 6x drop in power consumption in the edge anomaly detection. Leomar Mateus Radke, Max Feldman, Ivan Müller Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3588 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3589 The safety and stability of freight train operations are closely related to the wheel–rail contact dynamic forces. To evaluate and monitor wheel-rail dynamic forces based on the accelerations of the wagon components, a methodology based on data processing and machine learning methods was developed. The experimental results show adequate performance, identifying critical values that relate to the condition of the railway. The model obtained helps railway specialists in the assessment of the quality of the railway, showing georeferenced indicators. Pedro H. O. Silva, Raphael D. Marotta, Augusto S. Cerqueira, Erivelton G. Nepomuceno, Luiz A. S. Lopes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3589 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3590 This paper proposes a new approach for generating smooth trajectories for unmanned aerial vehicles (UAVs or drones) that can be executed in real time with limited processing embedded hardware. The objective is to perform autonomous aerial image acquisition, ensuring repeatability. In addition, a state feedback control law based on previously identified commercial hexacopter nominal parameters, with integral and feedforward actions was implemented and validated for trajectory tracking in the presence of wind disturbances, in a real and simulated environment. Wenderson Gustavo Serrantola, Fernando Lizarralde, Alessandro Jacoud Peixoto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3590 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3591 In Brazil, fish farming in recent years has developed intensely, having as a virtue the increase in production and the professionalization of the sector. For this, it is necessary to study technological developments to monitor water quality to reduce losses in the sector. The general objective of this work is to build a prototype of a system to monitor water quality and act on commercial aerators in fish farming, aiming to provide fish farmers with information on how the water quality is for the production of fish on their properties. A prototype was developed and validated. Marcelo D. S. Malmeto, Leandro Chies, Marcos Virgílio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3591 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3592 The present study emphasizes the synthesis of Linear Quadratic Regulators (LQR) applied to linear systems with norm-bounded uncertainty models. Therefore, the main objective is to establish new LMIs conditions, in order to guarantee the robust D -stability such that the transient response is achieved through classical LMIs restrictions. The mathematical analysis is based on the control design (by states feedback) of the power system stabilizer and the flexible AC transmission systems (FACTS) controllers, on what these devices are able to operate under actuators faults. Finally, comparative analyzes with the literature will be based on regions of feasibility, practical applicability and transient response of interest signals. Renan J. de Carvalho, Rodrigo P. Caun, Edvaldo Assunção, Marcelo C. M. Teixeira, Willian R. B. M. Nunes, Reginaldo N. de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3592 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3593 The knee is a very complex joint, extremely important for the movement of the lower limbs, so the rehabilitation of its functions after trauma or stroke is essential. Flexion-extension movements are largely used in the rehabilitation exercises. In this work we used OpenSim Moco to carry out predictive simulations to study some trajectories about this type of movement, as well as determine the best one to be used in rehabilitation exercises, improving the range of motion and reducing muscular fatigue. We have successfully achieved an optimal trajectory that can be used in knee rehabilitation therapies without the need for drastic changes in exercise. Denis Mosconi, Melkzedekue Moreira, Adriano A. G. Siqueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3593 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3594 The management of distributed energy resources has gained special attention in the field of research with the aim of exploiting the capacity of these resources to the maximum, where many expect from the correct management the solution to the problems of intermittence and increase participation of renewable energy sources. This work presents a management system for electric vehicle charging stations in the presence of distributed energy resources. In this context, uncertainties related to scheduled charges and the service of unscheduled charges are met by an algorithm that seeks to carry out the operation of the charging station in real-time. Furthermore, the ability of the proposed management system to meet the demand response signaling imposed by the distribution system operator is evaluated. Aérton MEDEIROS, Luciane CANHA, Vinícius GARCIA, Juliano MOREIRA, Rodrigo MOTTA, Rodrigo DOS SANTOS Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3594 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3595 Due to the predominance of hydro generation in the National Interconnected System (SIN), the operational policy based on the non-linear deterministic approach for medium-term operation planning may present storable spills in conditions of excess water resources. This article introduces a penalty procedure that prevents storable spillage in these situations. A case study with the SIN illustrates the observed problem and the effectiveness of the penalty procedure for its solution. Marcus Felipy Glatz Rodrigues, Secundino Soares, Thayze D’Martin Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3595 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3596 This article presents the use of three dynamic similarity metrics: Dynamic Time Warping (DTW), Edit Distance on Real signal (EDR) and Time Warp Edit Distance (TWED) for detection of disturbances (novelties) in Electric Power Quality (EPQ) signals. DTW, EDR and TWED are mathematical tools for comparing two vectors, generating a measure of similarity between them. The detection of novelties happens by comparing a reference frame (vector) with the frame being analyzed. If the distance between the two frames exceeds a threshold value, a novelty is detected. To assess the quality of the proposed methods, the detection probability and the false alarm probability are determined, using the ROC (Receiver Operating Characteristic) curve. The tests are performed in a Matlab® environment. The three metrics showed a good performance in detecting novelty of signals, mainly TWED for signals with SNR = 60 dB and EDR for signals with SNR = 30 dB, attesting to the importance of applicability in detecting disturbances present in Electric Power Systems (EPS). Paulo Victor Lopes Pires, Eder Barboza Kapisch, Leandro Rodrigues Manso Silva, Carlos Augusto Duque, Paulo Fernando Ribeiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3596 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3597 This work presents the design and implementation of an autonomous classifier that scores the quality of wire rod coil formation based on the irregularity of the coil formation on the roller table. Digital processing techniques were applied to grab images of the coil former/roller table. In the classifier design were consider regions of interest, in which attributes were extracted and labels were created. The scores estimated by the designed classifier are in consonance with the scores assigned by an expert in wire rod coils formation process. Thus, the classifier can be used to assist operational decision making related to changes in process parameters, such as formation speed, in order to increase the coils uniformity on the roller table, which can minimizes possible material losses and increases the production and the quality of the final product. Edgar Campos Furtado, Leonardo Adolpho Rodrigues da Silva, Celso Vidal Brito Filho, Jose Antonio Toledo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3597 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3598 The Quantile Graph (QG) method proved to be a promising technique for mapping time series into complex networks, due to the fact that, not only it made possible to use network statistics to characterize time series and time series statistics to characterize networks, but also it is a method with low computational cost, and it is simple to implement. However, in many cases, there is a possibility in which there is some sort of uncertainty in the time series, which implies in some adaptations of the QG method. Based on this matter, the goal of this paper is to analyze the consequences caused by the uncertainties which are present in the time series and to define the impact of these changes in the topology and behavior of the constructed network. Uncertainty is considered by changing the threshold of the quantiles and using Monte Carlo simulation. The results express the network’s metrics values for a time series with different values of uncertainty, mapped using the proposed method. Network’s metrics are compared with no-uncertainty QG scenario. The main results found are that the proposed method is able to express the changes in the constructed network caused by different types of uncertainties. Jonathan G. Ribeiro, Erivelton G. Nepomuceno, Andriana S. L. O. Campanharo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3598 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3599 Boats and ships have always been used throughout history as one of the main types of transportation. In recent years, due to the fast evolution of deep learning techniques and online datasets available, convolutional neural networks (CNN) have been widely used for ship and boat detection applications, such as surveillance of marine resources, helping in maritime rescue, monitoring illegal marine activities, among others. In this paper, we present a robust and efficient CNN-based on state-of-the-art YOLO model to perform boat and other water vehicles detection. The training dataset was built considering boats of different sizes, located on the coast and sea and taken with drones and satellites. We also applied data augmentation techniques such as flipping, cropping and changing brightness to increase the number of samples and improve the model robustness. A case study is presented considering a multi Unmanned Aerial Vehicles (UAV) to detect boats in a Coral Reefs Environmental Protection Area (APARC), where human activity is limited. We evaluated the developed system considering a testing dataset with images of the case study, achieving a recognition rate of 87,2% and a mean average precision of 97,23%. Vitor G. Santos, Diego S. Pereira, Luis B. P. Nascimento, Pablo J. Alsina Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3599 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3600 This paper aims to adapt the structure and design procedures of a power system stabilizer (PSS) to the context of the use of DC-DC converters to mitigate the oscillations due to connection of constant power loads (CPL). In this sense, a buck converter with voltage previously regulated by a controller is considered and based on the power variations gain and phase contributions cause in the system, the active auxiliary loop design is carried out to mitigate these effects. Furthermore, by modifying the structure of this loop, the performance and stability of the system are evaluated. Isaías V. de Bessa, Renan L. P. de Medeiros, Iury Bessa, Marenice M. de Carvalho, Florindo A. C. Ayres Jr., João E. C. Filho, Vicente F. L. Jr Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3600 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3601 This paper presents a design methodology for obtaining a robust proportional- integral-derivative (PID) multivariable controller for second-order linear systems with time- varying delay, guaranteeing a pre-established exponential decay rate. Relevant control challenges such as stabilization, modeling error and constant reference tracking are addressed within the proposed Linear Matrix Inequality (LMI) design approach. The design strategy is derived from a transformation that can be applied to obtain constant reference tracking for an actuated subspace of underacted systems. Furthermore, the integral action has an additional objective which is to increase the degree of design. Simulation case studies are used to highlight the benefits of the proposed results. Danielle S. Gontijo, Fernando O. Souza, José M. Araújo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3601 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3602 Navigation by autonomous robots is an application of robotics that can revolutionize society. In situations where the map of the space to be navigated is known, some probabilistic and iterative algorithms can be used to generate paths. Rapidly-exploring random tree algorithms are effective even for robots with multiple degrees of freedom. This article uses and compares two rapidly-exploring random tree algorithms for path generation. Following these paths is performed by a non-linear predictive controller. The results indicate that it is possible to plan and execute a route, using the proposed methods, that takes an autonomous vehicle from the initial to the final position, avoiding any obstacles along the way. João Pedro B. Ferreira, Renan P. Vieira, Téo C. Revoredo, IEEE Member Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3602 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3603 In this article methodologies and implementations are investigated into the SIMO converter, with focus on systems with two outputs using centralized control strategies. The control system is based in Parametric Robust Control and LQR techniques, using states feedback for output regulation purposes. To obtain the dynamics of the plant in the desire point it is accomplished the phenomenological study for the circuit through the current inductor curve. The simulations of the controllers and the circuit were done using toolbox Matlab/Simulink. The results and the discussions are submitted in the response graphics using performance integral index tables related with the error signal and the effort of the control system. Carlos Roozembergh Jr, Alvaro Christian Monano Saavedra, Walter Barra Jr, Renan Landau Paiva de Medeiros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3603 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3604 Depth sensing is essential to many robotic tasks, with mapping, localization and obstacle avoidance. In small robotic platforms, weight, volume and energy consumption limitations motivate the use of depth estimation using a monocular camera instead of depth sensors. This paper propose an approach for localization of autonomous mobile robots in an indoor environment using monocular vision aided by depth estimation maps from a single RGB input image applied to the concept of Transfer Learning linked to Convolutional Neural Networks (CNNs). The performance of classifiers in estimate the location was observed and compared using of a unique configuration of RGB-D images transformed into a mosaic image. The images were combined with the descriptive power of CNNs in the following scenarios: depth captured by the Kinect sensor and depth estimation generated by the AdaBins block. With the results, the performances of the classifiers were analyzed to evaluate the proposed approach. F. Geilson de L. Xavier, Suane Pires P. da Silva, J. Jerovane da C. Nascimento, Pedro Pedrosa R. Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3604 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3605 This work presents a hybrid optimization method between classical and meta-heuristic optimization to solve the Transmission network expansion planning and static and stochastic growth, considering the uncertain market characteristics, with wind generation and required expansion. Considering the planning inserted in a market environment, where the model of producers and consumers is negotiated, the electric energy through a pool-hour auction. The impact of limiting the annual investment cost is investigated, considering different auction scenarios. The study system is the 24-bus IEEE-RTS. The results of the transmission network show an investment in the expansion of the best environment for the delivery of distribution, in addition to the importance of considering variations in intermittent energy sources and demands, in addition to intermittent energy sources and demands, of growth scenarios. Lucas S. Nepomuceno, Edimar J. de Oliveira, Arthur N. de Paula, Monique R. da Costa, Leonardo W. Oliveira, Edmarcio A. Belati Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3605 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3606 This paper presents the estimation of the rotor position of a switched reluctance machine - SRM 6/4 with external rotor, operating at high speed (up to 50 krpm), in a Kinetic Energy Storage System (SAEC) - flywheel. The rotor position can be estimated using the phase current and flux linkage relationship, and rule bases based on the SRM magnetization curve. The SAEC is implemented in Matlab/Simulink and its control is performed in the Texas Instruments DSP (Digital signal processor), Delfino F28379D, using the Processor-in-the-loop (PIL) simulation technique. The simulation results are presented to show how the developed sensorless scheme works. Implementations are analyzed and optimized to be able to run on a real system using the same microprocessor model. Janito dos Santos Ramos, Luís Guilherme Barbosa Rolim Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3606 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3607 This work presents an augmented state-space model for decoupling model predictive controllers. The proposed model ensures a decoupled response from the reference to the output in the absence of active constraints. This kind of decoupled response is not usually achieved in closed-loop systems with model predictive controllers due to the decoupling cost. In comparison to similar works, the proposed approach guarantees closed-loop stability by using the standard constrained stabilizing ingredients. Hence, the proposed model is general, such that it can be combined with multiple stabilizing model predictive control strategies and multiple decoupling strategies. The conditions to ensure a decoupled response are discussed and a simulation example is presented to illustrate the benefits of the proposed strategy. Rodrigo Galvão de Souza Câmara, Tito Luís Maia Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3607 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3608 Weather forecasting is essential in the renewable energy sector, and it is indispensable to use climate information such as air humidity, atmospheric pressure, temperature, wind speed and solar irradiation, which can be considered variables for forecasts in a certain region. In particular, there is a notable potential for the use of photovoltaic solar energy in the Brazilian Northeast due to the high solar irradiation levels in the region and, from the climatic time series, it is possible to train deep learning models that seek to predict it at short and long term. This work aims to statistically analyze and predict a time series of total daily solar irradiation in the municipality of Quixeramobim, Ceará, through machine learning methods. The results obtained indicate that the models predict solar irradiance with low prediction error when compared to existing results in the literature. Raul Victor de O. Paiva, Tarcisio F. Maciel, Wilker de O. Feitosa, Nícolas de A. Moreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3608 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3609 Microgrids based on photovoltaic array supplying do not have capacity to compensate imbalances between generation and load demand, which can occur in islanded operation and cause voltage and frequency deviations. Therefore, battery energy storage systems are inserted to help in microgrid regulation. Grid-forming droop control is applied for PV/battery hybrid units to be capable of controlling voltage and frequency in the islanded mode of the microgrid. The objective of this article is to present a performance analysis of this control, considering several load levels in microgrid including the ones when battery energy storage systems state of charge limits are reached, what is followed by its turning off. For this purpose, simulations were conducted in the MATLAB/Simulink environment using a simplified low voltage system. The results point out to the effectiveness of the control when the battery is connected to the system despite load changes, regulating voltage and frequency levels. However, with the battery disconnection, the control is no longer able to regulate microgrid operation. Luana C. S. Soares, Pedro A. de Alcântara, Lindemberg R. de Lima, Camila M. V. Barros, Luciano S. Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3609 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3610 This paper presents a methodology for the design of multiple resonant controllers to the voltage regulation in uninterruptible power supplies (UPSs) operating in parallel. First, a state space representation of the interconnected system operating with decentralized controllers is obtained, based only on local measurements. Conditions are proposed in the form of linear matrix inequalities (LMIs) that guarantee the robust stability of the system given the insertion/removal of new sources or load variations. The synthesis of the controllers is based on the solution of a convex optimization problem directly related to the RMS value of the circulating current between the UPSs. Simulations considering the parallelism of two 3.5 kVA UPSs via droop control are presented to illustrate the proposed method. Guilherme Keiel, Jeferson V. Flores, Luís Fernando A. Pereira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3610 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3611 This paper presents the combination of a stability criterion for systems with time- varying delay and an unconstrained MPC for linear systems with future reference. The future reference knowledge is useful in some applications as the current control action is defined by taking into account a future prediction error. However, this kind of solution is typically achieved with MPC controllers based on optimization based solutions. In this work, the unconstrained solution of a linear MPC is obtained and analyzed to deal with systems with time-varying delay. An illustration case study is presented to illustrate the usefulness of the proposed analysis approach. Mateus dos S. Meneses, Bruno S. S. Pereira, Lucas C. da Silva, Tito L. M. Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3611 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3612 The use of battery-powered devices is restricted to the energy available in the battery. Therefore, it is important to have comprehensive mathematical models that can predict the state of charge of a battery. In order to develop and especially validate these models, real data regarding long duration tests of these batteries are needed. In this paper, the development of a battery testing platform (i.e., Testbed ) is presented, as well as a methodology for perform long duration controlled tests in order to automate the charging and discharging process. The platform and methodology are validated through a series of tests with Li-Po batteries. The results of these tests are presented and analyzed and it is possible to verify the efficiency of both the Testbed and the methodology presented for the development and analysis of tests using Li-Po batteries. Gustavo Eckhardt, Douglas F. Copetti, Leonardo A. B. Viera, Gustavo T. Machado, Paulo S. Sausen, Maurício de Campos, Airam T. Z. R. Sausen, Fabiano Salvadori Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3612 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3613 Studies carried out in real plants show that repeated and/or intermittent failures frequently occur during the operation of a system. When it comes to diagnosing the occurrence of repeated faults, the problem becomes one of determining the number of occurrences of the fault, i.e., for a given κ ∈ Z∗ , ensure from observation of events that the failure has occurred at least κ times. In this work, the problem of diagnosability of repeated failures will be revisited, and algorithms for diagnosability checking-κ based both in the construction of test automata and in the construction of verifiers will be proposed and, based on these automata, necessary and sufficient conditions for the κ-diagnosability will be presented. Guilherme M. O. Silva, João C. Basilio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3613 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3614 In this work, two control structures for the current loop applied to a VSI (Voltage Source Inverter ) connected to the network are presented. For the tuning of the controllers, the transfer function of the filter-network system was developed in an analytical way, considering all the dynamics of the system, in order to obtain the models in coordinates αβ and dq. With the system model in coordinates αβ, the PR controller was tuned and for dq the multivariable PI controller. Finally, the performance of both structures was compared, highlighting the multivariable PI controller, in terms of stability and decoupling of the reference axes. Renato Santana Ribeiro Junior, Eubis Pereira Machado, Damásio Fernandes Júnior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3614 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3615 This paper deals with the problem of robust output regulation of planar two degrees of freedom robotic manipulators. An internal model controller is synthesized by a systematic framework that considers polynomial mappings of the steady-state trajectory. The closed- loop stabilization is guaranteed by using a descriptor differential-algebraic representation of the system. This methodology allows the controller design problem to be cast as a convex optimization problem subject to linear matrix inequalities. Eduardo S. Saraiva, Aurélio T. Salton, Jeferson V. Flores, Rafael S. Castro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3615 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3616 Even with the exponential increase in the number of electric and hybrid vehicles in Brazil and in the world, it is expected that the propulsion technology based on internal combustion engines will still prevail until the year 2050. The current automobile scenario is facing ambitious goals of reducing emissions and improving energy efficiency. Several technologies have been applied to increase the efficiency and reduce polluting gases of internal combustion engines. The advantages of using these technologies are even more attractive in Brazil with the presence of sugarcane ethanol, which has a practically neutral carbon balance. However, technologies to make internal combustion engines more efficient and increased electronic content in modern vehicles make it necessary to have greater electrical energy availability in vehicles. The main objective of this work is the construction of a switched-flow in-wheel electric machine to increase the availability of electric energy in a light passenger vehicle and, consequently, improve the overall efficiency of the system. Diogo Pereira Vilela Galo, Gabriel Alves Mendonça, Thales Alexandre Carvalho Maia, Braz de Jesus Cardoso Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3616 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3617 This paper presents a computational approach for interval type-2 fuzzy evolving Kalman filters desingnig from experimental data. First, an initial parametric estimation of interval type-2 evolving fuzzy Kalman filter model is obtained considering an initial window of the experimental data. From this initial estimation, the parameters defined in the antecedent and consequent propositions of interval type-2 evolving fuzzy Kalman filter are updated recursively from each new sample of the dataset through a type-2 fuzzy version of evolving Takagi-Sugeno (eTS) clustering algorithm and a type-2 fuzzy version of Observer/Kalman Filter Identification (OKID) algorithm, respectively. Computational results and comparative analysis demonstrate the efficiency and applicability of the proposed methodology when applied to Mackey–Glass chaotic time series modeling. Daiana Caroline dos Santos Gomes, Ginalber Luiz de Oliveira Serra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3617 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3618 Monitoring the motor performance in the industry is important to ensure that energy is efficiently used. Thus, the search for more efficient systems has driven the development of new technologies and electrical machine drive topologies. In this context, the configuration of the Open-End Winding Induction Machine emerged, which proposes to feed the machine by two converters, one at each end of the machine winding. This configuration has several advantages over the conventional one such as higher reliability, lower dc-link voltage, and three-level operation capability. It is possible to use two isolated d.c. links, one for each inverter or a single shared dc link. However, zero sequence currents can flow in the configuration where the two converters share the same bus. This current, unwanted in some applications, can be used here, with advantages, to on-line estimate the machine stator resistance. This parameter is important, among others, in implementing high-performance control techniques, efficiency, and winding temperature monitoring. Mathematical modeling is initially developed. Then, the feasibility, operability, and performance of the method are evaluated through simulations. Lorrane Prado Silva do Carmo, Marcelo Martins Stopa, Allan Fagner Cupertino, Alex-Sander Amável Luiz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3618 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3619 The paper performs a modeling of the degradation curves in aircraft turbines under real flight conditions and also a comparison between machine learning techniques based on decision trees. The algorithms used are: Decision Trees (DT), Random Forest (RF) and Gradient Boosting (GB). Coefficient of determination, mean square error and root mean square error are employed as performance evaluation methods. The presented results show the best performance of RF and GB in estimating the values. The coefficients of determination of the algorithms reached average values higher than 0.98, thus showing the efficiency of the proposed models to be used in this application. Joaquim O. F. Moura Filho, Marcelo E. da Silva, Vandilberto P. Pinto, Márcio A. B. Amora Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3619 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3620 This work presents a control method applied to a non-sinusoidal PMSM in order to reduce the torque ripple. Due to the machine’s back-electromotive force (Back-EMF) not having a sinusoidal shape, there will be a torque ripple due to the interaction of the Back-EMF and the stator currents when classic vector control methods are used. In order to mitigate this problem, resonant controllers will be configured to minimize the 6th and 12th harmonics in the quadrature axis current. A state feedback controller is used and the controller gains are calculated by pole placement through the Ackerman Method. For the practical implementation, interpolating polynomials will be used that will allow to reduce the computational efforts. Simulation results demonstrate the effectiveness of the method to reduce torque ripple and improve machine electrical performance. Lucas Rossato Rocha, Eduardo Cattani Silva, Paulo Henrique Alves Silva e Silva, Rodrigo Padilha Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3620 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3621 Brushless synchronous generators are increasingly widespread in the installed park of industries and small power generation plants. Rotating diodes are considered the main components of the exciters that supply the field windings of these generators. The reliability and availability of power generation are strongly related to the exciter function. The difficulty of access, as they are components that rotate with the axis, makes it impossible to carry out predictive/detective maintenance. The present work presents a study of the impacts of diode failures of rotary rectifier bridges on operating voltages and currents of brushless generators, for comparison with a machine in perfect condition. Thiago B. Pierini, Pedro H. A. de Oliveira, Cláudio A. Conceição, Braz de J. Cardoso Filho, Thales A. C. Maia Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3621 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3622 Smart lamps actually have dimmable LEDs, which are feasible to vary their luminous intensity and, furthermore, as they have two high power LEDs (one is warm white and the other one is cold white), it becomes possible to control their Correlated Color Temperature. This review proposes an automatic activation of smart lamps as it gets on when ambience becomes dark, then automatic dimming until the lights are completely turned off at the end of the day. At the end, the conscious use of the Correlated Color Temperature through an automation suggesting the reduction of visible light frequency with high-energy in periods leading up to the sleep phase, in order to improve human welfare. The behavior of the automatic lighting system is presented in experimental tests for different situations in the ambience. Gabriel B. Takahashi, Fernanda Q. Rossi, André M. Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3622 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3623 In this work was evaluated the behavior of a wind power generation system connected to the electric grid using the permanent magnet synchronous generator (PMSG). The active and reactive powers are controlled by the machine side converter (MSC) in dq coordinates by the rotor magnetic flux orientation, and in the grid side converter (GSC) they are controlled in αβ coordinates through electric grid voltage. The active power filter (APF) is added to the GSC through an algorithm that allows to compensate the harmonic components present in the electric grid currents.The results were obtained using the computer simulation software Matlab / Simulink. Two case studies are analyzed to investigate the effectiveness of the control techniques employed, in which in case 1 the wind system operates only in the control of powers, and in case 2 the APF function is added to the GSC. The total demand distortion (TDD) of the grid current of 10.84 % (case 1) were decreased to 1.37 % (case 2) when the electric generator operates at its nominal conditions. Thus, the techniques used in the PMSG / APF set proved to be effective for generating wind power and improvement of power quality. Leonardo Pires de Sousa Silva, Adson B. Moreira, Lucas Taylan Ponte Medeiros, Vanessa S. C. Teixeira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3623 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3624 The increasing demand for the use of petroleum derivatives combined with high prices, has stimulated a great investment in the development of technologies for the entire production chain process of this industry, making it more efficient and reliable. Technologies based on digitalization, with massive use of ICTs, have been developed, one of which is the concept of digital twins. Digital twins are digital copies of equipments or complete industrial sites, in real time, and have been developed for the oil extraction stage. Among the component modules of a digital twin is the data acquisition module, which uses sensors to monitor the digitized equipment. The data obtained are better structured using an ontology. In this article we present an ontology for oil wells operated by electrical submersible pump system. This ontology will be used in a data acquisition module, in a project to develop a digital twin. Washington S. Pereira, Sérgio Gorender Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3624 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3625 Industry 4.0 has provided significant advances in several areas, one of them being in the mining sector. Within the mining process, the ore drying stage is characterized as an important phase in which the ore passes through rotating vacuum filters, in order to reduce its moisture. One of the problems at this stage concerns the detection of the quality of filters in the drying machine, with the clogging of the filtering medium being the main reason for the poor quality of the filter. Therefore, this work proposes the use of deep neural networks to recognize the quality of these filters for preventive maintenance. Unet and SegNet network architectures were applied, two types of convolutional neural networks, encoder/decoder. As a result, it was possible to obtain more than 90% accuracy in the correctness of the model, as well as the determination of a quality indicator for these equipments. Leonardo Souza Coelho, Giovani Bernardes Vitor, Willian Gomes de Almeida, Rafael Francisco dos Santos, Paulo Henrique Vieira Soares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3625 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3626 Power transmission lines are components highly susceptible to faults. Several works have already explored the use of computational intelligence, signal processing and other techniques in the construction of protective methods for quick verification and action in the occurrence of transmission line fault. Many of these works focus on approaches using signal processing such as Fourier or wavelet transforms. With the advance of machine learning, some techniques began to be used in this area with success. This work focuses on the offline classification of ten (AG, BG, CG, AB, AC, BC, ABG, ACG, BCG and ABC) types of faults that arise when a short circuit occurs in the transmission line, investigating the use of classical techniques such as notch filter and random forests. For comparative purposes, recently created techniques, called random convolutional kernel transform (Rocket) and MiniRocket, were used to extract features in time series and good results were obtained in the identification of faults that occurred in the transmission line. As a result of this paper, accuracies greater than 93% were obtained considering up to 1/16 cycle post-fault. For signals with 1 and 1/2 cycle post- fault, accuracies higher than 97% were obtained. Gabriel Aparecido Fonseca, Danton Diego Ferreira, Flávio Bezerra Costa, Aryfrance Rocha Almeida, Robson Rosserrani de Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3626 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3627 Compressed Sensing (CS) is a technique that takes advantage of signal sparsity in a given domain and allows sampling with sub-Nyquist sampling rates. A device that implements the CS model is the Analog-to-Information Converter (AIC), which obtains an output that is a digitized and compressed version of the input. This paper presents CS principles, analysis, and results obtained for a dual-tone sine signal applied to a version of a Random Modulation Pre-Integrator (RMPI) AIC. Hugo B. S. Araujo, Rubens M. B. da S. Lima, Adna Kallery Santos da Silva, Cleonilson P. de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3627 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3628 With the advance of the Industry 4.0, it is critical to ensure security against cyber attacks even in the field level of the industry. In this paper, we consider cyber attacks in automation networks, where an attacker eavesdrops communication channels in order to gather information about the system behavior. We propose a cryptographic scheme used in the application layer of the network which encrypt events without altering the size or structure of the transmitted data. This scheme is denoted by event-based cryptography, where an event is defined as any change in the binary vector transmitted in the network. In order to do so, we propose the use of a cryptography scheme called ChaCha20, which is known to have a high resistance to cryptanalysis. Públio M. Lima, Carlos K. P. da Silva, Claudio M. de Farias, Lilian K. Carvalho, Marcos V. Moreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3628 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3629 One of the ways to mitigate the EMI (Electromagnetic Interference) conducted in the LED drivers is through the choice of the CC-CC converter that has a low ripple in the input current, as seen in the case of the SEPIC converter with coupled inductors. Regarding the later converter, it is possible through the adjustment of the inductor’s parameters, to reduce the input current ripple theoretically to zero by a technique called ripple steering. However, in a practical experiment, this is difficult to achieve because there are uncertainties in the inductor’s parameters, which prevent the achievement of a converter with a null ripple with acceptable repeatability. The goal of this work is to decrease the input current harmonic content in the way that the component’s uncertainties don’t produce great ripple variabilities. The Monte Carlo simulation was used to make the uncertainty propagation. A case study with a 50 W lamp driven by a 127 V (rms) was done, in which a confidence level of 95% was obtained with a ripple of (30 ± 7, 5)%. Josué L. da Silva, Pedro Henrique C. Lopes, Pedro S. Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3629 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3630 This paper describes a system to detect anomalies in non-IP (Internet Protocol) industrial networks on Industrial Control Systems (ICS). Non-IP industrial networks are widely applied in ICS to connect sensors and actuators to control systems or business networks. They were designed to be in an air-gapped security environment and therefore contain almost no cyber security features and are vulnerable to various attacks. Even though they are part of the communication layers, a few external cyber security controls are applied in this crucial tier. As an extension of the work by De Moura et al. (2021), this study proposes and tests the proof-of-concept of an agnostic anomaly detection system (AADS) to detect anomalies on any non-IP industrial network (e.g., DeviceNet, CANBus) as an additional cyber security measure working at the physical network layer. The proof-of-concept is comprised of three modules, including hardware and software components: data gathering (sniffer), parser, and detection. Testing the proof-of-concept in an industrial lab network (i.e., a Profibus-DP lab network) showed the proposal's feasibility with a detection rate above 99% (overall accuracy: 99.59%; F1-Score: 99.18%). Ralf Luis de Moura, Virginia N. L. Franqueira, Gustavo Pessin Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3630 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3631 Among the various stages of development of a conceptual project for a photovoltaic power plant, the elaboration of the Annual Energy Production Certification (CPAE) is essential. This certification allows the entrepreneur to attest to the energy generation potential of the project. The Annual Energy Production Certification is required by the electric sector bodies that authorize the implementation and operation of new electric power generating plants, being a necessary requirement to prove the project's generation potential. This work presents a revisitation of the analyzes to estimate energy production, with details on each type of loss experienced by the system, and, finally, a case study is presented with the description of the parameters that influence the energy estimation. The simulations use the PVSyst program, a tool usually used in the certification processes of photovoltaic plants connected to the Brazilian electrical system. The estimated energy production, the main result of the simulations, has a relative error of +0.33% compared to the certified value for the enterprise. Mabelle S. M. Sobral, Renato L. A. Caldas, José F. C. Castro, Alecio B. Fernandes, José R. F. Delgado, Matheus R. Alves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3631 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3632 This work proposes a new design for the simplified filtered Smith predictor (SFSP) with feedforward action. The proposed strategy is based on a stable implementation structure and makes use of an auxiliary filter to obtain controller parameters more directly for first- order processes. The structure preserves the good robustness and noise attenuation properties of SFSP, while improving its disturbance rejection performance through the feedforward action. The evaluation of the proposed methodology is carried out through simulation results that show better performance indices when compared to other strategies in recent literature. José N. do Nascimento Jr., Gabriel F. Machado, José R. de Oliveira Jr., René D. O. Pereira, Bismark C. Torrico, Fabrício G. Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3632 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3633 A leishmaniose é uma doença comumente negligenciada que se apresenta em países tropicais e subtropicais, afetando 1 bilhão de pessoas. A Leishmaniose Visceral é a forma mais grave e pode levar à morte desde que não tratada. Nesse cenário, técnicas de Deep Learning são aplicadas para detectar Leishmaniose Visceral por meio de imagens de lâminas do exame parasitológico da medula óssea, auxiliando em um diagnóstico rápido e preciso. Utilizamos duas metodologias diferentes que realizam a classificação automática dessas imagens como positivas ou negativas para a doença. Na primeira, utilizamos uma CNN baseada na LeNet e treinada do zero; na segunda, utilizamos a extração de características com CNNs pré-treinadas e uso de três classificadores clássicos (Random Forest, SVM e XGBoost). Os resultados são relevantes, atingindo uma Acurácia de 78,7%, uma Precisão de 94,1%, um Recall de 64,0%, um F1-Score de 99,2% e um Kappa de 58,1% em nossa melhor técnica de classificação. Comparamos nossos resultados com quatro trabalhos relacionados no estado da arte, que mostraram que o método proposto apresenta resultados promissores em todos os casos. Portanto, demonstramos que modelos treinados com imagens de lâminas da microscopia de material biológico da medula óssea podem ajudar precisamente o especialista na detecção da LV em humanos. Clésio de Araújo Gonçalves, Armando Luz Borges, Viviane Barbosa Leal Dias, Nathália Batista de Andrade, Bruno Guedes Alcoforado Aguiar, Romuere Rodrigues Veloso e Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3633 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3634 This article aims to describe a new incremental model for learning interpretable rules based on MaxSAT, called IKKRR. This new model was based on two other approaches, one based on SAT and the other on MaxSAT. The one based on MaxSAT, called IMLI, presents a technique to increase performance that consists in learning a set of rules by applying the model in a dataset incrementally. This work shows which adaptations were necessary for a model based on SAT to be transformed into one based on MaxSAT. It also shows what was done to make it incremental. Finally, IKKRR and IMLI are compared using diverse datasets. Despite having a smaller number of variables, the IKKRR obtained results comparable to the IMLI. Antônio Carlos Souza F. Júnior, Thiago Alves Rocha Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3634 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3635 Energy management systems (EMS) has importance to utilities for several reasons, mainly for existing a necessity to allocate their resources in advance, requiring short, medium and long-term planning. Therefore, in this paper, a very short-term demand forecasting procedure was implemented, using a computational model based on Artificial Neural Networks (ANN) of the type Long Short-Term Memory (LSTM) to aid the Federal University of Paraíba (UFPB) analyzing peaks and off-peaks of active power throughout the past years being possible to use the forecast of One Hour Ahead as a input to a BESS for optimal battery power dispatch management, in order to reduce fines for excess contracted demand at UFPB. The study compares LSTM with a CNN model and to improve the performance of the LSTM, the network was evaluated under different aspects, as hyperparameters and considered a technique of periodicity using sines and cosines. Gabryel M. Raposo de Alencar, Camila Seibel Gehrke, Flávio da Silva V. Gomes, Lucas Vinicius Hartmann, Camila Maciel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3635 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3636 The article presents an analytical method for the development of an agricultural tractor with regard to the use case of planting, where it draws a row crop planter with traction from a hybrid produlsion system, where the specific goal is the sizing of the internal combustion and electric machines. With basis on operating and soil property parameters, it is possible to predict the torque and power requirements from the tractor at all of the high demand points and, hence, establish the peak power values for the system. The presented methodology is tested considering a soybean planting operation, in which a power-split planetary gearing topology of the hybrid powertrain is considered, and the results shows a possible