Microcontroller-based full control of ultrasonic motor with frequency and voltage adjusting

In this study, PIC16F628 microcontroller-based control of a traveling-wave ultrasonic motor has been implemented. A drive system including power supply, power electronic drives, and interface electronic circuits have been designed. The microcontroller has been integrated with drive system to achieve overall control of ultrasonic motor. Microcontroller generates start/stop, direction, and speed/position control signals for the motor drive system. Driving frequency and amplitude of two-phase voltages have been adjusted to realize speed and position control. Reference input signal has been generated directly with programmable on-chip voltage reference module of microcontroller. By using this method, control of the drive system has been successfully achieved without using additional interface digital/analog or filter circuits. Proposed drive and control system have been tested for various direction, speed, and position conditions. Transient responses and steady state operating conditions have been examined as well. The experimental results verify that the developed system is simple, reliable, and suitable for the control of the ultrasonic motor.