Servo Speed Control of Traveling-Wave Ultrasonic Motors Using Pulse Width Modulation

摘要

With the advantages of lightweight, compact size, fast response, power-off hold- ing torque and high-torque low-speed characteristics, the traveling-wave ultra- sonic motor (TUSM) is becoming attractive for servo application. This paper presents a new pulse width modulation (PWM) method for servo speed control of a TUSM. The key is to digitally control the pulse width, hence the fun- damental value, of the bipolar 2-phase voltages feeding into the Tusm.