基于双频激光干涉反馈的快速精密定位系统

Research of high-speed precision positioning system based on double-frequency laser interference

为了实现大量程、高精度测量系统的快速驱动与定位,结合双频激光干涉仪、可回收废气的空气静压导轨、精密滚珠丝杆以及伺服控制系统,研制了一套定位精度高、重复性好的快速精密定位系统。该系统以双频激光干涉仪为测长基准,实时反馈系统工作台位置信息;采用余气回收式空气静压导轨克服了传统气浮导轨余气对激光干涉测量光路系统的影响;在定位过程中引入PID运动控制技术,通过调节伺服控制器的PI参数使系统拥有快速平稳的响应特性。经实验测试,在500mm行程范围内,该系统的轴线双向定位精度可以达到0.266μm,重复定位精度可以达到0.173μm,具有较好地快速响应特性。应用所研制的精密定位系统对一维直线光栅样品进行了扫描,并与用Olympus共焦显微镜测得的数据进行了比对,表明系统具备良好的轴向定位能力。

In order to realize fast driving and positioning for a wide-range and high precision measurement system, a precision positioning system with good repeatability is developed combining double-frequency laser interference, aerostatic guideway with pipeline channeling off used air, precision ball-screw and servo control system. The system uses laser interference as length measuring standard, location information of the workbench is fed back by double-frequency laser interference in real time. Using aerostatic guideway with pipeline channeling off used air overcomes the residual air influence on laser interference measurement optical path system in traditional gas float guideway. PID control technology is applied in the process of positioning, the system has fast and smooth response characteristics by adjusting PI parameters of the servo controller. Experiments show that, in the range of 500mm, bidirectional accuracy of positioning of the system is 0. 266μm, and the repeatability is 0. 173μm, it has quick response. The scanning experiment of one dimensional linear grating sample is compared with the scanning result of Olympus confocal microscope, the result shows that it has a good ability in axial positioning.