A simplified method to provide evacuation guidance in a multi-exit building under emergency

This paper introduces a simplified method to provide evacuation guidance under emergency by employing an evacuation system, which intends to develop an effective evacuation scheme in advance to prevent overcrowding in front of exits caused by the asymmetrical layout of exits or pedestrians in a multi-exit building. A modified cellular automata model based on Floor Field theory is proposed to solve this problem. Two coefficients: exit weight coefficient and individual acceptance coefficient are put forward, which are used to redistribute the static floor field and represent personal acceptance degree of the guiding information respectively. The effectiveness of the modified model is validated by simulating a series of double-exit and four-exit evacuation areas, with uniform and concentrated distributed of pedestrian respectively. A more complex and real evacuation building is investigated to further prove the validity of the modified model. Simulation results demonstrate that proper exit weight coefficients can reduce the imbalance during evacuation procedures effectively and help to reach a higher evacuation efficiency, which can be transferred to the emergency evacuation guiding sub-system to guide pedestrians to a rational exit in the evacuation system. With the increment of individual acceptance coefficient, the evacuation time shows a downward trend. It is also found the concentrated distribution of pedestrians has an advert effect on evacuation time when compared with pedestrians’ uniform distribution in four-exit evacuation areas. By this simplified method, most pedestrians are given a faster route to leave the evacuation area and not bothered by the exit selection.