Adaptive Sliding Mode Fault-tolerant Control for Attitude Tracking of Spacecraft With Actuator Faults

In our study, an adaptive sliding mode fault-tolerant control scheme is proposed for attitude tracking of spacecraft with actuator faults. Two-power reaching laws are used for sliding mode control, which are designed not only to solve the chattering problem of the sliding mode variables near the sliding mode surface, but also to directly obtain more accurate convergence time expression of the sliding mode variables. At the same time, a redundant actuator configuration of spacecraft is considered especially, and it improves the fault tolerance of the system. Moreover, for unknown items in the system, an adaptive control technique is introduced to approximate them. Our proposed control strategy can ensure that the attitude error and the angular velocity error of spacecraft converge to a small area near zero even when some actuators fail completely. Finally, the effectiveness of our proposed approach is verified by a numerical simulation example.