The Generation Algorithm of Tool Path Based on the Discrete Data Points with Curves of Cross Sections
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摘要: 提出了一种利用截面线等误差步长法计算点云刀具路径的算法。首先定义一组截平面,运用点云切片算法求出截平面与点云的交线,作为刀触点(CC)轨迹。刀触点轨迹是由大量离散点组成的点集,本文中提出了一种等误差步长法对刀触点轨迹计算刀触点,然后利用最小二乘法拟合刀触点附近点获得平面,平面法矢作为刀触点的法矢,沿法矢偏置刀具半径得到对应的刀位点,并对生成的刀位点进行干涉处理。该算法计算出的刀具路径包含的刀位点数量更少,误差均匀且都满足最大误差要求,最后通过实例验证了算法的可行性。Abstract: This paper presents a new approach with cutter-contact (CC) curves of cross sections for the determina-tion of tool paths in the machining of discrete data points using 3-axis ball end milling.Firstly, a set of cutting planes are defined to compute the intersection curves with the point cloud and the curves are seen as CC point traces.Because the CC point traces consists of a series of intersection points, this paper presents a constant step-er-ror method to calculate CC points, and the K-nearest points of a CC point are obtained to fit a plane.The normal vector of the plane is seen as the normal vector of the CC point.The CC point is offset by the radius size along the normal vector to calculate the corresponding CL point.Finally, after detecting and eliminating all the CL points, the interference-free tool paths are generated.The tool paths generated by this approach meet the step error require-ment and keep the step error constant, and the CL points are fewer.The experiment result indicates that the ap-proach is feasible and efficient.
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Key words:
- algorithms /
- numerical control systems /
- NC /
- point cloud /
- cutter-contact
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