L型步行通道内行人转弯行为的实验分析与仿真

Experimental analysis and simulation study on turning behavior of pedestrians in L-shaped corridor

以L型步行通道内的单向行人流为研究对象,基于可控实验与微观仿真研究行人转弯行为.首先,构建转弯区无障碍物、障碍物沿转弯区对角线布局、以及障碍物垂直转弯区对角线布局三种实验场景,通过行人可控实验分析行人移动轨迹、速度分布等行为特征;然后,基于L型通道内的行人微观行为,改进基于Voronoi图的速度修正仿真模型,制定并嵌入行人通过L型通道的转弯规则;最后,分别对有/无障碍物以及非对称L型通道场景进行仿真研究,模拟再现行人的转弯行为,分析研究不同阶段行人速度与个体密度的分布情况.研究发现:基于行人的移动行为,L型通道可分为垂直直行区域、过渡区域、转弯区域和水平直行区域;行人在通过转弯区域时会形成“隐形瓶颈”和“弯道三角形闲置区域”,产生一定的流线压缩;改进的仿真模型,可以模拟再现行人通过弯道区域时呈现光滑弧线的移动轨迹,并能观察到“隐形瓶颈”和“弯道三角形闲置区域”现象;同时,行人流依次通过L型通道的四个区域时,其速度分布情况与行人实验数据相吻合,呈现先增后减再增“波浪式”变化的特点.该仿真模型也模拟再现了由于转弯行为导致行人局部密度变化的情况,彼此印证了行人速度与局部密度变化的统一性.对“隐形瓶颈”的认知,有助于合理利用和设计L型通道转弯区域.

In our study,the unidirectional pedestrian flow in an L-shaped corridor is taken as the research object,and the pedestrian turning behavior is studied based on controllable experiments and micro simulations.First of all,three experimental scenarios,namely,no obstacles in the turning zone,diagonal layout of obstacles along the turning zone,and diagonal layout of obstacles in the vertical turning zone,are constructed.Behavioral characteristics such as pedestrian movement trajectory and velocity distribution are analyzed through controllable experiments of pedestrians.Then,a velocity correction model based on the Voronoi diagram is constructed,and the turning rules of pedestrians passing through a 90-degree L-shaped curve are embedded in the model.Finally,simulation research is conducted on the scene with both obstacles and asymmetric L-shaped corridors as well as the scene with neither of them to simulate and reproduce the turning behavior of pedestrians,and analyze the distributions of pedestrian velocities and individual densities at different stages.The research shows that when pedestrians move in a normal non-panic status,they rarely present disorderly behavior and always approach to the inside of the corner of the L-shaped corridor.In the turning area,pedestrians always follow their original moving mode to pass through the corner like a stable arc.And in the process of moving,pedestrians do not move in a straight line,but keep shaking back and forth for zipper effect.Besides,in the process of turning,the longer the distance from the center of the corner,the longer the distance of the pedestrian around the arc will be.And the L-shaped corridor can be divided into vertical straight area,transition area,turning area,and horizontal straight area.When pedestrians pass through the turning walking area,the“invisible bottleneck”phenomenon and the“curved triangle idle area”phenomenon can be observed.Besides,the streamline compression and multiple rows of pedestrian track clusters can be seen in the region.According to the characteristics of pedestrians walking through the L-shaped corridor,the turning rules of pedestrians are made,and the scene with both of obstacles and asymmetric L-shaped corridor as well as the scene with neither of them is simulated.Then,through the pedestrian simulation by using our model,the turning behavior of pedestrians passing through curve like a smooth arc can be effectively reproduced.Moreover,the“invisible bottleneck”phenomenon and the“curved triangle idle area”phenomenon in the turning walking area can be seen in the simulation.At the same time,when the pedestrian flow passes through the four areas of the L-shaped corridor successively,the velocity distribution is consistent with the experimental data of the pedestrian,showing an increasing-decreasing-increasing“wavy”change characteristic.The simulation model is also used to simulate the local density change of pedestrians due to the turning behavior,which verifies the unity of pedestrian velocity and local density change.The cognition of invisible bottleneck is helpful in rationally utilizing and designing the L-shaped corridor turning area.