Adaptive Harmonic Diagnosis for Variant Spacecraft with Compound Actuator Faults

In this paper, a harmonic adaptive control scheme for spacecraft with variable structure with multi-position compound faults is studied. :hen the spacecraft adopts the variable structure method, the harmonic function with variable structure parameters as independent variables is designed to directly adapt to the output attitude change caused by the variable structure. Then, the extended sliding mode observer is used to estimate the occurrence time of all the faults in the nonlinear system, and the adaptive neural network is used to estimate the amplitude of all the faults. Finally, the proposed method achieves multiple fault estimation for flexible spacecraft with variable structure. The stability of the system is proved by Lyapunov theory, and the effectiveness and accuracy of the method are verified by experiments.