基于OBB检测的五轴干涉碰撞检测

Collision Detection of Five- axis Using OBB Trees

在五轴高档数控加工中,为了提高刀具与加工曲面的碰撞干涉检测速度,在构造层次包围盒时融合OBB与胶囊体包围盒的优点,能首先将多数明显不相交物体对快速排除。干涉检测分为粗检测和精检测两个阶段,先采用球包围盒与刀具胶囊体包围盒进行粗检,然后分层OBB结合工件八叉树OBB的算法,快速检测出可能存在干涉碰撞的叶子节点,在构建OBB和更新OBB方面分别采用"有数据再建立"和"用到再更新"的方法。在包含干涉节点的三角面片和刀具之间采用全局干涉的径向检测和局部干涉的轴向检测,实现详细干涉检测。此方法在VERICUT和MFC中得到很好的验证,充分证明在实际加工中具有高效性、实用性。

In five-axis NC machining,in order to improve the detection rate of collision interference,take the advantages of OBB bounding box and capsule body bounding box when constructing bounding box,can eliminate most obvious disjoint objects first quickly. Interference detection is divided into rough detection and fine detection,first use ball bounding box and tool capsule body bounding box for coarse interference,and then use algorithm by combination layered OBB and workpiece OBB,detect possible collision interference of leaf nodes quickly. In the construction of OBB and update the OBB respectively by using ＂ if have data then to build＂ and ＂ if nodes are used then to update＂ strategy. In order to achieve precise interference detection between leaf node which contains the interference triangles and tool,the article use radial detection when global interference and axial detection when radial interference. This method well validated in VERICUT and MFC,also proved that is efficient and practical in the actual processing fully.