Hysteresis in Piezoelectric Actuators: Modeling and Compensation

Abstract

AbstractPiezoelectric stack actuators are characterized by their high resolution and precision in micro and nanometric displacements, being capable of very fast responses and reaching bandwidth ranges in the order of kHz. Consequently, these actuators are extensively used both for positioning and active vibration damping in demanding applications such as SPM (Scanning Probe Microscopy), AFM (Atomic Force Microscopy) or manufacturing systems for MEMS (Micro-Electro-Mechanical Systems). However, piezoelectric materials and actuators suffer from two important drawbacks, which have to be taken into account for effectively reaching the highest combination of precision and speed: hysteresis and rate dependence. In this paper, we describe a framework for modeling stack-based piezoelectric actuators using a Bond-Graph representation. The model considers the hysteresis nonlinearity and the rate-dependence, taking into account both direct and inverse piezoelectric effects. Based on this representation, and on the variation of the effective electrical capacitance of the actuator due to the hysteresis phenomenon, a compensation strategy is developed. Experimental results obtained with amplified piezoelectric actuators are introduced for validating the model, the identification strategy and the benefits of the proposed compensation algorithm in comparison with previously reported work in the literature.