Contact analysis and performance evaluation of standing-wave linear ultrasonic motors via a physics-based contact model

Abstract

In this article, a novel physics-based contact model is proposed to investigate the complex contact dynamics of standing-wave linear ultrasonic motors (SWLUMs) involving intermittent separation, impact, stick-slip motion and ultrasonic vibration anti-friction effect. The effect of surface roughness and the real elasto-plastic characteristics of the contact are taken into account in this contact model, which account for the actual microscopic contact mechanics and friction drive mechanism between the stator and mover of SWLUM. Based on the developed contact model, a whole-machine dynamic model of a SWLUM is established to evaluate the motor performance, and the results show that both the transient and steady-state output performances of the motor under various input parameters can be evaluated accurately by comparing the simulation and experimental results. Furthermore, the influence of the surface topography on the motor performance under long-time running is investigated via the physics-based contact model.