NONLINEAR INPUT SHAPING CONTROL OF FLEXIBLE SPACECRAFT REORIENTATION MANEUVER

A design is presented of a novel feedforward controller for-a large-an gle reorientation maneuver of a spacecraft with flexible appendages, s uch as a telecommunication satellite. The controller combines collocat ed feedback and feedforward control. Its uses an efficient and concept ually simple numerical method for the computation of an optimal. feedf orward input shape for a nonlinear flexible system, The method is base d on a minimization of a single regularized performance index instead of solution of a terminal control problem, A proposed flexible spacecr aft testbed developed at the Canadian Space Agency is described, and a pplication of the designed control scheme to this testbed is studied. The designed controller is shown to provide excellent performance in c ompensation of residual flexible vibrations for the nonlinear system i n question.