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

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. © 2022 China Mechanical Engineering Magazine Office. All rights reserved.