Application of adaptive disturbance canceling to attitude control of flexible satellite

An adaptive inverse disturbance canceling method of an orbiting flexible satellite during normal pointing for "modal vibration disturbance", which is difficult to cancel by the PID method since it's modal frequency low and dense, and damping small, is proposed. Here, the adaptive inverse disturbance canceling, compared with the conventional feedback disturbance rejection method, performs in inner loop and is independent of dynamic response control loop. Since the adaptive inverse disturbance canceling performed is based on the PID control of dynamics response in this paper, the control structure is designed as following. Fist, the conventional PID method is designed for the dynamical control system of rigid satellite. Second, the modal vibration disturbance control is performed by adaptive inverse disturbance canceling method. The key of this approach is estimation of modal vibration disturbance, the difference is between disturbed output of the plant and disturbance-free output of the copy model, which is then input to the disturbance canceling filter which is a least squares inverse of rigid satellite model. Simulation results demonstrate the effectiveness of the controller design strategy for attitude control and modal vibration disturbance suppression.