configuration that has the best overall efficiency of the system. William K. Moreira, Prof. Dr. Julian C. Giacomini, Prof. Dr. Cassiano Rech, Prof. PhD. Vinicius K. Marini, Leonardo B. Vieira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3636 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3637 This paper presents a simulation of an Energy Management System operating in an electrical system with an on-grid photovoltaic system for one year with the implementation of a Battery Energy Storage System. The results show that for the system operation on the ”green” tax modality, the battery system investment payback occurs in 1.8 years. Jocélio Jairo Vieira Filho, Micael Praxedes de Lucena, Italo Roger Ferreira Moreno Pinheiro da Silva, Marcel Ayres de Araújo, Flávio da Silva Vitorino Gomes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3637 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3638 In this paper we present the creation of some models that consider the presence of distributed photovoltaic generators in the analysis of technical losses. This analysis is performed considering a test network, the IEEE 34 bars, reconciling the network modeling with the regulations required by ANEEL (Agência Nacional de Energia Elétrica), taking into account the presence of photovoltaic systems in addition to taking into account the data held by the energy concessionaire and ANEEL, to determine technical losses, using the OpenDSS (Open Distribution System Simulator) software as a resource. In view of the above, the methodological impact of the proposed changes is analyzed, searching for a more coherent way of representing and calculating technical losses in the electric power distribution system. In addition, other impacts that may occur in the methodology and in the electric grid are evaluated. Poleana Gehrke, Criciéle C. Martins, Micael M. Oliveira, Leonardo H. Medeiros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3638 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3639 Within the Digital Twins context, efforts are being made to minimize costs, increase safety, and speed up tests within a specific application, based on computer graphics tools for three- dimensional simulations. Thus, as a way to mitigate mainly the risks with the safety issue involving activities with autonomous vehicles, the present work proposes the modeling and structuring of an electric golf cart in a 3D virtual environment, so that it can serve for studies in the areas of perception, navigation, and control. Therefore, taking as a reference the proper vehicle existing at the university, Blender software was used together with the Gazebo simulator to perform the validation of this simulation environment. Different open source Environment Mapping (SLAM), Pattern Recognition (YOLO), and Autonomous Navigation algorithms were integrated to minimize possible errors regarding their integration in the actual vehicle. Finally, validation tests were performed on the Yolo algorithm, resulting in an accuracy of 98.9% with a margin of error of 1.1% in the identification of objects. Nalia Sánchez, Marcos V. Cruz, Rafael F. Santos, Rubén Hernandez, Willian G. Almeida, Giovani Bernardes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3639 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3640 The great current demand for photovoltaic electric energy generation has required the search for solutions to problems of operation of such systems. Among these, the so-called atypical photovoltaic string operating conditions stand out, leading the system to a loss of efficiency in its generation capacity or even to severe failures. Regardless of the cause of the atypical string condition, its effect is somehow registered in the electrical generation itself. Each causative factor results in an electrical signature, which allows it to be identified. Thus, the objective of this article is to identify the operating condition of a photovoltaic string among twenty possible states, one is the normal condition, and the others are atypical ones. It is used a non-intrusive monitoring method based on the use of electrical voltage and current samples generated by the PV string itself. A multistage classification methodology is adopted to divide a complex problem into smaller and less complicated sub-problems. Therefore, they are considered two classification stages and, in each one, the K-nearest Neighbors, Support Vector Machine, and Multi- Layer Perceptron classification technics are used. The results achieved led to an average accuracy of 93.9% when using the classifier with the best performance in each subproblem treated. Caroline T. S. Passos, Wanderley C. Celeste, Leonardo J. Silvestre, Hélder R. O. Rocha Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3640 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3641 Abstract: The dual unified power quality conditioner (iUPQC) is an active filter that has been studied to be applied as utility interface in microgrid applications. It regulates the voltage of the microgrid side and controls the power flow between the grid and microgrid side. Besides that, ancillary functions to grid side have been proposed to extend its power quality compensation. This paper presents a detailed analytical and numerical analysis of the power flow of an iUPQC, which operates as an utility interface in microgrid applications with the extended function of STATCOM. It can compensate not only the disturbances at the load or microgrid side but also provides an RMS voltage regulation at the Point of Common Coupling (PCC), thus, providing reactive power to the grid. Moreover, the iUPQC power flow was evaluated considering the implementation of the power angle control (PAC), a technique used to share and equalize the power processed by each converter allowing the optimization of this conditioner. In addition, a test setup to validate this analysis was proposed and built. Therefore, this study can support the understanding of the power flow of the iUPQC operating as STATCOM, to share and optimize the available power in the iUPQC converters using PAC. Matheus Montagner, Cassiano Rech, Marcello Mezaroba Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3641 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3642 Linear matrix inequalities are a powerful tool in the field of robust control for analysis and synthesis of control systems. This work presents new formulations based on linear matrix inequalities for ∞ robust control synthesis by state-feedback for discrete time-invariant linear systems. The formulations include an additional matrix variable, which allows the Lyapunov function to be parameter-dependent, and two scalar parameters that must be chosen by the designer. It is proposed to apply evolutionary optimization to determine the optimal values of these two parameters. There are three possibilities for determining the two parameters, setting the first, setting the second, or optimizing both. The proposed formulations include existing formulations in the literature for specific values of the two scalar parameters. Case studies are presented to evaluate the proposed formulations. Pauliana Rufino de Almeida Lima Oliveira, Eduardo Nunes Gonçalves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3642 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3643 Applications involving unmanned aerial vehicles (UAVs) have grown over the past decade. With the advent of technology, especially in sensors, batteries, and actuators, using this type of aircraft has proven cheaper than other solutions. However, it is necessary to guarantee safety and robustness in autonomous flight. In this sense, this paper implements a disturbance observer-based control (DOBC) architecture by combining a robust recursive linear-quadratic regulator with two distinct disturbance estimators. In addition, we tested three other controllers widely used in the literature inside the architecture. We perform practical experiments with a commercial quadrotor and analyze the effects of the parametric variations during flight. We compare the flight performance among the implemented controllers and analyze the performance of each of them with each disturbance estimator. The experimental results show the performance improvement of using a robust controller and a DOBC architecture in a system with parametric variations. Paulo V. G. Simplício, João R. S. Benevides, Marlon A. D. Paiva, Roberto S. Inoue, Marco H. Terra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3643 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3644 The generation of electricity through renewable sources, such as solar and wind, is constantly growing due to the ecological and economic advantages associated with its use. Thus, the monitoring and analysis of climate variables such as wind speed and solar irradiation is of paramount importance to define the wind and solar generation potential of a region. In this context, the present study highlights the elaboration of a Paraíba State database (PB) making use of spatial data interpolation techniques to determine values where there are no measurements. Thus, from the official National Aeronautics and Space Administration (NASA) database, two interpolation procedures were evaluated. In sequence, the Kriging method for creating a base with exclusive resolution of 0.05◦was applied (latitude and longitude) in relation to the original base for analysis of the wind, solar and hybrid potential of the state. Finally, it was seen, based on the developed index, that the intermediate geographical region of Patos is favorable for solar power generation and the regions of Campina Grande and João Pessoa have a high wind potential, while some cities in the Campina Grande region had good rates for hybrid generation, i.e., wind and solar. Miguel Marques Ferreira, Júlia Alves Santos, Lincon Rozendo da Silva, Helon David Macêdo Braz, Flavio da Silva Vitorino Gomes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3644 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3645 This paper proposes an algorithm based on LMIs to compute a switching control law and state feedback gains that stabilize a discrete-time switched system. The adopted design methodology is based on the existence of a quadratic Lyapunov function, which typically yields synthesis conditions involving the search for scalar parameters in terms of nonconvex inequalities. Differently from the available methods, in the proposed technique the switching law and feedback gains are computed simultaneously through an iterative procedure, without the need to resort to grid-based strategies (as usual in the literature), due to the fact that the scalar parameters appear affinely in the conditions. Numerical examples illustrate the results. Andressa M. Souza, Ricardo C. L. F. Oliveira, Pedro L. D. Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3645 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3646 With the growing opportunities in the most diverse areas of engineering associated with autonomous vehicles, much has been studied about the application of low-cost inertial sensors, especially of the Micro-Electro-Mechanical Systems (MEMS) type. However, the recognized predominance of stochastic errors in such sensors becomes an obstacle, since most of the documentation provided by the respective manufacturers is incomplete. In this sense, this work aims to investigate the Allan Variance (AV) technique as a tool for identifying the nature of Inertial Measurement Unit (IMU) stochastic errors. In addition, a discrete-time state-space model capable of reconstructing these errors from the stochastic characteristics identified for the inertial sensors is evaluated. Finally, an optimized version of the aforementioned technique is proposed, which is capable of refining the dynamic model of stochastic errors, as well as its correspondence with the AVs experimentally obtained for the inertial sensors. Experimental results, based on data collected from different commercially available low-cost IMUs, show that the models and techniques discussed are capable of adequately estimating the behavior of such errors and, therefore, guaranteeing the adequate tuning of eventual estimators (such as the Kalman filter, for example), when merging IMUs with auxiliary sensors for integrated multi- sensory navigation. Maia Á.H.A., Silva F.O., De Lima D. A., Meneses R. F. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3646 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3647 The energy theft generates significant losses for the electricity distribution concessionaires. Research over the past decade has focused on machine learning as a method of detecting energy theft by analyzing consumption logs. The use of convolutional neural networks is one of these methods. Operating procedures can affect the quality of consumption data, impacting the performance of machine learning methods. In this paper is evaluate how the procedure of concessionaries of use the consumption average affect the performance of the energy theft detection method using a convolutional neural network. Sérgio L. M. Lacerda, Alexandre C. Oliveira, Armando J. G. A. Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3647 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3648 A with the advancement of technology within the manufacturing area and an increase in the production process, the industry increasingly needs means that allow reliability in their manufacturing methodology. Thus, the Industrial Internet of Things (IIoT) becomes a new tool adopted in this environment, since this technology allows the connection of sensors with web databases to monitor the equipment present in the industry. As a consequence of this connectivity, a greater excellence in predictive maintenance applicability is possible, since IIoT technologies allow the visualization of monitored parameters in real time. Thus, this paper demonstrates the Motor Monitoring and Analysis System (SMAM) that measures temperature and three-phase motor input current with low cost devices, allowing the user to monitor these variables in an online dashboard. Jhennifer F. dos Santos, Lucas H. B. Santos, Wellington da S. Fonseca, Allan R. A. Manito****, Ramon C. F. Araujo, Marcelo de O. e Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3648 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3649 We propose a non-model based strategy for locally stable convergence to Nash equilibria in a quadratic noncooperative (duopoly) game with player actions subject to heterogeneous PDE dynamics. In this duopoly scenario where different players use different types of PDEs, one player compensates for a delay (transport PDE) and the other a heat (diffusion) PDE, each player having access only to his own payoff value. In order to compensate distinct PDE-modeled processes in the inputs of the two players, we employ boundary control with averaging-based estimates. We apply a small-gain analysis for the resulting Input-to-State Stable (ISS) coupled hyperbolic-parabolic PDE system as well as averaging theory in infinite dimensions, due to the infinite-dimensional state of the heat PDE and the delay, in order to obtain local convergence results to a small neighborhood of the Nash equilibrium. We quantify the size of these residual sets and illustrate the theoretical results numerically. Tiago Roux Oliveira, Victor Hugo Pereira Rodrigues, Miroslav Krstic, Tamer Basar Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3649 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3650 This article focuses on developing an energy management system (EMS) for a microgrid on a university campus. The microgrid comprises photovoltaic (PV) systems, Battery Energy Storage Systems (BESS), backup generators, and local loads. The proposed EMS seeks to optimize the power flow, enabling the bidirectional power flow between the microgrid, and the utility grid, through a mathematical model and algorithm that establishes BESS charging and discharging patterns -considering battery degradation via the rainflow algorithm- to minimize energy cost and consequently reduce emissions of Greenhouse Gases (GHG). The EMS is modeled through a Mixed-Integer Conic Programming (MICP) optimization problem aiming at minimizing the operational cost of the university campus. The results obtained showed that the EMS developed reached the proposed objective, minimizing the energy costs of the microgrid when choosing the appropriate device to meet the loads. In addition, potential improvements were identified for the analyzed microgrid, such as expanding the photovoltaic generation system and improving system management strategies and the use of the storage system. Walquiria N. Silva, Letícia F. Henrique, Bruno H. Dias, Leonardo W. de Oliveira, Madson C. de Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3650 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3651 Towards the growing pet market in Brazil, this work aims to create a product capable of being used to feed domestic animals in a residential environment. A stepper motor provides the device with great reliability, and a control system guarantees the execution of the requested tasks. Furthermore, a web application simplifies access to the device through any internet browser, allowing the motor to be activated directly or programmed. All activations performed are recorded in the system for monitoring activities, and a consumption analysis element is also implemented to help the user to keep control of feed consumption on the device. Felipe Franchi Pires, Marcelo Favoretto Castoldi, Alessandro Goedtel, Wesley Angelino de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3651 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3652 In this article, a iterative tuning of the PI trajectory controller of an AGV is performed using as performance parameters the gain and phase margins of the closed loop system. Three case studies are analyzed, with different specifications of margins for the same system. The AGV system it is a naturally unstable system, it is not possible to use methods that require open-loop information. For this reason, closed loop relay methods were used to estimate system margins. The results achieved validate the tuning method used. The performance criteria provided fast convergence and kept the system stable. José Adeilmo Nunes Barbosa Junior, Rafael Bezerra Correia Lima, Péricles Rezende Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3652 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3653 In this work, we approach the control of non-holonomic mobile robots. We designed a backstepping controller project focused on the trajectory tracking of mobile robots. Furthermore, an asymptotic stability analysis based on Lyapunov’s theory was presented to guarantee the robot’s stability from tracking errors. Initially, we reproduce a combined kinematic torque control law, developed using backstepping. Next, we approach a backstepping controller project to track non-holonomic mobile robots’ trajectories. The main objective of the addressed control algorithm is to design a robust output tracking controller. The kinematic tracking controller of a unicycle-type mobile robot is used to provide the desired linear and angular velocity values for the given trajectory. In this work, the simulation results show the effectiveness of the proposed non-linear controller in terms of precision and stability under a defined circular path. Adrian E. G. Barreda, Renan L. P. de Medeiros, João E. Chaves Filho, Florindo A. C. Ayres Junior, Iury Bessa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3653 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3654 In many situations, conductor rupture in distribution systems or even their contact with structures external to the systems (such as trees) does not sensitize protection systems. This type of occurrence and its variations are typically called high impedance faults, considered to be of high severity by the concessionaires. The present work aims to present a method for detecting high impedance faults based on the Energy Vectors of the Centroids of the Spectral Sub-bands. Regarding the validation of the method, a database was created through simulations performed in the Alternative Transients Program, based on a real distribution system. In addition to high impedance faults, load energization and capacitor bank switching situations were also simulated to test the robustness of the method against probable false positives. A database containing real oscillography of high impedance faults was also used. An Artificial Neural Network was trained in order to classify the disturbances using the proposed method. From the satisfactory results obtained, the viability of the developed method can be seen. Reginaldo B. G. Grimaldi, Fernando Augusto Moreira, Tarso Vilela Ferreira, Jugurta Montalvão, Wellinsílvio C. dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3654 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3655 This article describes the design and development of a mono-tank level plant to aid in teaching process control, systems identification, controller design. The use of accessible and low-cost materials allows other students to build their plant, also allowing the development of practical skills, relevant to the training of an engineer. In the context of control theory, level processes are found in different types of industry, such as petrochemicals, water distribution, chemicals, boilers, among others. Therefore, it becomes relevant to enable and encourage practical activities in the industrial processes area, providing the practical application of the concepts of process identification and control. The work presents the materials and points taken into account in the development of the real plant, as well as presents some of the identification and control techniques that can be applied to the plant, such as: classic identification techniques, PID (Proportional, Integral, Derivative) and GMV (Generalized Minimum Variance)-PID controllers. Caio Vinicius Silva do Carmo, Rejane de Barros Araújo, Raimundo Nonato das Mercês Machado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3655 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3656 This work presents a new microwave imaging system for breast imaging that consist of a pair of antennas being automatically positioned around the breast by robotic arms, providing better flexibility to different breast sizes and allowing a bigger number of measuraments when compared to other systems in the literature. The systems retrieves the outer shape of the breast utilizing a depth camera and uses it to position the antennas. The system was capable of autonomously decide the position of the antennas for two breast phantoms with minimum input from operator. Lucas G. Costa, Thiago Campos, Everaldo J. Maciel, Hugo A. Mendes, Maryam Liaqat, Emery Lins Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3656 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3657 The occurrence of failures in industrial automatic systems is usually related to a change on the machine’s vibration pattern. This work proposes a feature extraction based on the mobile standard deviation and a simple and efficient data classification model to be implemented as local processing of IoT (Internet of Things) systems. The proposed method is evaluated in a simulation of a non-invasive online condition monitoring experiment of a rotating machine, with the objective of detecting the condition of a dry running centrifugal pump. The results obtained reveals that the proposed algorithm has high precision to detect the failure condition on the behavior of the monitored machine. The development of these types of systems makes it possible to integrate them into automated industrial plants. Rodrigo D. B. de Araújo, José S. de Souza Neto, Thais N. de Carvalho, Emerson V. A. Dias, Geraldo L. B. Ramalho, Josias G. Batista Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3657 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3658 This paper aims to investigate the problem of designing dynamic output feedback stabilizing controllers for discrete-time Takagi-Sugeno fuzzy systems. It is assumed the realist scenario where the premise variables are partially or completely unmeasured, that is, some unmeasurable states are part of the membership functions. To the authors’ knowledge, very few papers have addressed this problem outside the observer-based approach. The fuzzy output controller is allowed to have a different number of fuzzy rules and a different set of membership functions from the T-S model. The design conditions are expressed as linear matrix inequality relaxations based on fuzzy Lyapunov functions and the use of slack variables introduced by Finsler’s lemma. The effectiveness and applicability of the methodology are shown through numerical examples. Tássio M. Linhares, Eduardo S. Tognetti Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3658 