光学非球面形摆臂式测量不确定度分析

Uncertainty Analysis on Swing-arm Profilometer for Optical Aspherics

在开发的摆臂式测量试验系统的基础上,对影响系统测量不确定度的各种误差因素进行了分析,建立了测量系统与被测工件之间的相对位姿误差、转台轴向窜动和径向跳动、测量臂的挠性变形以及测头半径之间的影响模型;同时对实际测量过程中的温度、振动等环境误差因素进行了实测。最后对直径200mm、顶点曲率半径1400mm的凹形抛物面镜进行了测量实验。分析与实验表明:测量系统合成标准不确定度小于0.5μm。

With the experimental set--up of swing--arm profilometry, all kinds of errors which will affect the accuracy were analyzed. The mathematical models of the posture errors, the axial and radial run outs,the radius of the probe,and the flexure of the measurement arm were built. Several environmental factors, such as temperature and vibration, were analyzed and tested practically. Finally, a concave paraboloid （R= 1400mm,D=200mm） was tested. The experiments indicate that the uncertainty of the set--up is better than 0.5um.