Modelling Simulation And Drive Control System Design Of Ultrasonic Micro-Motor

With the rapid development of MEMS, the micro-motor as a key executive component of MEMS has got more and more attention. So far, various micro-motors have come out, mainly including electrostatic micro-motor, electromagnetic micro-motor and ultrasonic micro-motor. Electrostatic micro-motor outputs very small force and torque. Electromagnetic micro-motor has coil and gearbox inside, so its structure is complex. Ultrasonic micro-motor uses the inverse piezoelectric effect of piezoelectric material to excite the stator to vibrate, and drive the rotor to rotate through the friction between stator and rotor. This particular working mechanism makes ultrasonic micro-motor own many advantages when compared with electromagnetic micro-motor, such as simple and compact structure, low speed and large torque, without gearbox, without electromagnetic interference, fast dynamic response, etc. So ultrasonic micro-motor is the most promising micro-motor.Existing ultrasonic micro-motors are designed all based on d33 or d31 inverse piezoelectric effect of piezoelectric ceramic. These ultrasonic micro-motors have various problems like complex structure, difficult to miniaturization, difficult to fully polarization and small output torque. So an ultrasonic micro-motor is designed using d15 inverse piezoelectric effect of piezoelectric ceramic in this paper. And its operating mechanism is detailedly analysed in this paper. Moreover, its modeling and simulation are provided in this paper. In addition, the drive and control system of ultrasonic micro-motor is designed in this paper. Brief achievements are as follows:1. An ultrasonic micro-motor is designed using d15 inverse piezoelectric effect of piezoelectric ceramic. Then according to the natural vibration and forced vibration theory of elastic body, the operating mechanism of ultrasonic micro-motor is detailedly analysed from the vibration of stator, the travelling wave of stator, and the elliptical trajectory of particles on the stator surface.2. The electromechanical coupled model of ultrasonic micro-motor is build from stator model, rotor model and contact model between stator and rotor. Moreover, the output characteristics of ultrasonic micro-motor are simulated based on the model.3. According to the design requirements of the drive and control system of ultrasonic micro-motor, the whole design scheme of the drive and control system is proposed. Moreover, according to the scheme, the hardware design of the drive and control system is completed, including the design of drive circuit and design of speed control system.4. According to the whole design scheme of the drive and control system, the software design of the drive and control system is completed from the PWM signal generation, motor speed detecton, motor speed control, communication and display.5. The experiment platform is build, and the drive and control system of ultrasonic motor is debugged, including the debugging of drive circuit and debugging of speed control system.