一种新的机床位置误差灵敏度分析方法

本文提出一种新的机床位置误差灵敏度分析方法。 首先基于多体理论和齐次变换矩阵建立了五轴龙门机床位置误差 模型。 其次通过截断傅里叶技术来表征与位置有关的几何误差参数,每个误差参数对位置误差的灵敏度值可表示为其傅里叶 幅值平方。 然后归一化处理,关键的几何误差参数为第 2,3,8,15 和 26 项误差。 通过与传统的 Sobol 法对比,仿真结果表明两 种灵敏度分析方法辨识的关键几何误差相同且灵敏度值相近。 此外,本文提出的灵敏度分析计算效率优于传统 Sobol 法。 最 后为了验证关键几何误差的有效性,提出了一个关于机床关键几何误差的补偿实验。 实验结果表明,补偿关键几何误差后机床 的加工精度提升了 48% 。 因此,本文提出的机床位置误差灵敏度分析方法是可行的和有效的。

A novel sensitivity analysis method for machine tool position error

This article proposes a new method for sensitivity analysis of machine tool position errors. Firstly, the position error model of five axis gantry machine tool is formulated, which is based on the multi-body theory and homogeneous transformation matrix. Secondly, the geometric error parameters related to the position are characterized by the truncated Fourier technique. The sensitive value of each error parameter to position error can be expressed as its Fourier amplitude square. After normalization, the key geometric error parameters are the 2nd, 3rd, 8th, 15th and 26th errors. Compared with the traditional Sobol method, the simulation results show that the key geometric errors identified by the two sensitivity analysis methods are the same and the sensitivity values are similar. In addition, the calculation efficiency of sensitivity analysis of the proposed method is better than that of traditional Sobol method. Finally, to verify the validity of key geometric errors, a compensation experiment on key geometric errors of machine tools is proposed. Experimental results show that the machining accuracy of the machine tool is improved by 48% after the key geometric errors are compensated. Therefore, the sensitivity analysis method of machine tool position error in this article is feasible and effective.