Observer-Based Fault-Tolerant Attitude Stabilization of Rigid Spacecraft with Prescribed Performance

This paper addresses the observer-based fault-tolerant attitude stabilization problem with prescribed performance in the presence of the reaction wheel fault, reaction wheel friction and external disturbance. An iterative learning observer, proven to be ultimately uniformly bounded, is firstly proposed to estimate the torque deviation rapidly and precisely. To guarantee the prescribed performance, the attitude quaternion is equivalently transformed to a state-constrained one via a state transformation. Subsequently, a composite controller is derived based on the proposed observer and the transformed state via sliding mode control. It is proven that the whole attitude stabilization system can be stabilized within prescribed performance. Finally, the effectiveness of the proposed control scheme is illustrated by numerical simulations conducted on a microsatellite.