关键词: 几何误差, 辨识方法改进, 九线法, 数控机床

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