一种大行程自动对焦的激光辅助加工平台

A Laser Assisted Machining Platform with Large-travel and Automatic-focus

为了提高激光辅助加工效率,设计一种自动对焦高精度大行程精密定位工作台。该平台的光学对焦理论以激光三角法为基础,这是典型的非接触式测量,不需要计算机的对比计算,这也是该机构精度大、误差小的原因之一。同时,该平台机构在竖直方向上的位移能够达到100μm,这是普通精密机构很难达到的。传动部分中,丝杠两端采用交叉滚子轴承作为支撑,提高机构精度和稳定性。同时,利用压电陶瓷与柔性铰链相连作为微位移驱动器,实现平台精密定位和自动对焦。对焦过程中,不同的离焦量对应不同的LED信号灯提示,同时报警器会发出相应的报警信号提醒。驱动部分应用双联机构,避免了直流电机在驱动时产生震颤的问题,很大程度上提高了对焦平台的精度和对焦效率。

In order to improve the efficiency of laser assisted machining, an automatic focusing accuracy large-travel precision po- sitioning platform was designed. The optical focusing theory of platform was based on laser triangulation method, and this was a typical non-contact measurement, as a result, the contrast of computer calculation was not needed, which resulted in great precision and small error for the platform. At the same time, the mechanism of platform on the vertical displacement was able to reach 100 microns, which was difficult to achieve in normal precision mechanism. On the transmission section, on both ends of the screw, cross roller bearings were used as the support, which improved the accuracy and stability of the mechanism. At the same time, the piezoelectric ceramic was used to connect to the flexible hinge as a micro displacement actuator to implement the platform of precision positioning and automatic focus. In the focusing process, different amount of off focusing was corresponding to different LED light hint, at the same time alarm was issued corresponding to remind. Driving part is applied of duplex structure to avoid the tremor generated when the direct current （DC） motor was driving, and the precision and focusing efficiency of focus platform are largely improved.