数控机床XY工作台单向运动二维阿贝误差分析与建模

Two-dimensional abbe error analysis and modeling of CNC machine tool XY table unidirectional movement

为了提高数控机床的加工精度,建立误差补偿模型。对温度影响下的数控机床XY工作台导轨系统各误差分量之间的误差相关性进行研究。首先,分析了XY工作台单向运动时各平动误差和角度误差的相关性和X向导轨系统二维阿贝误差的变化规律。然后,建立了Y轴导轨系统和X轴导轨系统误差相关性的阿贝误差计算模型。最后,分别进行了X轴导轨和Y轴导轨角度误差的相关性验证和导轨系统定位误差补偿效果对比实验。实验结果表明:利用工作台二维阿贝误差补偿后的定位误差2整体误差呈减小趋势,且比用传统方法补偿后的定位误差1最大相差3µm左右,占补偿后的工作台总误差的三分之一。本文所建立的导轨系统二维阿贝误差模型更符合数控机床XY工作台误差的实际变化规律,利用该模型导轨进行的工作台联动定位误差补偿效果比传统补偿方法的修正效果更好,为实时补偿数控机床误差,提高机床加工精度和在机测量系统的测量精度打下理论基础。

In this study,an error compensation model is established for improving the machining accuracy of computer numerical control(CNC)machine tools. The error correlations between the various error components of the XY table rail system of the CNC machine tools are studied under the influence of tem-perature. First,the correlation between the translation error and angle error and the variation law of the two-dimensional Abbe error of the x-direction guide rail system are analyzed. Then,an Abbe error calculation model is established for the y-axis and x-axis guide system error correlation. Finally,the correlation between the x-axis and y-axis guideway angle errors is verified,and the positioning error compensation effect of the guide rail system is investigated. The experimental results show that the overall error of "positioning error 2" after compensation by using the two-dimensional Abbe error of the workbench shows a decreasing trend;the maximum difference is approximately 3 μm from that of "positioning error 1" after compensation by the traditional method,which accounts for one-third of the total error in the compensated workbench. The established two-dimensional Abbe error model of the guideway system is more suitable for identifying the actual variation principle of the XY worktable error for CNC machine tools. The compensation effect for the worktable linkage positioning error based on the model guideway is better than that based on the traditional compensation method. Thus,this study lays a theoretical foundation for the realtime compensation of CNC machine tool errors and can be used to improve the machining precision and measurement accuracy of on-machine measurement systems.