Robust control of non-linear flexible spacecraft

Abstract

In this paper, the problem of attitude control of a ID non-linear flexible spacecraft is investigated. Three controllers are presented. The first is a non-linear dynamic inversion, the second is a linear μ-synthesis and the third is a composition of dynamic inversion and a μ-synthesis controller. It is assumed only one reaction wheel is used. Actuator saturation is considered in the design of controllers. The performances of the proposed controllers are compared in terms of nominal performance, robustness to uncertainties, vibration suppression of panels, sensitivity to measurement noise, environment disturbance and non-linearity in large maneuvers. To evaluate the performance of the proposed controllers, an extensive number of simulations on a non-linear model of the spacecraft are performed. Simulation results show the. ability of the. proposed controller in tracking the. attitude trajectory and damping panel vibration. It is also verified that the perturbations, environment disturbance and measurement errors have only slight effects on the tracking and damping responses. © Sharif University of Technology, June 2010.