Variable Frequency Drive using nonresonant ultrasonic motor for wear reduction

This paper is focused on control method of piezoelectric actuator through “Variable Frequency Drive” to get out the friction state and avoid abrasion. The NRUSM is used as piezoelectric actuator; AC voltage at constant amplitude sine wave has applied to input voltage, where drive frequency profile is designed according to the principle of frequency limit originated to static friction. We have improved the transmission efficiency under maintaining the acceleration, speed, positioning accuracy performances. The fact of the improvement of the transmission efficiency results in the slip to reduce wearing.