Desvio de Obstáculo para uma Formação de Robôs Utilizando Espaço Nulo

Abstract

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.