Sensitivity analysis of geometric error for a novel slide grinder based on improved Sobol method and its application

Abstract

In order to improve both the accuracy and efficiency of grinding slide, this paper designs a novel grinder with dual-lead-dual-head. Since the geometric error is one of the major contributors causing machine inaccuracies, the sensitivity analysis is performed to identify the critical geometric error terms, and an application to accuracy self-test is also given. The volumetric model of the grinder with 38 geometric errors is built using the homogeneous transformation matrix (HTM) and multi-body system (MBS) theory. An improved Sobol method with quasi-Monte-Carlo algorithm is utilized to perform the global sensitivity analysis (GSA) in the entire workspace. The particular sensitivity analysis is further carried out on the basis of the machining characteristics of a typical slide. All sensitivity analysis results are validated through the error compensation simulations. Besides that, some discussions are given to determine the total critical errors of the grinder considering both entire workspace and particular machining requirements. Finally, the pitch and yaw errors between the dual-grinding-head are investigated, and based on the sensitivity analysis results, a quick accuracy self-test approach is proposed to reduce the measurement load in practice.