Abstract: To study the role of helping behavior in evacuation and simulate the helping behavior of evacuees in evacuation process, a cellular automaton model considering helping behavior was built. Simulation of evacuation from a room were carried out. Through the simulations, the influences of helping behavior on the evacuation efficiency and evacuation process were studied, the relationships between the influences and the spatial distribution of the elderly were examined, and the time characteristics of the evacuees leaving the evacuation space were analyzed. The results show that the helping behavior of the young can improve the efficiency of the whole evacuation, but its effect is influenced by the help probability of the young, the proportion and the spatial distribution of the elderly, that when the proportion of the elderly is less than 80%, the effect of helping behavior is good, that when the elderly is distributed in the whole room, the effect of helping behavior is much higher, that the effect is also a function of the stages of the evacuation process, and that the helping behavior can optimize the distribution of evacuees' leaving time.

Key words: cellular automaton, helping behavior, proportion of elderly, help probability, evacuation, simulation