Simulation of pedestrian flow with evading and surpassing behavior in a walking passageway

The pedestrian flow with evading and surpassing behavior in a walking passageway is simulated based on a modified social force model in order to explore the influence of this behavior on evacuation efficiency, bottleneck passing capacity, and the macroscopic phenomenon. A pair of conjugated self-driven forces is introduced to enable a pedestrian to avoid a direct collision and keep a normal velocity magnitude while confronting an obstacle. The pedestrian avoiding time is used to define the triggering conditions of evading and surpassing behavior, and has been estimated through practical experiments. Simulation results show that in a passageway without spatial obstacles, the evading and surpassing behavior will increase the evacuation time under the condition that the pedestrian number is larger than a critical value. Moreover, when a spatial obstacle exists, both the rise of pedestrian numbers and the decline of bottleneck width would increase the evacuation time. Meanwhile, it is observed that compared with a bar-shaped obstacle, a circle-shaped obstacle corresponds to a larger bottleneck passing capacity and less evacuation time when the size of the spatial obstacle is above a critical value. In addition, a phenomenon of a triangle “evading region” caused by the evading and surpassing behavior also can be observed before the spatial obstacle through simulation and experiments. Furthermore, it can be concluded that a circle-shaped obstacle corresponds to a stronger guiding function and a larger area of “evading region” compared with a bar-shaped one, and induces a relatively higher bottleneck passing capacity in a walking passageway.

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Improved social force model for rescue action during evacuation

Modern Physics Letters B ◽

10.1142/s0217984920502735 ◽

2020 ◽

Vol 34 (25) ◽

pp. 2050273

Author(s):

Xiaoyong Tian ◽

Hongjun Cui ◽

Minqing Zhu

Keyword(s):

Emergency Evacuation ◽

Main Direction ◽

Force Model ◽

Social Force ◽

Counter Flow ◽

Social Force Model ◽

Evacuation Time

There often exist behaviors of moving against the main direction of evacuation in order to rescue or find the important missing people in real situations. However, the traditional social force model (SFM) often lacks consideration of such “counter flow”. Motivated by this, we improve the traditional SFM to study the counter flow and its influence on evacuation out of multi-exit rooms. We call the person to be rescued “superior” and the rescuers “subordinate”. Two different rescue situations are proposed: superior waiting in place (case 1) and superior moving towards the exit (case 2). The results show that the counter flow will always reduce the evacuation efficiency to a certain extent, and the evacuation efficiency of case 1 is lower than that of case 2. At the same time, for these two cases, increasing the number of rescuers increases the evacuation time. We also find that the existence of counter flow can enlarge the effect of “faster-is-slower”, while increasing the number of exports can significantly improve the rescue efficiency. We hope that this result can help to improve the efficiency of emergency evacuation with rescue.

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Influence of different merging angles of pedestrian flows on evacuation time

Fire Research ◽

10.4081/fire.2019.75 ◽

2019 ◽

Vol 3 (1) ◽

Author(s):

Manuela Marques Lalane Nappi ◽

Ivana Righetto Moser ◽

João Carlos Souza

Keyword(s):

Built Environment ◽

Computer Simulations ◽

Force Model ◽

Social Force ◽

Social Force Model ◽

Evacuation Time ◽

Emergency Evacuations ◽

Crowd Dynamics ◽

The Social ◽

The Impact

The growing number of fires and other types of catastrophes occurring at large events highlights the need to rethink safety concepts and also to include new ways to optimize buildings and venues where events are held. Although there have been some attempts to model and simulate the movement of pedestrian crowds, little knowledge has been gathered to better understand the impact of the built environment and its geometric characteristics on the crowd dynamics. This paper presents computer simulations about pedestrians’ crowd dynamics that were conducted based on the Social Force Model. The influence of different configurations of pedestrian flows merging during emergency evacuations was investigated. In this study, 12 designs with different merging angles were examined, simulating the evacuation of 400 people in each scenario. The Planung Transport Verkehr (PTV, German for Planning Transport Traffic) Viswalk module of the PTV Vissim software (PTV Group, Karlsruhe, Germany) program was adopted, which allows the employment of the Social Force approach. The results demonstrate that both symmetric and asymmetric scenarios are sensitive to the angles of convergence between pedestrian flows.

