黄罗毅
入学时间:2010级
答辩时间:2013年
论文题目:面向车路协同的车车通信机制研究
中文摘要
摘要
智能交通运输系统代表未来交通运输领域发展趋势。车路协同作为智能交通运输系统中一个前沿性研究方向,已经受到越来越多的关注。车路协同以车车、车路通信为基础,使用专用短程通信技术构建结点间的数据传输链路。车车通信作为车路协同的一种重要表现形式,有着广泛的应用。
IEEE 802.11p是近年出现的一种热门专用短程无线通信技术,被认为是下一代智能交通运输系统中无线通信技术的发展方向,已经受到一些研究机构和企业的关注。然而,由于支持IEEE 802.11p的产品尚未面市,可查阅文献中大部分对IEEE 802.11p的性能研究基于仿真软件和一些小范围、小规模的实地数据收集。根据现有文献对IEEE 802.11p性能测试和机制研究的不足之处,本研究将对IEEE 802.11p进行更全面和细致的实地测试和机制分析。
机制,可指事物内部组织和运行变化的规律,可引申为特定的关键技术和具体的性能表现。在一个系统中,机制起着基础性和根本性的作用。在车车通信中,无线通信必须为车路协同系统提供基础性和根本性的保障。本研究主要分析车车通信中性能指标和涉及特定通信的关键技术,并通过关键通信模型的构建,探寻IEEE 802.11p的运行机制。
首先介绍可应用于车路协同常用的无线通信技术,通过比较,选择IEEE 802.11p作为研究对象,从频段、通信机制等方面介绍车辆环境无线接入(Wireless Access in the Vehicular Environment,WAVE)协议栈相关内容,于实地构建通信距离影响、遮挡物影响、数据包大小影响和不同速度影响实验,对IEEE 802.11p的通信基础特性进行研究和分析。并实地构建了校园道路、高速公路、市郊道路和城市道路四种典型应用场景,进行了可行性和可靠性的研究,主要涉及RSSI、延迟、丢包率、分组接收率等关键技术指标。数据分析结果表明,WAVE协议在车车通信典型应用场景中具有一定的可行性和可靠性,可应用于车车通信的典型场景中。最后,对经典的Path Loss模型进行了改进,使其更好地适用于真实环境下IEEE 802.11p通信机制的表现,通过对改进的模型进行数据匹配,结果证明提出的改进模型具有更高的准确度。
关键词:车路协同,IEEE 802.11p,典型应用,通信机制
英文摘要
ABSTRACT
Intelligent Transportation System(ITS) represents the future trend of traffic engineering. Cooperative Vehicle Infrastructure System(CVIS) is one of the cutting-edge research topics in ITS areas, and has been received more and more attention. CVIS is based on vehicle-to-vehicle(V2V) and vehicle-to-infrastructure(V2I) communication by using Dedicated Short Range Communications(DSRC) technology to construct data link among vehicles. In CVIS, vehicle-to-vehicle communication is an important part, which has a wide range of applications.
IEEE 802.11p is becoming one of the popular DSRC technologies in recent years, which is considered as the next generation DSRC technology in ITS field and has been widely studied by research institutions and enterprises. However, some related literature mainly focused on the performance analysis of IEEE 802.11p in a simulation method due to the unmatured IEEE 802.11p device in current market. In addition, IEEE 802.11p prototype device was only used for data collection on a small scale. Different from the former work, this study aims to analyze the communication mechanism of IEEE 802.11p and evaluate its performance in a more comprehensive and subtle way through field test.
Mechanism plays a basic and fundamental role in a system, which can be described as a law of internal organization and operation. In addition, the mechanism is extended as the representation of key technology and specific performance. In vehicle-to-vehicle communication system, the DSRC technology should provide a basic and fundamental support for the system. This work mainly studies on the performance index and specific wireless technology in vehicle-to-vehicle communication. Moreover, the mechanism of IEEE 802.11p is explored by constructing key communication model.
Firstly, the frequently-used DSRC technologies applied in CVIS were introduced and compared. After the comparison, IEEE 802.11p was selected as the study object. Then, the WAVE(Wireless Access in the Vehicular Environment) protocol stack including frequency, communication mechanism etc. were presented. In addition to the theoretical analysis of IEEE 802.11p, field test of different communication distances, obstacles, packet lengths and speeds were conducted to evaluate the basic characteristics of IEEE 802.11p. Furthermore, various test sites including campus, highway, suburban and urban scenarios were selected to analyze the feasibility and reliability of IEEE 802.11p from the aspects of received signal strength indicator(RSSI), latency, packet loss rate, packet delivery ratio and other key indexs. In the end, classical path loss model was improved based on the data collected in the field tests. Test results show the WAVE protocol is feasible and reliable in typical vehicle-to-vehicle communication scenarios in a certain degree. Using the newly proposed model, data matching results indicate the proposed model in this study is more accurate than the classical path loss models.
