刘斌
入学时间：2008级
答辩时间：2011年
论文题目：基于检测数据的城市道路小型网络OD估计研究
中文摘要
摘要
随着城市化和机动化进程的加快，交通供给与需求的矛盾愈演愈烈，常态化交通拥堵现象日益加剧，对道路交通进行有效的管理及控制迫在眉睫。OD矩阵反映了最基本的交通需求信息，以往通过大规模调查获取静态OD矩阵的方法已经不能满足动态交通管理及控制的需要，因此，如何利用路段流量和路口转向比例来估计OD矩阵一直都是交通领域研究的热点问题之一。
对OD估计理论的研究已经有30多年的积淀，研究对象主要是实际数据较易获取的快速路及高速公路网络，论文在对OD估计理论中主要的七种模型原理及发展历程进行综述的基础上，结合ITS环境下先进的数据检测技术，确定以马尔可夫理论为基础，探究城市道路小型网络的OD估计问题。研究中综合利用交通工程理论、概率论及随机过程理论、数学规划理论和计算机仿真等方法对问题进行解析和验证，以期完善OD估计理论体系。
在建模分析的过程中，首先从解析城市道路网络中机动车交通流的实际运行状态出发，分别从点、线、面的角度抽象出交叉口、快速路网及市域道路网的拓扑结构，并采用吸收马尔可夫过程描述城市道路网络的交通流运行情况，建立了城市道路网络OD估计基本模型。考虑到实际数据的获取问题，在基本模型的基础上衍生出由若干路段流量反推OD矩阵的模型，并探讨了基于吸收马尔可夫过程的动态OD估计问题。
在模型参数标定方法的研究中，探讨了利用各种检测技术来获取模型所需数据的方法，包括路段流量、交叉口及路段进出口转弯流量比例等参数。并提出了利用线圈检测数据估计交叉口转向比例的方法。
在模型算法的研究中，首先对路网拓扑结构用矩阵的形式加以描述，并在MATLAB中编程实现了OD估计模型的求解算法。在此基础上分别对三种模型进行了适用性分析。另外，针对马尔可夫矩阵中零元素较多的问题，引入了稀疏矩阵技术，在降低所需存储空间的同时，大大提高了模型的计算速度。
在模型的精度评价中，提出了基于仿真的OD估计模型精度评价方法体系，给出了若干评价指标，并运用VISSIM仿真软件分别对快速路网络和“井”字型网络进行精度评价，算例说明模型可以很好的拟合实测路段流量，并获得较高精度的OD矩阵。
关键词：智能交通系统，马尔可夫理论，OD估计，城市道路网络
英文摘要
ABSTRACT
As the acceleration of urbanization and motorization, the contradictions of traffic supply and traffic demand become more and more intensely. At the same time, the traffic congestion becomes more and more seriously. It is high time that we took some measures to solve this problem. The origin-destination(OD) matrix reflects the most basic traffic demand, but the large-scale investigation we used before cann’t fit our requirement in the dynamic traffic management and control. So how to use the traffic counts and steering proportions to estimate the OD matrices have been hot issues in the Transportation field for a long time.
It has been more than 30 years since we began to study on the OD estimation. Most of the studies choose the expressway or highway as the objects, since the data is easier to obtain. Based on the review about the theory of seven modles used in OD estimation, combining the data collection technology, this paper will employ the Markov theory to explore the way to estimate OD matrices of the small urban road network. Meanwhile，some theories are referred in order to motivate the improvement of the method, such as traffic engineering，probability and stochastic process, Mathematical programming, simulation, etc．
In the study of the modeling, this paper draws the topological structures of the intersections, the expressway network and the urban road network, in the angel of point, line and area respectively. Then the Absorbing Markov Process is employed to illustrate the traffic flow in the urban road network. So the basic OD estimation model is formulated. Considering the different kinds of data we detected, the models using several traffic counts to estimate OD matrices are developed. The dynamic OD estimation is also discussed in this part.
In the study of the calibration of the parameters, this paper raises several ways to detect the data we need in the model, such as the traffic counts, steering proportions, etc. Furthermore, the method to estimate the steering proportions of the intersection is discussed.
In the study of the algorithm, this paper describes the topological structures by using the matrices, and then programmes the algorithms in the MATLAB. What’s more, the applicability of the three models is analyzed. Considering there are a lot of zeros in the Markov matrix, the sparse matrix technology is employed in this paper. While reducing the storage space, the computing speed can also be largely increased.
