Pedestrian Evacuation Based On An Ameliorating Multi-grid Model

With the rapid development of society and economy, the construction of large publicplaces is more and more, more and more public safety is threatened. Especially in places ofthe large crowd density, such as the stadium, hospital, school teaching building, if it happensthe event of emergency, how to reasonably, effectively and safely evacuate from these placesis the urgent requirement today. In recent years, more and more study on pedestrianevacuation and development is becoming more and more rapid. Now the research ofpedestrian evacuation has experienced several decades, the cellular automata model, the socialforce model and the lattice gas model, and the magnetic force model is widely used in thestudy of crowd evacuation. The characteristics of the population flow, the characteristics ofpedestrian walking and more other realistic factors is considered into the simulation of crowdevacuation and a macro crowd is built. But because the macro models do not consider thefactor of the relationship between pedestrians, cellular automata model, social force model,lattice gas model and magnetic force model was put forward and widely used in the study ofcrowd evacuation.Research and work of this paper is to expand the multi-grid model. Multi-grid modelis the aggregation of the social force model and the lattice gas model, which forms a newmodel. International forces including extrusion, repulsion and friction between two pedestrian,which is as a passive factor for the pedestrian evacuation. This article will introduce crowddensity factor into the model, and design a new model. In the theory, pedestrians can choosethe optimal solution according to their own experience or social rules. In this paper, forobtaining good evacuation behavior and reaching the export as soon as possible， thepedestrian will choose the direction which is the lower distance from the door.This articlewill add crowd density factor to the grid model，and a crowd density factors of pedestrianbecome a factor of choicing direction.In this paper, we study the evacuation’s model in the complex building. We search theoptimal path by Dijkstra algorithm, which is used to judge all the unit model which thepedestrian will pass. The paper add the concept of virtual door, and those models that have noreal door model can regard the virtual door model as the exit. This article has carried on theresearch of crowd evacuation in the3d building model. For the construction of building model, the pager introduced the software called3dmax to build the model and import the3d modelinto procedure by the fbx. Pedestrians choose the optimal path according to topological graphformed by the3d unit model properties, then the pedestrian is based on the optimal path toselect all unit models which the pedestrian will go through. The pedestrians in the unit modelmove by the rule of the improved grid model. This article simulate the rules of evacuation inthe monolayer model and double-deck model, and analyzes the different evacuation time inthe different number of pedestrians in the model.