Appointed-time fault-tolerant attitude tracking control of spacecraft with double-level guaranteed performance bounds

This paper investigates the issue of appointed-time fault-tolerant control for spacecraft attitude tracking in the presence of external disturbances and actuator faults. By “appointed-time”, it is meant that the maneuver completion time can be preassigned offline according to mission-oriented demands. Firstly, appointed-time performance functions are tactfully developed, which seek to impose a priori desired performance metrics on both the attitude and angular velocity errors (double-level). After that, an adaptive fault-tolerant controller is derived using structurally simple error transformations in combination of asymmetric barrier Lyapunov functions. Based on Lyapunov synthesis, it is then shown that the derived controller is capable of guaranteeing the boundedness of all the signals in the closed-loop system, and of achieving double-level guaranteed performance bounds for output tracking errors, despite the presence of external disturbances and actuator faults. In particular, the attitude tracking can be accomplished in a user-appointed time without resorting to judicious control parameters selection. Finally, simulation results are presented to illustrate the efficacy of the proposed control scheme.