光学非球面坐标测量中位姿误差的分离与优化

在开发了一种专用非球面坐标测量机的基础上,分析了测量系统与工件在空间6个自由度上的相对位姿误差的关系,建立了位姿误差的数学模型。利用模型参数估计的方法,建立了测量数据与名义面形之间基于最小二乘法的优化模型,得到了上述位姿误差的最小二乘估计,并据此对工件面形误差测量结果进行校正,消除了位姿误差的影响,提高了测量结果的可信度与精度,最终使测量系统精度达到0.5 μm,重复精度优于0.3 μm。

Separation and optimization of posture errors in optical aspheric coordinate measurement

Based on the development of a new special-purpose optical aspheric coordinate measurement machine, the effect of the relative posture errors between the measurement system and the workpiece in 6 degrees was researched, and its mathematical model was established. With a model parameter estimation method, the least square (LS) optimal model was established based on the measuring data and the nominal surface, and then the LS estimations of the posture errors were obtained to correct the measurement result. The experimental results indicate that the method can eliminate the effect of posture errors and increase the reliability and accuracy of the measuring data, which ensures the measurement system in a repeatability of 0.3 μm and an accuracy of 0.5 μm.