面向五轴加工的等距双NURBS刀具路径同步插补方法

Isometric double-NURBS synchronous interpolation algorithm for five-axis machining

针对由离散刀位点数据生成的五轴加工等距非均匀有理B样条曲线刀具路径中两条非均匀有理B样条曲线参数不同步的问题,建立了一种等距双非均匀有理B样条曲线参数的同步模型,实现等距双非均匀有理B样条曲线刀具路径插补过程中两条非均匀有理B样条曲线参数的同步运动。将三轴非均匀有理B样条曲线插补算法应用于五轴加工等距双非均匀有理B样条曲线刀具路径中的刀具中心点非均匀有理B样条曲线,根据参数同步模型将插补算法同步到刀轴点非均匀有理B样条曲线中。仿真表明,采用该算法能够使刀具始终沿着等距双非均匀有理B样条曲线刀路进行同步插补,参数同步插补精度主要集中在10-6 mm级数上,适用于复杂曲面的五轴加工。

The isometric double-NURBS toolpath for five-axis machining was generated by discrete tool path data, which parameters were not synchronous. For this problem, a parameter synchronization model of isometric double NURBS toolpath was proposed, and the synchronous motion of two NURBS curve parameters in the interpolation process was realized. The stable three-axis machining NURBS curve interpolation algorithm was utilized to interpolate the cutter tip points NURBS curve of isometric double NURBS toolpath for five-axis machining. In terms of parameter synchronization model, interpolation algorithm could be mapped to cutter points NURBS curve. MATLAB simulation results showed that the proposed model could make the tool interpolate synchronously along the isometric double-NURBS tool path, and could achieve high process precision which was mainly concentrated on the 10^-6mm series.