Abstract:

Aimed to improve the accuracy of tool path from triangular mesh surface model, a new weighted compensation vector approach was proposed to precisely compute the normal vector of the cutter contact point. The algorithm introduced a compensation vector and a blending function about the adjacent triangle areas and the distance ratio from the triangle vertexes, respectively. Then the accurate normal vector of the cutter contact point on the triangular mesh can be computed by nonlinearly interpolating the adjacent normal vectors.It makes the normal vector of the cutter contact point much closer to the one of corresponding point on the theoretical parametric surface. The examples and analyses demonstrate that the method can reduce angular deviation of the normal vector and the position deviation of cutter location point, thus improve the machining accuracy and quality. 

Key words: triangular mesh, cutter contact point, normal vector, weighted compensation vector, CNC machining

摘要：

研究面向三角形网格曲面数控加工刀位点的计算方法，提出了一种用于精确计算网格曲面上刀触点法矢量的方法。该方法引入了包含网格模型上刀触点所在区域附近的网格顶点的法矢量信息的加权补偿矢量及渐变影响函数，通过非线性插值三角形顶点处的法矢量得到位于网格模型上各刀触点的法矢量,使之更加接近理论参数曲面相应位置的法矢量。实例计算和误差分析表明，该方法可以有效地提高网格曲面上刀触点处法矢量的计算精度，对提高刀具轨迹上相应刀位点的位置精度和基于三角形网格曲面的数控加工精度有积极意义。

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关键词: 三角形网格, 刀触点, 法矢量, 加权补偿矢量, 数控加工