基于分步体对角线法的数控机床空间误差补偿

Volumetric Error Compensation of CNC Machine Tools Based on Method of Sequential Step Diagonal

空间误差的测量与补偿是提升机床加工精度的重要手段。本文采用一种基于激光多普勒位移测量仪的分步体对角线法测量辨识了机床的几何误差元素。然后,基于齐次坐标变换理论,建立了立式加工中心的空间误差模型,并采用离线修改G代码的方式实施了机床空间误差补偿。与激光干涉仪多线法相比,分步体对角线法更加简便快捷,通过4次测试快速获得12项关键几何误差元素。误差测试与补偿试验结果表明,加工中心的整体精度水平有了大幅度提高,体对角线误差降低为原来的32.5%。

The measurement and compensation of volumetric error is an important means to improve the machining accuracy of machine tools.A measurement method based on a laser Doppler displacement meter is used to identify the geometric error elements of the machine tool.Then,based on the theory of homogeneous coordinate transformation,the volumetric error model of the vertical machining center is established.And use offline modification of G code to implement machine tool volumetric error compensation.Compared with the laser interferometer multiline method,the method of sequential step diagonal is simpler and faster,and 12 key geometric errors can be quickly obtained through 4 tests.The results of error test and compensation show that the overall accuracy level of machining center has been greatly improved,and the body diagonal error has been reduced to 32.5%.