城市道路网络临界自组织现象及特征分析

发布时间：2018-04-24 23:01

本文选题：城市道路网络 + 临界自组织　；参考：《兰州交通大学》2017年硕士论文

【摘要】：随着近年来城镇化进程的不断推进,区域内的中心城市的规模开始快速扩张,不论是从城市面积还是人口密度的角度来看,中心城市已经成为各自所在区域的主要集中点。区域中心城市从区域内其他区域吸引而来的大量人口也造成了城市内系统性的交通拥堵,日益严重的拥堵大大限制了城市居民出行范围,造成了城市中的交通基础设施投资的极大浪费,城市交通系统中的道路资源因为城市中某些节点的拥堵而得不到充分的利用,而瓶颈路段却长时间处于拥堵状态。为解决这一问题必须从交通流本质和城市路网结构这一根源入手,将城市交通视为一个巨系统,如此才能从本源上缓解甚至解决这一问题。因此本文应用复杂网络理论从宏观角度分析城市道路网络临界自组织现象及特性,而且应用元胞自动机模型从微观角度深入剖析城市道路网络上交通流的相变特征,通过对城市交通网络运行状态进行微观参数的研究,可以为缓解城市交通拥堵提供新的思路。复杂网络理论自提出以来,已经运用于多个学科领域,将复杂网络理论应用于交通网络中可以从宏观层面上很好的理解整个网络的结构特性、拥堵的传播特性、级联失效特性、网络内部的动力学特征等相关特性。而元胞自动机从微观层面上能够动态地刻画出城市道路网络上交通流的微观物理现象以及内部耦合机理,并且将其应用的灵活多样,可以根据不同的城市路网条件建立符合实际情况的交通流模型。本文借鉴吸收国内外已有研究,对城市道路网络的临界自组织现象及特征进行深入分析,基于复杂网络理论与元胞自动机对城市道路网络的级联失效过程和相变过程进行分析,主要的研究内容如下:首先,在对国内外城市道路网络临界自组织现象和特征研究进行梳理的基础上,阐述论文的研究背景、意义以及城市道路网络的基本特征,探讨了城市交通复杂性与复杂网络之间的关系,为城市交通复杂网络拥堵的产生、传播、消散分析提供理论基础,为缩短延误时间,降低出行成本的研究提供思路和模型框架;其次,介绍复杂网络中可以描述网路结构特征的相关统计量,运用复杂网络理论对城市道路网络临界自组织现象及特性进行分析,建立基于可调负载重分配的级联失效模型,研究不同的容限系数、重分配范围、重分配的均匀性对整个网络的级联失效时间和规模的影响,得出影响城市道路网络的抗毁性包括重分配的范围、重分配的均匀性等管理控制因素和网络规模、容限系数等设计因素。通过适当调节负载重分配的范围和均匀性,可以保证城市道路网络的抗毁性处在一个较高的水平。适当的提升道路的宽度,可以避免网络级联失效现象的发生;然后,建立NaSch和BML耦合模型,运用matlab进行模拟仿真并分析其的临界相变。计算结果表明,路网运行的状态和初始密度紧密相关,初始状态密度小于某个特定值时,路网保持自由流状态,反之,若系统初始密度超出某条件时,完全拥堵现象极易发生,同时完全堵塞的构行将会出现;最后,建立更符合现实情况的随机更新的城市道路网络模型,引入转向概率,分析网络规模、转向概率对各个方向上的流量影响。随着系统尺寸增大,临界密度降低,并且引起更急剧的跃迁,当网络尺寸继续增大时,临界密度趋于稳定。在网络中的车辆通过增加从右(上)向上(右)方向的转向概率,即urp(rup)增加时固定rup(urp),上行(右行)车辆的平均速度会随之增加,除了当rup(urp)取值较小时有轻微的下降,然而,右行(上行)车辆的平均速度会在增加前下降。
[Abstract]:With the progress of urbanization in recent years, the scale of central cities in the region has been expanding rapidly. Whether it is from the perspective of urban area or population density, central cities have become the main concentration points in their respective regions. A large number of population attracted by the regional central cities from the other regions in the region have also been caused. Urban traffic congestion and increasingly serious congestion have greatly restricted the travel scope of urban residents, resulting in a great waste of urban transportation infrastructure investment. The road resources in the urban traffic system are not fully utilized because of congestion in some cities, but the bottleneck section is in a long period of congestion. In order to solve this problem, we must start with the root of traffic flow nature and urban road network structure, regard urban traffic as a giant system, so as to alleviate or even solve this problem from the source. Therefore, this paper applies complex network theory to analyze the critical self-organization phenomenon and characteristics of urban road network from a macro perspective and its application. Cellular automata model analyses the phase transformation characteristics of traffic flow on urban road network from a microscopic point of view. Through the study of the microscopic parameters of urban traffic network operation state, it can provide a new idea for alleviating urban traffic congestion. Since the complex network theory has been put forward, it has been used in many disciplines and complex network theory. On the traffic network, we can understand the structure characteristics of the whole network, the propagation characteristics of congestion, the cascading failure characteristics, the dynamic characteristics of the network and other related characteristics from the macro level, and the cellular automata can dynamically depict the microscopic physical phenomena of traffic flow on the urban road network from the micro level. The internal coupling mechanism, and the flexible and diverse application of it, can set up the traffic flow model according to the different urban road network conditions. This paper draws lessons from the existing research at home and abroad, analyzes the critical self-organization phenomenon and characteristics of the urban road network, and based on the complex network theory and the cellular automata to the city The cascading failure process and phase change process of road network are analyzed. The main contents are as follows: first, on the basis of combing the critical self-organizing phenomenon and characteristics of urban road network at home and abroad, the research background, significance and basic characteristics of urban road network are expounded, and the complexity of urban traffic is discussed. The relationship between complex networks provides a theoretical basis for the formation, propagation, and dissipation of traffic congestion in urban traffic complex networks, and provides a framework for reducing the delay time and reducing travel costs. Secondly, it introduces the related statistics that can describe the characteristics of network structure in complex networks, and uses complex network theory to the urban road. The critical self organizing phenomenon and characteristics of the road network are analyzed, and a cascade failure model based on adjustable negative load distribution is established, and the influence of different tolerance coefficient, redistribution range and redistribution uniformity on the cascading failure time and scale of the whole network is studied. Management control factors such as distribution uniformity, network scale, tolerance factor and other design factors. By properly adjusting the range and uniformity of load redistribution, the destruction of urban road network can be guaranteed at a higher level. The proper promotion of road width can avoid the occurrence of network cascading failure; then, establish N The coupling model of aSch and BML is used to simulate and analyze the critical phase transition with MATLAB. The calculation results show that the state of the road network is closely related to the initial density. When the initial state density is less than a certain value, the road network maintains the free flow state. Conversely, if the initial density of the system exceeds a certain condition, the complete congestion phenomenon is very easy to occur. At the same time, the completely blocked construction will appear. Finally, a random updated urban road network model, which is more consistent with the reality, is set up, the steering probability is introduced, the network size is analyzed, and the steering probability affects the flow in all directions. As the size of the system increases, the critical density is lower, and a more sharp transition is caused, when the network size continues. When increasing, the critical density tends to be stable. By increasing the steering probability in the right (right) direction from the right (right), that is, the URP (RUP) increases the RUP (URP), the average speed of the upward (right) vehicle increases, except when the value of the RUP (URP) decreases slightly, however, the average speed of the right line (upper) vehicle will be at the average speed Drop before the increase.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U491

【参考文献】