Preshaping Profiler for Flexible Spacecraft Rest-to-Rest Maneuvers

A new feedforward algorithm for flexible spacecraft maneuvers is presented. We call this preshaping profiler the nil-mode-exciting (NME) profiler. This algorithm is designed particularly for single-axis rest-to-rest rotational maneuvers (switching maneuvers) with linear actuators. Generally spacecraft with large flexible structure has a lot of large-mass flexible-modes. Therefore, uncertainity of high-order modes needs to be considered for high-accuracy controller design. This paper presents an extra-insensitive maneuvering method which overcomes above-mentioned difficulties. This algorithm includes a preshaping profiler formulated from sampling function (also known as sinc function), consequently feedforward control inputs generated from the preshaping profiler have no frequency response above a certain designed frequency. Therefore residual vibration at the end-point of maneuver can be highly reduced with minimum loss of maneuver agility.