Speed Control Of Ultrasonic Motor Based On DSP

The ultrasonic motor (USM) is a new kind of motor that utilizes the converse piezoelectric effect and the friction coupling operation between the stator and the rotor to perform the energy conversion from the electric energy to the mechanical energy. It has been paid more and more attention to by many researchers all over the world.Speed and position control of the traveling wave type ultrasonic motor are mainly concentrated on in this dissertation. By the experiments to the traveling wave type ultrasonic motor of 60 mm diameter under no load, three methods for driving and controlling USM are analyzed including frequency modulation, voltage modulation and phase difference modulation, as a result of which both the frequency modulation and the phase difference modulation are adopted for USM control.For better control effect to USM, the USM control system based on DSP is designed, which is composed of the upper machine, the driver and the controller of USM and the USM testing platform. A new kind of DSP chip TMS320C2812 of TI Company is used in the driver and the controller of USM, which improves the performance of the USM control system a lot.On the platform mentioned above, the speed tracking control of USM for trapezoid, triangle and sinusoid is studied by means of P-control, PID-control and fuzzy-p control. Besides, the position tracking control of USM for triangle and sinusoid is studied by means of P-control. Experimental results indicate that the proposed methods can be implemented conveniently and offer good performance.Furthermore, the performance of USM used as step motor is studied in this dissertation. Although the experimental result is not good, it offers a reference for the study on the characteristic of USM used as step motor.