复杂曲面加工中等距双NURBS刀具路径高效插补方法

摘要

为降低复杂曲面加工中采用相同节点向量生成等距双非均匀有理B样条(NURBS)刀具路径的插补误差并提升插补实时性,提出一种基于改进协同进化遗传算法及三阶导出Newton型参数计算的双NURBS刀具路径插补方法.基于误差控制选取部分刀具中心点和刀轴点离散数据,并采用同一节点向量构造双NURBS曲线,利用协同进化遗传算法调整刀轴点曲线的权重值,以降低曲线的拟合误差从而提高插补精度.实际插补时,采用三阶导出Newton方法提高插补参数的计算精度,以进一步降低插补误差,减少参数计算时间.仿真实验表明,与其他方法相比,该算法能够有效降低插补误差、提升插补实时性.%To reduce the interpolation error of dual-NURBS tool paths by using the same node vector and to improve real time performance in the process of sculptured surfaces machining,a double-NURBS interpolation algorithm based on improved Cooperative Co-evolutionary Genetic Algorithms (CCGA) and Newton-like parameter calculating was proposed.Based on the error control,some of the cutter tip points and cutter points were selected to construct dual-NURBS curves with same node vector.To reduce the fitting error and improve the interpolation precision,weights of cutter points NURBS curve were adjusted with improved CCGA algorithms.Newton-like algorithm was utilized to calculate parameter in the process of NURBS interpolation so that interpolation error and calculation time were further reduced.The experimental result showed that the proposed algorithm could effectively improve the interpolation accuracy and real time performance by comparing to other methods.