| In the place where the crowd gathers, if there isn't well scheme of evacuating in advance , once the incident or the emergency happens suddenly, the crowd is easy to get confusedly , crowdedly , even cause enormous casualties. It is valuable in practise to study the crowd's behavior of evacuation. But it is almost impossible to carry on the relevant experiment and study with the true man. People's behavior is affected by external world and a great deal of factors of psychology. It is impossible to put people in the confusion of the real accident phenomenon. So, imitate the crowd's behavior with the computer -virtual crowd simulation becomes an important .means of security study in the world.Most of research about crowd's evacuation is two-dimentional level in both domestic and international. There is still less research of using virtual reality technology for crowd simulation, especially in the field of traffic and transportation.While carrying on three-dimensional simulation of crowd, it faces besides the crowd law, route plan, collision detection and the algorithm of avoiding barrier that two-dimentional usually faces, still faces technological difficult points, such as the continuities of people's cartoon realizing, movements, speed of the drawing model, etc. . Crowd's group behavior is a very complicated, not only be affected by the calculation of mathematics, but also by everyone's psychology. Thesis simplifies detail of people's display at interpersonal dialogue and expression exchanged in one's eyes, and focus on people's choice route .Research work goes mainly on several following respects:1. The key technology of virtual simulation of crowd, including the virtual crowd's visualization, behavior modeling and behavior simulation is studied. The relevant factor which influenced crowd's behavior, such as psychological factor, individual's law, speed, space required, the ability of passing of building's exit, etc. is analyzed.2. Virtual people's route and algorithms of avoiding barrier is studied. According to the dynamic characteristic of the passengers in the station , everyone's behavior is designed to " Surveys-Esthesia-Make-Policy-Action", and the local dynamical algorithms of avoiding barrier of passengers' route combining with overall plan and local plan is realized. Single step detection is used for interference detection of moving. In term of the characteristic of the environment and the dynamic detection of research object, related rule is constituted. The algorithm of avoidingbarrier is divided into dynamic part and static part. Setted up crowd's flow model under the enviroment of station. Finally the corresponding avoiding touching algorithms between people and barrier is designed.3. Key frame technology is adopted to realize people's movements. Used the straight kinematics method to calculate out the speed, direction, position in real time, the crowd's course cartoon is realized. Static level detail technology is used. For example, setting up the static model of the different finely degree of 3 grades of people to ready. Combining texture technology, LOD technology, etc. The judgement algorithm of observability is worked out. So the data of the scene can be simplified.4. A simulation platform which can simulate stream of people under station, and carry on the mutual operated to the scene is developed. Through analyzing the characteristic of the station and passenger's route, the tactics of avoiding touching is confirmed. The procedure flow chart of the algorithms of avoid touching in people and main program flow chart of controlling virtual people is provide .The user interface of the software platform is made.5. A three-dimensional simulation of crowd under subway station with virtual reality technology is realized. The platform can imitate the behaviors of 400-600 passengers under the normal situation of the station and several kinds of special circumstances. Other types under the special circumstances can be expanded further according to the actual conditions, thus this platform can imitate practice the urgent prediction scheme of the station, so it can be served as the auxiliarytool to train staff members of the station for security.o... |
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