双转台五轴机床空间误差补偿技术研究

几何误差、热误差和切削力误差占到了机床总误差的75%,对这3项误差进行控制是提高机床加工精度的关键所在。以双转台五轴机床的空间误差作为研究对象,通过对加工位置、主要热源及电动机电流等相关因素进行分析,确定空间误差建模所需的位移变量、温度变量和切削力变量。以现有的多种误差建模方法为基础,通过对信息融合技术进行研究,提出一种机床空间误差的多模型融合预测方法,建立综合反映几何误差、热误差和切削力误差的最优空间误差模型。最后以DSP为核心,设计空间误差补偿器,实施空间误差补偿,验证补偿效果。结果显示,建立的模型预测精度较高,残差小于2μm,而实施空间误差补偿后,加工零件的轮廓误差也由15μm降到了5μm,补偿效果明显。

Research on Volumetric Error Compensation of Two Turntable Five-axis Machine Tools

Geometric error, thermal error and cutting force induced error account for 75% of total machine tool error, controlling these errors is the main way for improving the machine accuracy of CNC machine tools. Error compensation technology is used for reducing the volumetric errors of a two turntable five-axis CNC machine tool. In order to determine the displacement variables, temperature variables and cutting force variables required for volumetric error modeling, the main error sources of the two turntable five-axis machine tools will be analyzed, selected and optimized. According to the existing modeling methods, an optimized volumetric error model will be presented based on information fusion technology, and the influence of displacement variables, temperature variables and cutting force variables on volumetric error of the five-axis machine tool will be revealed. Finally, a volumetric error compensator will be designed for the experimental study of two turntable five-axis CNC machine tools, the compensation effect will be verified. The results show that prediction accuracy of the presented model is higher, the residual error is lower than 2μm, and the maximum profile error is reduced from 15μm to 5μm after volumetric error compensation.