工件分特征下的五轴数控机床关键几何误差分析与补偿方法

Key Geometric Error Analysis and Compensation Method of Five-axis CNCMachine Tools under Workpiece Feature Decomposition

提出了工件分特征下的五轴数控机床关键几何误差分析与补偿方法,将复杂工件进行特征分解,通过灵敏度分析辨识工件分特征下的关键几何误差并补偿,从而提高工件整体加工精度。以某一复杂工件为例,首先,将其分解为平面、斜面、圆柱和圆锥台四个典型特征;然后,基于灵敏度分析分别辨识出各典型特征对应的关键几何误差;最后,分特征地进行误差补偿。在AC双转台五轴数控机床上进行了实验验证,实验结果表明,辨识得到的关键几何误差灵敏度系数之和占比均大于90%,补偿后工件四个典型特征的加工精度提高了20%~30%。研究结果表明,所提方法能有效辨识不同工件分特征下的关键几何误差,从而提高复杂工件的加工精度。

A method was proposed to analyze and compensate the key geometric errors of five-axis CNC machine tools under workpiece feature decomposition.The complex workpieces were decomposed by the features,and the key geometric errors were identified and compensated through sensitivity analysis under the workpiece feature decomposition,so as to improve the overall machining accuracy of the workpieces.Taking a complex workpiece as an example,firstly,it was decomposed into four typical features:plane,inclined plane,cylinder and cone-frustum.Then,based on the sensitivity analysis,the key geometric errors corresponding to each typical feature were identified respectively.Finally,error compensation was made by feature decomposition.The experiments were carried out on an AC double-turntable five-axis machine tool,and the experimental results show that the sum proportion of key geometric error sensitivity coefficients obtained by identification are all more than 90%.After compensation,the machining accuracy of the four typical features of the workpiece is improved by 20%~30%.The results show that the proposed method may effectively identify the key geometric errors under different workpiece feature decomposition,thus improving the machining accuracy of complex workpieces.