Research on transient characteristics of a novel longitudinal-torsional ultrasonic motor

This paper introduces a longitudinal-torsional USM. Based on the electrical characteristics of the piezoelectric vibrator, a theoretical model was investigated. It can be used to derive the transient response characteristics of electrical parameters. The finite element analysis was also used to verify the correctness of the parameters change trend. The transient state of the analyzed parameters includes three time interval, the on transient state, steady state and off transient state. The simulation and experiment verified the validity of the theoretical model and performance of the USM. The above mentioned electrical and mechanical parameters rise or fall by degrees in accordance with an exponential form except that the speed of revolution falls linearly approximately. The revolution speed of this USM is about 45 r/min. Experimental results also showed that the response speed of the USM is fast, as the startup time is about 6 ms and the turnoff time is 2 ms.