Inverse control of a piezoelectric actuator for precise operation of a micro-motion stage

Abstract

The inverse control of a piezoelectric actuator for precise tracking operation of a three degree of freedom (DOF) micro-motion stage is presented in this paper. This stage, which provides translational motion in X and Y directions and rotation about the Z-axis, is actuated using three stack type piezoelectric actuators. Although capable of resolution in micrometres to sub-nanometres, the actuators exhibit a significant amount of hysteresis and creep, which may lead to substantial errors if the stage was used in a tracking application. Thus, for the stage to provide precise operation, it is necessary to mitigate the effects due to hysteresis and creep. To minimize these effects, an inverse, feed-forward, control strategy is presented in this paper. Experimental results are presented to display the effectiveness of this control strategy in precise operation of the stage over a wide band of amplitudes and frequencies.