Adaptive fault-tolerant attitude control for spacecraft under loss of actuator effectiveness

This chapter models the attitude stabilization of spacecraft during partial loss of actuator effectiveness by a multiplicative factor. It provides an adaptive fault-tolerant strategy for spacecraft attitude control when there is partial loss of actuator effectiveness. Specifically, by applying an adaptive backstepping control technique, a normal attitude controller is first derived for the rigid spacecraft system in the presence of external disturbances, in which all the actuators are fault-free and operating normally. The chapter presents spacecraft-attitude mathematical model and control problems. In the chapter, for the normal system without an actuator fault, a baseline attitude controller based on the adaptive backstepping technique is developed. Then, using the baseline controller, the fault-tolerant controller is derived. This guarantees that the actual outputs of the faulty actuators can still follow the normal command inputs, and the fault can be compensated online.