基于栅格的疏散人流数值测量方法

Gird-based methods for measuring evacuee flow numerical value

为获得人员疏散过程中的疏散人流更精确的数值,在Voronoi图方法的基础上,建立一种基于栅格的密度测量方法。通过研究Voronoi图中的被疏散人空间半径对密度测量的影响,计算最优半径以扩大现有方法的适用范围。设计栅格化的测量方法用以记录被疏散人转向数值,并生成转向图。以武汉某超市疏散为例,采用可视化与数值分析相结合的方式,对疏散过程中疏散人流数值进行分析。结果表明,密度和被疏散人转向的平面分布能够反映疏散场所建筑布局特征,并且由密度与被疏散人空间面积的变化可确定人群高密度状态的出现时间。被疏散人转向多发生在密度较低区域和高密度边缘区域。

In order to obtain more accurate numerical value of evacuee flow in the process of evacuation,based on Voronoi diagram method,a new grid-based method was worked out for density measurement. By studying the influence of evacuee space radius in Voronoi diagram on the density measurement,the appropriate range of the radius was calculated. In addition,a grid-based method was designed for measuring the change of direction when evacuees encounter obstacles. Finally taking a certain supermarket in Wuhan as an instance,variation in evacuee flow numerical value during the evacuation process was analyzed with the combination of visualization and numerical analysis. The results show that the plane distribution of density and direction changing can reflect layout characteristics of the building,that the point of time for getting into a crowded state can be determined on the basis of changes in both the density and predestrian space area,and that direction changing happens easily within low density areas and high density edge areas.