Development of 5-DOF Piezoelectric Actuator for Planar—Angular Positioning

Abstract

A novel five degrees of freedom (5-DOF) piezoelectric actuator is proposed and analyzed in this paper. The actuator can provide unlimited self-motion in the plane and angular positioning of the spherical payload. The actuator is composed of a cylindrical bronze frame and a piezo ceramic ring glued on top of the cylinder. The cylinder has three cut-outs used to form three supports. The top electrode of the piezo ceramic ring is divided into six equal sections. Three electrodes are used to control the direction of the planar motion, while the remaining three electrodes allow controlling angular motion. The planar motion of the actuator is induced by employing radial vibrations of the supports, while the rotational motion of the sphere is obtained when radial vibrations of the corresponding sections of the piezo ceramic ring are excited. The proposed design of the actuator allows reducing coupling between vibrations of the different segments and ensures the possibility to obtain 5-DOF motion. The piezoelectric actuator is excited using a single harmonic signal switched between electrodes via a digitally controlled switch box. The numerical and experimental studies of the actuator were performed, and the operating principle was validated. The maximum linear velocity of 19.8 mm/s and angular speed of 31.3 RPM were obtained when the payload of 55.68 g and excitation voltage of 200 Vp-p was applied.