基于OBB与八叉树的数控加工碰撞干涉算法的研究

Research on NC Collision Interference Algorithm Based on the OBB and Octree

为了提高碰撞干涉的检测速度,在构造层次包围盒时融合OBB与包围球的优点,能首先将多数明显不相交物体对快速排除。干涉检测分为快速检测和详细检测两阶段,先采用分层OBB结合八叉树的算法,快速检测出可能存在干涉碰撞的叶子节点;再在包含干涉叶子节点的三角面片和OBB的三角面片之间采用基于三角面—三角形相交检测算法,实现详细干涉检测。由于刀具路径离散点具有连续性,可以设置缓冲区来减少需要处理的节点数。这些改进有效简化算法,从而提高了碰撞干涉检测的效率。

In order to improve the speed of collision interference detection, taking advantage of the characteristics of OBB and sphere when constructing the Hierarchical bounding box could firstly rule out quickly most obvious disjoint objects. The collision interference detection was divided into rapid collision interference detection and detailed collision interference detection. Firstly, the colliding leaf nodes on the detected surfaces were detec- ted quickly through the algorithm which combined hierarchical OBB with octree; and then the detailed collision interference detection between triangle strips of that leaf nodes and OBB was dealt with the test of triangle-triangle intersection. Because of the continuity of discrete points of tool path, the cache could be setup up to reduce the nodes needed to cope with. These improvements simplified algorithm effectively, thus the efficiency of collision interference detection was improved usefully.