Research On DDS-based Drive And Control For Ultrasonic Motor

Ultrasonic Motor (USM) is a new type of micro motor, which has important features such as high torque at low-speed, no electromagnetic interference, rapid response, running without noise, high holding torque when the electric input power is shut down and so on. Due to these features, ultrasonic motor has been anticipated as the new compact actuator in the field of non-continuous motion and rigorous motion control. Nevertheless, ultrasonic motor has some disadvantages such as non-linear, time-varying and strong-coupling, etc., which have affect its performance. In order to improve motion performance, research in ultrasonic motor drive and control is conducive to ultrasonic motor application widely.According to ultrasonic motor drive and control requirements, in this paper, DDS-based ultrasonic motor drive controller had been designed. The drive controller is mainly composed of DSP as core of control unit, CPLD as core of implementation unit and power electronic devices as core of drive unit three parts. The drive controller can give two sinusoidal signals, which consistent with the requirements of ultrasonic motor. It is not only could achieve high-resolution frequency modulation, phase modulation, amplitude modulation, but it is also can realize low-frequency PWM on-off control, which satisfy the demand of ultrasonic motor drive and control.According to ultrasonic motor application, this paper analyzed error analysis of DDS signal generator, and gave the results of quantitative analyzed, which provide evidence for DDS signal generator design and parameters selection. At self-developed platform, according to ultrasonic motor motion characteristics, to combine the advantage of single neuron control and PID control method, this paper designed a single neuron adaptive control algorithms, realize the speed closed-loop control. From experimental results, it shows that the drive and control system has high control precision and good stability.