A new driver circuit design for dual mode control of travelling wave type ultrasonic

Travelling wave ultrasonic motors (TWUSM) are recently being used in industrial applications. The rotor velocity of TWUSM is controlled by three quantities. These are amplitude, the phase difference and frequency of applied voltages. In this study, in order to investigate the speed response of a travelling wave ultrasonic motor under dual-mode operation, a micro controller based digitally controlled novel speed driver system was proposed and implemented. In the experimental tests, frequency and amplitude of applied voltages have been used as the control inputs. The obtained simulation and experimental results were analyzed and presented with comparisons. It was seen that the rotor velocity of the TWUSM can be controlled more widely by the proposed technique with frequency; while the amplitude of the phase voltages has less effect on the speed interval.