A Hybrid Control Scheme of Vibration Reduction of Flexible Spacecraft during Attitude Maneuver

Abstract

This paper presents an investigation into development of feed-forward and feedback control strategies for active vibration suppression and attitude control of flexible spacecrafts. The feed-forward loop consists of a computed-torque scheme and a command shaping technique based on component synthesis vibration suppression (CSVS) method. For relaxing the requirements of dynamic linearity in traditional input component command in CSVS method, a new approach is developed for designing the input component command by utilizing a structure in which the modal forces of flexible modes vibration are shaped according to a predefined trajectory, which improves the performance of CSVS method in vibration suppression for the nonlinear attitude dynamics. On the other hand, to follow the predefined trajectory identically or at least as closely as possible, a model-independent feedback control loop is proposed, which can accomplish further reduction of the residual vibration of flexible appendages. Numerical simulations demonstrate the effectiveness of the control strategy.