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Pedestrian Arching Mechanism at Bottleneck in Subway Transit Hub

Information ◽

10.3390/info12040164 ◽

2021 ◽

Vol 12 (4) ◽

pp. 164

Author(s):

Wei Luo ◽

Pengpeng Jiao ◽

Yi Wang

Keyword(s):

Simulation Experiment ◽

Dynamic Evolution ◽

Width Ratio ◽

Force Model ◽

Pedestrian Flow ◽

Social Force ◽

Social Force Model ◽

Unidirectional Flow ◽

The Social ◽

The Relationship

Under the massive pedestrian flow, pedestrians arching phenomenon forms easily at bottleneck in subway hubs, which might stampede and crush. To explore pedestrian arching mechanism at bottleneck in subway transit hub, this paper conducts a series of simulation experiment. Firstly, movement preference characteristic in subway transit hubs was introduced into the social force model which considers multiple force. Then, after setting basic experiment scenario, unidirectional flow at different bottlenecks were simulated. Finally, the mechanism of pedestrian arching phenomenon at bottleneck was quantitative analyzed with the help of experimental data. Some main conclusions are summarized. Pedestrian arching phenomenon could be divided into four stages: Free, arching formation, arching stabilization and arching dissipation. In addition, the relationship between bottleneck scenario and passing time could be built to a function model. With the different of bottleneck width ratio, passing time presents positive correlation. The research results could give some helps for understanding the dynamic evolution process of unidirectional flow at bottleneck, improving the pedestrian efficiency at bottleneck and optimizing pedestrian facilities in subway transit hub.

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A social force evacuation model considering the effect of emergency signs

SIMULATION ◽

10.1177/0037549717741350 ◽

2017 ◽

Vol 94 (8) ◽

pp. 723-737 ◽

Cited By ~ 7

Author(s):

Zhilu Yuan ◽

Hongfei Jia ◽

Linfeng Zhang ◽

Lei Bian

Keyword(s):

Visual Field ◽

Movement Direction ◽

Force Model ◽

Herd Behavior ◽

Security Risk ◽

Social Force ◽

Social Force Model ◽

Evacuation Time ◽

The Social ◽

Improved Model

In this paper, we investigate the effect of emergency signs on evacuation dynamics under smoke conditions. We assume that in a smoky hall the visual field of pedestrians is limited to a certain range, and they do not know the exact location of the exit. In this kind of evacuation process, we analyze the influence of emergency signs on movement direction and speed, and the herd behavior of pedestrians. In the analysis, we divide the emergency signs into two types: the wall signs (WS) and the ground signs (GS). Then, we analyze the variation of pedestrian behavior when they encounter the WS, the GS, and the exit in the evacuation process. Combined with the analysis results, we build our improved model based on the social force model. In the simulation, we study the evacuation process in the case of WS and GS. According to the result of the simulation, we consider that the effect of the emergency signs on herd behavior and the desired speed is an important factor to improve evacuation efficiency. We find that, from the perspective of evacuation time, the evacuation in the case of WS is more efficient, but from the perspective of the interaction between pedestrians, the evacuation in the case of GS presents less security risk. Finally, we explore how to design a mixed layout scheme of WS and GS.

