中文摘要：

为了充分利用直线超声电机响应快、分辨率高的特点，并实现电机的微步距控制，研究了激励信号对电机微步距输出特性的影响。首先，通过分析电机的瞬态特性，研究了电机单步距作动过程；其次，为了实现电机激励信号的精确控制，分析了双PWM拓扑结构超声电机驱动器的工作原理，并通过实验对驱动器关断控制进行了研究；最后，分别研究了激励信号周期数、激励电压峰峰值和激励时间间隔对电机微步距特性的影响。实验结果表明，当驱动器采用具有泄放回路的零相位关断时，能够实现激励信号的精确控制。当以激励电压作为参变量，激励时间间隔大于10ms时，电机微步距特性曲线具有较强的线性特性，有利于电机微步距控制；激励时间间隔小于3ms时，能够有效降低电机平均速度，实现低速控制。

英文摘要：

In order to make full use of the characteristics of fast response and high resolution of linear ultrasonic motor, and realize the micro-step control of motor, the influence of excitation signal on characteristics of micro-step output was discussed. Firstly, the transient characteristics of the motor were analyzed to study the process of single step response. Secondly, to obtain high precision control of excitation signals applied on motor, the working principle of dual-PWM topology structure ultrasonic motor driver was analyzed, and turn-off control of the driver was considered by experiments. Finally, the influence of the cycles of excitation signals, the peak to peak value of excitation signals, and the interval of excitation signals on characteristics of micro-step output was studied, respectively. Experimental results show that it’s available to achieve precision control of excitation signals when the driver signals turned off at zero phase and a quick discharge circuit is built. It is good for micro-step control of motor due to the linear characteristics of micro-step output when the interval of excitation signals greater than 10ms, and the excitation voltage as control parameter. It’s possible to reduce the average speed of the motor for low speed control when the interval of excitation signals less than 3ms.