Research On Evacuation Model In Public Place Based On Cellular Automata

With the development of social economy, a variety of entertainment centers, theaters, business centers and other public places have began to emerge across the whole country continually, it brings a range of security risks as the public places become highly integrated and large-scale. This was reflected staff-intensive, large span of space in public places most of time, which is very prone to fire. If the fire couldn’t be controlled in time, toxic gases caused by the spread of the fire will endanger people’s lives and property safety, which will lead to disastrous consequences. In our real life, this kind of security risk usually can’t be found easily, and the risk is difficult to predict, so it’s very important for us to research the evacuation model of public places, which has been become a significant research topic to public safety. In order to minimize the damage and avoid people wouldn’t know what to do when faced with unexpected situations, we should develop an evacuation project which is necessary and reasonable to take preventive measure.Cellular Automata can simulate complex phenomena. This paper, based on two-dimensional cellular automata theory, study the unexpected emergency evacuation in public places. Previous studies are generally based on some objective factors to judge and select the evacuation rules and project, such as the distance that pedestrian from the exits, occupant density in the region of the exits. Generally, the closer pedestrian from an exit, the greater the probability of their choosing that exit, and the probability of selecting other exits is much smaller. In addition, if the occupant density of the exit is smaller, the probability of pedestrians choosing the exit is greater, so the probability of choosing other exits is smaller. Based on these basic rules, we make a further development in this paper, the main content is organized as follows:(1) Define the mobile rulesDifferent from previous research, which utilize the random selection method or the shortest distance method when research the emergent evacuation. However, in view of the mobile rules, this paper makes a corresponding improvement, and put forward a method called the shortest distance priority. Practice has proved that, the method of the shortest distance priority accord with the mobile rules when people in paroxysmal emergency situation.(2) Define the formulas of selecting the exitsThis paper gives a comprehensive probability formula for judging and choosing the exits, based on two factors that people’s distance from the exits and the occupant density in the region of the exits in some different public places.(3) Study the embodiment and influence of psychological effect in the process of evacuationThis paper mainly introduces some different factors to research people’s psychological reaction and behavior regulations when they meet with the some unexpected emergencies in public places with multiply exits, these factors contain the influence of different obstacle shapes in public places, the region that fire and smoke spread, and some subjective psychological factors, such as mindset effect, draw on the advantages and avoid disadvantages effect, bandwagon effect.(4) Experiments and results analysisAfter determining the rules of the program, this paper gives several different groups of experiments, to simulate the evacuation model in public places that with different internal environments by the method of computer programming, and also analyses the evacuation regulations and the rules that people how to choose exits in these public places which with different layout, and explores how the internal environment and layout in different public places affect the evacuation efficiency, to give a more reasonable design of evacuation. It can provide a scientific basis for learning the reasonable evacuation rules when people meet with the unexpected emergencies, which can retrieve the loss of life and property as much as possible. Therefore, this study has practical significance.The experimental results show that the evacuation scheme we proposed is reasonable, and it can reflect the real scene of evacuation truly in the event of unexpected emergencies. Meanwhile, in the same public places, the shapes of obstacle, the different fire scene, the spread region of fire or smoke, all put a significant impact on the evacuation efficiency. In addition, the study also shows that the bandwagon effect of group members has adverse effect to the whole evacuation process. When the number of group members is large, these group members don’t have to complete the collection in the public places, the wisest choice is they should evacuate from the public places respectively as fast as possible, which could improve the evacuation efficiency, thus it can protect people’s lives and property more effectively.