Fault-Tolerant Attitude Control for Flexible Spacecraft with Input Saturation

Abstract

Fault-tolerant constrained attitude controllers are proposed for flexible spacecraft in the presence of input saturation and actuator fault, as well as model uncertainty and external disturbance. Two input saturations, that is amplitude saturation and, amplitude and rate saturation are considered and simple and effective compensators are designed to deal with the effect of input saturation. Two parameter update laws are designed to endure stuck fault, partial and complete loss of effectiveness fault. The stability of the resulting closed-loop systems by the proposed controllers is guaranteed by Lyapunov-based approach. The effectiveness of the proposed algorithms is assessed through numerical simulations.