Influence of the exits’ configuration on evacuation process in a room without obstacle

Abstract

The floor field model is the most popular cellular automata (CA) model which is used to simulate the pedestrian’s behaviors. In the floor field model, the interaction between pedestrians is expressed by the dynamical field. In this paper, we proposed an improved and simple method to calculate the floor field. In our method, the pedestrians are treated as the movable obstacles which will increase the value of the floor field. The additional value is interpreted as the blocking effect of preceding pedestrians. And then, the influence of the exits’ configuration on evacuation process in a room without obstacle is simulated. The evacuation time for different widths and positions of the exits is investigated.In the case of single exit, there is a power law relationship between the evacuation time (T) and the exit width (Dw) with a negative exponent when Dw≤6. Mean flow rates and the using efficiency of each exit cell obtained by our model are higher than other models. The simulation results indicate that pedestrians do not choose the shortest path but a faster path in our model. For the case of two exits, the relationships between the location of the exits and evacuation time are discussed. When the total width of two exits is small (i.e. Dw=2), the main factor affecting the total evacuation time T is the exits’ capacity. If the total width of two exits is large (i.e. Dw=12), the moving distance of pedestrians to exits is the main factor affecting the evacuation time, and the corresponding phase diagrams are given.