Improvement Of Dedign For Ultrasonic Motor Driving Power Based On FPGA

Ultrasonic motor makes use of the converse piezoelectric effect of piezoelectric materials.It has the advantages of simple structure,high positioning accuracy,no noise pollution,low speed,high torque,self-locking and no electromagnetic interference compared with traditional electromagnetic motor,which makes it suitable for fields such as instruments and meters,precision positioning,aerospace and so on.This paper aims to improve the shortcomings of the exiting ultrasonic motor driving power supply such as low speed,poor extensity,poor reliability of the driving board,unstable of control and so on,then a kind of ultrasonic motor driving power supply based on FPGA is designed.Ultrasonic motor driver power supply is composed of control board,driver board and impedance matching board,and related research is developed.According to the characteristics of the inverter circuit flow easily damaged,the driver board added the protection of PWM wave phase error and over current,which improved the reliability of the driver board.Based on electrical impedance curve,the composite dynamic branch model is put forward,and it is closer to the truth than the traditional single dynamic branch model and impedance matching parameters are designed with good effect.The controller uses SOPC system based on FPGA and established Nios II soft core and relative module,designed PWM module,I2 C communication module and speed measuring of the encounter module.Monitor and control of the motor is implemented via a serial port communication of control module and Lab VIEW based on upper machine.Finally,the experimental platform is set up and tested and the output waveform and bridge driving signal waveform of the controller meets the requirements.The protection signal can be generated timely by the two protection circuits when the corresponding event occurs,and the open-loop control and closed-loop control is realized with good effect by the controller.