行人初始位置布局不平衡的多安全出口疏散过程,是行人疏散流仿真研究的热点.利用行人流动态参数仿真模型,在实际距离和假想距离"极大极小"路径选择机理的基础上,改进假想距离的计算方法及其拥堵计算区域,实现疏散过程的动态平衡;提出行人位置布局的不平衡系数,以描述疏散空间内行人初始位置布局的不平衡性.从行人初始位置随机和固定布局的角度,仿真研究正常疏散环境下行人布局的不平衡性对疏散时间的影响,并将仿真结果与原始模型做对比分析.研究表明,模型能有效地实现行人流疏散过程的动态平衡,行人疏散时间受行人位置或安全出口布局的影响较小,而与安全出口总宽度、行人的初始数量以及拥堵感知系数有关.
Simulation of pedestrian evacuation from a room with multi-exit and asymmetrical pedestrian layout is presented based on an improved dynamic parameter model in this paper. The computation and the count-area of imaginary distance are improved based on the "Max-Min" evacuation path selection of actual and imaginary distance in order to reduce evacuation imbalance caused by the asymmetry of pedestrian layout. An imbalance coefficient is introduced to describe the asymmetry of pedestrian layout. The effects of pedestrian layout asymmetry on the evacuation time are analyzed respectively from fixed and unfixed pedestrian initialization site. The simulation results of the improved and original models are compared and analyzed, and the improved model can effectively reduce evacuation imbalance. Simulation results show that under normal evacuation condition with considerring reasonable pedestrian and jam around exits, evacuation time is hardly affected by pedestrian and exit layout and depends mainly on cognition coefficient, total width of exits and pedestrian initialization amount.