Key Words:CVIS, IEEE 802.11p, typical application, communication mechanis
汪亮
入学时间:2010级
答辩时间:2013年
论文题目:考虑排队约束的快速路主线车道与入口匝道信号协调控制研究
中文摘要
摘要
随着机动车保有量的快速增长,上海、北京等城市的快速路系统交通拥堵现象日益突出,尤其在快速路入口匝道交汇区——常发性交通瓶颈区域,经常出现匝道车辆无法进入主线或由于匝道车辆汇入时带来的车道变换所导致主线交通拥堵或事故频发等现象。
针对以上状况,以往多实施入口匝道流入交通控制策略,并收到了显著的效果,但是该控制方式是以主线绝对优先为前提的,其目的是为了转移入口匝道的交通需求,平顺匝道车辆汇入过程。然而,中国城市快速路及其交通特征决定交通流入或交汇控制与管理的特殊性。主要体现在:1.城市快速路大多是高架形式,若采取入口匝道控制常带来待行车辆停停走走,不利于交通安全;2.快速路匝道形式较为复杂,特别是快速路-快速路入口匝道,其车辆通行权与主线车辆往往具有同等性;3.匝道车辆没有可替代路径,所以实行匝道控制所引起超长排队常造成对相邻道路的交通阻碍。因此,本文提出了快速路主线车道与入口匝道交通协调控制问题,并进行探索性研究。
首先,论文从入口匝道交汇区需求与特征分析入手,解析快速路交汇区流量、速度、交汇区驾驶行为特征以及揭示无控制与协调控制下的交通冲突状态,从交汇区基本特征和规律上论证无控制模式下主线与匝道交通流交通效率低下,交汇区通过能力显著下降的特征,进一步论证主线车道与入口匝道交通协调控制的需求性,并在此基础上,对主线车道与入口匝道协调控制系统功能及组成部分进行了分析,为主线车道与入口匝道交通协调控制提供了基础支撑和技术支持。
其次,论文对协调控制策略的实施控制进行了模型建立。主要从主线车道与入口匝道交通协调控制逻辑、交通控制基本参数等着手确定协调控制下的控制方案。其中,交通控制参数的确定主要包括相位相序、信号周期、绿灯时长以及排队约束下的排队长度以及头车等待时间的确定。为主线车道与入口匝道协调控制策略的实施提供了理论基础和保障。
最后,论文对主线车道与入口匝道交通协调控制进行了适应性分析,主要从双车道入口匝道、单车道入口匝道以及进出口较近的交织区进行了仿真场景的应用,从控制方式和效果进行评价,进一步的提供了主线车道与入口匝道协调控制在高交通需求下的可行性和显著的效益提升。
在匝道交汇区无控制以及匝道控制的背景下,主线与匝道车辆之间的干扰依然存在,特别是无控制模式下的自组织行为,造成了交汇区通行效率和通过能力极大的下降,因此,本文探索性的从主线车道与入口匝道交通协调控制的角度出发,对快速路入口匝道交汇区的交通控制问题进行分析,不仅规避了交汇区主线车道与匝道车辆之间的相互干扰,并在交通需求较大的情况下,收到了较好效益,还从理论研究上进一步丰富了入口匝道控制理论体系,对后续相关研究也有一定的借鉴意义。
关键词:主线车道、入口匝道控制、信号协调、排队约束、仿真实验
英文摘要
ABSTRACT
With the rapid growth of vehicle population, phenomenon of traffic congestion can be increasingly prominent in the operation of urban-expressway system in many big cities including Shanghai, Beijing. Especially in urban-expressway ramp merging area, the recurrent bottleneck area, the phenomenon including ramp vehicles cannot merge in mainline, traffic congestion and traffic accident in merge area, which are caused by the disturbance of lane change can be frequently observed.
For the above situation, ramp metering strategies have been proposed and applied, also it received a significant effect. However, these control strategies give the mainline absolute priority, and hope that it receives the purpose which transfers ramp traffic demand, smooth the procedure that ramp vehicles merge in mainline. But it is difficult to popularize the metering strategies in China because of some reasons, such as: (a)most of urban expressways are elevated form, while stop and go behavior character which are brought by ramp metering is terrific detrimental for traffic safety. (b)ramp forms of complexity require specific strategies, especially for Freeway - Freeway ramp, the main vehicles and ramp vehicles should enjoy the same right-of-way and fairness; (c)ramp vehicles have no alternative path, because of the implementation of the ramp metering, excessive queue of vehicles will emerge and disturb the adjacent road, form a series of traffic congestion. Therefore, coordinated signal control between urban expressway lane and on-ramp is presented, and then this paper analyzes the related issues explorative.
