双五轴机床几何误差补偿策略

Geometric Error Compensation Strategy for Double Five-axis Machine Tools

针对双五轴镜像铣机床加工时的几何误差辨识与补偿问题,基于激光干涉仪,运用“十二线”辨识法对五轴镜像铣机床平动轴的误差元素进行测量与辨识;基于R-test测量仪对五轴镜像铣机床转动轴的误差元素进行测量与辨识。以误差抵消为基本思想,提出一种基于参数误差模型的镜像铣机床精度补偿策略,计算刀触点和刀轴矢量在工件坐标系中的空间误差。运用解耦计算首先对转动轴进行补偿计算,再对平动轴进行补偿计算,通过修改NC代码分别对五轴镜像铣机床的铣削侧和支撑侧进行精度补偿。实验结果表明,补偿后的机床铣削侧和支撑侧的平均相对位置和方向精度分别提高了73%和60%,达到了镜像铣加工的精度要求,证实了该误差补偿算法的有效性和可行性。

Based on laser interferometer,the identification method of“twelve lines”is used to measure and identify the error elements of the translational axis of the five-axis mirror milling machine.The error elements of rotation axis of mirror milling machine were mea⁃sured and identified based on R-test measuring instrument.After the basic thought of offset error,error model is put forward based on the parameters of mirror like milling machine precision compensation strategy,to calculate the contact and knife axis vector space error in workpiece coordinate system,first calculated by using decoupling compensation for the rotational axis is calculated,to compensate for the translational axis is calculated,by modifying the NC code respectively mirror on five-axis milling machine milling side and side of precision compensation.The experiment results show that,after compensation,the average relative position and direction accuracy of milling side and support side of the machine tool are improved by 73%and 60%respectively,which meets the accuracy requirements of mirror milling,and proves the effectiveness and feasibility of the error compensation algorithm.