Finite time reaction wheel fault reconstruction based on slide mode observer for spacecraft

A novel finite time fault reconfiguration scheme is proposed for a rigid spacecraft activated by four reaction wheels in the presence of actuator failure and external disturbances. This method can realize the faults and disturbance reconstruct precisely via designing a sliding mode observer. And the contrivable expectation control moment can guarantee the closed-loop attitude system is globally stable and robust in the presence of reaction faults and disturbance. Finally, a numerical simulation example are executed aiming at various faults of one type spacecraft for spacecraft attitude control system. Simulation results are also presented to verify the proposed scheme can realize the high accuracy fault construct online.