双转台五轴机床旋转轴位置无关几何误差的辨识

Identification of Position-independent Geometric Errors for Rotary Axes of Five-axis Table-tilting Machine Tools

旋转轴的位置无关几何误差(PIGEs)是影响五轴机床加工精度的重要因素。以AC双转台五轴机床为研究对象,提出一种基于差分演化算法的旋转轴PIGEs辨识方法。首先,建立机床旋转轴PIGEs和球杆仪杆长变化的关系模型,使用已有的辨识方法获得机床旋转轴PIGEs初始解,然后定义优化目标函数,通过差分演化算法整体优化求解旋转轴PIGEs,提高旋转轴PIGEs辨识准确性。实验与仿真的结果表明提出的旋转轴PIGEs辨识方法可有效提高辨识准确性。

PIGEs of rotary axes were the important factors that affected the machining accuracy of five-axis machine tools.Taking AC type five-axis table-tilting machine tools as an example,an identification method of PIGEs of rotary axes was proposed based on the differential evolution algorithm.Firstly,a mathematical model of PIGEs and length change of ball bar was established.The initial PIGEs may be identified by existing methods.Then,an optimization objective function was defined,and the PIGEs of the rotary axes were optimized as a whole by a differential evolution algorithm to improve the identification accuracy of the rotary axes PIGEs.The experimental and simulation results show that the proposed method may effectively improve the identification accuracy of the PIGEs of the rotary axes.