基于三坐标测量机的立方镜标定精度分析

立方镜是航天器产品制造过程中不可缺少的工艺基准。针对基于三坐标测量机的立方镜标定精度问题，进行了不同采样策略的采样试验，获得了立方镜夹角测量重复性数据。并利用解析法和蒙特卡罗方法两种理论分析方法分别对立方镜相邻面夹角测量不确定度进行了评估。数据表明，试验和理论分析结果一致， 两种理论分析方法得到的立方镜相邻面夹角测量不确定度相差微小，且夹角的测量不确定度随着采样点的数量增多而减小，最小接近0.0020°。利用理论分析的方法可以进行面向测量任务的立方镜标定精度的评估和采样规划。

Analysis of Calibration Precision for Cube-mirror Based on CMM

The cube-mirror is used as process reference for the spacecraft products manufacturing. To analyzing calibration precision for cube-mirror based on CMM, tests with different sampling strategies were done, the repeatability data of the measurement for cube-mirror angle is obtained.Besides, two theoretical analysis methods of analytical and Monte Carlo method are used to calculate the measuring uncertainty for the angle between the adjacent surfaces of the cube-mirror respectively. Data show that, the results of experiment and theoretical analysis are consistent, the measurement uncertainty of the angle between the adjacent surfaces of the cube-mirror obtained by the two theoretical analysis methods is almost the same, the measurement uncertainty of the angle decreases with the increase of the number of sampling points, the minimum value is close to 0.0020°.The method of theoretical analysis can be used to evaluate the calibration precision and planning sampling of cube-mirror for measuring task.