Robust Adaptive Saturated Fault-tolerant Control of Autonomous Rendezvous with Mismatched Disturbances

This paper investigates the robust adaptive relative pose control design for spacecraft rendezvous and docking missions in the presence of parametric uncertainty, matched and mismatched disturbances, actuator saturation and faults. An adaptive saturated fault-tolerant controller is developed by incorporating the anti-windup compensator to adaptive backstepping technique. In contrast to traditional saturated fault-tolerant controllers for the spacecraft systems, the advantage of the proposed control approach can deal with the mismatched disturbances in the model. Also this approach does not require exact knowledge of the actuator faults and is implemented with uncertain value of fault information. Lyapunov analysis is employed to prove the ultimately uniformly bounded stability of the closed-loop system, where relative pose and velocities converge to adjustable small neighborhoods of zero. Numerical simulation results demonstrate the effectiveness of the proposed control approach.