摘要

This paper investigates the problem of attitude fault tolerant control (FTC) for satellites subject to multiple disturbances and actuator faults. Due to the limitation of the physical characteristic, actuator saturation exists quite widely in practical processes. An anti-windup FTC approach based on disturbance observer is presented for satellites with actuator faults, input saturation and multiple disturbances in this paper. The multiple disturbances can be divided into an uncertain modeled disturbance and a norm-bounded equivalent disturbance. Disturbance observer and fault diagnosis observer are designed to estimate the uncertain modeled disturbance and time-varying fault, respectively. By virtue of fault accommodation and disturbance observer-based control, an anti-windup FTC strategy is designed with polytopic representation of the saturation function. Different from the previous results, disturbance rejection, fault accommodation and state feedback controller are considered as a whole for input saturation. The proposed fault-tolerant controller design can guarantee the closed-loop system to be quadratically stable with a prescribed upper bound of the cost function. Simulation results are given to show the efficiency of the proposed approach.