NURBS曲线自适应插值拟合算法

摘要

针对从DXF文件中构造的NURBS曲线,提出了一种曲线的自适应分解算法.该算法结合了NURBS曲线的形状信息,通过计算比较插补点的曲率半径与给定阈值的大小,以决定当前插补类型为直线段或是圆弧段,在满足加工精度的前提下,采用伸缩步长法使得拟合的区间尽可能大.经实际运行表明,此方法拟合的加工程序段少,能简化数值计算和编程,减少数控机床的预处理时间.该算法具有通用性,为其他曲线的插值拟合也提供了一种有效途径.%This paper introduces a way of adaptive interpolation for NURBS curve constructed form DXF. The algorithm combines shape information of the NURBS curve By comparing the size of curvature radius of the interpolation points and the given threshold to determine the current interpolation type is line segment or arc segment. On the premise of satisfying the precision, telescopic step method makes sure the fitting range as large as possible. Experimental results show that this way is simple and efficient,and can shorten the CNC pre-processing time.The algorithm is universal, and it provides an effective way for other curves interpolation.