In the study of the precision assessment, this paper raised an accuracy evaluation system based on the simulation. Then the VISSIM simulation software is employed to evaluation the models on the expressway and urban road network respectively. The outputs of the model show that the traffic volumes and OD matrices can be estimated accurately.
Key Words：Intelligent Transportation System, Markov Theory, OD Estimation, Urban Road Network
王景辉
入学时间：2008级
答辩时间：2010年
论文题目：信号交叉口右转车道及控制信号优化方法研究
中文摘要
摘要
右转交通是城市道路交叉口交通流的重要组成部分，它与同进口道直行车流、相交道路车流、对向车流以及慢行交通流都会产生相互干扰，合理地组织右转交通与其它交通流之间地有序通行，对提高交叉口的通行效率和安全性有着至关重要的作用。但目前由于受重视程度不高，右转交通的研究成果较少，本文旨在通过对右转车道及控制信号的优化设计进行深入系统地研究，提出相关的科学方法，为合理组织右转机动车与其它交通流在交叉口处的有序通行提供理论指导和科学依据。
论文首先分析了右转交通在信号交叉口的运行特征，在此基础上，总结了右转交通在信号交叉口存在的问题，主要有：右转车流与慢行交通流的冲突、右转车流与其它社会车流的相互干扰、右转车流与公交车流的交织冲突等。依据存在的问题并结合综述内容，确定本文研究的重点。
在右转车道的优化设计研究中，论文首先对直右混行模式下直行车受右转机动车转弯影响产生的延误作了深入研究，其研究结果表明，该延误并不能作为右转车道设置的依据；而后论文通过对比设置右转专用道前后的机动车延误，提出了右转专用道的设置条件（此处考虑通过拓宽进口道来增加一条右转短车道的情形），并利用系统建模的方法提出了确定右转车道存储长度的方法；最后，分析了设置右转车道对相交道路出口道通行能力的影响，给出了需采取管制措施以避免右转车流对出口道通行效率产生影响的临界流量条件，同时，对右转车道与路边型公交专用道处理模式的适应性进行了分析。
在右转控制信号的优化设计研究中，论文首先对右转控制策略作了概述，并选取典型的控制策略作重点研究，利用系统建模、统计分析等方法分别确定了基于机动车延误、非机动车通行能力、行人通行能力的右转控制临界条件，并综合考虑右转机动车和行人的通行需求，给出了基于二者通行需求的右转控制条件；此外，对典型控制策略的适应性进行了分析。
关键词：右转交通，运行特征，右转车道，右转控制，临界条件
英文摘要
ABSTRACT
Right-turn traffic, which is an important part of traffic flow at urban intersections, may probably conflict with cross-flow, the flow from opposite approach, the straight-through flow of the same approach, or pedestrians and bicycles. The efficiency and safety of traffic organization at intersections are strongly related to the treatments of right-turn traffic. In other words, inappropriate right-turn treatments may probably disturb the whole intersection. However, it seems that the research of right-turn treatments hasn’t been emphasized as left-turn treatments. The purpose of this paper is to provide scientific method and theoretical guidelines for the design of right-turn lanes and control strategies, which is helpful to well organize right-turn traffic and to improve the efficiency and safety of intersections.
Based on the analysis of the operation of right-turn traffic at signalized intersections, the problems have been obtained, including the conflicts between right-turn traffic and pedestrians & bicycles, the conflicts between right-turn traffic and bus transit, and the disturbance between right-turn flow and other social vehicle stream. Combining the reference review, the research contents have been confirmed in this section.
In the fourth chapter, delay for straight-through vehicles in shared lanes has firstly been deeply studied, which demonstrates that it is not appropriate for this delay to be the criteria for the setting of right-turn lanes. Then, through the comparison of the delay with and without short right-turn lane, the setting critical conditions of right-turn lane are suggested, and the method of calculation for storage length of right-turn lane is also raised. Finally, this study gives an analysis about the impact of right-turn flow on the capacity of cross-flow and also suggests the critical flow condition for taking measurements to pretend cross-flow from the impact of right-turn flow. Meanwhile, the adaptability on the treatment between right-turn lane and bus lane has also been quantitatively given analysis.
