基于干涉原理的高精度直线度误差测量

将空气劈尖产生的等厚干涉与CCD图像处理技术相结合,提出了一种测量连续空间直线度误差的新方法。此方法利用待测工件的直线度误差改变空气劈尖顶角,并用一元线性回归方法对CCD的像元序号与所接收到的干涉条纹光强极值序号之间线性关系进行拟合,进而确定出空气劈尖顶角大小。由导出的直线度误差与空气劈尖顶角之间的关系,用最小包容区域法对工件的直线度误差进行了评定,评定结果为8.11±0.62μm。测量结果表明,新的测量方法是可行的,而且测量系统具有精度高、应用范围广的特点,也可应用到锥角、圆度误差等其他几何量的精密测量中。

High Precision Measurement of Alignment Error Based on Theory of Interference

With the combination of the equal thickness interference formed by an air wedge and the CCD image-processing technique, a new method is presented to measure spatial alignment error. The angle of the air wedge is designed to be changed by the alignment error and the computed with the unitary linearity regress method which is used to fit the relation between the serial number of the CCD cells and the serial number of the intensity extremum of interference fringes. The relation between the alignment error and the angle of the air wedge is educed and used to evaluate the object′s alignment error with the least envelop area method. The result is 8.11±0.62 μm. The measuring result proves the feasibility of the new method. The measuring system has the characteristics of high accuracy and wide-ranging application and can be applied to measurement of the cone angle error and the roundness error, etc.