Volumetric error measurement and compensation of three-axis machine tools based on laser bidirectional sequential step diagonal measuring method

摘要

This paper proposes an approach to the measurement, modeling, and compensation of the volumetric errors for three-axis machine tools, using laser bidirectional sequential step diagonal measurement. Disparate measuring tracks are specially arranged for forward and backward paths, and the conforming error decoupling method is demonstrated. By decoupling, all the geometric errors which can result in volumetric errors are distinguished simultaneously, including translational and angular errors. In comparison with the traditional unidirectional measuring method, the proposed bidirectional method distinguishes more geometric errors (the angular errors) by measuring the same four body diagonals. Uncertainty analysis based on the Monte Carlo simulation was conducted, followed by experimental validation on a vertical machining center. The result of the experiment indicates that the diagonal systematic deviation of positioning is reduced by 90% after volumetric compensation.