【作者】 岳昊；

【导师】 邵春福；

【作者基本信息】 北京交通大学 ， 交通运输规划与管理， 2009， 博士

【摘要】 在我国城市道路交通中,由于行人和非机动车的存在,混合、低速、高密度交通流凸显出了明显的特色。步行是人类最基本的交通出行方式,无论采用何种交通方式出行,在其起点和终点都离不开步行。在我国许多大城市,上下班高峰期间可以观察到在地下通道、过街天桥、公共交通枢纽、地铁站等各种行人通道中形成的拥堵行人流。行人交通拥堵不仅给人们的出行带来了很大不便,导致出行延误时间的增加,而且在行人大量聚集的各种游行、集会等行人群体活动中,以及行人非常密集的体育场馆、大型游乐场等娱乐场所中,还会由于行人的推挤造成重大的踩踏事故。近年来各国政府越来越重视行人交通流的研究和行人交通问题的解决,然而行人交通拥堵造成的各种事故时有发生,不仅给社会带来巨额的经济损失,而且对人们的生命构成了严重威胁。在城市人口与日俱增和城市交通压力不断增加的今天,通过对行人流微观特征和宏观特征的研究,建立科学的行人交通流理论,指导行人设施的规划和行人流的管理和控制,有效诱导行人流,避免和缓解行人流拥挤,实现行人设施利用限度的最大化,是行人流研究的热点。本论文基于元胞自动机仿真理论,在分析研究行人微观行为特征的基础上,建立行人流仿真模型。通过仿真行人流中微观个体的微观行为特征,实现由单个个体之间相互作用形成的宏观行人流的特征研究,探索基于仿真的行人流宏观现象和特征的生成机理,建立行人微观行为特征和宏观群体特征之间的联系。本论文分别以横向干扰行人流、对向行人流、疏散行人流为仿真研究的对象,对以下几方面的内容进行深入研究:(1)从行人流个体微观特征和群体宏观特征两个角度阐述了行人流特征研究的国内外现状;在分析阐述计算机仿真技术已经成为行人流研究主要工具的基础上,从连续性仿真模型和离散性仿真模型两方面阐述了行人流仿真模型研究的国内外现状。(2)建立了基于元胞自动机的行人流动态参数仿真模型。在仿真模型中,行人可以选择等待或者向周围八个方向移动,在特别的条件下行人之间可以相互交换位置。同时模型引入了方向参数、空格参数、前进参数和类别参数这四个动态参数来描述单个行人对自身周边交通条件的判断认知情况。模型引入移动收益的概念来描述行人对每个移动步伐收益的评价,并通过移动收益来建立行人与可选择位置之间的评价与被评价的关系。模型假设每个行人在移动的过程中以尽可能短的路线到达目的地的思维来选择路径,行人在移动过程中会快速且不间断地对自己可选的不同位置进行利弊权衡。行人对可选位置移动收益的评价是通过反映行人周围动态交通情况的四个动态参数来计算的,从而实现行人对自身周围交通环境的反应。行人在移动的过程中会选择移动收益最大的位置作为自己下一时间步的目标位置。(3)利用行人流动态参数仿真模型,以横向干扰行人流(垂直行人流和四向行人流)为仿真对象,分析研究了不同系统规模的行人流仿真速度-密度曲线和流量-密度曲线。探讨了系统规模、不同权重系数对仿真曲线和系统临界密度的影响。从行人的移动规则和模型仿真结果两个角度,对动态参数模型与其他现有模型作对比分析。(4)基于行人流动态参数仿真模型分别从方向比例、系统规模、行人移动习惯三个方面仿真研究了对向行人流的宏观行为特征。分析研究了对向行人流的仿真速度-密度曲线和流量-密度曲线。探讨方向比例、系统规模、行人移动习惯对仿真曲线和系统临界密度的影响,同时仿真研究了不同初始条件下的对向行人流演化过程。为了描述行人向右移动的右行习惯,引入了右行参数的概念,详细阐述了右行参数的定义和赋值范围。(5)基于行人流动态参数仿真模型,从疏散环境中无障碍、存在障碍物和行人视线受影响三个角度仿真分析了疏散行人流的宏观特征。分析研究了在无障碍疏散中,安全出口宽度、疏散行人密度、安全出口布局等因素对行人疏散时间的影响。在存在疏散障碍物的情况下,提出了基于欧式距离的存在障碍物环境的静态领域参数计算方法,由此计算存在障碍物疏散环境下的行人方向参数值,并分析研究了不同障碍物布局的行人疏散演化过程。在行人视线受影响的仿真研究中,从无疏散标志的行人盲目移动和有疏散标志的行人沿墙移动两个角度分析研究了行人疏散流的动态特征。通过视野半径把疏散空间划分为可见安全出口区域、可见墙壁区域和不可见墙壁区域。分别定义了不同区域内的方向参数计算方法,以描述行人在不同疏散环境下的微观行为特征。仿真研究了行人视野半径对行人疏散时间和疏散空间内滞留人数的影响。更多还原

