Fault-Tolerant Adaptive Asymptotic Attitude Tracking Control for a Rigid Spacecraft

This paper proposes an adaptive asymptotic fault-tolerant attitude tracking control approach for a rigid spacecraft. The control algorithm is designed based on backstepping method with a modified prescribed performance control (PPC) technique. It is required that the attitude tracking error converges to a user-predefined region within a user-predefined time. Thus, two positive constant parameters, representing the upper bounds of the region and the time, respectively, are available for users to set arbitrarily. Besides, compared with traditional PPC-based attitude tracking control methods, the proposed one removes the limitation on the initial value of attitude tracking error by introducing a novel tuning function. Moreover, by applying a new adaptive control method to approximate system uncertainties, the attitude tracking error can converge to zero asymptotically even under actuator faults and external disturbances. Finally, Lyapunov approach proves the system stability, and two simulation examples verify the effectiveness of the proposed control strategy.