Firstly, this paper analyzes the needs and characteristics of on-ramp merging zone, and then analyzes the traffic volume, speed, driver behavior character and reveals traffic conflict under no control or coordination control. By comparison of traffic efficiencies and capacity of the two controlling modes, the demand of coordination control is needed and based on this, the function and the component are analyzed, and this provides basic support and technical support.
Secondly, based on the concept of coordinated signal control between urban expressway lane and on-ramp, the control model is built. It mainly is beginning from coordination logic and traffic control parameter set up and then determine the control method. Among these parameters are phase sequence, signal cycle, green time, queue length and the first car waiting time. This section provides a theoretical basis and guarantee for the coordination control.
Finally, in order to show coordinated signal control strategy effectiveness, VISSIM simulations are developed by three situation including the single lane ramp, two-lane ramp, import and export ramp. To a certain extent, this provides an applicability description and reference for selection of control strategies.
Under the background of no control or existing ramp metering, the disturbance of the mainline and ramp flow still exists, especially self-organizing behavior in no control environment, the efficient and capacity in merge area thus decrease. This thesis makes an exploratory research on coordinated signal control between urban expressway lane and on-ramp. This study enriches ramp control theoretical system, also will bring some references to follow-up study.
Key Words:urban-expressway mainline lane, ramp metering, signal coordination, queue constrain, simulation
杨静
入学时间:2010级
答辩时间:2013年
论文题目:信号交叉口与路段通行能力匹配交通设计方法研究
中文摘要
摘要
交通设计是面向交通实际需求与问题优化设计交通方案的中间技术环节,上承交通规划,下接交通设施工程设计与交通管理,指导交通设施的土木工程设计以及系统的最佳利用。为改善和预防交通拥堵,本文将通行能力匹配的设计理念引入交通设计体系,以信号交叉口及其相连路段为研究对象,从信号交叉口通行能力匹配性评价方法、面向规划阶段和管理阶段的通行能力匹配交通设计方法三方面展开研究。
本文首先解析机动车流流过信号交叉口的实际运行过程,分析影响交通流运行的典型道路通行能力断面,包括上游路段断面、交叉口进口道停车线断面、出口道断面和下游路段断面。针对上述四个断面分别构建其通行能力的计算模型和规划阶段的通行能力简化模型。然后,本文提出评价相邻两个道路断面的通行能力匹配性评价指标——匹配度,并提出规划和管理阶段信号交叉口通行能力匹配性综合评价方法。最后,利用一个示例验证了规划阶段信号交叉口通行能力匹配性综合评价方法的可行性。
在面向规划阶段的交通设计方法研究中,本文建立以信号交叉口通行能力匹配度为目标函数,以路段车道数、进口道车道数、车道功能划分、出口道车道数、进出口道短车道长度、绿信比和周期长度等时空资源为约束条件的最优化模型,并给出求解模型的算法流程。并研究了交叉口进口道渠化设计、进口道车道数设计和路段车道数设计的方法,并给出相关设计建议。
在面向管理阶段的交通设计方法研究中,本文将信号交叉口通行能力匹配和饱和度均衡两种理念引入交通设计体系中,建立以信号交叉口延误、通行能力匹配度和饱和度方差为目标函数,以交叉口时空资源和交通流量为约束条件的最优化模型,并给出求解模型的算法流程。最后给出了管理阶段常见信号交叉口的总流量建议。
关键词:交通设计,信号交叉口,通行能力,匹配
英文摘要
ABSTRACT
Traffic design, which was based on traffic planning and practice,should be added into the program of roadway construction. In order to alleviate traffic congestions, we added capacity matching as the optimization target of traffic design program.Signalized intersections were used as the research objects. Evaluationmethodology of matching degree of signalized intersection capacity and traffic design methodology which provided a theoretical basis and guidance for traffic planning andmanagement were studied in this paper.
The potential spots were explored by analyzing the normal operation of vehicles in the signalized intersection system, which were upstream segment, intersection approach, exit and downstream segment. The capacity models of the above 4 spots were established separately for traffic planning and management. That what was the definition of capacity matching was given based on an index called matching degree. According to the proposal of matching degree, comprehensive evaluation methodology of matching degree of signalized intersection capacity were established separately for traffic planning and management.
An optimization model which took capacity matching degree as objective function and constraint to segment lanes, approach and exit lanes, allocation of turns to lanes, short lane length, split and cycle was established to obtain the optimized scheme considering the conditions in traffic planning.Then algorithm was given. Taking different conditions of traffic planning into account, the design advice of lane-use assignment etc. for typical signalized intersections was given at last.
