Experimental studies on a fuzzy-logic control scheme for an Ultrasonic Motor

This article focuses on the development of an embedded control scheme coupled to an advanced power electronic amplifier for a Travelling Wave Ultrasonic Motor (TWUM). The operation of TWUMs relies on the formation of a mechanically induced travelling wave on the motors stator. Utilizing a customized full-bridge resonant inverter and a micro-controller that monitors the error between the desired rotors angle and the actual one, a command control is derived relying on fuzzy logic principles. This command affects the ultrasonic electrical resonant frequency, the relative amplitude and the phase-difference between the provided voltages by the amplifier. The concurrent control of these critical parameters affects the performance of the TWUM and experimental studies illustrate the efficiency of the proposed scheme.