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3659 In mobile robotics environment, has been essentially necessary the implementation of distributed systems, compound of any modules, like sensors, computers, embedded systems and IoT devices. Once this demand exists, the second version of Robot Operation System framework, the ROS 2, have communication protocols, libraries and tools for help the implementation of this systems for robotics, given support for real-time applications. However, looking for a wider application of ROS, the MicroROS gives the possibility to embed ROS 2 in a microcontroller and making possible to use the system in low and high levels, connected by an agent. Since this integration exists, the knowledge about the real efficiency and strengths and weaknesses of this communication is little, considering the application in a robotic system. Thus, for evaluate the communication benchmarking, latency, jitter, data loss and determinism characteristics will be analyzed, testing the growth of callbacks processing and rise of data input frequency. Thereby, the results show that the MicroROS susceptible to two situations: (i) the quality of service influence on system response and (ii) for estable operation frequencies, the system shows deterministic and real-time processing. Lastly, in the comparison of SingleThread and MultiThread tests, was prove that MicroROS have a critical point for latencies and topic loss registered. Gabriel Toffanetto França da Rocha, Giovani Bernardes Vitor, Rafael Francisco dos Santos, Willian Gomes de Almeida Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3659 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3660 Industrial Control Systems (ICS) are responsible for controlling critical infrastructures that often are targets of cyber attacks motivated by political, military, or financial interests. Supervisory Control and Data Acquisition (SCADA) systems are among the main components of ICS, are highly interconnected systems, and employ solutions common to conventional computer systems. Malware is among the top cyber threats to these systems. However, testing the cyber resilience of a real ICS requires testbeds and simulations to verify the harmful behavior of these threats without putting the original system at risk. This paper presents the results of an experiment that analyzed the impact of attacks with real malware on a SCADA system connected to a real-time simulated electrical system model in a hardware-in-the-loop testbed. The results show that even generic malware can impact the Modbus/TCP communication, causing interruptions and delays that can harm the SCADA system operation. This effect may affect the electrical system controls and protection actions, which require low latency reactions. Otavio Augusto Maciel Camargo, Elson Costa Gomes, Antônio Nascimento Filho, Anderson Fernandes Pereira dos Santos, Antonio Eduardo Carrilho da Cunha, Paulo César Pellanda Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3660 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3661 This work proposes a non-isolated single-switch DC-DC converter based on the integration of the classical single-ended inductance converter (SEPIC) and Zeta topologies using the graft technique. The resulting topology can provide high step-down or high step-up depending on the rated duty cycle. It also shows some interesting advantages, that is, both the input and output stage currents are non-pulsating with low ripple, resulting in low electromagnetic interference (EMI) levels. A thorough mathematical analysis is derived, from which it is possible to obtain simulation results aiming at validating the theoretical assumptions. Klaus Malone Martins Damasceno, Matheus Mulherchen Golz Costa, Caio Meira do Amaral, Enio Roberto Ribeiro, Fernando Lessa Tofoli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3661 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3662 Power Distribution Systems are a critical infrastructure, and there is a growing interest related to their capacity to deliver and maintain power supply to the final customer. In this sense, the failure response of a typical Distribution System (DS) must be correctly assessed, especially when considering Low Frequency, High Impact (LFHI) events, such as extreme weather scenarios. Previous studies focus on topological and qualitative approaches, thus not considering the impact of extreme weather on the DS’s reliability metrics related to the frequency and duration of the failure. In this work, a fragility curve model was used to sample time until failure and time to repair inside a daily time window of a real Brazilian DS while taking weather variables into account. The Monte Carlo method was used to verify both power flow parameters and weather variables’ influence on the frequency and duration of failures. A gradual node removal approach was also modelled to investigate the impact of energy not supplied. Results show that the weather variables values can drastically change the failure response of the DS in both the time window and node removal approaches. Furthermore, when considering redundancy (alternative energy paths), in the most extreme weather scenario, an increase in system redundancy did not improve failure response, contrary to what is expected. In this sense, an extreme weather failure response analysis is recommended in any investment study related to a DS - such as switch or protective device placement. Henrique O. Caetano, Luiz Desuó N., Matheus S. S. Fogliatto, Carlos D. Maciel Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3662 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3663 This work presents a method of restoring electrical energy by applying an induction generator connected to the electrical grid. The method uses a cylindrical flywheel with a high inertia coupled to the generator to store kinetic energy, which is converted into electrical energy. Toroidal inductors are used to mitigate the effects of current transients in the injection of energy to the grid. The proposal is validated, employing tests on an experimental bench. The results presented show that this system can supply under-voltage of up 0.2pu three-phase and 0.4pu per phase. Renato K. Miyamoto, Alessandro Goedtel, Marcelo F.Castoldi, Sebastião L. Nau, Adilson C. Machado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3663 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3664 The advancement of electronics allowed the development of several types of audio effects, mostly applied to musical instruments. One of these effects is distortion, which shaped the sound of electric guitar. Equipments that provided such effects became more robust and compact, combined with a greater diversity of tones. The digital electronics made possible equipments that have these effects, called multi-effect pedals, and unities that can model effects. One of the challenges in the development of these equipments is to truly replicate famous distortion tones. For that purpose, it is possible to model the desired effect through full knowledge of its electronic circuit or through modeling based on the identification of the system in question. This work proposes the digital modeling of the distortion pedal BOSS Blues Driver based on the identification of the used parametric model. The used model is based on a Wiener-Hammerstein and its parameters were optimized by a genetic algorithm. The results of the simulations were evaluated by time-error calculus and a blind hearing test with 30 people. Humberto Neto, Samaherni Dias, Kurios Queiroz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3664 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3665 This paper develops a day-ahead operational planning based on optimal power flow (OPF) for isolated microgrids which are equipped with battery bank, diesel generation and renewable resources. The renewable resources available in the studied microgrid are the photovoltaic solar and wind energies, which present an intermittent behavior, and so it is modeled by a probability density function in the proposed OPF formulation, in order to make the objective function sensitive to climatic uncertainties inherent to the intermittent resources. The objective function of the OPF incorporates in its formulation the costs associated with the operation of diesel generators and the use of the battery bank, in order to minimize fuel consumption and maximize the lifetime of the battery bank. The differential evolution optimization technique was used to solve the proposed formulation and to obtain a minimum cost of operation of the microgrid under study. The proposed formulation was tested in different scenarios and the obtained results showed that the day-ahead operational planning in microgrids is sensitive to variations in weather conditions, that occur at each hour of the day, and the changes made in the state of charge of the battery bank. Wagner F. S. Souza, Ádamo H. R. de Oliveira, Roman Kuiava, Gideon V. Leandro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3665 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3666 Least-Square Support Vector Machines (LSSVM) are solved from a linear system, unlike support vector machines (SVM), which require the application of quadratic programming. So it is preferable in some problems to use LSSVM because the complexity of the resolution will be lower. However, unlike SVM, LSSVM generates non-sparse solutions. A significant disadvantage, given that all training patterns will be support vectors of LSSVM. To overcome such non-sparse solutions, we propose an iterative solution with pruning without causing a loss of efficiency, named as FSLM-LSSVM. The proposed method is compared with two others in the literature, P-LSSVM and IP-LSSVM. Finally, the evaluation of the proposed solution consisted of comparing the averages of the hit rates. Davi A. Leão, Ajalmar R. Rocha Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3666 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3667 To reduce emissions, the incentive to commercialize electric vehicles has been encouraged in several countries of the world. With this growth, several challenges arise regarding the new form of vehicular propulsion and one of the main challenges is related to the autonomy of electric vehicles. In this sense, the development of DC/DC converters with the high power density and, mainly, high efficiency have been the object of study by automakers and researchers around the world. The objective of this work is to evaluate the impact of the efficiency of commercial auxiliary power modules in electric vehicles concerning their autonomy and to make a comparison between high levels of efficiency and high power density, important for vehicular applications. Dener A. de L. Brandão, Mariana de F. Ramos, Igor A. Pires, Thales A. C. Maia, Braz de J. Cardoso Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3667 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3668 This work presents the development and implementation of a cascade controller and a feedforward controller to increase the energy efficiency of the SAG grinding circuit of the Sossego plant, belonging to Vale S.A. Aspects of the procession, and instrumentation present in the circuit, are discussed in the construction of the proposed control system. The results of a three-month application at the Sossego plant indicate an increase in SAG mill energy efficiency of 7.8% and an increase in circuit productivity of 1.9%. Thomás V. B. e Pinto, Higor S. Barbosa, Marlon Souza, Thiago A. M. Euzébio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3668 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3669 Federated Learning is a promising technology to address crucial problems, such as those related to data privacy, involved in training Machine Learning (ML)/Deep Learning (DL) models in a distributed way. On the other hand, Human Activity Recognition (HAR) has recently gained more attention due to the evolution of the technologies involved, such as sensor availability, advances in ML/DL/Edge AI, and IoT. Due to computational resource constraints, techniques must be employed to reduce the effort required to train the model on the device. Meanwhile, there’s the need to customize the ML model of each Federated Learning (FL) client with the specific data collected by that client. The present work explores the FL of an ML model for HAR in a set of twelve simulated FL clients, each with its own set of data from smartphone sensors. The FL loop starts from a global model that was previously trained in a centralized way, using a large dataset, different from the data used individually by each client during the FL. In this way, the FL constitutes a fine-tuning of the base model. The metrics collected are balanced accuracy and loss. Data is pulled from the ExtraSensory dataset, creating a benchmark for future applications across device farms and in-the-wild devices. The results show that our models achieve equivalent or better performance than most methods found in the literature, using a relatively simple Multilayer Perceptron (MLP) model. The proposed method can then reduce the time needed to retrain the model when data is acquired from the device’s own sensors. Wandemberg Gibaut, Alexandre Osorio, Amparo Munõz, Sildolfo F. G. Neto, Daniel Miranda, Felipe Santos, Michelle Scarassati, Fabio Grassiotto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3669 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3670 This work presents an analysis on the effect of performance metrics on the selection of supervised methods for running-in detection in reciprocating hermetic compressors. Since the running-in phenomenon takes place only in the first few hours of the lifespan of such devices, datasets extracted from the compressor operation during this period and in its normal operation are usually more representative of its post running-in behavior, and, even after balancing the dataset, an adequate choice of the performance metric might reduce the undesired effects of this situation in classification models. In order to reach the proposed goal, parameters of random forest models and of data preprocessing methods were optimized for the following performance metrics: the area under the receiver operating characteristic curve, the F -score with three different configurations, and the Matthews correlation coefficient. When applied to experimental data, the results obtained with such models showed the Matthews correlation coefficient and the F -score with more weight attributed to precision (β = 0,5) as the most appropriate ones to the given case study. Gabriel Thaler, João V. B. Menegali, Ahryman S. B. de S. Nascimento, Antonio L. S. Pacheco, Rodolfo C. C. Flesch, João P. Z. Machado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3670 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3671 Control systems of aircraft dynamics focus on choosing configurations that meet certain criteria related to speed response, damping ratio, error in steady state, among others. Aeronautical engineering applications have safety requirements, and in this respect, the use of optimization algorithms assist in the ability to develop models of increasing complexity. Therefore, the main objective of this work is to develop a methodology for optimal tuning of fractional order proportional integral derivative (FOPID) controller based on particle swarm optimization (PSO) for multiple input multiple output (MIMO) aircraft model. This work can contribute to the aeronautical performance through the development of simulations seeking the best parameters from the controller, allowing flight conditions according to pre-established requirements. Three stochastic optimization algorithms were studied: global random search (GRS), local random search (LRS) and PSO. The PSO delivered the best results. Different performance indices based on the integral of error were used as objective functions. The ITAE (integral of time multiplied by the absolute error) index was chosen for presenting the best performance. It was necessary to limit the input values of the models, taking into account the limitation of the integrator term of the controller based on the anti-windup (AW) technique. Based on the prerequisites for the aircraft, the performance metrics achieved results considered adequate to the challeging demands of the task. Odilon L. C. Mendes, Guilherme A. Barreto, Mauricio A. V. Morales Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3671 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3672 This paper approaches the problem of Luenberger-like observer design for a class of LTI discrete- time descriptor systems. We present and prove sufficient conditions for the observer design with a guaranteed decay rate where the admissible descriptor systems. In addition, assuming some standard controllability properties, a separation principle is demonstrated considering an observer-based output feedback control law. The observer design is also extended to cope with model disturbances in an H2 sense. The effectiveness of the proposed methodology is illustrated by numerical examples. Lázaro Ismael Hardy Llins, Daniel Coutinho, Carlos E. de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3672 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3673 Tank level measurement is extremely important for the correct functioning of hydraulic systems. Generally, the ease of implementation combined with the costs involved are prioritized, which leads to the installation of a single sensor. However, this can decrease the reliability of the results and make the system dependent on the good functioning and durability of the sensor, generating frequent maintenance and recalibration expenses. In this sense, a solution consists of using multiple redundant sensors, enabling the use of fault detection techniques and data fusion for a more accurate estimation. In this article, an ultrasound level measurement system and data fusion based on Maximum Likelihood is presented, together with online supervisory monitoring. In this way, the process of construction and integration of hardware and software is described, as well as its experimental results and cost survey. Alan R. D. do Nascimento, Lucas D. de Oliveira, Juan M. M. Villanueva, José H. B. da Silva, João S. da S. Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3673 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3674 This article investigates the quality of electrical energy and a proposal for a solution to problems presented the microgeneration photovoltaic consumer units with caused by the intermittence of the solar source in electrical distribution systems through a combination of a solar energy generation system with an energy storage system (SAE). The solar power generation system is connected to the DC bus by a DC stage (boost converter) incorporated into a maximum power point tracking algorithm (MPPT). The SAE is composed of a battery bank and a bidirectional converter DC-DC (BDC) responsible for charging and discharging the batteries through a control proposal and by connecting the bank to the DC link. The connection with the distribution transformer that interfaces with the three-phase electrical grid is made by the voltage source converter (VSC) that also acts as a parallel active filter (FAP) at the common coupling point (PCC), at this point, non-linear loads present in consumer units of distributed microgeneration are connected. The method used for system synchronization was the Dual Second Order Generalized Integrator (DSOGI-PLL). The proposed system presented a good functioning and a good energy management strategy. The DSOGI-PLL performed well in the face of various disturbances in the electrical grid. The network current Total Harmonic Distortion (THD), with the action of the FAP, was significantly reduced. The P&O tracking algorithm presented high performance against a system without shading and is easy to implement. Lucas Taylan Ponte Medeiros, Adson Bezerra Moreira, Leonardo Pires de Sousa Silva, Arthur C. Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3674 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3675 This work presents an application of non-linear model predictive control (NMPC), combined to a kinematic model based in dual quaternion of a comercial robotic manipulator. The 6—DOF serial manipulator, VP-6242 by Denso Robotics was used as reference. Having developed the system’s explicit model, optimal control actions are computed in a prediction horizon according to an objective function to be minimized. The optimization problem, considers the structure constraints determined by the robotic system, guaranteeing physical integrity. Dual quaternion algebra adds robustness to the model regarding singularities and computational advantages when compared to traditional homogeneous transformation matrices methods. For NMPC, is possible to deal with multiple variable problems of non-linear nature, which solution is provided by MATLAB MPC Toolbox. Simulation results are presented, showing that the implemented algorithm is capable of generating safe and smooth routes to the highly complex system. Arthur da C. Vangasse, Andressa M. Oliveira, Allan de M. Martins, Ícaro B. Q. Araújo, Heitor J. Savino, Glauber R. Leite Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3675 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3676 Nowadays digital security systems are ordinary tools on a day by day, going by biometrics such as digital and facial recognition to the traditional users and passwords methods. Noticing the popularization of wearables, this paper proposes a biometric recognition method using ECG signals that can be obtained by the current technology of smartwatches, that differ from traditional 12-lead ECGs. First it was used a blind segmentation method to the electrocardiogram signal, which was treated with a Butterworth filter to attenuate signal noise. It was applied the Stockwell transform to the signal, shifting it from time domain to time- frequency domain, therefore obtaining the unidimensional complex trajectories of each sample as the MLP’s input. The proposed MLP model were able to obtain an 95,96% of accuracy using a data window of 500 discrete samples, showing its ability to set apart each subject signal. A. Barbosa, P.P. Rebouças Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3676 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3677 Solar energy is available abundantly in nature, and a substantial drop in the costs related to photovoltaic systems was observed in the last years. Therefore, solar-based systems have assumed a leading position in the search for alternative sources of energy. Although the use of solar tracker in those systems is not essential, it is known that its use can boost the collected energy. To meet this increasing demand, it is necessary to consider the effect of several parameters that can harm the performance of solar trackers, such as different periods of time, geographical and weather conditions. For that reason, this paper aims to compare the performance of fixed photovoltaic systems and tracking systems in twenty cities in different regions in Brazil as well as their efficiency under different levels of diffuse irradiance and spacing among arrays of photovoltaic modules. Simulations were performed and compared for each location. The results show that the correlation between the tracker gain and diffuse index is -0.9063 for a 6 m pitch, -0.9101 for a 7 m pitch and -0.9184 for an 8 m pitch and the change of the pitch from 6 m to 8 m led to an average increase of 4% in the gain obtained. Therefore, it is envisaged the existence of an inverse correlation between the diffuse indexes and tracker gain as well as the influence of the chosen pitch for each location. Nadine Figueiredo Rezende Braz, Eduardo Verri Liberado, Flávio Alessandro Serrão Gonçalves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3677 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3678 This paper presents a technique for processing simultaneous errors in decoupled generalized state estimation via geometric tests considering both models: bus-branch modeling and substation level modeling. Geometric tests are able to compose sets with suspicious information and identify the source of the error without the need for re-estimation. In addition, the purpose of this work covers the processing of errors in measurements for distribution systems, combining geometric tests with decoupled methods. The performance of the proposed methodology was evaluated through simulations involving the IEEE 30-bus transmission system, modeled at the substation level, and a 141-bus distribution system, represented as a bus-branch network, where various combinations of measurement errors and topology are evaluated. Andressa L. Monteiro, Elizete M. Lourenço, Odilon L. Tortelli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3678 