Flexible satellite attitude maneuver control using pulse-width pulse-frequency modulated input shaper

Considering the condition that modern spacecraft are always of large flexible appendages and the fact that the flexible vibration often degrades the control system performance, this paper employs a method that consists of a feed-forward compensator and a closed-loop feedback to fulfill attitude maneuver rapidly with little residual vibration. Including a pulse-width pulse-frequency modulator and a PD controller, the feedback control loop is designed to achieve the desired maneuver; the feed-forward compensator, a multi-mode input shaper based on pade approximation, is designed to eliminate the system residual vibration. Simulation results show that the proposed multi-mode input shaper has shorter time duration and can provide robustness to parameters uncertainty. During maneuvers, the presented control strategy introduces less overshoots and shorter system response time.