以直径为30mm的环型行波超声波电机(RTWUSM)为例,设计了一种利用正弦波信号直接放大后驱动的RTWUSM驱动控制电源。电源采用DSP高速CPU控制系统,采用可编程逻辑器件(CPLD)和D/A组成的直接数字频率合成(DDS)电路来产生两相正弦波、双极性晶体管组成的线性功率放大电路和光电编码器采集的速度信号为反馈的速度闭环控制技术,利用DDS原理,通过D/A来调节输出的驱动信号的频率、相位和幅值,实现了RTWUSM的准确定位控制。驱动部分采用电源峰峰值跟踪和并联谐振技术,降低了驱动控制电源的损耗,提高了效率。通过对RTWUSM30的位置控制,证实了该驱动控制技术的可行和正确性,为进一步扩大环型行波超声波电机的应用奠定了基础。
One direct driving source for ring-type traveling-wave ultrasonic motor with 30mm diameter of the stator has been designed in this paper. The controlling CPU is DSP, the DDS circuit is composed of DSP and CPLD, the linear power amplifier is adopted by bipolar transistor, and the feedback of the speed is acquired from the sensor named photoelectric encoder. The driving and controlling signal can be adjusted the frequency, the phase, the amplitude, and the phase difference of the two sino wave exciting signals through the data/analogue module used by DDS technique, and it can drive RTWUSM30 in the high accuracy position control, and the efficiency of the whole source can be improved by the tracing and parallel resonant techniques in the driving part. The source has been designed and manufactured and verified feasible and valid through the position controlling for RTWUSM30.