Fault detection and fault-tolerant control for drag-free satellite actuators: An approach based on adaptive sliding mode technique

Abstract

In addressing the challenge of actuator failure in drag-free satellite within complex deep space environments, this paper introduces a fault diagnosis method and a fault-tolerant control strategy based on adaptive sliding mode technology. Initially, the dynamic model of the drag-free satellite, featuring two test masses (TMs) is established. Subsequently, fault detection and fault estimation observers are formulated utilizing adaptive sliding mode techniques, aiming to identify and accurately estimate any potential actuator faults in the drag-free satellite. Building upon this foundation, an active fault-tolerant controller is devised, incorporating fault estimation information and employing an adaptive backstepping sliding mode control method. This ensures the drag-free satellite’s continued stable and precise operation even in the presence of faults. At last, the stability of the designed observer and fault-tolerant controller is subsequently established through the application of Lyapunov’s theorem. Simulation experiments are conducted to verify the effectiveness of the proposed approach.