三维坐标点集的空间直线度高精度快速评定

针对3维坐标点集合空间直线度误差评定时出现的精度不高、评价效率低的问题,提出一种具有较高精度和较好鲁棒性的3点高精度快速算法(3PHFA).该算法依据国家标准规定的空间直线度有效判别形式,通过3维最小二乘法(3DLSA)拟合、空间坐标转换、坐标投影和确定最小包容圆(MCC),并最终确定最小包容圆柱面(MCS).通过在3DLSA基础上增加高效搜索算法,空间直线度评定精度提高约20%,耗时1s以内.对比不同评定算法表明:3PHFA具有效率高、精度高、鲁棒性好的优点,其误差评定精度全面优于3DLSA,适用于三坐标测量机(CMM)这类实时处理系统,具有良好的实用价值.

High-Precision and Fast Evaluation of Spatial Straightness Error of 3D Coordinate Point Set

Abstract： This paper proposed a novel high precision, robust and fast spatial straightness error evaluation algorithm called 3 points high precision fast algorithm (3PHFA) to deal with the problem of low precision and low efficiency when evaluating spatial straightness errors. With reference to the related national standard for construction of mathematics models, the algorithm mainly includes 3DLSA fitting, space coordinate translation, coordinate projection, and determining minimum circumscribed circle (MCC), which can determinate the minimum cylindrical surface (MCS). By adding the highly effective search algorithm to the 3DLSA algorithm, it almost improves the evaluation accuracy by 20% in less than 1 second. Compared with other evaluating algorithms, the 3PHFA has the advantages of high efficiency and accuracy, and better robustness. It is applicable to the real time processing system such as coordinate measuring machine (CMM), and has a good practical value for evaluating machine parts.