Identification of geometric errors of five-axis machine tool through volumetric error measurement

Abstract To improve the volumetric precision of five-axis machine tools, this paper proposes a method for measuring and identifying all geometric errors through volumetric error measurement. The method establishes a complete volumetric error model that explicitly addresses the mathematical implications of error matrix multiplication order (left vs. right multiplication) in homogeneous transformations. Utilizing a laser tracker enables rapid volumetric error measurement, with measurement trajectories planned as coordinated movements across five axes, thereby enhancing measurement efficiency. Position-dependent geometric errors (PDGEs) are modeled as polynomial functions, whose coefficients are determined using the Levenberg-Marquardt algorithm to decouple and identify different geometric errors. The proposed method’s accuracy in identifying geometric errors is experimentally validated, demonstrating that volumetric errors within the machine tool’s workspace can be forecasted and corrected based on the identified geometric errors.