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An extended social force model for pedestrian evacuation under disturbance fluctuation force

International Journal of Modern Physics C ◽

10.1142/s0129183120501028 ◽

2020 ◽

Vol 31 (07) ◽

pp. 2050102

Author(s):

Juan Wei ◽

Wenjie Fan ◽

Yangyong Guo ◽

Jun Hu ◽

Yuanyuan Fang

Keyword(s):

Mathematical Expression ◽

Momentum Equation ◽

Position Vector ◽

Force Model ◽

Pedestrian Flow ◽

Social Force ◽

Social Force Model ◽

Fluctuation Force ◽

Pedestrian Evacuation ◽

Crowd Density

In order to characterize the disturbance fluctuation of pedestrian flow caused by the disturbance during evacuation and the state change of pedestrian flow, this paper improves the social force model by introducing disturbance fluctuation force. First, a momentum equation is established to describe the change of pedestrian flow under the influence of disturbance fluctuation, and the mathematical expression of disturbance fluctuation force is given. Second, the evacuation processes of pedestrian flow with and without “queue jumpers” are simulated with the simulation experimental platform, and the key factors influencing the performance of the model are deeply studied through numerical analysis. The results showed that: when the expected velocity is the same, the bigger the angle between the cross-section position vector and the initial expected velocity is, the more serious the congestion occurs at the exit. In addition, when the crowd density is small, the larger the angle, the higher the evacuation efficiency and vice versa.

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A Simplified Estimation of Critical Pedestrian Number on Lateral Vibrating Footbridge Based on Social Force Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.99-100.268 ◽

2011 ◽

Vol 99-100 ◽

pp. 268-272

Author(s):

Huan Ye ◽

Zhi Gang Song

Keyword(s):

Critical Value ◽

Dynamic Interaction ◽

Structural Vibration ◽

Force Model ◽

View Point ◽

Social Force ◽

Social Force Model ◽

Interaction System ◽

Control Equation ◽

Lock In

Abstract. Lateral pedestrian loads and flexible footbridge form a dynamic interaction system, which has a special lock-in phenomenon and results the instability of the dynamic system when the pedestrian number reaches certain critical value. A simplified theoretical equation to model the dynamic interaction system and to estimate critical pedestrian number is proposed. The lateral pedestrian loads resulted by structural vibration is first analyzed from a view point of social force model. And then, combined with structural vibration equation, the control differential equation for describing the dynamic interaction system is proposed. The control equation explains why the lock-in phenomenon is resulted and how to estimate the critical pedestrian number. Two typical footbridges are investigated and the results show that critical pedestrian number estimated by the model is more close to those by field observation.

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Modeling the Gender Effects of Pedestrians and Calibration of the Modified Social Force Model

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118758673 ◽

2018 ◽

Vol 2672 (31) ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

S. M. P. Siddharth ◽

P. Vedagiri

Keyword(s):

Reaction Times ◽

Group Behavior ◽

Interaction Force ◽

Gender Effects ◽

Force Model ◽

Pedestrian Flow ◽

Social Force ◽

Social Force Model ◽

Boundary Interaction ◽

Gender Factor

The design of pedestrian sidewalks depends on pedestrian flow, which is related to the speed of pedestrians on the sidewalk. The social force model (SFM) is a microscopic pedestrian simulation model that has been able to reproduce many self-organization phenomena of pedestrian flow such as lane formation. Studies have shown that the SFM has been modified to model particular pedestrian behaviors in different situations by introducing new forces or introducing new factors in existing forces. Also, the literature shows that pedestrian speed varies because of pedestrian characteristics such as age, gender, group behavior, and so forth. There are no studies that model the effect of these pedestrian characteristics using the SFM. Therefore, in this study, we have modeled the effect of gender of pedestrians by introducing a gender factor [Formula: see text]. A sidewalk in Mumbai, India has been chosen for this study. Pedestrian flow and speed were collected from the site. A base SFM containing the driving force, pedestrian–pedestrian interaction force, and pedestrian–boundary interaction force was coded in MATLAB. This model contains six parameters, which were calibrated using a genetic algorithm. Next, the SFM was modified to include different reaction times for the male and female pedestrians, [Formula: see text] and [Formula: see text], respectively. Keeping other parameters as constant, [Formula: see text] and [Formula: see text] were calibrated and found. Gender factors [Formula: see text] and [Formula: see text] are found by dividing the reaction time [Formula: see text] and [Formula: see text] by [Formula: see text], respectively. These gender factors could be found for the different male/female composition of pedestrians, which would help in analyzing the level of service of sidewalks.

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