Active fault-tolerant attitude control of spacecraft based on iterative learning observer

This article proposes an active fault-tolerant control strategy based on the iterative learning observer for a kind of spacecraft subjects to external disturbance and actuator faults. Firstly, the kinematics and dynamics models of spacecraft attitude control system with external disturbances and actuator faults are established. Based on the traditional iterative learning observer design, an improved learning algorithm is designed to accurately estimate the comprehensive fault value of the system by introducing state estimation error information in the previous time. Furthermore, based on the sliding mode control and predefined-time stable theory, an active fault-tolerant controller is designed by using the fault estimation information. Compared with the existing active fault-tolerant control schemes for spacecraft, the advantage of the proposed algorithm is that the attitude of the faulty system can track the command signal at the predefined time. Through the Lyapunov method, the stability of attitude control system is proved theoretically. Finally, numerical simulations show the effectiveness and feasibility of the proposed scheme. © 2023 South China University of Technology. All rights reserved.