基于角度分割的截面线数据匹配点对建立算法

Algorithm Based on Angle Segmentation to Construct Matching Points for Cross-sectional Data

研究了从截面线数据到B样条曲面拟合的过程中,建立最佳匹配数据点对的问题。提出了一种基于角度分割建立截面线数据匹配点对的算法,该算法利用各层截面线的公共几何中心,计算各点到中心的斜率,再利用基于斜率的插值获取给定角度在原参数曲线上的参数值。最后运用德布尔点的递推公式得到参数对应的坐标。当处理完所有的截面线数据,就得到了一组采样个数统一的匹配点对。该算法在进行截面线数据重采样的同时就完成了对数据点的对正处理,不仅适用于对凸轮廓的处理,而且也能处理层间形状变化较大的截面线数据。

This paper researches on the construction of matching points in the process of fitting B-spline surfaces for cross-sectional data, and presents an algorithm to construct optimal matching points based on angle segmentations. The common geometric centers of section curves on every layer are used in the algorithm to compute slopes of the lines defined by every point of section curves and the geometric center on every layers and to obtain the parameters of these angles on the original curve in the basis of the interpolation of slopes and then the coordinates corresponding to these parameters are calculated by using De Boor recursive formula. After processing all c/＇oss-sectional data, we get matching points with uniform number of samples. This method can be used to construct the matching points and re-sample cross-sectional data. It is able to deal with not only convex contours, but also cross-sectional data with large shape difference between different layers.