Speed Sensorless Control of Linear Ultrasonic Motors Based on Stator Vibration Amplitude Compensation

Abstract

In some applications of linear ultrasonic motors (LUSMs), not installing speed/position sensors can reduce the size and cost of the system, changes in load will cause fluctuations in the speed of the LUSM. To eliminate the influence of load changes on speed, a speed sensorless control scheme based on stator vibration amplitude compensation (SSCBVC) is proposed. This scheme is implemented under the framework of the stator vibration amplitude-based speed control (VBSC) and frequency tracking. Based on the stator vibration amplitude-speed and the output force-speed curves of the LUSM, the relationship between the load changes and stator vibration amplitude (SVA) to be compensated is established, realizing a speed sensorless control of the LUSM under variable load conditions. The experimental results show that the maximum fluctuation of the speed is about 2.2% when the output force changes from 0 to 6 N with SSCBVC. This scheme can effectively reduce the influence of load changes on the speed of the LUSM without using speed/position sensors.

DC Voltage Sensorless Predictive Control of a High-Efficiency PFC Single-Phase Rectifier Based on the Versatile Buck-Boost Converter

“…In [ 5 ], a field-oriented control of a permanent magnet machine drive with an estimation of the currents and voltages of the LC-filter connected in series is presented. In [ 6 ], a speed estimation of a linear ultrasonic motor is used to avoid speed/position sensors. In [ 7 ], a motion control of a linear resonant actuator with two degrees of freedom is implemented without a position sensor.…”