中文摘要：

通过超声电机的工作原理分析，选定驱动频率作为其速度控制变量。将模糊·PI技术用于超声电机的控制。其中，PI控制在于减小稳态误差，模糊控制旨在实现电机快速定位。为设计模糊控制器，选定位置偏差和转速为其输入变量、驱动频率为其输出变量，并分别以三角、高斯型函数定义了输入、输出变量的模糊子集；根据电机手动操作经验，建立了超声电机模糊控制规则；基于GO-400控制卡构建控制系统，实现了电机控制；实验结果表明模糊-PI技术可实现超声电机快速高精度（偏差≤0.17°）定位。

英文摘要：

In order to control an ultrasonic motor （USM） , the paper presents a hybrid controller that is composed of a fuzzy logic controller （FLC） and a PI sub-controller. The working principle of the USM has been studied for selecting a drive frequency to regulate its speed. The PI controller is used to offset the USM＇s stable position error. The FLC, aimed at making the motor run to a desired position as fast as possible, is designed to be one with the position error and speed of the USM as its input and the manipulated value of drive frequency as its output. In designing the FLC, Gaussian type and triangular-type member functions are selected to define the fuzzy subsets of the FLC＇s input and output variables respectively, and a set of fuzzy reasoning rules are derived from the USM＇s speed/frequency characteristics. A control system based on the GO-400 motion control card is constructed to implement the USM control. Results show that quick and orecise positioning can be achieved with such a hybrid controller.