Effect of a Moving Obstacle on Pedestrian Flow Through an Exit


  • Han Xu State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, China
  • Weiguo Song State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, China
  • Jun Zhang State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, China




moving obstacles, unidirectional pedestrian flow, exit, social force model, density profile, fundamental diagram


Current studies about moving obstacles mainly focus on uncommon evacuation scenarios, while there lacks researches on common egress scenarios, such as evacuation from an exit. This study aims to prove that pedestrian flow through exit can be improved by the presence of a moving obstacle and investigate the effect of a moving obstacle on regulating pedestrian flow. Unidirectional pedestrian flow simulations based on social force model are conducted to study the influence of a moving obstacle, that is a mobile robot, on the pedestrian flow through an exit. The robot reciprocates parallel to the wall of the exit with a constant speed 0.5m/s, and the gap between the robot and the exit is set to 1.0m. The pedestrians need to obey the rule of avoiding collision with the robot. By comparing the distributions of individual evacuation time with and without a moving obstacle, it is proven that that the average evacuation time can be reduced by a moving obstacle obviously. The moving obstacle can lead to the inhomogeneous distribution of the crowd near the exit by observing the density profiles. Furthermore, the crowd near the exit is classified into four groups according to movement direction (left or right) and position (the left or right part relative to the center of the exit) of the robot. It reveals that the moving obstacle impedes the evacuation of small proportion pedestrians, but promotes the evacuation of the large proportion pedestrians by the analysis on the fundamental diagrams of the four groups.


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How to Cite

Xu, H., Song, W., & Zhang, J. (2022). Effect of a Moving Obstacle on Pedestrian Flow Through an Exit. Collective Dynamics, 6, 1–16. https://doi.org/10.17815/CD.2021.125



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