Research On Group Evacuation Model Based On Improved Social Force

The research on the evacuation is based on ensuring the safety of public.It can not only maintain the order of venues,but also escort the life in the emergency,and reduce the harm to society from unexpected accidents.Therefore,the study of evacuation has important social significance.This thesis study the group phenomenon during crowd evacuation,propose group structure models.Meanwhile,the scope of application of the social force model has been expanded to make it suitable not only for evacuation studies on horizontal ground,but also for evacuation of inclined ground caused by accidents such as train stations,subway stations,and reef hits.Details as follows:First,the significance of the research is explained;the evacuation problem is divided into basic models,scene modeling,and group type studies.The research status is sorted and analyzed one by one,therefore,the research content of this thesis is introduced.Secondly,two basic group structure models are proposed—a leaderless group evacuation model and a leader group model.Groups of classmates,colleagues,and family members generally exist in the crowd.Leaderless group need to take into account the evacuation situation of the group,formulate an evacuation strategy,and complete the evacuation.A leader group member will first select one of the members as the leader.The leader will take into account the evacuation of the group,while the other of the group follow the leader to complete the evacuation.This thesis focuses on the effects of group structure on evacuation,including the number of groups and members,the intimacy of the group,and the effect of "faster is slower" effect.The experimental results show that the group structure is indeed conducive to evacuation.Both group structures weaken the "faster is slower" effect,and the group with leaders is always better than leaderless,However,if the group members are too "intimate",it will not be conducive to the effective evacuation.Finally,an improved social force model,gravity induction model,is proposed.For adapting the social force model to the evacuation scenarios of inclined ground such as train stations,subway stations,and ship dumping,a social force model suitable for evacuation on inclined ground is proposed.The effects of tilt angle and tilt direction on evacuation efficiency and "faster is slower" effect are studied.Combined with the group structure model,the social force model is extended to the study of crowd evacuation on inclined ground.The experimental results show that the desired speed has an important effect on the evacuation results.When the desired speed of the person is greater(than 1.5m/s),it is more conducive to evacuation when the exit is located on the slope.Because the inclined ground stretches the crowd distribution and reduces the "faster is slower" effect caused by congestion.However,when the expected speed is small,the result is exactly the opposite.