Adaptive Sliding Mode Observer Based FTC Method Design for Rigid Satellite Against Actuator Faults

In this paper, an adaptive sliding mode observer based fault tolerant control (FTC) design method is proposed for the rigid satellite attitude control systems in actuator multiple fault case. The rigid satellite attitude control systems can be described by the dynamic equations and kinematic equations. The actuator fault model is given to represents the bias fault and loss of effectiveness fault. Then a novel nonlinear sliding mode observer is designed in order to get the estimation value of the effects of unknown actuator faults. An fault tolerant attitude controller is further designed for the rigid satellite attitude systems by utilizing the estimated fault information and backstepping control scheme. Meanwhile, the stability of closed-loop attitude control systems is analyzed by using Lyapunov appraoch. Finally, simulation results are given to demonstrate the effectiveness of the developed FTC scheme.