>>2006, Zhong Zheng, Real-time Spatial Information Transferring and Multi-dimensional perception in Virtual Road Collaborative Design
Abstract
Road surveying and designis a very complex process, whichrequiresdifferent professional participants. It is also a process of multi-professional collaborative design, which is affected by different kinds of factors. The unsuccessful design of an important engineering would bring huge economical expense to our country. Now the way which can guarantee the quality of design depends on the experience of experts. So this way cannot evaluate the design scientifically. It’s becoming an urgent need for government official, planning designer, geographer, forestry export,travel export, psychologist, and evenpublic to participate planning, designing, evaluating and sensing the route in virtual design environment. The collaborative designs in a virtual road environment become fascinating works increasingly.
The collaborative designs in a virtual road environment need mediate different professional goals, plans, knowledge and actions in road survey and design, and support multi-discipline and multi-users to implement parallel interactive collaborative design. The dissertation puts forward a type of whole technical framework of Virtual Road Collaborative Design Environment (VRCDE), in order to solve multidisciplinary collaborative design and many kinds of data share and interoperability. The framework manages the spatial data by integrating linear reference system (LRS). Moreover the dissertation designs an agent model, which not only can describe spatial characteristics and attributes of geometric models, but also has a reasoning component according to the rules within a knowledge set. The functions of the reasoning component include sensation, perception, conception, hypothesizer and action. Agent models are used to solve the key problem for real-time spatial information transferring and multi-dimensional perception in VRCDE. The main research work of this dissertation is as follows:
（1）Based on the characters, procedure, development of road collaborative surveying and design and the requirement of virtual environment, the dissertation puts forward a whole technical framework of VRCDE, which applies the architecture of chairman-committeeman pattern to it. The pattern is based on collaborative visualization layer, collaborative management layer framework and distributed locking mechanism technologies, and realizes the collaborative management and data transferring for multiple participants.
（2）To solve multi-user collaborative operations, data share among multiple views,and intelligence in spatial information acquisition and handling in VRCDE, the dissertation puts forward a management way integrating linear reference system. Based on LRS, the relationship between the linear coordinate and spatial coordinate are built. Dynamic segmentation can represent the linear character of multiple attributes, realize the bi-query between road’s geometry data and attribute data. The way facilitatesevaluating and analyzing the road design in VRCDE.
（3）To solve the real-time spatial information transferring in VRCDE, the dissertation designs an agent model, which connects spatial data of design model with its behavior. Each agent model comprises the geometric model of describing the objects’ spatial characteristics, the behavior model with reasoning function. Moreover, the dissertation puts forward a way to organize agent models to agent communities according to the object’s spatial relationship, which make multi-Agent system and virtual environment tightly couple. The dissertation puts forward a communication mechanism based on KQML. The mechanism solves communication content and intent among agents in VRCDE. For design results are exchanged by dynamic data format，state updating and synchronization in VDE are implemented through messages communication among agents in VRCDE.
（4）Collaborative awareness is a very important aspect in VRCDE First the dissertation puts forward a way for VRCDE to integrate data in road CAD system, which integrates geometric data and attribute information of design model and terrain data for uniform management and representation. Then, the dissertation discusses a collaborative mode between two systems, and puts forward a way to connect virtual environment’s spatial database with road CAD system based on Facade pattern and agent model, and agent can autonomously implement monitoring object changes in virtual environment. Agent models realize intelligent interactivity, multi-dimensional collaborative perception, active updating, and the share of models’ data among multi-users. Finally an example illustrates agent reasoning procedure in VRCDE. The agents construct and maintain a representation of the relevant objects in VRCDE using a Function-Behavior-Structure formalism in order to reason about the intended and actual functions of the designed objects in VRCDE. XML is applied to describe agent’s sensor, effector and reasoning processes, and facilitates reasoning process to exchange data and communicate, realizes the perception to cooperate in VRCDE.
This dissertation designs a prototype system for VRCDE on road survey and design. The system implements multi-user different-place real-time design, cooperative management, collaborative information display and control, internet conversation and design object updating intelligence in agent-based VE. The practice proves that the system can meet the requirements about real-time collaborative design, quick response, well robustness, and achieve the basic goal.
Key Words
road engineering, collaborative design, virtual environment, agent, agent community, collaborative awareness
PhD. Dissertation