Research On Distributed Virtual Environment Modeling

Virtual Environment (VE), vivid and realistic environment in computers, usually refers to the multiple dimensions information space, in which computers are used as the core equipments and modern high-tech techniques are applied so that many senses such as vision, hearing and touching are integrated together and characteristics of Time and Space are possessed and Virtual Reality technology is embodied concretely. Virtual environment, which can be the nonexistent environment at present, can preview the future works to the people in advance; which can also be the ultra-limit environment that the people can not arrive because of limit of time, space and physical strength, ability, can control and display those objective things vividly, directly, figuratively and racily; which can take place of the expensive realistic environment, economize the time and space and decline the cost. In brief, in virtual environment, the people can interact mutually with an object in virtual environment naturally and affect each other conveniently, thus the feeling and the experience of real world can be obtained through virtual environment. Virtual environment base on the real world, surmount it, and then intelligentize it and predict the future scientifically.The Modeling of the Distributed Cooperative Virtual Environment is emphasized particularly on in this dissertation. The key techniques, theories and methods about the modeling mechanism, communication mechanism and time synchronization mechanism oriented to distributed cooperative work in virtual environment are studied systematically at first. Therefore, mutual operation and reuse of tools and resources is realized, and the function of distribution, interaction, parallel and cooperation is embodied. Furthermore, special virtual environment analysis models for particular application are made and the application systems are developed at last and carried on in specific ompany andenterprise. The major results and innovations are as follows:(1)The strategies and theories about converting the traditional three dimensional CAD models to static and dynamic models, which possess geometry accuracy and figure reliability at the same time, are proposed and explained in details and then verified by the example: virtual design of Involute- Column-Gear. The step for converting a great deal of existent models to virtual environment models is so inevitable in future according to the research methods from CAD/CAPP/CAM to virtual reality that its practical value is obvious.(2) Two kinds of interior virtual environment modeling techniques is proposed, based on image and geometry virtual environment modeling. That is, while interior design is taken as the object, two dimensions real object panoramas in which browse is supported according to real object picture and three dimension virtual environment according to the virtual object modeling in which virtual traveling function is constructed.(3) Distributed processing techniques specially used for virtual environment is studied, including network structure and communication protocol of DVE, and transfer mechanism and the structure of Agent for intelligent virtual environment is emphasized and an example of distributed virtual decorating design based on VRML and JAVA is carried out.(4) The method for realizing virtual product design system under the customer Web-VR environment is proposed based on the former chapters and three dimension product geometry models is reconstructed and product feature information are represented in suitable format and communication and association mechanism between customers -designers are realized together.(5) The original content of virtual assembly is enlarged. Based on the original structure of virtual assembly system, the layer structure of virtual assembly is considered and then layer tree assembly modelsbased on disassembly is constructed and strategies of automatic assembly sequences layout is developed and then an example of virtual assembly of Double Grade Involute Column Gear Retarder based on WTK is cited and discussed for demonstrating the process of virtual assembly.(6) Some basic quests and researches are done in the realm of multiple robots cooperative virtual assembly operation. Based on the layer structure of structure of virtual environment, layer driven robot operation is proposed to realize multiple robots operation control in virtual environment and then cooperative operate strategy based on layer-mixed structure is researched in details and information synchronization controlling based on Petri-net and mixed communication models is researched and multiple robots cooperation virtual modeling modules is built up.The theory of distributed cooperative virtual environment modeling is expansive and intensive in this dissertation. As a new type research method and technology measure, its application and expansion in each profession can be expected soon, therefore this dissertation also have the important theory meaning and practical values.