VIBRATION CONTROL OF PIEZOELECTRIC ACTUATOR BY IMPLEMENTATION OF OPTICAL POSITIONING SENSOR

PZT bimorph actuator is used to design mini-sized vibratory feeder applied in the micromedical industry. Since the vibration trajectory of PZT bimorph actuator will be controlled to obtain desired parts feeding, optical positioning sensor is used to provide non-contact measurement with precise displacement. Because the torsional vibration causes the rotary motion of the actuator, the angle between the optical sensor and the PZT plate is subjected to change during the vibration procedure. Optical loss due to a varying reflection angle is compensated by multiple-segment micrometer calibration. Satisfactory hysteresis suppression and good waveform tracking is obtained with implementation of optical sensor in piezo-actuating system.