Through analyzing the principle of spline curve interpolation in CNC machining, a real-time non-uniform rational B-spline(NURBS) interpolation algorithm based on Newton iteration method was proposed. The proposed algorithm firstly controls the velocity design to meet the machining accuracy, then uses the Newton iteration method to calculate the interpolation parameters. The method can avoid derivative calculation of traditional methods. The second order Taylor expansion was simplified into simple linear recursive equation, which can be used to get the initial value of interpolation parameters. Simulation and experimental results show that the proposed algorithm has advanced features of good stability and high precision. And the proposed algorithm can meet with the real-time interpolation requirements and reduce the feedrate fluctuation to idea level.%通过分析数控机床加工中样条曲线插补原理,提出了一种基于牛顿迭代法的非均匀有理B样条(NURBS)曲线插补算法.该算法首先进行速度控制,保证了加工精度,然后利用牛顿迭代法来计算插补参数,避免了传统方法的大量求导运算.通过将二阶泰勒展开式化成简单的线性递推方程来预测插补参数的迭代初值,进一步减小了运算开销.仿真对比实验表明,该算法稳定性好,运算精度高,能够满足实时插补的要求,且能够将实时插补产生的速度波动限制到理想的水平.
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