An optimization model which took delay, capacity matching degree and saturation level variance as objective function and constraint to space-time sources and flow was established to obtain the optimized scheme considering the conditions in traffic management. Later, the design advice of traffic flow for typical signalized intersections was given.
Key Words:traffic design, signalized intersection, capacity, matching
张抒扬
入学时间:2010级
答辩时间:2013年
论文题目:城市轨道交通突发事件下的客流疏散需求特征研究
中文摘要
摘要
在城市紧急事件管理与安全领域,城市轨道交通突发事件下的应急客流疏散与后续接驳服务是其中的重要组成部分。随着轨道交通系统在我国各大城市中扮演着愈发重要的运输动脉角色,有必要对突发事件后客流疏散需求特征进行合理分析,从而根据此制定应急预案及组织后续公共交通客运服务,维持正常的城市客运系统运营秩序,保障运输服务可靠性。本文基于城市轨道交通突发事件,轨道交通客流分布特征及事故后公交接驳服务的相关研究,展开对于城市轨道交通突发事件下的客流疏散需求特征的探讨研究。
在综述国内外相关领域研究成果的基础上,本论文首先分析了城市轨道交通突发事件的特点及其分类,然后从宏观和微观两个层面讨论了造成轨道交通突发事件的原因,并对其影响机理进行了分析。
论文以制定轨道交通突发事件下的客流疏散流程为目标,结合突发事件救援流程和突发事件后的客流应急疏散流程,分析轨道交通突发事件的客流疏散特征。在研究轨道交通客流时空分布特征以及轨道交通突发事件对客流影响的基础上,分析轨道交通突发事件下的客流疏散需求特征,并结合SP调查进行定量分析。随后考虑实地调研情况提出影响轨道交通突发事件下客流疏散的主要外部环境因素。从城市客运交通一体化的角度出发,分析了公交接驳在轨道交通客流疏散中的作用,并进一步研究突发事件下公交接驳运输方案的决策算法。其中既考虑到轨道交通客流疏散的需求和时效,又考虑到应急公交运能最小化以降低对正常公交运营的干扰,研究结合2011年9月27日上海轨道交通事故进行案例分析,结果表明该算法可以一定程度上减少应急接驳公交的使用数量,对于研发一体化的城市公共交通客运应急管理系统具有重要的理论价值。
最后,在总结全文研究成果的基础上,对论文的创新点和不足进行了归纳,并对相关领域后续研究内容进行了简要的讨论。
关键词:交通工程,轨道交通突发事件,客流疏散流程,客流分布特征,公交接驳
英文摘要
ABSTRACT
In emergency management and safety area, passenger evacuation and subsequent transit service are important parts in dealing with the urban rail transit emergency. Since the rail transit system is playing a more and more significant role in metropolis all over the country, it is necessary to make study on the passenger demand analysis of urban rail transit emergency, thereby to make contingency plan and organize follow-up transit service, and this is a vital task that to maintain the order and reliability of regular urban transit service. This thesis based on relevant research of urban rail transit emergency, rail transit passenger distribution characteristics and subsequent shuttle bus service, to carry out passenger demand analysis of urban rail transit emergency.
Based on summary of domestic and foreign related research in this field, the thesis first analyze the urban rail transit emergency characteristics and their classification, and then discuss the causes of rail transit emergency from macro and micro level, and study the influence mechanism of rail transit emergency.
This research combined emergency disposal process and passenger evacuation process, resolved the passenger evacuation characteristics of rail transit emergency, thus determined passenger evacuation process of urban rail transit emergency. After discussing about the passenger distribution features and the impacts of rail transit emergency to the passengers, the study made qualitative analysis of passenger characteristics in rail transit emergency and quantitative analysis based on SP survey. Further, the study put forward the main environmental factors that affect passenger evacuation based on field investigation. Then, the study proposed a set of structured steps and optimization models for handling bus assignment problem from the perspective of urban transit integration, which considers both the requirements of rail transit passengers evacuation and the emergency bus vehicle capacity, and a case study based on September 27 2011 metro accident in Shanghai is developed to illustrate the approach. The results showed that the proposed method significantly decreases required bus number for temporal substitute service while maintaining bus service at an acceptable level. The study has important theoretical value for studying and developing the integrated urban transit emergency management system.
In the end, on the basis of sum up the conclusions of this thesis, I made a short discussion of innovations, inadequacies and further work of the research.
Key Words:transportation engineering, rail transit emergency, passenger evacuation process, passenger distribution characteristics, bus shuttle service