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3679 This article proposes the use of the supervised learning method to establish a scenario of classification and identification of possible customers of electric energy distributors with signs of irregularities. Using this method, the failures identified by energy utilities during the target generation process can be mapped, contributing to better assertiveness and decision making in the field. The model will use data belonging to a large electricity distributor in the state of Rio de Janeiro, to make a comparison between different processing and pre-processing approaches to point out evidence of fraud. For this, tests were carried out with different classifier algorithms and feature extraction methods, obtaining as a best result an average accuracy close to 70%. J. J. Borges Oliveira, V. H. Ferreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3679 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3680 The implementation of microgrids in Brazil has increased considerably in recent years due to the shortage of water resources that result in increased electricity tariffs. The installation of these systems besides being environmentally advantageous and economical for the prosumer, allows for more autonomy and independence from the grids controlled by the energy distributors. However, microgrids are composed of several elements with distinct features that must operate in optimal synergy to achieve the maximum energy and economic benefits. In view of this, this paper proposes a model for managing the flow of energy among the elements that compose a residential microgrid. The proposed model is composed of energy sources such as the local utility grid and a photovoltaic system, storage devices and loads commonly found in the homes of Brazilian consumers. The problem results in the formulation of a Mixed Integer Linear Programming (PLIM) mathematical optimization model that has the objective of reducing the cost paid by the prosumer while minimizing the energy consumption of the utility grid. Computational simulation results are presented to verify and evidence the effectiveness of the proposed model. Vlademir Freire Junior, Lúcia Valéria R. de Arruda Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3680 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3681 This paper presents the performance analysis of a variable speed wind turbine with a doubly fed induction generator during a grid voltage dip. Simluations are performed with and without the installation of the crowbar protection, tipically present in this kind of wind turbine. It was possible to observe the consequences of the voltage dip on the generator, as well as the importance of the protection to keep the wind turbine within the safe operation conditions. Vítor M. Ramos, Damásio Fernandes Jr., Washington A. Neves Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3681 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3682 The present work aims to make a comparison between two control strategies in a multivariable system. Using a three-port DC-DC converter as the application, the strategies discussed are the decentralized control (k-factor method) and the Linear Quadratic Gaussian Compensator - LQG (centralized control). The controller designs are carried out and simulation results are presented in order to support the work. Debora Pereira Damasceno, Clauson Sales do N. Rios, Samanta Gadelha Barbosa, Wilkley Bezerra Correia, Demercil de Souza Oliveira Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3682 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3683 This paper presents a planning and operational strategy to improve the recoverability of the distribution systems (DSs) against a set of possible line fault scenarios. Within this strategy, the planning actions consist of allocating dispatchable distributed generation (DG) units while the operational actions include the complete dynamic restoration process. The restoration process considers the radial system reconfiguration and islanding operation, all while simultaneously considering the pre-positioning and displacement of mobile emergency storage units. The proposed strategy is formulated as a single objective stochastic scenario-based mixed- integer linear programming model, considering uncertainties associated with the solar irradiation and demand consumption in a multi-period formulation. The objective function minimizes the investment cost of new dispatchable DG units and the amount of energy shedding within the system. The proposed model is validated using the 33-node DS under different cases and results show the benefits of simultaneously solving the planning problem with a restoration process. Juan M. Home-Ortiz, Lucas C. Yamaguti, Jairo G. Yumbla, Ozy D. Melgar-Dominguez, José R. S. Mantovani Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3683 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3684 The navigation of a mobile robot in an environment for trajectory tracking is an important application for this class. In this context, this work aims to study the implementation of a controller for trajectory tracking using the Linear Quadratic Regulator (LQR) as a state feedback control method applied to mobile skid-steering robots with wheels. Two LQR controllers are designed from two distinct state-space representations, both considering a virtual reference robot for linearization of the problem. The AGV Husky robot will be used as a test platform, resulting in a study for mobile robot navigation at the GAZEBO simulation tool. Lorenna Santos Vilas Boas, Andre G. S. Conceição Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3684 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3685 This paper investigates the problem of PID (Proportional-Integral-Derivative) control design for uncertain linear systems. Starting from the definition of intervals for the gains of the controller, a state space realization of order 2 for the PID controller is employed for the feedback of SISO dynamic systems of arbitrary order with uncertain time-invariant parameters belonging to polytopes. Therefore, in closed-loop, one gets a linear uncertain system depending on uncertain parameters and on the controller gains belonging to known intervals. A procedure based on the iterative subdivision of the space of the controller parameters is applied and parameter-dependent Lyapunov functions are used to identify the stable regions and, then, to assure a guaranteed H∞ performance index for each region. Numerical examples, including comparisons with one method from the literature, are presented to illustrate the advantages of the proposed technique. Danilo L. Matias, Ricardo C. L. F. Oliveira, Pedro L. D. Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3685 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3686 This work presents a study on the efficiency of static power converters at partial cascade configuration. In the introduction, a contextualization of the problem is realized, as well the main points to be observed on the design of a practical application of this topology, intended for driver devices for LED lighting. A modeling for the indicated topology is proposed in order to study the efficiency of the pre-regulator and power controller set, which employs non-idealities that represent the real operating conditions. Simulations are performed in order to verify the behavior of the model and analyze the total efficiency. Finally, a prototype is implemented to validate the modeling and observe in practice the performance of the set of converters. Célio Antônio Degaraes, Juliano de Pelegrini Lopes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3686 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3687 In Robotics, location is an essential task, allowing the robot to navigate and thus carry out its activities. In this article, we propose a new approach to localization and navigation for mobile robots in a virtual environment using topological maps and classification with an option to reject from the Structural Co-occurrence Matrix (SCM) in omnidirectional images. To prove the high performance of the considered technique, an analysis is performed between several feature extractors and classifiers, established in the literature. Parameters such as processing time and accuracy are calculated to demonstrate the reliability and effectiveness of the approach, since these properties are paramount in embedded systems. Regarding the proposed approach, the SCM obtained an average accuracy of 99.27% and the shortest extraction time, 0.0786s, among all the feature extractors, proving to be an expressive method in the activities of location and navigation. SCM also achieved 100% accuracy in navigation tests. José Jerovane da Costa Nascimento, Suane Pires Pinheiro da Silva, Pedro Igo Sousa Lucas, Adriell G. Marques, Luís Fabrício de F. Souza, Pedro Pedrosa Rebouças Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3687 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3688 This work approaches the problem of distributed monitoring of water distribution networks focusing on leakage detection, using computational simulation of water distribution networks and machine learning techniques. The implemented machine learning technique is based on Graph Neural Networks, which are structures with the capacity to take into account the spatial displacement of the measurement points in the network alongside the measurement data, thus providing insight regarding the leak location. A case study application was developed to evaluate the capacity of the algorithm. A hypothetical water distribution network was implemented in a software environment to enable data collection in diverse operation scenarios, especially leakages in different locations. The initial results demonstrate that the graph-based approach is a viable methodology for water leakage detection. Rodrigo P. Rolle, Lucas N. Monteiro, Lucas R. Tomazini, Eduardo P. Godoy Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3688 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3689 This paper investigates the problem of control through a Wireless Sensor Network (WSN). Such communication channel is digital (the system to be controlled must be sampled and its mathematical model is discretized) and is also semi-reliable, since it admits the possibility of packet loss (that can be modeled by means of a Markov chain). The aim is to assure the stability of the closed-loop system and a good controller performance (measured in terms of the H2 norm) while trying to reduce the energy consumption of the network. For this purpose, an index that relates those conflicting criteria (H2 norm and energy consumption) is proposed, allowing the designer to choose the best WSN setup. The strategy adopted to develop the trade-off index consists in evaluating different network data rate settings, which implies: distinct sampling rates (better or worse digital representations of the continuous-time plant); distinct energy saving levels (due to higher or lower number of transmissions/receptions per seconds); and distinct probabilities of packet loss (due to, among others, increased network congestion). A numerical example based on the H2 state-feedback networked control of a Furuta’s inverted pendulum is presented to illustrate the employment of the proposed trade-off method. In this example, the statistical data used to model the communication channel are obtained from a WSN workbench. Gabrielly B. P. do Carmo, Leonardo Delforno, Jonathan M. Palma, Frank H. Behrens, Cecília F. Morais Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3689 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3690 The increasing penetration of distributed generation poses significant challenges for the ideal and safe operation of distribution systems, adding variability and uncertainty to modern networks. New methodologies need to be developed to reduce the negative impacts of distributed generation on the distribution system and to improve operators’ situational awareness in the control center. Hence, this paper presents a critical review of the main challenges that operators face in developing situational awareness in the operation of active distribution systems. Besides technological limitations, the bibliography review shows that the lack of standard features regarding operational requirements for security, quality, and performance cause inadequate situational awareness of the network. In this context, the performance of eight indexes representing the system’s operational criteria is analyzed in the IEEE 34-bus test system through the variation of the penetration level of distributed generation, changes in system loading, and network reconfiguration. The results highlight the importance of a complete picture of the system for situational awareness to help the operator’s decision-making during the dynamic network operation. Ellen C. Cruz de Souza, Felipe M. dos S. Monteiro, Eduardo N. Asada Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3690 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3691 In this work, the characteristics of the linear hybrid model used in electric power transmission systems expansion planning are analyzed in detail. The analysis takes into account the origin of the mathematical model, the usefulness of the model in the historical process and the possibilities of use in the current context of modeling and solving the electric power transmission systems expansion planning problem. It should be noted that the linear hybrid model was not properly used in the process of evolution of mathematical models until reaching the most complete mathematical model, which is the AC model. Comparative tests with other models and results are presented using data from electrical systems of medium and very high complexity. Marcos Schiavinato, Leonardo H. Macedo, Rubén Romero Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3691 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3692 Power transformers are essential equipments for the electrical system and their useful life is regulated by internal temperatures that accelerate the degradation of their solid insulation. In this sense, studies to understand and improve the thermal performance of these equipments are justified. This article presents a thermal performance analysis of transformers with directed/forced oil cooling system, through heating tests carried out in a prototype unit equipped with 31 fiber optic sensors to measure temperatures along its active part and points such as oil top and radiator inlet. Also, through a complete test setup, the oil circulation speed imposed by the hydraulic pump was varied and its impact on each of the cooling systems was evaluated. In this way, the obtained results make it possible to evaluate the performance of cooling systems under different conditions, contributing to transformer thermal designs and operation. Micael M. Oliveira, Leonardo H. Medeiros, Antônio M. Kaminski Jr., Pedro O. Bacin, Richard G. Cornelius, Rafael C. Beltrame, Carlos E. G. Falcão, Vitor C. Bender, Tiago B. Marchesan, Marco A. Marin, Helena M. Wilhelm Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3692 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3693 This work proposes a practical NMPC-based model predictive control approach with surge avoidance to natural gas networks. A minimal order state space-type model formulation based on an analytical expression of the step response has been proposed by linearizing the partial differential equations (PDE) for pipe flow. The simulation results showed that the proposed controller succeed in tracking the reference points meanwhile avoiding to remain on risk conditions, violating the surge line constraints. The closed-loop computational cost is also compatible with the pipeline network dynamic with an average time of around 2.5 s. Such results present the potential of the proposed approach compared to literature techniques such as simplifications on PDE or data-driven models. Rodrigo L. Meira, Márcio A.F. Martins, Ricardo A. Kalid, Gloria M. N. Costa Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3693 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3694 In this work, a control structure based on an observer-predictor for discrete time- delay systems is proposed. This strategy allows attenuating both polynomial and sinusoidal disturbances with known frequencies at steady-state from the process output. For this purpose, first, an extended observer-predictor based on the disturbance model is used to estimate the process states with zero error at the steady-state. Then, a predictor-based state-feedback gain is computed to obtain the desired setpoint response. Finally, to evaluate the performance of the proposed controller, it is compared through simulations with another recently published controller. Gabriel F. Machado, Juliana S. Barros, Bismark C. Torrico, Fabrício G. Nogueira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3694 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3695 This paper proposes an hydrothermal scheduling model for hydrothermal systems based on robust optimization. In the proposed model, the uncertainties in the water inflows to the system’s reservoirs are handled by means of the robust optimization approach, in which water inflows are treated as variables and optimized within a range of values denominated uncertainty set. The generation and operational policies obtained by the model are “immunized” against the uncertainties in the inflows, within the previously established uncertainty set, providing greater security and operational reliability to the system. The results obtained from 100 simulation processes of the decisions calculated by the proposed model show the robustness of the decisions obtained, which are 100% immunized in the range of the region of uncertainty, as expected. João Paulo Manarelli Gaspar, Leonardo Nepomuceno Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3695 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3696 Recently, a new architecture for decentralized diagnosis called Decentralized Syn- chronous Diagnosis has been proposed. In this scheme, local diagnosers are computed based on the fault-free behavior of the system components, which reduces the size of the diagnosers for implementation. Although this method has been successfully implemented, its main drawback is the growth of the fault-free language of the system for diagnosis, which reduces the diagnosis efficiency. In this work, in order to circumvent this problem, we propose a decentralized synchronous diagnosis with coordination (DSDC) that refines the diagnosis status using cluster automata of the local components. To do so, we also propose a communication protocol between local state estimators and the coordinator. We show that this method prevents the growth of the fault-free language for diagnosis, which guarantees the same diagnosis performance as the traditional centralized diagnosis method. In addition, to show the usability of the method, a practical implementation in a didactic manufacturing system is presented. Patrícia C. Mayer, Felipe G. Cabral, Marcos V. Moreira, João Pedro F. de Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3696 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3697 This paper proposes an iterative algorithm based on linear matrix inequalities (LMIs) for the synthesis of state feedback controllers through distributed parallel compensation of Takagi-Sugeno fuzzy systems using homogeneous polynomial on the state Lyapunov functions. The proposed technique explores LMI conditions where the state-feedback gains appear linearly, so they can be treated directly as decision variables of the optimization problem, allowing the imposition of magnitude limitations on the gains in a straightforward way. The use of the decay rate as an objective function for the designed controller is also an immediate extension of the iterative algorithm, since it employs a relaxation directly related to such performance criterion. Numerical examples are used to compare the proposed method with another technique available in the literature based on quadratic Lyapunov functions, demonstrating the advantages of the proposed approach. Yara Q. Marinho, Ricardo C. L. F. Oliveira, Pedro L. D. Peres Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3697 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3698 Faults in distribution systems directly affect the indices of power quality and the system’s reliability, causing high financial costs. Therefore, precisely determining the fault location reduces the time spent for the system’s maintenance and restoration, especially when there are permanent faults. The objective of this work is to present a fault location algorithm based on the theory of traveling waves. The algorithm consists of analyzing the high frequency signals of the fault, using the Discrete Wavelet Transform, which accurately detects the reflected waves, after the fault, at the ends of the line. The proposed approach was validated using simulations in the software PSCAD/EMTP, considering the CIGRE test system with radial topology. The results obtained are promising, since the faults were located with average errors less than 1%. C. V. C. Grilo, L. S. Lessa, D. V. Coury, R. A. S. Fernandes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3698 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3699 This paper aims to analyze the influence of input variables on the performance of electric motor bearing fault classifiers. For this, the decision tree algorithm is used to determine and order the relevance of each input variable in the classification process. In this case, the relevance of seven time-domain variables associated with motor shaft vibration signals are analyzed (RMS, peak, minimum, maximum, standard deviation, kurtosis and creast factor). Then, a performance analysis is performed between the number of fault classifier inputs by the accuracy obtained by it. With this, one can observe the best relationship between efficiency and effectiveness of the classifier. The results were obtained using data from the benchmark of Case Western University. Rafael Fernando Silva e Souza, Mailson Ribeiro Santos, Luiz Affonso Guedes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3699 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3700 This article presents a comparison between IoT architectures focused on monitoring the purified water production station of a pharmaceutical industry. The main difference between the two architectures presented is in the configured topology and in the communication protocols used to collect data from IoT devices installed on the equipment. The first architecture is based on the use of the MQTT (Message Queuing Telemetry Transport) protocol, where each device sends the collected data individually and the consumer is responsible for the organization. The second architecture is based on a wireless sensor network using the ESP-Now protocol, in which a centralizing device is added to manage and synchronize data. The results demonstrated the greater stability and reliability of the second architecture, but there are advantages and disadvantages in the two configurations detailed in the article. Hugo Brian de Carvalho Cortez, Lucas Batista da Fonseca, Heitor Medeiros Florencio, Jefferson Doolan Fernandes, Vitor Vale Pereira, Gabriel Cavalheiro Francisco Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3700 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3701 Facial recognition technology is constantly being used in the most diverse sectors, from facial expression analysis to measure customer satisfaction in stores to a police instrument for identifying people. To summarize, from an image obtained by a camera, the technique identifies faces contained in that photo and compares them with a database of faces previously registered in the system. Based on advances in terms of algorithms and processing of hardware obtained in recent years, it was possible to provide solutions for verification and facial recognition through modern cell phones. The present work addresses the problem of facial recognition analysis that has the potential to scale for applications based on server processing. Using Histogram of Oriented Gradients to extract face features and the FaceNet Convolutional Neural Network this study brings results in different public (Labeled Face in the Wild and CelebFaces) and private databases. This study obtained satisfactory results with an accuracy of 90% in the best cases for private databases. As part of the work, this study also sought to evaluate the effect of partial occlusion on faces from the use of face masks because of the Covid-19 pandemic scenario, obtaining satisfactory results above 80%. Iago Belarmino Lucena, Lucas de Oliveira Santos, Matheus Araujo dos Santos, Adriell Gomes Marques, João