Geometry-Based Collision Analysis Of A 3D Underground Water-Supplying Network

Collision analysis has been studied for a very long time in many fields, such as robot motion planning and computer graphics. With the development of technologies of virtual reality and distributed interactive simulation, it has attracted a great attention of researchers in recent years. This dissertation focuses on the following aspects of 3D collision analyzing system (CAS) for geometry-analysis based underground water-supplying network: (1) Collision analyzing algorithm base on geometric analysis. (2) Collision analyzing algorithm of using mixed-product. (3) Design and implementation of CAS.Firstly, the research background of CAS and current research status were described, and the basic problems of collision analysis were discussed. In addition, a brief introduction of the main research work in this dissertation was also given.Secondly, the concept of collision detection and some algorithm were introduced with emphasis on the following algorithms: collision detection by four-dimensional intersection testing, collision detection using hierarchical bounding box, collision detection based on space segmentation, as well as collision detection based on graphics process unit.Furthermore, the advantages and disadvantages of all the algorithms had been compared. Thirdly, collision analyzing algorithm bases on geometric analysis (GA) was studied. The basic idea is to judge position relations of two pipelines, and determining the collision situation according to the different position relations. On the basis of GA, the mixed product (MP) idea was introduced– using the MP firstly, if collision happened, then use the GA to judge again. The results of experiment showed that the MP algorithm is faster than the GA algorithm.Finally, the design and implementation of CAS system were discussed and the systematic software prototype of CAS had been set up. This system prototype was developed by using OOP. It can abstract the problem of CAS effectively, and also reflect the substance of the problem objectively. The CAS system includes collision analyzing module, 3D display module, data parsing module, network transferred module, etc. The systematic prototype was developed using the software engineering method, which makes it have good expansibility and practical value.