Modeling Pedestrian Evacuation With Small Group Effect In Multi-exit Scenarios

When an emergency occurs,the people to be evacuated in the scene often cannot make full use of each exit in the scene,resulting in the congestion of the people to be evacuated at some exits,affecting the evacuation efficiency of pedestrians.The phenomenon of small groups in the process of pedestrian evacuation is also a behavioral factor that cannot be ignored.Once the small group force is too strong,the evacuees will blindly follow family members,friends,and classmates for evacuation,which affects the evacuation efficiency and seriously threatens the safety of people’s lives and property.Therefore,it is the main content of this thesis to guide the people to be evacuated to reasonably use each exit in the multi-exit scenarios,and study the impact of small group force on evacuation.The multi-exit selection strategy of this thesis considers three factors: the distance between pedestrians and exits,the density of pedestrians near exits,and the width of each exit.By comparing three experiments: the multi-exit pedestrian evacuation considering distance only,considering both distance and density and the comprehensive consideration of three factors,it is found that the multi-exit selection evacuation strategy considering three factors can improve the utilization of exits and improve the evacuation efficiency.Based on the multi-exit selection evacuation model,considering the influencing factors of small group behavior,this thesis constructs a comprehensive evacuation model.The pedestrians in the scene are divided into different small groups,and the influence of small group forces on pedestrians in the evacuation process of multi-exit scenes is studied through a series of experiments.The experimental results show that the small group force reduces the pedestrian evacuation efficiency.In the process of an emergency evacuation,we should artificially intervene the small group phenomenon to ensure the safety of pedestrians.Finally,in order to verify the robustness of the evacuation model,the experiment of pedestrian initialization non-uniform distribution is carried out.The experimental data show that under the condition of considering small group force in the multi-exit scenario,pedestrians will consider three factors to find the best exit both in non-uniform distribution and uniform distribution experiment.And the influence of small groups on pedestrian evacuation still exists,which proves that the evacuation model is reliable.