Matheus Lima Lucio, Luís Fabrício de Freitas Souza, Paulo Antônio Leal Rego, Pedro Pedrosa Rebouças Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3701 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3702 Complex control applications, such as robotics and aerospace engineering, often require nonlinear control strategies. In the backstepping, feedback linearization, and sliding mode control, online trajectory generation is a major requirement in improving the controller performance, leading to high precision tracking. Its purpose is to generate continuous and bounded trajectories that are derivatives of a rough input reference signal, such as steps and pulses. In this context, this paper proposes the use of a non-parametric filter based on the real- time Singular Spectrum Analysis (SSA) method for online trajectory generation. The SSA is highly adaptive to the behavior of signals, including non-stationary ones, through its spectral decomposition. Additionally, is more selective than a simple Finite Impulse Response (FIR) filter, commonly used for generating trajectories. It can identify and extract components, smooth, and denoise a signal. Some experimental results show that SSA can be used as trajectory filter, by successfully generating bounded derivatives from discontinuous input signals. Moreover, empirical adjustment of the fixed filter parameters resulted in similar responses as those obtained for a parametric trajectory filter. These findings provide a potential mechanism for further researches regarding complex and non-stationary signals. Emerson Alves da Silva, Leonardo Amaral Mozelli, Víctor Costa da Silva Campos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3702 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3703 Stroke is the second leading cause of death worldwide. Those who survive usually experience vision loss, speech, paralysis, or confusion. Agile diagnosis proves to be decisive for patient survival. This paper presents a proposal for rapid stroke segmentation in cranial CT scans, with 1 second, on average, by sample. The segmentation stage uses Parzen window density estimation to classify potentially injured regions in this approach. A proposed adaptation of the µ-law algorithm is applied to enhance damaged areas about healthy brain regions. The results show that the proposed method has the highest mean of accuracy, reaching 99.85%, with a specificity of 99.94%, surpassing classical methods by 16%. On the other hand, the algorithm presented similarity indexes of 93.39% for the Matthews correlation coefficient and DICE of 93.35%. The proposed methodology also compared the results with four approaches that use deep learning; it proved to be equivalent in accuracy, DICE, and specificity, with superior results in sensitivity up to 8% to one of the approaches based on the recent Detectron2 neural network. The results indicate that the proposed method is competitive concerning the approaches already presented in the literature. Lucas de O. Santos, Aldísio G. Medeiros, Pedro P. Rebouças Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3703 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3704 Recenlty, many face reid strategies have been developped. These strategies create vectorial spaces capable of representing data on reduced dimensions. Such representations are produced by deep learning models that learn to maximize the intra-class similarity and minimize the inter-class similarity. The method described in this article proposes a new face reid strategy based on the Facenet model. It consists of training support vector machines on the euclidean distances calculated between the embeddings of the Facenet model, notably reducing the false positive rate. Yves Augusto Lima Romero, Ajalmar Rêgo da Rocha Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3704 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3705 This paper presents the design of a robust PI controller for a building automation thermal system. The objective of this work is to designing a controller that, when introduced in the system, keeps it stable and with desirable characteristics even with small variations in the parameters of the plant. The robust controller design was successfully carried out and through simulations, a behavior that meets the design specifications is observed, even with variations in plant parameters and the control signal remained at adequate values Vanessa de Souza de Oliveira, Márcia Lissandra Machado Prado Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3705 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3706 Controllers with Proportional, Integral and Derivative (PID) actions are widely publicized and implemented in academia/industry. However, embedded applications in Programmable Logic Controllers (PLCs) in industrial processes is still a novelty. In this article, we present the development and simulated results of a PID controller algorithm with null Integral (I) and Derivative (D) actions to be embedded in PLCs, with application in the operational speed control of steel belt feeder of a car dumper, conceived in the CODESYS virtual simulator and embedded in a virtual PLC, also in the CODESYS simulation software, still in this context, the PID controllers algorithm is tested and validated in the MATLAB software. José Pinheiro de Moura, João Viana da Fonseca Neto, Bianca Fontenele Lemos Veras Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3706 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3707 Partial shading conditions can significantly reduce the efficiency of a photovoltaic (PV) system. The literature has presented increasingly sophisticated techniques to deal with this problem, considering that conventional maximum power tracking (MPPT) approaches are inefficient in such a case. In this sense, this paper presents a comparison among four techniques for determining the maximum power point (MPP) when the irradiance levels incident on the PV modules are not uniform. Gray wolf optimization (GWO), differential evolution (DE), bat algorithm (BA), and golden section optimization (GSO) are chosen for this purpose. Simulation results on a total-cross-tied (TCT) PV string connected to a dc-dc single-ended primary inductance converter (SEPIC) are presented and discussed to compare the aforementioned approaches. Fábio Inácio da Silva, Caio Meira Amaral da Luz, Enio Roberto Ribeiro, Fernando Lessa Tofoli Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3707 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3708 Automatic speech recognition is essential for machines to understand the content of words and sentences in a spoken language. Machine learning models known as deep neural networks are the focus of actual research in the artificial intelligence area, obtaining superior results compared with classical models and enabling the learning of features through unlabeled data. Despite the significant advance in applying these models to languages with a low volume of labeled data, there is still a barrier to the practical use of speech recognition models caused by the domain mismatch between training and inference data. This article proposes a methodology for simulating radio communication characteristics, enabling the development of datasets oriented to the robust training of neural models. The simulation was carried out through the implementation via software of a narrowband FM transmitter and receiver, together with the noisy communication channel. A state-of-the-art speech recognition architecture is also implemented and trained using advanced regularization techniques. When performing the training with the simulated data, it is was observed a relative reduction of 51.7% in the character error rate considering the most challenging noise level (SNR of 0 dB), with a similar decrease at all noise levels. We expected that the methodology developed in this work would open space to develop more robust speech recognition models with future applications in radio communication. Lucas Grigoleto Scart, Raquel Frizera Vassallo, Jorge Leonid Aching Samatelo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3708 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3709 This work aims to present a hybrid solution for kinematic models. For this purpose, the closed-form solution and the parametric Denavit-Hartenberg solution are combined. The robot geometry chosen is a four bars pantograph with three DOF. The mathematical model was developed and simulated using the software GNU Octave and tested on an embedded system. The motion command used is based on a real-time online kinematic translator that allows the use of a general Cartesian CNC to command a non-Cartesian robot. The kinematic model was validated by comparing a desired commanded trajectory to the translated, executed trajectory. This proved that the mathematical solution is simple enough to be implemented in a low-cost embedded system. Kassio M. Kienitz, Eduardo José Lima II Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3709 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3710 This article performs the electromagnetic study of a transformer prototype, through the application of computer simulations with the Finite Element Method (FEM), using the ANSYS Maxwell© program. The study aims to analyze the transient energizing currents in transformers and the consequent Lorentz electromagnetic forces in the equipment windings. For this, the geometry of the transformer windings is designed with divisions, allowing the measurement of radial and axial Lorentz forces at different locations in the windings. Four cases were simulated, each case refers to a reclosing instant in the voltage wave angle. Two cases are recurrent in the bibliography, such as maximum and minimum Inrush current situations. The other two cases are intermediate and proved to be relevant for understanding the operation and design of transformers. Gabriel C. Nogueira, Richard G. Cornelius, Leonardo H. Medeiros, Micael M. Oliveira, Vitor C. Bender, Carlos E. G. Falcão, Tiago B. Marchesan, Rodinei Carraro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3710 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3711 This work proposes a hybrid wind power generation system connected to the power grid through a back-to-back converter. The Grid Side Converter (GSC), connected to the eletric grid via an L filter, mitigates harmonic currents and corrects the power factor of a non- linear load connected to the Point of Common Coupling (PCC). The Machine Side Converter (MSC) implements the Rotor Field Oriented Control (RFOC) in dq Synchronous Reference Frames (SRF). This technique enables independent and decoupled control of the torque and magnetization of the Squirel Cage Induction Generator (SCIG). The torque reference is obtained through the Maximum Power Point Tracking - Optimal Torque (MPPT-OT), this method tracks the maximum power point based on the calculation of the optimal electromagnetic torque obtained from the measurement of the mechanical speed of the generator. Joham Lucas Dos Santos Albuquerque, Isaac Rocha Machado, Samelius Silva De Oliveira, Alan Robson De Sousa Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3711 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3712 This paper describes the implementation of an engine automation system that uses ESP-NOW and MQTT (Message Queue Telemetry Transport) protocols to send data. The main objective of the system created is to avoid data loss due to eventual failures in the communication network. To this end, the system developed has the ability to use two network topologies: Mesh and Ad Hoc. As a way to verify its operation, tests were performed, where the implemented system was allocated to control an exhaustion system, a compression system, and a water level control system. After the tests carried out, it was found that the system achieved its main objective and its use in production lines in the industrial sector is feasible. Lucas H. Santos, Eduardo J. da Silva, Marinelson P. de Santana, Lucas R. Morais, Elen P. Lobato, Wellington S. Fonseca, Marcelo de O. e Silva Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3712 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3713 Offshore oil and gas production units need to treat and dispose their produced water respecting the limits and reference measurement methods imposed by current laws. The main index to be controlled of this treatment process is the Total Oil and Grease (TOG) in the water to be discarded, which has its official value available for only about 20 days after the disposal is carried out. This work evaluates two neural network models with Long Short-Term Memory convolutions to estimate the TOG value from process variables, laboratory analysis and other data. Due to the dynamics of the process, data windows of 48 hours are used before the TOG value to be estimated. The results obtained indicate that the proposed models are as good as those presented in the literature, and better than simpler models to estimate the TOG value. These results corroborate the feasibility of using methods based on recurrent neural networks in the industry as a means to implement an online sensor capable of estimating the TOG and assisting in the decision-making of a platform operators regarding the continuity of water disposal to the sea. Karina dos Reis Teixeira, José Marques Oliveira Júnior, Ricardo Emanuel Vaz Vargas, Patrick Marques Ciarelli, Celso J. Munaro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3713 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3714 Given the current situation of electronic waste (e-waste) production, aiming at reducing costs and development of sustainable laboratory practices, this article proposes a low-cost platform to develop experiments for automation course using e-waste. The practices are about flow and level control, which make up many industrial processes and students have the opportunity to work from the characterization of the sensors used to the controller. The developed platform can be controlled by microcontrollers or industrial programmable logic controllers (PLC) and experiments that were carried out in different subjects are discussed, which demonstrates that the platform can be versatile and flexible, being used in multidisciplinary experiments (which may involve instrumentation, control, data acquisition, human-machine interface, among others). The total cost of the platform was approximately R$104.50 and to evaluate the result, a questionnaire was applied to students who indicated that they had approved the use of the platform. It is expected that this type of solution will be increasingly disseminated to the community. Pedro Marcelo Vieira Leite Júnior, Pedro Marcelo Vieira Leite, Ademar Virgolino da Silva Netto, Carlos Alberto de Souza Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3714 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3715 As part of the modernization of distribution systems, distribution companies install wireless smart concentrators in low-voltage electrical networks to communicate with smart meters installed in final consumers. Such concentrators record information that the distribution companies can use in their planning and operation studies. However, in extensive electrical networks, the installation of these concentrators requires a high investment on the part of distribution companies. To assist in the study of optimized allocation of wireless smart concentrators, the computational intelligence techniques genetic algorithm, particle swarm and variable neighborhood search are analyzed in this work, as they present a rapid convergence within the search space. The objective function of the problem considers the minimization of the number of installed concentrators to maintain the coverage of all the nodes of the electrical network. Additionally, as the extensive low voltage feeders cover regions with different radio propagation characteristics and each wireless communication technology has a different range, a mathematical model was used that considers that each concentrator may have a different coverage radius, depending on the type of communication device used and the urban obstacles that are in its surroundings. Thus, in the optimization process, the availability of two different communication systems based on ZigBee technology was considered, according to the signal range, propagation characteristics in the study area and operation and maintenance costs. Cristoercio A. Silva, Gian C. Garcia, Renzo Vargas, Ivan R. S. Casella, Joel D. Melo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3715 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3716 This work presents the development of the mathematical equations of the Active Disturbance Rejection Control (ADRC) technique in its order n , followed by an computational implementation of the controller. As from the computational implementation, two systems are considered for its validation: a mass block position control system and a liquid level control system. All simulations were performed in the virtual laboratory of control systems iDynamic. The simulation results show that ADRC presents good smoothness for system reference changes, less wear and control effort when well configured, in addition. Lívia de Maria C. M. Soares, Leony O. Bernardo, Lilian G. P. Santos, Pedro H. M. Isidoro, Glauber R. Leite, Allan M. Martins, Ícaro B. Q. Araújo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3716 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3717 The employment and incorporation of new technologies in the agriculture field allows a new mean- ing to productivity and efficiency. Among its various pillars, autonomous robotics promotes improvements in production, through increased safety in the coexistence between robots and humans, in the execution of various activities. This work presents the use of a low cost prototype controlled by two Fuzzy techniques.The proposed model allows representing the dynamic behaviour of a mobile robot in presence of changes in the environment. A Hierarchical Weighted Fuzzy Logic Controller composes the second navigation system. Simulation results are presented allowing a comparison among both systems and showing the ability of the mobile robot to navigate among obstacles in different scenarios (navigation environment). Márcio Mendonça, Wagner F. Godoy, Rodrigo H. C. Palácios, Carlos Renato Alves Oliveira, José Augusto Fabri, Emerson Ravazzi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3717 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3718 Simulations applied in the educational context are capable of providing considerable support in the learning process of a given area of knowledge. This work proposes the development of an interactive, free and open source simulation software for educational use in the context of Linear Systems Modeling and Analysis. Within the scope of the discipline, the proposed software allows creating and graphically simulating variations of user-defined scenarios in real time or instantly. Using data from a plant of tanks created and measured in one of the related works, it was possible to validate the software implementation of this work by replicating the same experiment virtually. By obtaining a model response relatively similar to the original study, we concluded the validity and relevance of the simulation system in the target context. Ítalo A. Aguiar, Marcus V. Paula, Rodrigo A. Ricco, Rodrigo G. Ribeiro Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3718 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3719 In this article we propose a numerical method to compute an observer-based output feedback controller for fuzzy Takagi-Sugeno (T-S) systems subject to state and control constraints, based on the theory of invariant sets. Sufficient conditions are established for a polyhedron defined in the augmented state space (state + estimation error) to be positively invariant in two cases: when the membership function associated with the fuzzy T-S model can be calculated directly from the measured output of the system or when it has to be calculated from the state estimated by the observer. From these conditions, a bilinear optimization problem is formulated for the simultaneous calculation of the gains of the controller and of a positively invariant polyhedron guaranteeing the satisfaction of the constraints. Two examples illustrate the effectiveness of the method. Isaac D. Isidório, Carlos E. T. Dórea, Eugênio B. Castelan Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3719 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3720 The Brazilian Sign Language (Libras) enables deaf people to understand and interact with others in order to facilitate their access to culture, knowledge and social integration. However, there are only few solutions to reduce the communication barrier between deaf and hearing people. In this work, we propose a solution based on deep neural networks for sign language recognition. This is an exploratory study in which signs in Libras (“Hello”, “Good morning”, and “Thank you”) are used in training, recognition and classification in continuous and real-time mode. We compared two machine learning models that were trained on the LSTM and BiLSTM neural network architectures. The results point to superior assertiveness of the LSTM model, with an accuracy of 84.71% compared to the 77.07% achieved by the BiLSTM model. Therefore, the LSTM architecture is more suitable for classifying the signals investigated in this study. Besides, its use in sign image recognition systems in Libras proves to be viable. Jhon Lucas S. Silva, Gabriel S. Vieira, Afonso U. Fonseca, Fabrizzio Soares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3720 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3721 The main drawback of identification of Discrete Event Systems with aim of fault detection is that if the system is composed of several subsystems with concurrent behavior, it may be necessary to record a huge amount of data to obtain the monolithic model with a view to guaranteeing that a large part of the possible fault-free system behavior has been observed. In these cases, we can use a distributed identification technique, where models for the fault-free behavior of the subsystems are obtained, and then these models are run in parallel for fault detection. In this work, we present a method for identifying concurrent subsystems based only on the observation of the input and output controller signals. A virtual plant, simulated using a 3D simulation software and controlled by a programmable logic controller, is used to illustrate the proposed method and to compare the efficiencies of the fault detection methods using the subsystem models and the monolithic model. José G. V. de Castro, Gustavo S. Viana, Marcos V. Moreira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3721 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3722 Against with several disturbances that affect the distribution system, High Impedance Faults (HIF) are considered one of the biggest problems faced by electricity supply concessionaires. This phenomenon occurs when the primary conductor comes into contact with a high impedance surface, generating fault currents with low amplitudes. In this way, the currents coming from a HIF, cannot sensitize conventional protection devices that are driven by overcurrent’s. However, this type of fault evidences peculiar characteristics in the current signals and, therefore, through the characteristics, this present work has as main objective to develop an algorithm capable of detecting as HIF, through the junction of the Wavelet Transform (TW) with the Linear Predictor (PL) defaults on typical fault currents signals, using a test system model of um Brazilian electric power utility, varying the contact surfaces, buses and their respective loads, showing promising results in the detection of HIF. Ariel L. Damião, Reginaldo B. G. Grimaldi, Márcio da S. P. Bove, Flávio C. T. Maia, Tarso V. Ferreira, Wellinsílvio C. dos Santos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3722 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3723 This paper deals with recursive robust regulator problem for polytopic discrete- time systems with state delay. We assume all matrices of the system are subject to polytopic uncertainties. Based on the augmented approach, the delay system is converted to an augmented delay-free polytopic linear system. The state-feedback control is then obtained by the convex optimization problem in which the polytope vertices are weighted altogether. The provided solution is given in terms of augmented Riccati equations presented through a symmetric matrix arrangement. With a numerical example, we evaluate the proposed control and compare its performance with other control approaches. Elizandra K. Odorico, Marco H. Terra Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3723 