Abstract: Considering nonlinearity of step motor’s output torques and low frequency vibration characteristics of flexible payload, a method for designing control command of step motor is proposed to suppress the residual vibration in this paper. The dynamics model of step motor driving flexible load is derived, indicating proper step logic design is a feasible solution of vibration suppression . Furthermore, as a feed forward control strategy of vibration suppression, the input shaping technique is analyzed and its modification for flexible payload driven by step motor is put forward. Simulation results validate that this method can be used to generate step logic for SA antenna slew mode.

Key words: step motor, flexible payload, step logic, vibration suppression