基于误差椭圆理论与蒙特卡罗方法的圆直径测量不确定度评定

利用三坐标测量机(CMM)测量圆几何特征的功能,建立了基于误差椭圆理论与蒙特卡罗方法的测量不确定度评定模型.以误差椭圆表征采样点的不确定度,结合蒙特卡罗方法仿真所得较少的测量样本数据快速得到了最小二乘拟合条件下的圆直径测量的不确定度.同时,与实验测量和文献公式计算的结果进行对比,验证了其有效性.结果表明,所建立的模型能够准确评定圆直径测量的不确定度.

Measurement Uncertainty Evaluation on Circular Diameters Based on#br# Error Ellipse Theory and Monte Carlo Method

Abstract： The measuring circle function of coordinate measuring machine (CMM) is studied and a new uncertainty evaluation model is established in the paper based on error ellipse theory and Monte Carlo method. The uncertainty of the sample points is expressed in the error ellipse. The paper uses the Monte Carlo method to get the uncertainty of diameter in circle fitted by the least square method. The method is more quickly as the less sample data involved.Comparison the experimental measure with the results by method proposed in the paper, it can draw a conclusion that the method can evaluate the diameter uncertainty accurately.