Analytical and numerical modeling of an ultrasonic stepping motor using standing waves

Piezoelectric motors (usually called ultrasonic) show interesting characteristics. Not only they deliver high torques at low speeds but their structure confers to them a braking torque without energy supply. This paper firstly present a list of possible solutions for this type of motors. Thereafter, the most promising solution is chosen and developed more in detail. Finite elements simulations of the vibration modes of the motor are carried out with the aim of determining the resonance frequency of the system for the selected mode. A theoretical modeling of the operating principle of the motor is established in order to be able to characterize the position, speed and torque according to the selected parameters. Lastly, the feasibility and the characteristics of such a motor are discussed. © 2004 IEEE.