Abstract: In order to quickly and systematically identify the geometric errors of rotation axes of dual-five-axis CNC milling machines, an error measurement and identification method was proposed based on R-test. According to the error model of R-test, the relationship among the error measurement values and various error parameters was studied, and the installation errors and motion errors of rotation axes were obtained by identifying the geometric error items of rotation axes. Two displacement errors and two perpendicularity errors were identified respectively by the method of plane circle fitting and line fitting based on the principle of least square method. Based on the theory of multi-body system and the method of homogeneous coordinate transformation, the homogeneous coordinate transformation model of tool coordinate system and workpiece coordinate system was established to identify three movement errors and three rotation errors. Finally, the X-direction and Y-direction displacement errors were identified according to the identified values compensation. The experimental results show that the X-direction and Y-direction displacement errors are significantly reduced after compensation, and the error compensation results verify the accuracy and effectiveness of measurement and identification.

Key words: dual-five-axis CNC milling machine, rotation axis, error identification, thin wall part, homogeneous coordinate transformation

摘要： 为了快速、系统地辨识双五轴数控铣削机床旋转轴几何误差，提出了一种基于R-test的误差测量辨识方法。根据R-test误差模型研究误差测量值与各项误差参数的关系，辨识旋转轴各个几何误差项以得到旋转轴的安装误差和运动误差；利用最小二乘法原理平面圆拟合和直线拟合的方法分别辨识出2项位移误差和2项垂直度误差；基于多体系统理论及齐次坐标变换方法建立刀具坐标系与工件坐标系的齐次坐标变换模型，并辨识出3项移动误差和3项转动误差；最后，根据所得辨识值对X向和Y向位移误差进行补偿。实验结果表明，补偿后X向和Y向位移误差明显减小，误差补偿结果验证了测量、辨识的准确性和有效性。

关键词: 双五轴数控铣削机床, 旋转轴, 误差辨识, 薄壁件, 齐次坐标变换