Abstract: Aiming at the distortion problem of measured length change caused by the combined effect on geometric errors of linear axes and installation errors in double ball bar test,a method for separating geometric errors of linear axes and installation errors was proposed based on parametric modeling.A comprehensive model of bar length changing included installation error and geometric error of machine tool was established based on homogeneous coordinate transformation.Combing with the position-dependent characteristics of geometrical errors,the parametric models of geometric errors were established.The solvable length change model of the double ball bar was built with the modeling of straightness errors incomplete polynomials.In addition,the separation of the installation error and geometric errors was realized.The validation of the proposed method was verified by simulation.In the actual circular test,the installation errors in X and Y direction were removed as 4.3 mm and 18.7 mm.The variation range of the comprehensive geometric errors component in X and Y direction changed from 30.7 mm and 27.9 mm to 13.6 mm to 11.4 mm.

Key words: double ball bar, linear axes, installation error, geometric errors, parametric models

摘要： 针对球杆仪圆测试中直线轴几何误差与球杆仪安装误差共同作用造成检测结果失真的问题,提出了基于参数化建模的球杆仪安装误差与直线轴几何误差分离方法。首先,通过齐次坐标变换建立了包含球杆仪安装误差与直线轴几何误差的杆长变化模型;其次,结合直线轴几何误差的位置相关特性对其进行参数化建模;接着,通过对直线度误差缺项建模,构建了可解的杆长变化参数化模型,实现直线轴几何误差与球杆仪安装误差的分离;最后,仿真验证了分离方法的正确性,并应用于实际的圆测试中,分离了数值为4-3 mm和18-7 mm的X向和Y向安装误差,X向与Y向综合几何误差分量变化范围由30-7 mm、27-9 mm减小为13-6 mm、11-4 mm,实现了球杆仪安装误差与直线轴几何误差的有效分离。

关键词: 球杆仪, 直线轴, 安装误差, 几何误差, 参数化模型