Research on robust fault-tolerant cooperative control for multi-stage satellites

Abstract The ultra-agile, ultra-stable, and ultra-pointing platform (ASP) is introduced on the basis of the satellite platform by using two-stage control to realize stable control and agile ability of the payload. In order to improve the reliability and attitude control capability of multi-stage satellites with a two-dimensional scanning motion mechanism, a robust fault-tolerant cooperative control algorithm for multi-stage satellites is proposed in this paper when the actuators of the ASP are faulty. Firstly, a dynamic model of a multi-stage satellite and typical fault models of actuators are established. The impact of faults on the multi-stage system is also analyzed in this paper. Secondly, a sliding mode fault observer is proposed for multi-stage satellites aiming at solving the problem of actuator failure. An adaptive sliding mode fault-tolerant control algorithm is designed, and the switch function is also improved which is chattering-free. The stability of the proposed controller is proved by using the Lyapunov stability principle. Finally, the effectiveness of the proposed control algorithm is verified through numerical simulations, and the comparison between four other fault-tolerant control algorithms demonstrates the superiority of the algorithm proposed in this paper.