基于移动最小二乘法测量数据的数控刀轨生成

Tool path generation on measured data using moving least squares method

为解决激光快速成型方法精度和效率低的问题,提出了一种采用移动最小二乘法将测量数据直接生成粗精加工刀具路径的算法,并对拟合误差进行了分析。粗加工采用层切法快速切削材料,首先按照粗加工余量生成偏置点云,采用移动最小二乘法拟合点云切片数据,并生成偏置曲线,划分子加工区域,生成Zigzag方式的粗加工刀具轨迹。精加工采用球头刀保证加工精度,按照球头刀半径偏置点云并删除局部干涉的点生成偏置点云,对偏置点云进行切片处理,并拟合确定刀位点,有序连接生成精加工刀位轨迹。实验结果表明,粗加工具有较高的效率,精加工能够满足给定的加工精度并避免局部干涉。

To solve low accuracy and efficiency problem of rapid prototype manufacturing in reverse engineering,a new algorithm was proposed to generate roughing and finishing tool paths on measured data directly by using Moving Least-Squares（MLS）method,and corresponding fitting error was analyzed.Roughing was performed in a slice-by-slice manner to remove material rapidly.An offset point cloud was firstly produced by the given machining allowance,and slicing data points were fitted by using MLS method to generate offset curve.Then whole region was partitioned into several sub-cut regions.Cutting path with a Zigzag way for roughing was obtained.Ball-end cutter was selected to guarantee machining precision,and offset point cloud was generated by offsetting point cloud a cutter radius and removing local interference points.Then,slicing data points were fitted to locate cutter location points.Data points were connected consequently to generate final cutting paths.Experimental results showed that the proposed method was efficient for roughing,and finishing could satisfy given accuracy while avoid local interference.