Abstract:For spacecraft attitude control systems with actuator faults and external disturbances, in this paper, we design a fault reconstruction and fault-tolerant control scheme based on a time-varying learning intensity learning observer. First, a time-varying learning intensity learning observer is designed to fit the learning intensity curve by analyzing the system operation and the error trend to enable tuning of the system state and fault signal reconstruction process. On this basis, the control strategy is dynamically adjusted according to the fault reconstruction results, which significantly improves the system control performance under fault conditions. Then, it is proved by the Lyapunov stability theory that the designed scheme can guarantee the asymptotic convergence of the system to a small region. Finally, simulation results show that the proposed design method can make the estimation results smoother, effectively improve the estimation performance and reduce the impact of faults on the system.