行波型超声波电动机定位控制系统

摘要

Speed control and positioning cotrol are two difficulties to be overcome in ultrasonic mtors(USMs) ,and the positioning control envolves to be a key issue due to the fact that it usually contains speed adjustment process (speed control ). The complex noninear characteristics of USMs makes the traditional control method unable to meet the demand. Therefore a novel positioning control system combining the advantages of fuzzy and PID control scheme was proposed. Firstly, the fuzzy control scheme was used to rapidly approach the setting position by regulating the frequency, and then PID scheme was adopted when the USM approaches the setting position. The fuzzy-PID controller of this system was utilized to regulate the frequency and the voltage difference. Experiment shows that the proposed strategy can perform precise positioning control for traveling wave ultrasonic motors(TSUSMs) and that its precision can be guaranteed.%速度控制和定位控制是超声波电动机控制的难点,而定位控制又因其时常包含速度调节过程(即速度控制)成为研究热点.由于超声波电动机复杂的非线性关系,常规的控制方法根本不能满足其控制需求.本文设计了一种新型的超声波电动机定位控制系统,该系统结合了模糊与PID控制算法的优点,即首先采用模糊算法调节频率控制量的参数值,改变电机速度实现初步定位;其次在设定目标值附近切换成PID控制策略,通过调节两相输入电压的相位差使其精确定位.本系统通过模糊PID控制器分别实现对超声波电动机两相输入电压的频率和相位差进行控制,通过实验证明,模糊PID控制策略能有效的实现对行波型超声波电动机的定位控制,其定位精确性可以得到保证.