A new geometric error budget method of multi-axis machine tool based on improved value analysis

Abstract

The improvement of the accuracy grade of main components in the production process through balancing between function and cost helps to improve the overall accuracy of machine tools. Therefore, this paper presents an improved value analysis method and uses the method of global sensitivity analysis and geometric error correlation analysis to analyze and optimize the error parameters of a 4-axis machining tool based on the proposed method. The geometric error modeling of the 4-axis machine tool was established by using the homogeneous transformation matrices (HTMs). By using global sensitivity analysis, the degree of influence of each error parameter on the accuracy of machine tool was obtained, and functional coefficient and cost coefficient of value analysis were gained by correlation analysis. An optimization model for geometric error budget of machine tool was established according to the improved value analysis theory, and the machining accuracy of machine tool was optimized according to the improved value analysis method.