Simulation Of Social Groups In Transport Hub Based On Combined Model

As the network nodes of urban rail transportation,rail transit hubs are one of the largescale distribution center of pedestrians,which includes the function of distributing and transferring passenger flow for multi-rail routes.Meanwhile,there are severe existed problems within the transit hub such as over-crowded passenger flow,inconvenient transfer,and security issue around bottleneck areas.As one of the important parts of passenger flow,social groups has great impact on the pedestrian traffic research and its related simulation.However,the current research on the pedestrian traffic topic only focuses on the interaction among independent individuals and ignores the social groups,leading to the insufficient study on the relationship between interactive behaviors and pedestrian traffic.Therefore,it is necessary to investigate further traffic features and principles of social groups with the help of model analysis,master its influences on the pedestrian traffic organization and management,increase the operation efficiency of pedestrian infrastructure,and optimize the pedestrian traffic principle within the transit hubs.This paper uses video observation,theoretical modeling and pedestrian micro-simulation methods to carry out the traffic research of companion pedestrian groups in rail transit hubs on the basis of summarizing the current domestic and international pedestrian traffic research.The main research contents are as follows:First of all,through the actual observation data of Fuxingmen subway track hub,the traffic characteristics and special traffic behavior analysis of social groups were carried out.Based on the video data,the static and dynamic traffic characteristics of social groups in the subway track hub are obtained.The typical traffic behaviors of social groups were summarized.Secondly,in order to realize simulation modeling,several current mainstream models and commercial software are introduced and analyzed,and the conclusion that the social force model is more suitable for pedestrian simulation of social groups is obtained.The adaptability of particle discrete element theory in pedestrian simulation of social groups is analyzed from the aspects of research object,modeling basis,simulation realizability,simulation efficiency and simulation accuracy.The innovation lies in(1)improving the calculation of psychological force and contact force of the social force model by combining particle discrete element theory,and overcoming the pedestrian contact problem that pedestrian simulation is trying to avoid.(2)The pedestrian area is introduced to optimize the judgment and calculation of force so as to make the repulsive force between obstacles & pedestrians and the repulsive force between pedestrians more reasonable.It solves the problem that the social force model has too much psychological force to prevent pedestrians from overlapping.The hierarchical pedestrian area judgment solves the problem that contradiction between two pedestrians is in the whole space while the stress range of pedestrians is very small.(3)The Moussa?d social group force model was improved by take the influence of speed difference into account between pedestrians and social groups on visual power.By improving the group clustering resultant force,the social group can be regrouped.and the problem that the size of the social group is too large to keep the group form can be solved.(4)The introduction of intimacy and pedestrian area and the comprehensive treatment of particle discrete element theory have realized that the social group pedestrians with high intimacy will walk close to each other without overlapping.Then,the parameters of the combined model were calibrated by the measured data of Beijing Fuxingmen subway track and the research in related fields at home and abroad,which solved the problem of too large a set of social psychological repulsion parameters.The simulation boundary conditions are formulated and the simulation platform is developed with Python programming environment.Finally,micro-simulation is carried out on the pedestrian of the track hub considering the social groups.The simulation results of pedestrian speed change caused by different social group structure and different social group ratio under specific pedestrian flow conditions are analyzed.According to the measured data of Fuxingmen,an example analysis of the influence of channel width change on the traffic characteristics of social groups was carried out,and the optimal range of the width of walking facilities is obtained,which provides help to establish and perfect the theory of pedestrian flow and to formulate a scientific plan for pedestrian flow organization and management.