考虑多群体恐惧传播的行人流模型及应急扩散研究

Study on pedestrian flow model and emergency spread with nonlinear multi-group fear propagation

为了有效描述突发情况下人群扩散状态和演化机理,基于社会力和非线性多群体恐惧传播方法构建了一种新的行人流模型。该模型首先基于自驱力、排斥力、吸引力和恐惧传播力对传统的社会力模型进行改进。同时结合人群扩散的非线性特征和人员之间的异质特征,将人群分为多个子群,通过引入非线性传播力来刻画恐惧传播特征,并给出恐惧消除平衡点的计算方法。最后,利用搭建的仿真平台进行试验,深入研究了影响该模型的关键因素,如人群扩散速度、人群扩散距离、人群扩散时间、人群数量等。结果表明:人群扩散速度呈现先快速增加后降低的趋势;相对于人群数量而言,突发事件初始影响范围对人群扩散距离影响更大。

The present paper is inclined to propose a novel pedestrian flow model based on the social force and nonlinear multigroup fear propagation method in hoping to depict the crowd spreading status-in-situ and its evolutionary mechanism in case of emergency effectively.The traditional microscopic pedestrian flow models(such as social force,cellular automata,etc.)lack the clear-cut definition and description of pedestrian behavior features from the analysis of the crowd psychological factors,especially when the crowd shows a spreading state that is different from the normal one in unexpected situations.This paper,however,intends to describe and analyze the fear psychological status-in-situ and the transition and transmission feature of the crowd in an emergency situation,with a new pedestrian moving model as a social force and nonlinear propagation of the multigroup fear or horror.That is,first of all,we would like to improve the traditional social force model based on the self-driving force,the repulsive force,the blindly attractive force and the horrible transmission force.At the same time,joining the nonlinear features of the crowd diffusion and the heterogeneous specialty among the crowd,the crowd escapers can be divided into multiple subgroups.And,then,the term of the nonlinear propagation force can be used to depict the features of their propagation,with a calculation method of the balance point of fear elimination being given.And,finally,the simulation mode can be used to simulate the crowd spreading in emergency,with the key factors affecting the model,such as the crowd diffusion speed,the crowd spreading distance,the crowd spreading time,with their number conducted via the simulation platform.The simulation results can help us to conclude that:(1)The crowd spreading rate indicates a tendency to increase fast at first,and then,keep on a high-speed propagation,finally,decrease,and disappear in smaller numbers in a fast disappearing rate;(2)Relative to the large number of crowds,the initial impact range of an emergency may have a greater impact on the distance of the crowd spreading;(3)The crowd spreading time is positively correlated with the number of crowds,with their growing rate turning to be slowing down gradually.