基于空间样条曲线的数控五轴机床误差辨识研究

在划分球杆仪空间误差辨识区域的基础上,基于NUBRS空间样条曲线生成辨识轨迹。分析球杆仪空间辨识原理,并依据此原理建立适用于NUBRS空间曲线的误差辨识模型,该模型包含18个误差因素。依据五轴机床多体运动学的分析结果,提出了一种空间误差辨识方法。通过激光干涉仪的测量及误差补偿,在消除9项空间位移误差的基础上,使用生成的NURBS曲线对剩余9项角度误差因素进行辨识。经实验验证,在进行NUBRS曲线修正后,该方法可有效辨识出3个坐标系中的18项误差因素。

Research on Error Identification of CNC Five-axis Machine Tool Based on Spatial Spline Curve

On the basis of dividing identification region to the spatial error of the ballbar, the identification trajectory was generated based on the NUBRS spatial spline curve. The spatial identification principle of the ballbar was analyzed. An error identification model suitable for NUBRS space curve was established based on this principle, which contained 18 error factors. A space error identification method was proposed based on the multi body kinematics analysis results of five axis machine tools. Through measurement and error compensation of the laser interferometer, on the basis of eliminating 9 spatial displacement errors, the generated NURBS curve was used to identify the remained 9 angle error factors. The experimental results show that after NUBRS curve correction, the method can be used to effectively identify 18 error factors in 3 coordinate systems.