Research On The Key Technologies Of Synchronous Collaborative CAD/CAM System

With the development of information technology, CAD/CAM systems are renovated to distributed and collaborative, which aims to meet the increasing demands of globally collaborative design and manufacturing trends. Collaborative CAD/CAM system is an integrated multi-person-machine-task system, which lends itself to facilitate designers dispersed to share design results or cooperate in the same design region via Internet/Intranet, so as to undertake design and manufacturing simultaneously and harmoniously. The key technologies of synchronous collaborative CAD/CAM system are studied in depth and a synchronous collaborative CAD/CAM prototype system, C-Superman, is constructed.A new CAD/CAM application pattern is presented. In this mode, service center provides softwares for use and users don't need to buy softwares or maintain them. According to this thinking, applying B/S structure and J2EE, the composite architecture made up of centralization and replication is designed for C-Superman. Session control is researched. A center-controlled mechanism combined with token passing for floor control is proposed, which can realize the concurrent control and consistency maintenance.Collaborative design modeling is kernel to distributed collaborative CAD/CAM system. A solution that Java3D constructs gridding model's display on the client side and the server side realizes geometric modeling function ground on ACIS is proposed. A special mesh manager for C-Superman is developed to generalize triangular gridding data rapidly. In order to support users'interactions such as picking and geometric modification, a mapping between geometric models and triangular gridding models is established on the basis of four directional mappings of geometric element and identifier. Based on the incremental transmission, an algorithm for mapping maintenance between geometric models and triangular gridding models is given.Session communication and data exchange plays an important role in system usability and real time for synchronous collaborative CAD/CAM system. Star topology is adopted to realize the basic communication function of...