VIBRATION REDUCTION FOR MICRO-STAGE EMPOYING DISPLACEMENT MAGNIFICATION MECHANISM WITH PIEZOELECTRIC ACTUATORS

This paper deals with a vibration reduction problem for a micro-stage with a displacement magnification mechanism, which consists of flexible hinges, lever mechanisms and piezoelectric actuators. Although the present micro-stage is able to provide large displacement, it is subjected to severe residual vibration because only little damping is engaged in the system. Input shaping is an effective method to reduce such motion-induced vibration by modifying input commands for positioning systems. In this case, however, hysteretic characteristics of piezoelectric actuators deteriorate the performance of input shaping. A dynamic analysis for the present stage, which takes into account characteristics of the piezoelectric actuators, is performed to investigate the effects of the actuator hysteresis on the present micro-stage. Then, a rigorous simulation is made to find a better input shaper for the stage. A series of simulations and experiments prove that the proposed dynamic model is very useful to investigate the present system and that input shaping can successfully reduce the residual vibration of the micro-stage system over a wide range of input.