A revised social force model considering the velocity difference between pedestrians

The social force model is a widely used simulation model for describing pedestrian movement and studying evacuation dynamics. There is a psychological repulsive force in the model to reflect the inner tendency of pedestrians keeping a certain distance from other individuals or obstacles. This repulsive force between two pedestrians is mainly determined by their relative distance, that is, the closer the distance between two pedestrians, the greater their repulsive force. Because the impact of the relative velocity between pedestrians is not considered, unreasonable oscillation phenomenon often occur in the simulation process. In order to solve this problem, we introduced the influence of pedestrian velocity difference in the psychological repulsive force. Research results show that the simulation effect of the revised model is more realistic. The relationship between the evacuation time and the velocity factor which reflects the influence of the velocity difference is also studied. This modification makes the model more suitable for studying the evacuation of crowds containing fast individuals.