提出了一种基于望远光学系统的同时测量直线导轨四自由度误差的新方法。首先利用望远系统对角度误差和平移误差高倍放大,再利用位置敏感探测器(PSD)分别采集放大后的角度误差和直线度误差,实现了水平和竖直方向直线度及俯仰角、偏摆角四个自由度误差的高精度实时测量。搭建了系统实验平台,分析了系统的测量原理,进行了测量的校正、稳定性和重复性实验。理论分析和实验结果表明,系统测量直线度的分辨率小于0.2 μm,角度的分辨率小于0.3″,在测量距离为10 cm的条件下,直线度、角度测量精度分别为±0.7 μm /cm,±0.3″/cm。测量方法具有精度高、结构简单、实时快速的特点。

A novel method for measuring four-degree-of-freedom geometric errors of a linear stage is put forward. A telescope is used to magnify the straightness errors and angular errors in many times. Position sensitive detector (PSD) is used to sense the errors very fast. So the horizontal and vertical straightness errors as well as yaw and pitch errors can be measured simultaneously with high precision. The four-degree-of-freedom measuring system has been developed,and the theory of measurement has been analyzed. The calibration,stability and repeatability experiments are completed. Experimental results and theoretical analyses show that the system has the resolution of less than 0.2 μm for straightness error measurement and 0.3″ for angular error measurement,and the measurement accuracies of straightness error and angular errors are about ±0.7 μm/cm and ±0.3″/cm respectively within the measurement range of 10 cm.