Design Of Drive And Control System For The High Power Ultrasonic Moter

Ultrasonic motor is a motor driven by the piezoelectric effect of piezoelectric ceramics. Ultrasonic motors have many advantages, including the following aspects: low speed with large torque, fast response speed, no electromagnetic interference, power off self lock, small size, light weight and so on. Because of these reasons, it is very suitable for the capturing mechanism,which improves the existing capture mechanism of fault tolerance and reduces the size and quality of the capture mechanism. It has high reliability.The self-made ultrasonic motor is a traveling wave longitudinal bending composite high power ultrasonic motor, driven by 4 vibration. The content of this paper is to design the drive and control system for the self-made ultrasonic motor, which mainly includes of the driving power supply and control system.The driving power supply is based on the direct digital frequency synthesis technology, 8 channel PWM signal are put out from the FPGA, and flow through then the isolation, 2 full bridge inverter circuit and filter circuit, generating two channels sinusoidal driving voltage which can precisely regulate the amplitude, frequency and phase difference. The control part mainly used code disk speed to acquie the motor speed information, and the collected information is transmitted to the DSP. The DSP calculate the corresponding control word and transferr it to the FPGA to track the motor speed, which form a closed loop system.The hardware of this paper is the model of DSP+FPGA+power amplifier board. The controller use the TI's DSP chip TMS320F28335 as the core. FPGA board is applied to Altera's FPGA chip EP4CE6E22C8 and the amplifier board is designed by myself, which includes full bridge inverter circuit and auxiliary circuit. The control interface is written in LabVIEW, and it can be use to transmitted to the FPGA control word in order to control the drive power.In this paper, the principle and function of the driving power source are introduced, and the performance of the signal source is verified by simulation and experiment. The driving circuit is designed according to the requirements of the ultrasonic motor power. After the completion of the power supply design, the control system of moter designed by the PID algorithm to achieve the motor speed control.