基于NURBS曲线的数控机床几何误差实时补偿研究

Investigation on Geometry Error Real-time Compensation of NC Machine Tool based on NURBS Curves

阐述了一种基于NURBS曲线的数控机床几何误差补偿技术,利用误差模型计算预设的NURBS路径与控制点之间的位置偏移能得到NRUBS误差补偿函数控制点,通过插入新的节点产生新的函数控制点,并提高NURBS曲线表达误差补偿函数的柔度,从而得到更高的补偿精度。结果表明,在公差精度为0.0005mm的情况下,沿3种不同工作路径的误差补偿精度都小于1mm。

In this paper a new method for the geometric error compensation of CNC machine tools based on NURBS curves is elaborated. By calculating the position offset between default NURBS path and control point based on the error model, the control point of NRUBS error compensation function can he get. After that higher compensation accuracy can be achieved through the systematic insertion of new knots which creates new control points and raises the flexibility of NURBS in representing the error compensation function. The simulation results show that the error compensation accuracy along three different paths is smaller than 1mm with 0. 0005mm tolerance accuracy.