基于教室人群疏散实验,从中归纳出疏散过程中行人的基本运动特征.将桌椅分别视为不可穿越和可穿越的静态障碍物,而行人则被当成可移动的障碍物,这将导致背景场随人群的运动而动态更新,因此可以更好地反映前方拥挤程度对后面人群路径选择行为的影响.采用基于动态背景场的元胞自动机模型研究了不同桌椅排列和出口宽度的教室人群疏散过程,给出了疏散时间的空间分布以及平均和最大疏散时间,再现了实验中人群疏散的基本特征.数值模拟结果表明。疏散时间取决于桌椅的排列方式和教室出口的宽度.对于同一种排列,出口越小则疏散时间越长;对于给定的出口宽度,通常随着过道数的增加,疏散时间随之减少;当过道数增加且过道宽度不足以两人并行,从两侧进入过道的行人会发生冲突,使疏散效率有所降低;靠近出口一侧墙壁设置过道有利于人群的疏散.文中进一步分析了模拟与实验结果存在差异的原因.
It is of fundamental importance to investigate the evacuation process from a room with obstacles. The typical case is the evacuation of students from a classroom. Based on evacuation experiments from a classroom, the essential features of evacuee are concluded. In the original floor field model, the dynamic floor field is introduced in order to reflect the interaction among pedestrians. A pedestrian may follow the virtual trace of another one in front. The static floor field does not consider the influence of pedestrians. In this paper, the original dynamic floor field is ignored. These desks and chairs are treated as impassable and passable static obstacles, respectively. The static and passible obstacles, such as chairs, lead to the delay of movement of pedestrians. Furthermore, pedestrians are regarded as movable obstacles. The effect of static obstacles on floor field does not change with time. However, the effect of movable obstacles on floor field is dynamic. Therefore, the whole floor field is updated dynamically according to the movement of crowd. Pedestrians may try to find another uncongested path or exit when they find the crowd in front. It provides a better description of the influence of downstream congestions on upstream crowd. The cellular automaton model based on the dynamic floor field is used to investigate the evacuation process in the case of four layouts and three exit widths. The spatiM distributions of evacuation time in different conditions and also the average and maximum evacuation times are obtained. Numerical simulations reproduce the evacuation process observed in the experiment quite well. The evacuation time depends on arrangement of these desks and the exit width. For a given layout, the smaller exit leads to longer evacuation time. It is found that the evacuation time does not decrease monotonically with increasing the number of aisles, which depends on the width of aisle as well. When the aisle is not wide enough, the conflict of pedestrians from both sides reduces the efficienc