Study on the influencing mechanism of the obstacle layout to improve the pedestrian egress

参考我们去年进行的实验分析，我们今年开发了建模和仿真部分。在以前的实验中，障碍物产生了一个瓶颈，减少了行人的步行宽度，不同的障碍物布局对应于不同的出口效率。为了重现这一结果，我们开发了一种数学方法，估计出口效率的基础上的密度流量基本图（FD）。该方法将步行场景抽象为一个方案，将瓶颈作为链路，将不同区域作为节点。我们成功地再现了不同布局下的疏散时间，并由此估算出了维持稳定疏散效率的障碍物尺寸和障碍物出口宽度的合理范围。另一方面，我们基于真实的行人轨迹数据，探讨了不同条件下FD的不同形状，因为FD的形状会影响仿真结果。具体来说，我们发现，在高峰时间在火车站，一个违反直觉的高密度，高速度FD可以观察到。我们预计，高密度，高速度FD是由于行人的期望速度的变化，这是支持的模拟结果的基础上修改的基于代理的社会力模型，其中更高的密度对应于更高的速度。这表明，在探讨障碍物的影响时，除了障碍物的几何布局外，关注行人的状态也很重要。

Referring to the experimental analysis we conducted last year, we developed the modeling and simulation part this year. In previous experiments, the obstacle created a bottleneck that reduced the pedestrian walkable width, and different obstacle layouts correspond to different egress efficiency. To reproduce this result, we developed a mathematical approach that estimates egress efficiency based on the density-flow rate fundamental diagram (FD). This approach abstracts the walking scenario as a scheme with bottlenecks as links and different regions as nodes. We successfully reproduced the egress times under different layouts, from which we estimated a reasonable range of obstacle size and obstacle-exit width that maintains stable egress efficiency.On the other hand, we explored the different shapes of the FD under various conditions based on real pedestrian trajectory data, as the shape of the FD affects the simulation results. Specifically, we found that during rush hours at railway stations, a counterintuitive high-density-high-velocity FD can be observed. We expect that the high-density-high-velocity FD is due to the variation of the pedestrian's desired velocity, which is supported by the simulation results based on a modified agent-based social force model, where higher density corresponds to a higher velocity. This suggests that, besides the geometrical layout of the obstacle, it is also significant to focus on the pedestrian's status when exploring the obstacle's influence.