Compensation of the residual error from the charge feedback control of a piezoelectric-actuated stage

Abstract

Charge control for a piezoelectric actuator is supposedly unaffected by the hysteresis effect; however, the voltage applied to the actuator covers both the effective force-generating voltage and the hysteresis voltage. In this article, this hysteresis nonlinearity is considered an extra disturbance over a linear system. A novel approach entailing the use of the parasitic capacitance charge feedback in conjunction with a Preisach model to estimate the hysteresis disturbance is proposed. The estimated extra voltage enables the controller to augment its effort with an additional term to compensate for this loss. The article also describes the establishment of an adequate Preisach model. The proposed approach applies a low-pass filter and feedforward compensator to improve the tracking performance. Control results under sinusoidal reference and staircase reference tracking confirmed the effectiveness of the proposed compensation in eliminating the hysteresis effect and achieving high-precision control.