A sensitivity method to analyze the volumetric error of five-axis machine tool

Geometric errors have a comprehensive influence on the volumetric error of the five-axis machine tool. The identification of the vital geometric errors that have major effect on the volumetric error is the key problem to improve the machine tool accuracy. Therefore, a sensitivity analysis method to identify the vital geometric errors is proposed in this paper. The volumetric error model of a five-axis machine tool with 41 geometric errors is established based on the multi-body system method. Through the projection of the error vectors and the introduction of the effective cutting length, LSIL and GSIL are defined as the sensitivity indices for the local and global sensitivity analysis, respectively. Simulations are conducted for the local and global sensitivity analysis in which the LSIL and GSIL are used. And the analysis results have proven the validity of the proposed sensitivity analysis method. Compared with the conventional sensitivity analysis method, the proposed sensitivity analysis method has considered the position and posture error of the cutting tool simultaneously, which is more effective and efficient. The analysis results are helpful to improve the accuracy of the five-axis machine tool.