考虑人群动态分布的可变向应急疏散标识的影响研究

On the influence of the emergency evacuation signs with adjustable directions on evacuation considering the dynamic distribution of the crowds

提出了一种可变向的应急疏散标识(EES),能够根据出口距离和人群分布动态改变指示方向,变化的方向利用离散选择模型确定。并对元胞自动机疏散模型进行了改进,使得模型能够模拟EES作用下的人群疏散过程,考虑到惯性效应对疏散行为和EES作用距离进行了修正。通过对双出口场景的疏散模拟,结果表明:变向EES可以有效地提高疏散效率,但前提是EES的数量和变向间隔满足一定条件,对于所研究场景,标识数量需大于2×2小于5×5;当人群密度较高时,随变向间隔增加疏散时间先减少再增加,需设置合适的变向间隔以免变向频繁造成疏散者的信息混乱,最佳变向间隔为300 s;变向EES具有分散人群拥堵的作用,能够减小惯性效应和从众行为的负面影响。

This paper presents a kind of emergency evacuation sign（ EES） capable of adjusting its displayed direction according to the distance from EES to the exits under the dynamic escapers＇ distribution. The adjusting direction of EES can actually be determined by the actual discrete choice model. In proceeding with our research,we have made a simulated escapers＇ evacuation process under the effect of EES by means of a cellular automaton based floor field model. Considering the physical and cognitive delay,we have introduced an idea of the inertia floor for correcting the regularity of the evacuation behavior and proposed a method for calculating the effective distance of EES which is different from the visibility distance. By simu-lating the evacuation of the uniformly and non-uniformly scattering escapers in a room with two exits,we have made an analysis and discussion of the impacts of the number of EES,the interval of adjusting direction of EES,and herding and inertia behavior on the evacuation time. The results of our study show that：（ 1） The EES with adjustable directions can significantly promote the evacuation efficiency through a comparison with the most of EES in reality which fail to offer effective instructions for the available exits. The promotion is on the premise of the appropriate number and direction-adjusting intervals of EES. What is more,we have worked out the effective number of EES that should be made between 2 × 2 and 5 × 5while taking into account the evacuation space.（ 2） On the other hand,when the EES density is high,the evacuation time tends to be delayed first and then it can be made to increase with the increase of the interval of adjusting directions. Therefore,an appropriate interval should be badly needed to avoid confusing the evacuees in spite of the quick-adjusting direction information for the evacuation. The optimal interval according to our study should be 300 s.（ 3） With the increase of the level of herding and inertia,the evacuation time tends to decrease first and then increases. However,there is less increase when the directions of EES are adjustable. Therefore,the adverse effects of herding and inertia behavior to the evacuation can be reduced by EES with adjustable directions to avoid the non-uniform or congested distribution of the actual evacuation numbers.