The Design Of A Hybrid Motor By Stepper Motor And Ultrasonic Motor And Study Its Control System

The traveling wave ultrasonic motor (USM) developed very quickly as a new motor in recent years, the ultrasonic vibration of stator is acquired by inverse piezoelectric efficient of piezoelectric ceramic and produces traveling wave, then the mechanical energy is converted to power by the friction between stator and rotor. It has following features:low speed, high torque, high-precision position control, no electromagnetic interference, so they are widely used in aerospace, robotics, precision instruments, and so on. However, the working time of traveling wave ultrasonic motor is not more than2000hours, due to the friction between stator and rotor, which cause the traveling wave ultrasonic motor application limited.So as to solve the working time problem of the traveling wave ultrasonic motor, this paper presents a new hybrid motor which combined by traveling wave ultrasonic motor and stepper motor. It has the advantages of the traveling wave ultrasonic motor and stepper motor, and overcome their shortcomings. This hybrid motor approaches the stepper motor on working time, and has the same precision position control as traveling wave ultrasonic motor.In order to coordinated control stepper motor and traveling wave ultrasonic motor, the control system of the hybrid motor is consisted of field programmable gate array (FPGA) and its peripheral circuit. So as to achieve precision position control of hybrid motor, the preceding movement of hybrid motor is driven by the stepper motor, the last driven by ultrasonic motor. Through processing and converting the signal, the hybrid motor can speed stability and high-precision position control, and has a longer working time.