A Novel Multi-Degree-of-Freedom Ultrasonic Motor with a Composite Ring-Shaped Stator

Abstract

With the rapid development of optical tracking systems, laser pointing systems, robotics, and other fields, multi-degree-of-freedom ultrasonic motors have attracted more and more attention for their advantages of flexible design, compact structure, and high positioning accuracy. Although a few multi-degree-of-freedom ultrasonic motors have a bonded-type piezoelectric stator, their output performances are poor, and their drive circuits are complicated, severely restricting their practical applications. To solve the above problems, a novel multi-degree-of-freedom ultrasonic motor with a composite ring-shaped stator is proposed. The harmonic response analysis is carried out through the finite element simulation, and the three working modes and geometric dimensions of the stator are determined. The motion trajectories of the four driving feet are studied through the transient analysis. Then the vibration characteristics of the manufactured stator are measured and compared with the simulation results. The performance of the motor prototype is finally experimentally investigated. The feasibility of the proposed motor structure and the correctness of the working principle are verified by numerical simulation and experimental investigation.