Robust attitude control for flexible satellite during orbit maneuver

A robust attitude control approach is proposed for the flexible satellite attitude control system with orbit control force during orbit maneuver. Considering orbit control force and other system internal and external disturbances as one whole unknown bounded disturbance, a robust attitude control approach which is insensitive to parameter perturbations of the flexible satellite attitude control system is presented. In this approach, the controller contains two parts: sliding mode attitude controller designed to keep the closed-loop system asymptotically stable, and the adaptive controller designed to estimate boundary value of the unknown bounded disturbance and achieve disturbance rejection. Since the boundary value of the whole disturbance is not required to be known previously, the great robustness to orbit control force and disturbance is guaranteed. Furthermore, the active vibration suppression compensator is designed for the flexible mode and its velocity to increase the attitude control accuracy. The simulation of the flexible satellite attitude system demonstrates the validity and the correctness of the designed proposal.