Design and Analysis of a Stepping Piezoelectric Actuator Free of Backward Motion

Abstract

Although the stick-slip principle has been widely employed for designing piezoelectric actuators, there still exits an intrinsic drawback, i.e., the backward motion, which significantly affects its output performances and applications. By analyzing the generation mechanism of backward motion in stick-slip piezoelectric actuators, the elliptical trajectory was employed to design a novel stepping piezoelectric actuator free of backward motion. Accordingly, a prototype of piezoelectric actuator was designed, which utilized a flexure hinge mechanism and two vertically arranged piezoelectric stacks to generate the required elliptical trajectory. The compliance matrix method was used to theoretically analyze the flexure hinge mechanism. The theoretical and measured elliptical trajectories under various phase differences were compared, and the phase difference of 45° was selected accordingly. Under a critical relative gap, output performances of the actuator working under the elliptical trajectory were characterized, and then compared with that obtained under the normal stick-slip driving principle. Experimental results indicated that forward and reverse stepping displacement with completely suppressed backward motion could be achieved when employing the elliptical trajectory, verifying its feasibility. This study provides a new strategy for designing a stepping piezoelectric actuator free of backward motion.

An umbrella-shaped flexible mechanism piezoelectric actuator with driving foot trajectory control

“…Wang et al designed a piezoelectric actuator based on an asymmetric stiffness bridge mechanism to extend the stepping stroke, but its load capacity is weak [28]. Yang et al achieved elliptical motion of the driving foot by investigating a flexible mechanism driven by two piezoelectric stacks with sinusoids [29], which completely eliminates backward motion.…”

Impact Force Analysis in Inertia-Type Piezoelectric Motors

“…Recently, to enhance the controllability of positioning with direction-dependent step sizes, many piezoelectric inertia-drive-type motor structures, where two piezoelectric elements are embedded in a stator [11][12][13][14][15][16][17][18][19][20][21][22][23][24], have been developed. To achieve the same motion in both directions, a sawtooth signal actuates the piezoelectric elements one at a time.…”