Modeling And Simulation Of Pedestrain Evacuation Based On Cellular Automata Model With Finer Space Represetation

With the public safety issues continue to occur, more and more people started to pay attention to the research in the field of pedestrian flow. Major accident happen every year because the lacking of proper evacuation technology and overcrowding of the pedestrian flow. In order to prevent such accidents from happening again, the study of safety issues in urban public areas has become one of the primary concerned matters. An effective crowd evacuation strategy can be developed by studying the behavior characteristics of pedestrians and the establishment of emulated models about pedestrian flow. In addition, it also helps to improve the standard of the building evacuation and supply a solution on solving practical problems in evacuation which has an important significance both in theoretical and practical aspects.Cellular automata model with finer space representation is a kind of important simulation model of pedestrian flow. It has been widely used in simulation of occupant evacuation and achieved a series of major achievements because of its unique advantages in the description of characteristics of pedestrian flow. But due to the complexity of pedestrian flow, there are many problems to further explored. In this thesis, based on the behavior characteristics of pedestrians at exit, several improved models with avoidance mechanism are proposed to investigate pedestrian evacuation, unidirectional and bidirectional pedestrian flows, respectively. And the numerical simulation are applied to show the effectiveness of the model. The main contents of the thesis are as follows:The first part will talk about the improvements that have been made on the cellular automata model with finer space representation which tackles the description of the evacuation problem when the exit width is relatively small. The influences of different dispersion degree and maximum step length on the evacuation process have been studied as well as the relationship between the width of exits and the evacuation efficiency. The evolution process of unidirectional pedestrian flow is simulated with different initialization conditions. The results of the simulation experimentation data and real experimentation data will be compared to verify the reliability and practicability of our approach.The second part will establish a bidirectional pedestrian flow evacuation model based on the improved cellular automata model with finer space representation. The analysis of the influences of direction ratio of pedestrian flow on the evacuation process has been conducted and the study of evacuation process on different exit width and system scales has been carried out. The numerical results demonstrate that: Interference between both sides of the pedestrians is the key factor to determine the efficiency of bidirectional pedestrian flow evacuation. The greater the disturbance, the longer the evacuation time.The last part will simulate and discuss the bidirectional pedestrian flow by using improved model from the pedestrians’ walking habit. The Right-hand-parameter is introduced to describe and reflect pedestrian’s walking habit of keeping to right in their movement. By comparing with the model in second part and the experimental data, it is found that the habit of walking on the right hand side can effectively improve the efficiency of the evacuation to some extent.