数控机床热误差补偿最佳转速选择

为提高数控机床热误差补偿模型在实际工程应用中的补偿精度和稳健性,研究了热误差补偿建模时机床最佳转速状态的选择方法。首先,以Leaderway V-450数控加工中心主轴Z向为研究对象,控制机床主轴在空转状态下,以图谱和恒定转速两种方式进行了多批次实验。然后,采用模糊聚类结合灰色关联度选择温度敏感点并建立多元线性回归模型。最后,分析不同转速类型下模型的预测效果并对同种转速类型下模型预测效果进行相对评价,从而给出热误差补偿建模时机床最佳转速状态的选择方法。实验结果表明,根据国际标准中不同主轴转速类型建立的热误差补偿模型,对于机床热误差预测效果存在较大差异。根据实际工程应用选择的最佳转速状态建立的补偿模型有较好的预测效果。

Selection of optimum spindle speed to thermal error compensation of machine tools

To improve the compensation accuracy and robustness of a thermal error compensation model for Computer Numerical Control(CNC) machine center in practical engineering applications, a selection method for the optimal speed of CNC machine center was presented. For the Z-axis of Leaderway V-450 CNC machining center, several batches of experiments were carried out at a variable speed spectrum and a constant speed by controlling the spindle in an idling condition. Then, fuzzy clustering method combined with the gray correlation was used to select the temperature sensitive point and establish multiple linear regression models. Finally, by analysis of the model predictive effect in different type speeds and comparison of the model predictive effect in the same speed type, a selection method for the optimum spindle speed of CNC center in modeling of thermal error compensation was given. The research results show that thermal error compensation models established by different spindle speed regimes based on the international standard have great differences in the thermal error predictive effect of machine tools. It suggests that the compensation model based on optimum spindle speeds selected by practical engineering application will provide a good prediction effect.