Adaptive fault-tolerant attitude control for satellite reorientation under input saturation

This paper studies the rest-to-rest attitude reorientation problem of a three-axis stabilized satellite subject to inertia uncertainties, external disturbances, actuator faults and input saturation. An arc tangent function is first adopted to model the constrained control input, and meanwhile an augmented plant is constructed to facilitate the control law derivation. Then, a novel adaptive fault-tolerant control scheme is proposed by incorporating the prescribed performance control and adaptive estimation techniques into backstepping design. Exploiting the dynamic surface control method, the complexity problem residing in traditional backstepping approaches is effectively averted. It is shown that the control algorithm developed is not only robust against environmental disturbances and adaptive to unknown time-varying inertia properties caused by the mass displacement of large-scale deployable appendages, but also able to steer the attitude reorientation errors along prescribed transient and steady-state behavioral bounds, despite the presence of actuator faults and input saturation. Based on standard Lyapunov synthesis, all signals in the closed-loop system are proved to be semi-globally uniformly ultimately bounded. Finally, simulation experiments carried out on a miniature satellite testify the effectiveness of the proposed control approach.