disturbance rejection, linear matrix inequalities, multi-resonant controller, quaternions, Stewart platform
Abstract
This paper presents the design of a robust disturbance rejection control scheme for Stewart platforms. To fully take into account the system nonlinearities, the quaternion based description is used along with Quasi-Linear Parameter Varying representation. In order to provide robust output regulation, in the presence of frequency-varying disturbances, we propose the design of a multi-resonant internal model controller. The closed-loop stability is guarantee by the state-feedback law synthesized via a convex optimization problem subject to linear matrix inequalities. Simulations show the effectiveness of the multi-resonant controller applied to a Stewart platform in the case that the platform is used as a stabilization device on the ocean where the ocean waves generate frequency-varying harmonic disturbances.
