Research On Geometrical Model Sharing Technologies For Internet-Driven Collaborative Design

The Internet-Driven collaborative design opened up a new domain for engineering design and established a new work mode for people in the era of information, which was grouped, distributed, interactive and cooperative. One of the kernels of concurrency engineering was still the presentation, establishment and application of product information models, especially the product models, which supported the sharing of collaborative design. One of the linchpins of collaborative design is to share 3D geometric models in the activities among members of a distributed design teams, which form the kernel of Internet-Driven collaborative design. Therefore the problems of sharing this 3D data should be solved. The work described in this paper was funded by the National Natural Science Foundation, China (Grant No. 50175113) and a special Foundation of Education Department (Grant No. 20040611006). The 3D geometric model sharing technologies for Internet-Driven collaborative design were researched. The major work described in this paper was as follows.A distributed Client/Server system was developed, in which the multi-server system controlled the collaborative clients by the mechanism of collision arbitration. This was made to avoid collaborative clients to become completely dependent on single server and to improve the stabilization and reliability of the server system. A mathematic model of multi-server system based on queuing theory was presented. The solution of mathematic model was analyzed, which included the average utilization frequency of servers, the length of queuing and waiting time. The theory system, which was intuitionistic and convenient, was redounded to reflecting the dynamic data change of the system, reasonably organizing the system and optimizing the design methodology of the multi-server system.It was presented that the multi-granularity description approach was composed of geometric knowledge of 3D model, the form feature information relative manufacturing process and life-cycle of product. A multi-granularity description and data structure of 3D geometrical model was presented. Traditionally, the roughness-granularity description was fastened excessively on the format of information presentation. On the other hand, the minuteness-granularity description emphasized excessively the content of information presentation. This meant, that neither the pure roughness-granularity nor...