A novel finite-time prescribed performance control scheme for spacecraft attitude tracking

Abstract

This paper studies the issue of finite-time prescribed performance control for spacecraft attitude tracking with inertia perturbations, external disturbances, actuator saturations and faults. To the best of the authors' knowledge, limited results have been reported in the relevant literature, and how to achieve the prescribed performance attitude tracking within a preset time interval is still an open problem. A novel finite-time prescribed performance function (FTPPF) whose settling time can be arbitrarily preset is first proposed. With the FTPPF predefining the envelope of tracking-error trajectories, the original spacecraft model is transformed into a new error system. Based on the barrier Lyapunov function of converted errors, the attitude controller is derived via backstepping design. During the process, the fuzzy approximation is used to handle inertia perturbations and external disturbances, while the Nussbaum gain technique is adopted to compensate for the efficiency loss caused by actuator saturations and faults. Finally, a finite-time fault-tolerant control scheme that guarantees both transient and steady-state performances (e.g., the maximum overshoot, steady-state error, and settling time) is developed. To verify the effectiveness of the solution, numerical experiments involving comparisons with related achievements are performed.