直线超声电机伺服系统快速精密位置控制方法

Fast and precise position control method of linear ultrasonic motor servo system

为实现大量程高速、高精度定位,文章设计制作了基于PC机的直线超声电机伺服定位系统;基于超声电机的工作原理和其位置分辨率高、断电自锁、响应快等性能特点,提出了基于电机启动停止频率与启动占空比的电机步进控制方法和基于电机工作频率与速度非线性关系的bang-bang位置控制策略。试验结果表明,步进控制的步距随启停频率和启动占空比的降低而减小,可实现小量程高精度位置控制;分阶段bangbang控制可实现大量程快速定位;两者组合控制,并利用步进控制进行误差补偿,可实现快速大量程微米级精度定位。

In order to realize fast precision positioning in large travel, the PC linear ultrasonic motor servo positioning system is designed and built. As the ultrasonic motor has the characteristics such as high position resolution, power-cut self-locking and fast response, the step control method based on the motor start-stop frequency and duty ratio is put forward, and the bang-bang position control strategy based on the nonlinear relationship between motor speed and frequency is presented. The test resuits show that with the decrease of the start-stop frequency and duty ratio, the step distance shortens. The step control method can realize high precision positioning in short distance, and the bangbang control can realize fast positioning in large travel, therefore the step control can compensate the position error caused by the bang-bang control. With the integration of step control and bang-bang control, fast positioning in large travel with micron-sized precision can be accomplished.