Combined feedback control and input shaping for vibration suppression of flexible spacecraft

A new control strategy is proposed, which integrates input shaping technique with feedback control for vibration reduction of rigid-flexible spacecraft. This strategy could ensure the achievement of attitude maneuver and the suppression of appendages vibration simultaneously. Considering the absence of the knowledge of modal variables of flexible appendages and the presence of external disturbances, a feedback controller which only requires spacecraft attitude and angular velocity measurement is designed. Combined with the feedback controller, a robust multiple mode input shaper is designed to enhance the system performance. This input shaper requires the eigenvalues of the whole close loop system, rather than the natural frequency and damping ratio of the flexible appendages. Simulation results show that the presented control strategy reduces the system response time and suppresses the vibration of the appendages successfully during the attitude maneuver. In addition, it can provide strong robustness to system parameter uncertainties.