关键词: 多体系统, 几何误差, 模型, 综合误差

Abstract: As the main error source of machine tools, the geometric accuracy is studied theoretically and experimentally. A modeling method of synthesis error is established in the coordinate system of machine tools based on the multi-body system theory, which is applied to a 3-axis CNC machine tool considering the interaction of error terms such as positioning errors, straightness errors and angular errors. By using the laser interferometer system, the positioning errors, straightness errors and angular errors are illustrated by a large number of experiments, which indicates that the positioning errors value is much higher than others. And the distribution and evolution of the synthesis error subjected to the coupling effect of all axes errors are studied in the workspace further. It is found that the synthesis error in the direction of a certain axis is close to its positioning error, which proves that the positioning error is the decisive factor contributing to the synthesis error. The analysis of geometric accuracy is of theoretical and practical significance to error compensation.

Key words: Geometrical error, Model, Multi-body system, Synthesis error