基于自修正模型的五轴机床RTCP标定方法

A RTCP Calibration Method of Five-Axis Machine Tool Based on Self-Correcting Model

针对传统五轴机床回转中心的标定方法的精度和效率问题,提出一种带有自动修正功能的双摇篮式五轴机床RTCP的标定方法。应用最小二乘拟合的粗自动标定和“自校验-自修正”的精自动标定方案,通过引入试切校验思想,使用接触式探头和标准球对现有RTCP参数进行精度自校验,并根据误差反推RTCP参数,然后再次校验,不断迭代优化并逐步逼近最优解,形成闭环标定。经过试切和标准球校验显示,经过自修正精度优化的结果单方向误差在0.01 mm以内,对比粗标定误差0.03~0.06 mm,精度提升66%以上,且多组实验的重复性能良好。

Aiming at the problem of precision and efficiency of traditional calibration method of rotation center of five-axis machine tool,an automatic calibration method for the RTCP of a double-cradle five-axis machine tool with self-correction function is proposed,which used the rough automatic calibration using least square fitting,and the fine automatic calibration using "self-checked and self-correction function ".In this method,the tried-cut calibration idea is implemented,the accuracy of the existing RTCP parameters are self-checked by using the contact probe and the standard ball,and the RTCP parameters are corrected according to the error,and then checked again.The method is iteratively optimized and gradually approximates to the optimal solution to form a closed-loop calibration.After trial cutting and standard ball verification,the single-direction error is less than 0.01 mm,compared with the rough calibration error of 0.03~0.06 mm,the accuracy is improved by more than 66%,and the repeatability of multiple groups of experiments is stable.