曲面笔式加工刀位点曲线的实时拟合

Real-time generation of cutter location curves for pen-cutting of sculptured surface

针对曲面高速高精度加工问题,给出一种刀位点轨迹实时生成算法。该方法的实现包括曲面上离散刀触点的生成和基于三次非均匀B样条曲线的刀位点轨迹实时高精度拟合两部分。第一部分,由导动曲线和刀触点轨迹的运动学关系,通过计算导动曲线参数,间接得到投影在曲面上的离散刀触点;第二部分,通过合理参数化、构建模长因子等实现刀位点参数曲线的分段实时拟合。仿真实例表明该算法简单易于编程,曲线拟合精度高,适用于自由曲面笔式加工中刀具路径计算与生成,从而满足复杂曲面高性能数控加工需求。

Aimed at the high speed and high precision machining of sculptured surface, an algorithm is proposed on the real-time generation of cutter location curves. This algorithm includes the generation of discrete cutter contact points and real-time high precision fitting of cutter location points based on cubic B-spline curves .The first stage is that the parameter of driving curves can be calculated based on Taylor series expansion according to the kinematics and geometric relation between cutter contact loci and driving curves. Then cutter contact points on the surface can be indirectly achieved. The second is that cutter location curves are fitted section by section by rational parameterization and constructing module gene. Examples and analysis results have indicated that the algorithm is simple and prone to program. The algorithm can realize the tool path regeneration and satisfy the demand for the high precision of NC machining.