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3724 This work investigates the application of the type-2 fuzzy control’s technique in general anesthesia. Firstly, a literature review was made for the work. On this review, type-1 and interval type-2 fuzzy controllers were studied. And for the realization of the case study, an investigation of procedures in anesthesia was also made. After this study, a pharmacokinetic/pharmacodynamic mathematical model of the effect of the drugs Atracurium and Isoflurane in the human body was implemented. Type-1 and interval type-2 fuzzy controllers with two and four inputs were designed using the Fuzzy Logic Toolbox in MATLAB. Simulations of the control of anesthesia, from the mathematical model, were created using MATLAB scripts and validated with Simulink using four controllers for a performance comparison. Simulation results showed type-2 fuzzy controllers’ superiority against type-1 with the same number of inputs, however it was possible to see that the bigger number of inputs were beneficial for type-2 control as well as type-1. And finally, a comparative analysis was made, thus the conclusion was that type-2 fuzzy logic is a good alternative to control multivariable and nonlinear systems. Giovanni O. de Sousa, Cleonor C. das Neves, Carlos Tavares da Costa Junior, Marcus Ciro Martins Gomes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3724 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3725 In recent decades, the search for alternative energy sources with low environmental impact has intensified. In this context, the concept of Energy Harvest emerged, which refers to the use of ambient energy and its conversion into electrical energy in order to power low- power electronic devices. Among the most varied forms of energy available in the environment, thermal energy has been highlighted, particularly in the conversion of thermal energy into electrical energy through Semiconductor Thermoelectric Generators (TEGs). In this article, experimental results of the behavior of a commercial TEG will be shown when subjected to different thermal standards applied to it. For this, a generator of thermal patterns was developed using the software LabVIEW, making it possible to determine values of temperatures that will be submitted to the TEG with the support of a Thermal Emulation Platform. Therefore, it is possible to analyze the dynamics of the electrical voltage effectively generated by the TEG in different thermal scenarios. Mariana Marques Ferreira, Maria Paula Medeiros Gomes Miguel, Cleonilson Protásio de Souza Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3725 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3726 Automated Guided Vehicles (AGVs) are essential for industry material transportation. In the Industry 4.0 and Industrial Internet of Things scenario, edge computing combined with new generation networks may support the navigation control of AGVs. Centralizing on edge not only facilitates the integration of the control system with the other factory systems but also reduces the cost of vehicles and battery consumption once the edge computing allocates the tasks which require more computing power. From the results of previous experiments, we found that Model-Based Predictive Control, together with edge computing and wireless networks, is a robust control solution for AGVs. The Model Predictive Control’s predictive nature can keep vehicles stable even in delays or packet loss on the network. Besides that, this approach promotes free navigation without fixed paths, which reduces costs and facilitates layout changes. Therefore, based on previous results and literature review, we propose an architecture for AGVs control with edge computing using the Model Predictive Control in this paper. The proposed architecture can support the AGVs navigation on smart factories of Industry 4.0, also in cases of network signal degradation. Rômulo A. L. V. de Omena, Danilo F. S. Santos, Angelo Perkusich Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3726 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3727 This paper examines regulation, operation, and performance of the Brazilian retail electricity market. In March 2021 was approved the Law Nº 14.120, that includes mechanisms for the switch-off of consumers inserted into the retail trader profile in the Chamber for Commercialization of Electricity (CCEE). After this new regulation it is expected a market modernization and increase of retail competition for all consumers to join the free market. In addition, a set of concepts related on retail electricity market is presented, focus on retailer. Following on, studies of retail market operation involving CCEE are performed, analyzing risks and the financial viability of this new market commercialization model. To demonstrate the consumer migration process, from regulate to free market, using retail trader, are analyzing the process transition, risks and economic profits. Artur Bello Rodrigues, Flávio Antonio Becon Lemos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3727 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3728 Ainda hoje, máquinas de corrente contínua (cc) de grande porte são muito utilizadas, porém, a operação dessas apresenta como principal gargalo coleta de corrente; suas condições ditam a vida útil, a frequência e a gravidade das falhas, assim como o número e o custo das manutenções. Este trabalho pretende investigar o desempenho da comutação em função da alteração do material da escova, da pressão de molas implementada, da corrente de operação e de outras variáveis relevantes; em todos os casos, propõe-se conduzir o estudo sob a perspectiva da formação e conservação do filme de carbono, buscando reduzir o coeficiente de atrito e, consequentemente, o desgaste das escovas e do comutador. Ao final, visando a previsão do desempenho da comutação antes de testes operacionais, apresenta-se um procedimento experimental para a medição do atrito e da temperatura no contato seco de uma máquina cc do metrô de Belo Horizonte com histórico de desgaste anormal no coletor e elevado consumo de escovas. Igor H. M. Campos, Thales A. C. Maia, Marco T. C. de Faria Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3728 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3729 The load imbalance in the low-voltage grid phases compromises the load stability also power quality provided to the final consumer. In this, sense, the phase-load-balance of grid by dynamic switching, is an efficient way for this problem. However, is important to establish a load stability for a long-lasting. This article proposes a phase balance local controller model based on combined algorithms, that considers beyond the current state of monthly load consumption (of final consumers) its twelve-step forward forecast. Providing, an optimal switching selection based on, the load consumption future state in the final consumer’s phases. The model is developed in Hierarchical- Petri nets. The results point to an efficient attenuation of phase imbalance, applied to three kinds of consumers (single-phase, bi-phase, and three-phase). Therefore, ensuring in low- voltage circuits, the load balance for long-duration. José R. Sicchar, Carlos T. Da Costa Jr., Raimundo C. De Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3729 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3730 The knowledge of the electromechanical modes of the power system allows the operator to identify possible small-signal stability problems and to evaluate if the continuous supply of electrical energy may be compromised. This paper proposes a multistage algorithm to estimate electromechanical modes based on measurements of Phasor Measurement Units (PMU). At each stage, the algorithm determines a mode that minimizes the mean squared error with respect to the corresponding measured signal. Thus, the algorithm starts by estimating the first mode and each subsequent stage corresponds to the estimation of another mode. The algorithm converges when the error between the measured and the reconstructed signals is smaller than a pre-defined threshold. Case studies using real PMU measurements are presented and discussed, and illustrate the effectiveness of the application of the proposed algorithm. Murilo E. C. Bento, Tatiane C. C. Fernandes, Ahda P. Grilo-Pavani, Rodrigo A. Ramos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3730 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3731 This work presents a modified version of the Merlin-Back constructive heuristic algorithm applied to the distribution system reconfiguration problem. The Merlin-Back algo- rithm is well known for its simplicity in understanding and computational implementation. This algorithm finds good-quality solutions in very short computational times. However, as the complexity of the reconfiguration problem increases, the Merlin-Back algorithm does not find the optimal solutions. In this work, the Merlin-Back heuristic is analyzed in detail, identifying its quality and defects. In this way, it was possible to introduce a modification in this heuristic to increase the potential to find excellent quality solutions. The tests show that the modified algorithm finds the optimal solutions of three electrical systems widely used in the literature for distribution system reconfiguration. Amanda Bortoloci, Leonardo H. Macedo, Rubén Romero Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3731 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3732 This paper presents an experimental study on the impact of the temperature of bearings employed in a dynamometer bench for motor performance testing on the test results. To evaluate the relationship between the variables, an automatic test bench capable of measuring small variations of electric power was developed, adapted with a heating system for the motor bearings. The tests were performed with low-power brushless DC motors (electric power of about 10 W) and with grease lubricated metal ball bearings. The results showed that raising the operating temperature of the bearings to a point above that they would naturally reach during operation guarantees a fixed condition for the tests, thus reducing the variability of electrical power between tests from 0.82% to 0.04%. As a consequence, the use of the temperature control system for the bearings is capable of reducing the power variability within a test, as well as guaranteeing that tests performed in different time instants are under the same condition. Those characteristics enable the possibility of performing consecutive tests and improve the reproducibility of the test results. João P. Z. Machado, Rodolfo C. C. Flesch, Mauricio M. Schaefer, Gabriel Thaler Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3732 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3733 Power plants operating in a combined cycle have higher thermal efficiency (up to 80% INEE, 2022) and greater generating power when compared to traditional single cycles, such as gas or steam turbines operating alone. Gas turbines have unique characteristics in the steel making process, being able to operate with gases of low calorific value from steel plants, such as blast furnace gases (BFG), and with conventional fuels, such as natural gas, and even with a mixture of these gases enriched with the steel plant gas (BOF). This study aims to dynamically model and simulate the behavior of gas turbines and propose solutions for the optimization of the distribution of fuel gases in gas turbines operating in a combined gas/steam cycle, finding the ideal solution in terms of cost reduction and maximization of net income. The plant has a combined cycle block formed by two gas turbines of 90 MW each and a steam turbine of 320 MW, totaling 500 MW. The model was simulated with the GT operating in parallel with the power grid and the combined cycle with compressor inlet guide vane (IGV) control. The model was developed in MatLab's Simulink®. Geisa Moura Costa, Walbermark Marques do Santos, Domingos S. L. Simonetti Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3733 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3734 This paper presents a technical analysis that shows the relevance of considering the ZIP model in the load flow problem applied to electric power distribution systems. The main objective of the analysis is to numerically evaluate the impact of this modeling in the solution of optimization problems traditionally addressed in the planning of power electrical systems. The mathematical analysis performed using the IEEE 118-bus theoretical network demonstrates that the technical losses and voltage profiles obtained in the optimal solution of the problem differ when three ZIP model scenarios are considered, which means that this approach should not be neglected in system planning and operation studies, since non-consideration of the ZIP model can bring impacts on the network diagnostic and consequently lead to imprudent investments from the perspective of the minimum overall cost required by ANEEL. Arthur O. Silva, Lina P. G. Negrete, Gelson A. A. Brigatto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3734 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3735 This work presented a version for the power flow method via current injection fast decoupled, BX version. A comparative study between some existing techniques in the literature for solving the power flow based on power injection equations and on current injection equations is presented. Results for different loading values and R/X transmission line ratios were presented. In larger systems, for loading conditions close to the critical point, the proposed method presented a superior performance to the conventional method. C. C. de Oliveira, A. Bonini Neto, D. A. Alves, C. R. Minussi Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3735 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3736 In this work, Lagrangian Neural Networks (LNNs) were applied to determine the Lagrangian of a mechanical system and to predict its trajectory in the state space. Neural networks, Lagrangian mechanics, Newtonian mechanics, dynamic models, numerical integration, parametric optimization, and evaluation criteria were applied for the case study of a non-linear mass-spring-damper system. The trajectories predicted by means of the Lagrangian Neural Networks were compared to the data generated by means of computer simulations of Newton’s second law. The main conclusion of this work is that it is feasible to predict the trajectory of this system by means of Lagrangian Neural Networks. Furthermore, the flexibility of the LNN allowed the modeling of non-linear dynamics in the system. Sara A. Dias, Icaro M. F. de Santana, Saulo O. D. Luiz, Antonio M. N. Lima Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3736 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3737 Dynamic systems models are essential to perform tests and determine behavior of real systems in different situations, but their determination is often complex. The present work presents the use of an LSTM neural network (Long-Short Term Memory) to identify a tank system. The results of the training of two models are presented, one with a single neural network and the other with a split neural network and the results demonstrate that for the problem addressed, the use of the model with a split neural network can meet the purpose of simulating the system of tanks with a low error (on the order of a few millimeters) between the real value and the one estimated by the model, both for the prediction and simulation approaches. Kaíque G. Machado, Welington S. Santos, Daniel L. Martins, Adrião D. D. Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3737 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3738 The main objective of this research is to carry out a probabilistic short circuit analysis, using the Monte Carlo Method (MCM), applied to Voltage Source Converter (VSC)- High Voltage Direct Current (HVDC) systems. The definition of stochastic parameters and a method to ensure statistical significance of the phenomenon under analysis are addressed. Due to the large number of cases involved in the MCM calculation, parallel programming hosted in a cloud computing environment was used. This procedure saves a considerable amount of time in the process, especially considering the time that would be spent using conventional transient programs. The result is the probabilistic density function that shows the probability of overcurrent and overvoltage magnitudes that the system may experience. This information is particularly important for component design, protection setting, life time expectancy assessment, grid stability and maintenance planning. Guacira Costa de Oliveira, Renato Machado Monaro, Denis Vinicius Coury, Mario Oleskovicz, Gilney Damm Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3738 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3739 This paper presents a proposal to expand the Temperature Control Lab (TCLab) educational tool for the ESP32 embedded platform, with a software interface adapted to the Firmata protocol and Sysex commands. This migration adds ESP32 features as DAC, bluetooth, WiFi and RTOS compatibility with its dual core architecture. Besides validating the usual PID control experiments, a brain emotional learning algorithm (BELBIC) was simulated and deployed, aggretating new educational skills and perspective to TCLab continuous development. Gustavo Pereira da Fonseca, Josenalde Barbosa de Oliveira Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3739 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3740 This work proposes linear matrix inequalities (LMI) conditions for the consensus of homogeneous multi-agent systems subject to disturbances and uncertainties in the topology of communication between agents. The consensus problem is rewritten as a stabilization problem, and a full-order dynamic output feedback controller is designed to guarantee the stability with ∞ performance criterion. The results are illustrated by numerical simulations that show the effectiveness of the proposed method. Natalia O. Borges, Bruno M. C. Silva, Eduardo S. Tognetti, João Y. Ishihara Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3740 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3741 In recent decades, CubeSat nanosatellites have made it possible for universities and small companies to study these technologies and go to space. In this context, the National Institute of Spatial Research (INPE) proposed the CONASAT project, which has as its goal to update the Brazilian Environmental Data Collection System (BDCS), replacing the old satellites with a new CubeSat constellation. The BDCS, beyond satellites, is also composed of ground stations and Data Collection Platforms (DCPs) spread across the Brazilian territory. This paper presents the design of an onboard computer (OBC), made of components off-the-shelf (COTS), for low-orbit CubeSat satellites. Aiming to obtain the requisites for digital systems in low- orbit, it proposes the electronic schematic and the printed circuit board (PCB) of an onboard computer compatible with the architecture and with all subsystems of the first satellite in the BDCS constellation, the CONASAT-01, as well as the software and operating system required for the mission. The developed board embeds FreeRTOS on an STM32 microcontroller to manage and execute the missions’ tasks, such as housekeeping, supervising telecommand & telemetry, and sending and receiving data from ground stations. All the communications drivers were also developed. The nationalization of the OBC compatible with the scheduled mission and with the global market is one of the main contributions of this paper: it strengthens Brazilian satellite research as it helps to develop the next CONASAT CubeSats. Camila Barbosa, Samaherni Dias, Kurios Queiroz Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3741 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3742 Microgrids aggregate technologies that represent the main drivers of a disruptive transformation in the energy sector: decarbonization, decentralization and digitalization. The distributed and varied nature of the energy resources of a microgrid promote the fragmentation of the electric sector value chain, making the optimal dispatch more complex. In this regard, this paper presents three distributed optimization methods, Consensus, Diffusion and Exact Diffusion, applied for the solution of the optimal dispatch of an islanded microgrid. The methods are enhanced in order to ensure better performance and balance among generation, demand, and energy storage. The optimization approaches have demonstrated suitable results with emphasis to the performance of the Diffusion and Exact Diffusion methods, which have been little explored in the literature so far and have presented a considerable efficiency gain to microgrids optimal dispatch purposes. Natalia Pimentel Lado Ces, Nathanael Duque Gadelha, Janaína Barbosa Almada, Ruth Pastora Saraiva Leão, Raimundo Furtado Sampaio Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3742 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3743 This work proposes a methodology to estimate the electric power generation by a photovoltaic array of an autonomous convertible Unmanned Aerial Vehicle (UAV), along a known flight path. The methodology evaluates the integral of a vector field through the UAV surface to estimate the power generated by the cells of the photovoltaic array, in each instant of the fight. The models and calculations were performed in the software MATLAB, where were performed simulations of the photovoltaic power generation in the UAV. From an analysis of the power generation by the photovoltaic array and the energy consumption of the other power systems of the aircraft, results were obtained about the increase of the UAV’s energy autonomy due to the absorption of solar energy during the flight. Henrique S. de Sá, Leandro B. Becker, Guilherme V. Raffo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3743 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3744 Real-time simulation programs and hardware-in-the-loop (HIL) systems have been increasingly used in electrical engineering, each one with its own peculiarities. The company Typhoon HIL Inc. has software and hardware for HIL simulations. The complexity of the network, for example when there are multiple power converters, influences the modelling. Hardware model also impacts the circuit configuration. Therefore, depending on the complexity, it is necessary for the user to partition the circuit. Furthermore, the division into subcircuits tends to cause conflicts between elements, demanding the configuration of snubbers. In this context, the present work aims to present a modeling in the Typhoon HIL software, using as an example a network containing a Unified Power Quality Conditioner (UPQC), demonstrating a methodology for the correct functioning of the circuit and as a preparation for its use on a HIL system. In addition, an evaluation of the interference of the configured snubbers is performed. Victor S. Monteiro, Mateus C. Costa, Bruno W. França Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3744 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3745 Atmospherical wind wakes in wind farms can be the cause of efficiency loss, extra mechanical efforts, maintenance anticipation and component replacement. In this paper it’s presented a review of the recent studies that highlight the impact of these phenomenom and the strategies used to mitigate these negative impacts. Basic concepts are presented in order to have a better understanding about the issue, such as wind wake and wake steering effects. Wind wake analysis are also provided via LIDAR and SODAR data indirectly collected, whose results reinforce the idea of wind wake effects studies require precise models in order to preview the performance of wind turbines. Erika T. I. Barbosa, Renan C. Assis, Clóvis B. M. Oliveira, Audalio R. Torres Junior, Osvaldo R. Saavedra, Francisco L. A. Neto, Ramon M. de Freitas, Arcilan T. Assireu Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3745 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3746 A eletrificação veicular tem sido bastante discutida e aplicada em todo o mundo. Além da vantagem de reduzir as emissões de gases poluentes na atmosfera, a hibridização de veículos pesados pode trazer redução de custos operacionais, focando numa estratégia de redução do consumo de combustível. Este trabalho aborda o projeto do sistema de acionamento elétrico para hibridização de uma retroescavadeira. São apresentados os dimensionamentos de componentes, respeitando normas acerca do tema e, por fim, o projeto 3D inicial de uma bancada protótipo para posterior validação das estratégias de hibridização. Dener A. de L. Brandão, Mariana de F. Ramos, Thiago M. Parreiras, Thales A. C. Maia, Igor A. Pires, Braz de J. Cardoso