【Abstract】 In developing countries,mixed traffic flow and pedestrian traffic flow play an important part in urban traffic flow in which walking acts as the most basic mode of trip for human beings.Whatever the vehicle adopted,walking cannot be spared at the trip origin and destination.In many metropolises of China,crowded pedestrian flow occurs in the pedestrian facilities such as pedestrian channel,overpass,public transport hubs and subway station in the traffic peak hour.Congested pedestrian traffic flow not only causes much inconvenience for pedestrian’s trip but also results in an increase of trip delay time.Moreover,pedestrian stampede-crush accident might happen caused by severely assembled pedestrians in the mass campaign such as parade or assembly and audience in large stadium and cinema,etc.In recent years,national governments have been laying more and more emphasis on the study of pedestrian traffic flow and solutions to pedestrian traffic problem.However,pedestrian accidents caused by pedestrian traffic jam do occur now and then,which not only brings large amounts of economic loss to the society but also poses serious threat to people’s lives.Therefore, the population explosion and the increasing traffic pressure in metropolises call for a great need to establish scientific theories of the pedestrian traffic flow based on the research on micro- and macro-characteristic of the pedestrian flow so as to guide pedestrian facility planning and pedestrian flow management and control to realize efficient and effective pedestrian flow guidance;avoid or alleviate pedestrian flow jam; and consequently maximize the utility of pedestrian facilities.In this dissertation,the simulation model of pedestrian flow is established based on the cell automata(CA) simulation theory by analyzing the micro-characteristics of pedestrian flow behavior. The study on emergent group behavior of pedestrian flow caused by the interaction of individual pedestrian micro-behaviors is carried out based on individual micro-behavior simulation,in which the formation mechanism of macro-characteristics of group behavior is explored and the relationship between micro- and macro-characteristics of pedestrian flow behavior is established.In the dissertation,laterally-interfered pedestrian flow,bi-direction pedestrian flow and pedestrian evacuation flow are simulated and analyzed based on CA.The main content of this dissertation is summarized as follows:(1) An overview of researches at home and abroad on micro and macro-characteristics of individual pedestrian and pedestrian group behavior are presented.It is then followed by an overview of studies on simulation of pedestrian flow at home and abroad from the perspectives of continuous and discrete simulation models based on the fact that computer simulation technology has become a major tool to study pedestrian flow.(2) The CA-based Dynamic Parameters Model(DPM) of pedestrian flow simulation is established.In the Dynamic Parameters Model,pedestrians can choose to wait or move to the eight neighboring cells as the next possible occupant position.In particular,the exchange of occupant positions is allowed in the pedestrian movement according to specific conditions.Meanwhile,four dynamic parameters: Direction-parameter,Empty-parameter,Forward-parameter,and Category-parameter are introduced to describe how individual pedestrians make their judgments on the conditions around.The concept of transition payoff is introduced to describe the relative advantages to be obtained by a certain pedestrian,through which the relationship between pedestrian as evaluator and available cells is established.It is assumed that the route choices made by pedestrians are driven by an intention to approach their destinations in a route as short as possible.Therefore,they are constantly weighing different possible choices of step.The transition payoff entailed to each cell for a pedestrian with a certain destination is represented and computed through these four dynamic parameters,which reflect the factors involved in the movement of pedestrians. While moving,pedestrians prefer the position with the largest transition payoff with an aim to acquire a movement benefit as large as possible.Therefore,the pedestrian would choose the cell with the largest value in the matrix of transition payoff as his or her target position.(3) Laterally-interfered pedestrian flow including four-way and perpendicular pedestrian flow is simulated and discussed by using Dynamic Parameters Model.The velocity-density and volume-density relationships will be studied and analyzed with different system sizes and parameter weights.The effect of system size and parameter weight on the simulation curve and critical density is analyzed.Comparisons between Dynamic Parameters Model and published pedestrian simulation models are carried out from pedestrian movement rules and simulation results.(4) Bi-direction pedestrian flow is simulated and discussed by using Dynamic Parameters Model from the perspectives of direction split,system size and walking habit respectively.The relationships of velocity-density and volume-density will be studied and analyzed.The effect of direction split,system size and walking habit on simulation curve and critical density is also analyzed.The evolution process of bi-direction pedestrian flow is simulated with different initialization conditions.The Right-hand-parameter is introduced and defined in great detail in this part to describe and reflect pedestrian’s walking habit of keeping to the right in their movement.(5) Pedestrian evacuation flow is simulated and discussed by using Dynamic Parameters Model with three possible circumstances taken into consideration,involving the evacuation conditions under which there is no visible adverse effect,or there exists obstacles or pedestrian’s visual field is affected.The effect of exit number,pedestrian density and exits layout on evacuation time in the evacuation room without adverse effect is discussed.In the simulation with evacuation obstacle,the method of computing the value of static floor field with obstacles is presented based on Euclidean distance, through which the direction-parameter is computed and the pedestrian evacuation from rooms with different layouts of obstacles are simulated.In the simulation with pedestrian’s visual field affected,the pedestrian evacuation characteristics are discussed considering the cases in which pedestrians blindly move without evacuation sign or pedestrians move along the wall with evacuation sign available.The evacuation room is divided into exit visible area,wall visible area and wall invisible area by pedestrian sight radius.Different methods of computing direction-parameter in these areas are presented to describe pedestrians’ varied movement characteristics under these circumstances.The effect of pedestrian sight radius on evacuation time and the number of remaining pedestrians is also discussed.更多还原