Surface Acoustic Wave Motor Modeling and Motion Control

Abstract

For miniaturization of ultrasonic transducers, a surface acoustic wave device has an advantage in rigid mounting and high-power-density operation. A surface acoustic wave (SAW) motor has been investigated, and its superior performances have been demonstrated. From investigations based on experiments, it was found that slider surface texture affects motor performances such as speed and thrust. Theoretically, however, the effect of the physical property of a slidertextured surface on motor performance had not been investigated sufficiently. A physical modeling of the SAW motor has been attempted, one slider projection was modeled including the compliance of the slider and stator materials, and also the stick and slip at the boundary. Using the slider projection modeling, operations of the SAW motor were simulated, and then, the results were compared with the experimental results. For servo control system application, a feed back controller compensating a nonlinear dead zone of the motor is reported. The feed back controller is simple and very effective. For an advanced motion control, a precise modeling of the SAW motor has been studied.