Abstract: The nine-line method is one of the common methods for measuring the geometric error of translational axis of CNC machine tools,but there are difficulties in tracing the source of the error and poor identification stability in practical applications.In view of these problems,the measurement process and identification principle of the nine-line method were systematically analyzed,and an improved identification method was proposed.Utilizing the dependency relationship between the geometric error and the measurement coordinate system,the position of the coordinate system was reasonably arranged,which was ensure the traceability value of the identification result,and beneficial to guide the machining and debugging of the machine tool.Meanwhile,the matrix structure and parameters of the identification model were optimized by increasing the measurement dimensions and searching for the optimal measurement point combination to improve the stability of the identification.The results of simulation analysis and measurement experiments showed that the improved identification method exhibited higher resolution accuracy and significantly enhanced identification stability.

Key words: geometrical error, modified identification method, nine-line method, CNC machine tool

摘要： 为解决测量数控机床平动轴几何误差常用的九线法在实际应用中存在的误差溯源困难、辨识稳定性差的问题,系统分析了九线法的测量过程和辨识原理,提出一种改进的辨识方法。利用几何误差和测量坐标系之间的依附关系,合理布置坐标系的位置,保证了辨识结果的溯源价值,有利于指导机床加工和调试。通过增加测量维度和搜索最优测点布局,对辨识模型的矩阵结构和参数进行优化,以提高辨识的稳定性。仿真分析和测量实验结果表明,改进的辨识方法求解精度较高,辨识稳定性显著提高。

关键词: 几何误差, 辨识方法改进, 九线法, 数控机床