螺纹量规三维数字化计量模型参数计算及精度分析

针对实体螺纹量规加工难、成本高、易磨损、检定工序繁琐等问题，提出了一种基于三维点云的螺纹量规数字化计量模型建立及参数计算方法。为实现实物螺纹量规数字化，首先获得其三维数字化模型，并获取模型大径、中径、小径、螺距与牙型角等关键参数。其次对模型进行单项误差与综合误差分析，得到各参数相对误差均小于5%。最终得到数字化模型各项参数的不确定度与扩展不确定度，证明螺纹量规数字化计量模型的准确性。该结果为螺纹量规数字化发展提供了研究基础，对计量行业的数字化转型具有参考价值。

Parameter calculation and precision analysis of 3D digital measurement model for thread gauge

Aiming at the problems of solid thread gauges including difficult to process, high cost, easy wear and cumbersome verification procedures, a digital measurement model establishment and parameter calculation method of thread gauge based on three-dimensional point cloud was proposed. In order to realize the digitization of the physical thread gauge. First, the 3D digital model was obtained, and the key parameters of the model such as large diameter, middle diameter, small diameter, pitch and tooth profile angle were obtained. Secondly, the single error and comprehensive error of the model are analyzed, and the relative error of each parameter is less than 5%. Finally, the uncertainty and extended uncertainty of each parameter of the digital model are calculated, which proves the accuracy of the digital measurement model of thread gauge. The results provide a research basis for the digital development of thread gauge and have reference value for the digital transformation of measurement industry.