Bidirectional Active Piezoelectric Actuator Based on Optimized Bridge-Type Amplifier.

Weiqing Huang,Mingyang Chen,Junkai Lian,Dawei An

doi:10.3390/mi12091013

Abstract

Piezoelectric actuators based on bridge displacement amplifying mechanisms are widely used in precision driving and positioning fields. The classical bridge mechanism relies on structural flexibility to realize the return stroke, which leads to the low positioning accuracy of the actuator. In this paper, a series bridge mechanism is proposed to realize a bidirectional active drive; the return stroke is driven by a piezoelectric stack rather than by the flexibility of the structure. By analyzing the parameter sensitivity of the bridge mechanism, the series actuation of the bridge mechanism is optimized and the static and dynamic solutions are carried out by using the finite element method. Compared with the hysteresis loop of the piezoelectric stack, the displacement curve of the proposed actuator is symmetric, and the maximum nonlinear error is improved. The experimental results show that the maximum driving stroke of the actuator is 129.41 μm, and the maximum nonlinear error is 5.48%.

Highlights

Optimized Bridge-Type Amplifier.Piezoelectric (PZT) actuators are widely used in ultra-precision machining and measurement, large-scale integrated circuit manufacturing, scanning probe microscopes, aerospace, micro-robots, optics, and the medical field due to their high resolution and high positioning accuracy [1,2,3,4]
The main objective of this study is to reduce the nonlinear error of the actuator output turn stroke are driven by the PZT stack, which overcomes the drawback due to the c displacement curve and reduce the dependence on the computing power of the controller
Using COMSOL Multiphysics 5.5 software (COMSOL Corporation, Stockholm, Sweden), the static and dynamic analysis of the series bridge mechanism was carried out to verify the rationality of the structure parameters

Summary

Introduction

Optimized Bridge-Type Amplifier.Piezoelectric (PZT) actuators are widely used in ultra-precision machining and measurement, large-scale integrated circuit manufacturing, scanning probe microscopes, aerospace, micro-robots, optics, and the medical field due to their high resolution and high positioning accuracy [1,2,3,4]. Since the driving stroke of the PZT stack is only about 0.1% of its own length [5,6], many scholars have designed various types of displacement amplification mechanisms to increase the output displacement of the PZT stack [7,8,9]. Sun et al proposed a two-dimensional micro-positioning platform with equal stiffness and equal stroke based on the hourglass displacement amplification mechanism, with a displacement magnification close to 10 times [10]. Jun Hyung Kim proposed a three-dimensional series double-bridge flexure hinge mechanism, and when appropriate structural parameters were selected, the displacement magnification reached 30 times [11]. Chen et al designed a two-stage lever mechanism using elliptical flexure hinges, with a displacement magnification of 40 times [12]

Objectives

Methods

Results