Filho, Anderson Nascimento Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3746 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3747 This paper presents the development of a virtual real-time test platform for intelligend electronic devices (IEDs) with high impedance fault detection function. High impedance faults are very common events in overhead distribution systems, being difficult to detect due to it’s low current magnitude. Considering the difficulty of recording oscillographies of these faults, and the availability of real-time digital simulations, this paper proposes a test platform for protection devices. In order to accomplish this, a real-time simulation platform from Typhoon HIL Inc., equipped with a Typhoon HIL 604 is used. The elaboration and validation process of the high impedance fault model proposed by Gautam and Brahma (2013) is demonstrated, testing the parameters of three different surfaces. The results reflect what is expected for high impedance faults, with the tests occuring dynamically through the accesses of the low-level interface of the used IED. Jhonatan A. Cassol, Aldair Wontroba, Isabella B. Pereira, Ângelo F. Sartori, Fernando G. K. Guarda, Adriano P. de Morais Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3747 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3748 The constant incentives for distributed generation (DG) have led to a significant growth in the number of photovoltaic generators connected to electricity distribution systems. However, the effect of DG on low voltage networks is complex and difficult to analyze, since several factors, such as the ambient temperature, solar radiation and rated power of the generators, influence the power available in the electrical system. In this study, the limits of photovoltaic generation insertion in electricity networks were determined through the analysis of the impacts on technical losses and the voltage levels in steady state. Real parameters of feeder systems in the Celesc Distribution network were considered and simulations were performed using MATLAB and OpenDSS software. In addition, different combinations of power and location of the generating units were randomly selected and analyzed using the Monte Carlo method. Based on the results obtained, limits for the insertion of photovoltaic generation in the feeder systems under study were defined. André I. Cantão, Bruno S. Dupczak, Edison A. C. Aranha Neto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3748 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3749 PID controllers are still widely used in industrial processes, and their efficient operation requires the design of a filter. This filter makes the derivative action feasible and attenuates the measurement noise, reducing the variability of the control action. However, it influences the closed-loop performance and robustness. In this context, we analyze the effects of introducing a non-parametric noise filter based on the Singular Spectrum Analysis (SSA) technique. The SSA decomposes a signal into a set of additive components, including the measurement noise, in an adaptive manner. The filter was tested in First-Order Time Delay (FOTD) models, typical in industrial processes, for PI and PID controllers, designed by a optimized method, in scenarios with and without measurement noise. The Integral Absolute Error (IAE) metric measured the performance and the Total Variance (TV) the signal variability. The lag-dominated dynamics showed high sensitivity to changes in the filter attenuation degree in comparison with other processes. In contrast, for balanced and delay-dominated dynamics, the filter could improve both TV and performance. The PID achieved better performance than the PI for all processes and scenarios considered, but for higher TV. Emerson Alves da Silva, Leonardo Amaral Mozelli, Michel Carlo Rodrigues Leles Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3749 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3750 This work proposes the Allan Variance application to characterize the stochastic noises included in MEMS sensors signal to remove them through a dynamic filter. As an application, we use the SIRRS01-03 gyrometer to measure the Earth’s angular velocity. The Kalman filter implementation improved the performance of the characterized sensor, both in measurement accuracy and in the time required to converge to the value of the Earth’s angular velocity. The results indicate that it is possible to use this sensor in an inertial measurement unit to perform a self-alignment and a self-calibration procedure, which are essential in an inertial navigation system. Rafael G. F. Silva, Marcelo H. Jeronymo, Havena L. Pavan, Marcelo C. Tosin Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3750 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3751 In this work, the identification of the thermal system of a neonatal incubator is performed using a local ARX LPV model whose scheduling variable is the ambient temperature. The LPV model performance indices are VAF=97.90% and RMSE=0.0077. The performance of this model is compared with ARX LTI models obtained by fixing the scheduling variable of the LPV model. The identified model is used for the synthesis of an RST LPV controller by solving a PLMI by sum of squares relaxation. The closed-loop responses for the same reference step at different levels of the scheduling variable are quite close to each other. The pole map shows that the poles are confined around the desired target poles. The RST LPV controller is compared to fixed RST controllers. Igor R. Sousa, Felipe J. S. Vasconcelos, Fabrício G. Nogueira, Guilherme A. Barreto Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3751 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3752 In this paper, the optimized placement and sizing of capacitors for the compensation of the reactive power and the unbalance power in medium voltage distribution networks with unbalanced loads is proposed. The proposed capacitor allocation reduces power losses in power networks caused by reactive power demand and unbalance. The powers are calculated as proposed in the IEEE STD 1459- 2010, and presented real values of electrical magnitudes in unbalanced three-phase systems. The results of the capacitor placement obtained from the proposed method are compared with the placement of single-phase capacitor and the placement of balanced three-phase capacitor bank. The results allow to observe the efficient performance of the proposed method for reducing power losses in a 34-bus medium voltage power network with the presence of the neutral conductor. Four cases are simulated with results optimized by the Chu-Beasley genetic algorithm. The purpose of the optimization algorithm is to minimize line loss and capacitor costs. Marcelo Semensato Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3752 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3753 This paper proposes the implementation of the soft sensor based on an unscented Kalman filter, aiming at experimental validation of variables of difficult measurements, such as fluid viscosity, productivity index, and production flow rate in a pilot plant operated by ESP (Electrical Submersible Pump), completely instrumented with supervision system, collect and data registration. ESP operates under severe conditions, and loss or failure of unknown variables is still a recurring problem in the oil fields onshore and offshore. The suitable tuning of the soft sensor in an experimental scenario, resulted an efficient solution of the variables within the 95% confidence interval in a continuous ESP operation within 26 hours of the experiment. Odilon S. Luiz de Abreu, Erbet A. Costa, Tiago de O. Silva, Marcos Pellegrini Ribeiro, Leizer Schnitman, Márcio A.F. Martins Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3753 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3754 The objective of this research is to identify the energy management efficiency level of state public schools in the state of Ceará, using as parameters infrastructure data, operating characteristics and electricity consumption. For that, data envelopment analysis was used with an input-oriented variable returns model. The results indicate that schools with a higher level of infrastructure have a higher level of energy management and that the Ceará Department of Education can save about 5.1 million reais by making all its units reach the maximum efficiency benchmark. Gabriel Marçal da Cunha Pereira Carvalho, Daniel Barboza Guimarães, Fernando Luiz Marcelo Antunes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3754 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3755 This article aims to explain the application of a recent intelligent technique that is supported by the four basic operations of mathematics (+, −, ÷, ×) whose name is Arithmetic Optimization Algorithm (AOA). Therefore, the recent method is used, in this work, in order to solve the static planning of the expansion of electric power transmission systems, which is a complex issue, since it is a problem of Mixed Integer Linear Programming (MILP), presents several solutions and can lead to the phenomenon of combinatorial explosion due to the different alternatives. Finally, a comparison is made with the Genetic Algorithm (GA). All simulations were performed in the academic system IEEE 24 bus and the results show the applicability and efficiency of AOA in solving the problem in question. Renato Andrade Mosqueira Furtado, Ivo C. Silva Junior Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3755 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3756 This paper investigates the impact of the transmission line parameter calculation formulations in the evaluation of power and energy dissipated in line surge arresters. The results are achieved by simulations in ATP software, considering typical Brazilian conditions of transmission lines. The calculation of the line parameters is computed in three ways, namely: i) Carson’ formulation, ii) Nakagawa’s formulation considering the ground parameters constant with frequency, and ii) Nakagawa’s formulation considering the frequency-dependent characteristics of soil. Taking as reference the results determined by Carson’s formulation (since this formulation is the most used in programs for calculating transients), it is shown that Nakagawa’s formulations considering both constant and frequency-dependent soil parameters can lead to differences in energy dissipated in surge arresters in transmission lines partially or totally protected by surge arresters. According to the results, depending on the case, maximum differences in power and energies of up to 10.547% and 11.76%, respectively, can be found. Jaimis S. L. Colqui, Rodolfo A. R. Moura, Marco Aurélio O. Schroeder, José Pissolato Filho Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3756 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3757 One of the most common processes in modern control is the liquid level. Traditionally, the designers used the conventional PID (Proportional–Integral–Derivative) controller. However, the liquid level’s behavior is nonlinear, and in this way, the PID controllers only show a good performance near a determined operating point. This restriction produces limitations in the improvements to the system’s behavior, which compromises the economic benefits. As alternatives to the conventional PID, the researchers proposed several nonlinear controllers. But, some of them show very complex implementations in a real scenario. Thus, in this work, we propose a controller to the liquid level which does not require an operating point, has a simple design and implementation, is robust to external disturbances, uncertainties, and variations in the parameters. The work, beyond the proposed controller, presents results of stability analysis and simulations. Samaherni Dias, Kurios Queiroz, Aldayr Araújo Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3757 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3758 The success of research in the field of Artificial Intelligence has expanded the application possibilities of Service Robots. Among them, Social Robotics, which includes applications for the elderly, people with disabilities and other areas useful to society. A study indicated that the elderly dependency ratio in Europe would double from 28.4% in 2010 to 58.5% in 2060. Availability of smart home systems at reasonable costs for people with disabilities, may still depend on their adoption by the non-disabled population. This work presents the development of a low-cost Human-Robot Interaction system, based on Raspberry Pi. The system was initially tested with a simple interaction protocol for a small social robot under construction, obtaining good results in terms of object detection accuracy. Dialog processing speed can be improved and at the end of this study some ways to achieve this goal were identified. Leonardo Parra Melati, Lucas Heije M. Miura, Carlos José Steninger, Renato Mendes Teixeira, Marilza Antunes de Lemos Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3758 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3759 A critical activity in mining industrial environments is the inspection of regions that present unsanitary working conditions for human professionals, such as caves, pipelines and dam galleries. A possible solution to this problem is the use of a robotic platform for remote inspection. This article focuses on the inspection of galleries with repeated patterns and a limited number of bifurcations. As in this type of task, teleoperation is hampered by several factors such as communication limitations, one solution is autonomous operation. In this context, two autonomous navigation techniques are presented for the exploration of galleries: the first consists in a control by vector fields, while the second is a PID controller implemented with a state machine. Both methods are based on maze solving algorithms, lightweight and easily implemented depending only on a LiDAR sensor. The navigation systems are validated in simulations and with a real robot. In addition, the techniques are compared using two performance metrics, the first one is the total distance traveled and the second one is the absolute distance related to wheel spin. The results obtained hightlight the different characteristics of the navigation strategies according to the inspected environments. Israel Amaral, Carolina Fany, Guilherme Pereira, David Simon, Gilmar Júnior, Adriano Rezende, Victor Miranda, Vinicius Gonçalves, Jacó Domingues, Gustavo Pessin, Gustavo Freitas Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3759 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3760 In this paper, we propose a fault diagnoser for the drilling process on a CNC machine. The fault diagnoser uses only the spindle power and Z axis displacement read directly from the system controller, and does not need any additional sensors. The proposed diagnoser is capable of identifying the occurrence of a wrong sequence of events executed by the system and the use of a material different from the expected. Marcos V. Moreira, Anna C. Araujo, Yann Landon Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3760 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3761 The new Brazilian National Curriculum Guidelines (DCNs) estabilish theory and practice as inseparable. The practical experiments are an essential tool for the development automatic control skills. Thus, the present work presents a low cost motor-tachogenerator didactic module. The manufacturing process of the module is presented and the files of the electronic board, the 3D printed parts and the optional laser cut cover are made available in an online platform to allow reproduction. The module is validated experimentally to demonstrate its applicability. After analyzing the results it is found that the module meets requirements for an adequate practical experiment as well as its manufacturing cost is compatible with other low-cost works in the literature. Rafael Oliveira Pedrisch, Amanda Maria Monteiro Cerezini de Souza, André Luiz Barbosa Marinho, Artur Vitório Andrade Santos, José Diogo Forte de Oliveira Luna Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3761 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3762 This work describes a multiplatform system for testing and validating attitude determination systems based on magnetic and inertial sensors (MARG). The platform concept involves a simulation system and an electronic system. The first simulates body dynamics, MARG sensors data, and tests attitude determination algorithms. The electronic system, in turn, is modular and allows Software- and Hardware-in-the-loop simulations together with the simulation model. Thus, it allows algorithm testing with real sensor data and the analysis of these sensors. The work presents the project and the concept of the multiplatform and a prototype built with development boards. Results demonstrates the sensor calibration and attitude determination using two sets of MARG sensor data available at the prototype. Isadora Martines Ferreira, Daniel Strufaldi Bastista, Marcelo Carvalho Tosin, Francisco Granziera Jr. Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3762 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3763 This work presents a methodology for implementing the Local Modular Control Structure in Function Blocks of the IEC 61499 standard, in which the OPC-UA protocol is used in the communication between the plant and the controller. The presentation of the methodology is based on a case study, developed on a virtual plant of the FACTORY I/O, and the control of this plant is done through the FORTE execution environment, of the Eclipse 4diac platform. Ricardo Paes Rech, André Bittencourt Leal Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3763 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3764 The battery energy storage systems (BESS) have been gaining notoriety in recent years due to the high penetration of renewable energies in distributed generation, with the aim of providing a dispatchable and reliable energy source, in addition to serving ancillary services and assisting in infrastructure and energy management. It is noteworthy that in this implementation a multi-cell converter is used, in order to expand the power supply capacity, reduce the ripples in the electrical variables and reduce the volume occupied by the inductors of the dc/dc converters. This study presents the design and simulation implementation of a decentralized Phase Shedding strategy for an energy storage system. The converter is modeled and control equations are presented, as well as the development of Phase Shedding and Auto- Interleaving, bringing the results obtained. Vitor G. Neves, Renata C. da Silva, Maria J. F. Ramos, Clodualdo V. de Sousa, João L. da Silva, Victor F. Mendes Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3764 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3765 This paper evaluates the Volt-Var and Volt-Watt controls applied to photovoltaic distributed generators in order to raise the hosting Capacity (HC) of a distribution grid. The simulations compare the independent and joint performance of both Volt-Var and Volt-Watt controls using OpenDSS. Finally, their behavior is compared and the low voltage distribution network HC estimation tool is validated. This developed tool is flexible in terms of allowing implementation of advanced ancillary services and microgrid control. Hugo R. Torquato, Thiago M. Braga, Hélio M. A. Antunes, Danilo I. Brandão Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3765 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3766 The present work deals with algorithms for lateral position control and steering of land vehicles. The lateral position control is based on the Lookahead algorithm, and two methods for steering control are analyzed: classical and LQT. The Lookahead algorithm and the two designed controllers are evaluated in simulations for straight and circular paths. It appears that both architectures achieve satisfactory results, although they have significant design differences. Renan R. Sacco, Maicon de Miranda, Fábio E. Bisogno Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3766 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3767 This article identifies the parameters of the dynamic model of the Fresnel solar collector installed at the Escuela Técnica Superior de Ingenieros (ETSI), in Seville, Spain. The parameters identified are: the average thermal efficiency, the specific mass, the average heat capacity of the working fluid, the coefficients of thermal losses to the environment, the coefficient of heat exchange between the metallic tube and the working fluid. The model is integrated in time with integration steps of ∆t = 5s, and in space with discretizations of ∆x = 1m. The identification algorithm performs an optimization seeking to minimize the normalized squared error between the model prediction and measurements of the solar collector outlet temperature. The purpose of the identifier is to be able to update parameters throughout the life of the plant for control and optimization of operation, start-up and shutdown. The partial results show that the model obtained satisfactorily follows the collector outlet temperature measured data with a coefficient of determination R2 = 0.995 and mean square error of RMSE = 2.93◦C, considering 207605 steps of integration. The following works must validate the model comparing new measured data not correlated with the identification. Diogo Ortiz Machado, Gustavo A. de Andrade, Julio E. Normey-Rico, Carlos Bordons Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3767 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3768 Multivariable (MIMO) processes are commonly found in the industry. The coupling between the different loops makes the controller design difficult. To solve the problem of controlling these processes, MIMO proportional integral (PI) controller design methods have been found in the literature. In this paper, the review and the experimental application of MIMO PI controller tuning methods with linear matrix inequalities constraints are presented. The considered tuning methods are formulated as a non-convex optimization problem. Linearization of the concave part around a known point is performed using the concave-convex procedure. Frequency-domain process data are used to solve problems. The application of the methods is done in two different processes: temperature module and Peltier module. Anna Paula V de A Aguiar, George Acioli Júnior, Péricles R Barros Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3768 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3769 Fruit harvest can be automated by low-cost robots integrating computer vision systems. For this purpose, the SVCf is a computer vision system appropriated to UAVs and collector robots based on Agriculture 4.0 technologies. Initially, mango fruit (Mangifera Indica) was chosen to validate the proposed model used at SVCf. This proposed model can also be generalized to other types of fruits. R-CNNs were used to identify the fruits and color segmentation in the HSV space to identify the peduncles. In terms of results, the accuracy is about 97% in the correct identification of cut points in the peduncle of fruits located in real trees. Carlos Hairon Ribeiro Gonçalves, André Luis Albuquerque Pinheiro, Pedro Henrile Salvador, José Marquês Soares Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3769 Wed, 19 Oct 2022 00:00:00 -0300 https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3770 This work proposes the development and application of an autonomous navigation system for an electric wheelchair, based on tactile floor tracking. This approach is based on the installation pattern of tactile floors, a mandatory item in public buildings, which allows a simple and quick mapping of the environment, also being useful as natural landmarks for the development of an efficient localization system for the wheelchair . This locatization system is performed through computer vision based on the color segmentation of tactile floors. The proposed system is also composed of a human-machine interface by voice commands, which allows the individual to choose the location of a known environment to which he wants to move. The proposed approach was implemented in an electric wheelchair and tested at the Federal Institute of Sergipe, Campus Estância, where autonomous movements could be performed between different locations correctly. For safety reasons, the tests were conducted with an empty chair, in other words, with nobody on board. Mateus de Oliveira Soares, João Pedro Juchum Chagas, Raimundo Silvério Freire, Phillipe Cardorso Santos, Stephanie Kamarry, Roberto da Silva Macena Copyright (c) https://www.sba.org.br/open_journal_systems/index.php/cba/article/view/3770 Wed, 19 Oct 2022 00:00:00 -0300