Sensitivity analysis of machining accuracy reliability considering partial correlation of geometric errors for Horizontal Machining Center

With the increase in working time, the geometric errors of a Horizontal Machining Center (HMC) will also increase under load, temperature, and wear conditions, decreasing the machining accuracy. As HMC is a high-accuracy machine tool with a high nonlinear system, there is a complex coupling relationship between errors. Therefore, how to thoroughly evaluate the ability of a machine tool to maintain its machining accuracy with the extension of working time is an important way for HMC to control its machining quality. In this paper, this ability is defined as machining accuracy reliability, that is, under specified conditions, the machine tool can work normally to achieve the corresponding machining accuracy ability. To solve this problem, a new analysis method is proposed for evaluating machining accuracy reliability based on the nonlinear correlation between errors. The nonlinear relationship between machining accuracy and errors was determined using multibody modeling technology. The effect of interaction between errors on machining accuracy reliability was analyzed by introducing and calculating partial correlation coefficients. Finally, the method was validated using a four-axis machine tool.