关键词: 虚拟砂轮, 随机磨粒, 凸多面体, 碰撞检测

Abstract:  The bounding sphere was usually used to detect the collision of grinding grains in the virtual grinding wheel modeling methods. When the bounding spheres were in contact， there was still a large gap between the abrasive grains， which resulted in a big difference between the virtual and actual grinding wheel surfaces. To solve this problem， a virtual grinding wheel modeling method was proposed based on convex polyhedron collision detection. The mathematical model of the random positions of abrasive grains on the grinding wheel surface was derived in detail. The interferences of grains were judged based on the convex polyhedron collision detection method， and the virtual grinding wheel was finally generated. The virtual grinding wheel surfaces generated by convex polyhedron and bounding sphere collision detections were compared. The improved method may generate virtual grinding wheel with 60% volume fraction of abrasive grains， while the original method may not generate virtual grinding wheel with more than 50% volume fraction of abrasive grains. The results indicate that the improved method may generate a virtual grinding wheel with a higher abrasive volume fraction and more randomness surface. Finally， the virtual grinding wheel surfaces were compared with the actual grinding wheel surfaces， and results show that the virtual grinding wheel surface has the characteristics of actual grinding wheel surface. 

Key words: virtual grinding wheel, random grain, convex polyhedron, collision detection