数控机床旋转轴转角定位误差测量方法

New method to measure angular position errors of rotational axis of CNC machine tool

为实现多轴数控机床空间误差的补偿,提出一种基于球杆仪组合路径的数控机床旋转轴转角定位误差的测量方法.根据转角定位误差敏感方向,通过组合切线测量和平动轴圆轨迹测量方法,无需机床空间误差模型和繁琐的误差解耦计算,便可直接辨识转角定位误差.采用模型仿真验证该方法的可行性和对照实验验证可靠性.实验结果表明组合路径测量方法的辨识结果与激光测量结果吻合较好,两者的测量结果差异δ≤0.007 8°.该方法测量过程操作简单、辨识原理直观易懂,可用于机床旋转轴定位精度的评估以及为误差补偿提供依据,从而提高机床加工精度.

In order to carry out the error compensation of multi-axis machine tools, this paper presents a novel measurement method, a combined paths measurement method （CPMM） based on ball bar, to identi- fy the angular position errors of a rotational axis of a machine tool. According to the error sensitive direc- tion, angular position errors could be directly identified by combining the tangential direction measurement and circular path measurement of translational axes without a mathematical error model of a machine tool and the complicated error decouple process. The simulation and contrast experiments were conducted to verify the feasibility and reliability of the method. The results show that identified value by CPMM is con- sistent with that by laser measurement method, the maximum difference is 0. 007 8~ . The operation process of CPMM is simple and its corresponding identification algorithms are easier to understand. The established measurement method can be used for the precision evaluation of a rotational axis, and provide the basis for the error compensation to improve machining precision of machine tools.