Machining, Measurement, and Control Laboratory

Dynamic characteristics and dual control of a ball screw drive with integrated piezoelectric actuator
Tomoya Fujita, Atsushi Matsubara, Daisuke Kono, Iwao Yamaji

This paper describes the precision continuous path tracking control by using a dual-actuated single stage. First, fine-drive mechanism and the dynamic model of the entire drive system are described. In the simulation model, the dynamic characteristic of the dual-actuated stage is investigated to see whether it can provide precise motion by using dual control. Second, the fine motion controller is designed. Adjusting the control parameters, a positioning resolution of 20nmand a bandwidth of 260 Hz were obtained. Third, the frequency responses of coarse and fine drives are experimentally investigated. After that, the dual controller is designed based on the investigated dynamics. Finally, whether coarse motion and fine motion could work complimentarily by the dual servo is examined in the experiments. By using the simultaneous dual controller, tracking errors were reduced sufficiently compared to the single coarse control.
Key Words:   Precision positioning, Dual servo control, Ball screw drive, Piezoelectric actuator