As to the research of right-turn control, the control strategies for right-turn flow are overviewed, on the basis of which two typical strategies are chosen for the focused objects of this study. Through the method of modeling and statistical analysis, the critical conditions of right-turn control (based on the capacity of bicycles and pedestrians and the delay of right-turn vehicles) are put forward. Then the research on the adaptability of the two strategies is also conducted, which provides the guidelines for the choice of right-turn control strategies.
Key Words:right-turn traffic, operational characteristics of right-turn flow, right-turn lanes, right-turn control, critical condition
吴迪
入学时间：2008级
答辩时间：2011年
论文题目：现代路面有轨电车交叉口优先信号控制方法研究
中文摘要
摘要
在大力发展公共交通以缓解城市交通压力已成为共识的今天，沉寂百余年的现代有轨电车又重新活跃在大中城市的道路上。现代有轨电车作为一种轨道交通，以其运能适中、灵活性较强、绿色环保、乘坐舒适、成本相对较低等特点备受欧美城市的青睐。我国上海、天津、广州等城市也陆续引进现代有轨电车系统并已投入运营。有轨电车相对社会车辆以及常规公交等交通方式，有其独特的行驶特性，若沿用传统的信号控制方法会对其运行的效率及安全产生不利影响。我国城市交通相比欧美各国有其一定的特殊性，如混合交通、交叉口间距短等特点，因此国外的控制系统或方法在国内有其局限性。基于有轨电车的行驶特性及国内的行驶环境，如何对有轨电车进行交叉口信号优先控制成为一个重要的课题。
论文主要针对对有轨电车行驶特性及国内行驶环境的分析，研究有轨电车在交叉口的信号优先控制方法。论文的主要目的为通过信号控制的手段，给予有轨电车在交叉口时间上的优先通行权以保障其服务水平，同时考虑背景车流的交通效益。论文研究的重点为有轨电车交叉口信号控制参数确定方法、交叉口单点在线优先控制方法、离线协调优先控制方法。
论文首先分析有轨电车行驶特性及国内行驶环境，解析其与有轨电车交叉口信号优先控制策略思想与参数的关系，建立与被有轨电车行驶特性及环境影响的控制内容的映射，明确论文需要重点研究的对象及内容，为核心章节的研究打下基础。
研究了有轨电车运行条件下的交叉口信号控制基本参数确定方法。包括黄灯时间、绿灯间隔时间。提出的方法兼顾有轨电车特性以及对国内行驶环境的考虑，兼顾了效率与安全。在此基础上，提出了有轨电车运行条件下的交叉口周期时长确定方法。以交叉口车均总延误最小为目标建立模型，约束条件中考虑短连线交叉口、通行能力约束、有轨电车通行需求等因素。
提出了有轨电车交叉口单点在线优先控制方法。基于有轨电车到达交叉口停车线时间段的预测，以交叉口总体人均效益最大化为目标，兼顾有轨电车晚点情况、能耗与乘坐舒适性、其它社会车辆交通效益等因素，为有轨电车提供单点实时条件优先控制。为有轨电车提供时间优先权的同时不对背景车流产生较大的影响。优先方法包括有轨电车绿灯延长、红灯缩短、相位插入。
研究了有轨电车离线协调优先控制方法。以交叉口背景车流绿波带宽最大为控制目标，约束条件包含有轨电车绿波带宽要求。若控制方案不能满足有轨电车绿波带宽要求，则将控制目标改为有轨电车绿波带宽最大，重新进行求解。最后，论文在离线协调控制方法的基础上，提出了在线微调可采用的方法：单点优先与离线协调控制相结合、有轨电车动态驻站与速度引导控制相结合。
关键词：现代有轨电车，信号优先控制，控制参数，单点优先控制，协调控制
英文摘要
ABSTRACT
It has been the common sense that we should develop public transit system now, and the modern streetcar is back to the city transportation system again after a hundred years. Modern street is a kind of rail transit, it is popular in the cities of Europe and America because of the characteristics such as high passenger capacity, good flexibility, environmental protective, ride comfortable, relative low cost and so on. The modern streetcar system has been introduced into Shanghai, Tianjin, Guangzhou cities in China, also has been in operation. Because of the different driving characteristics of modern streetcar compared with common bus, it will have the bad effect on the efficiency and safety of streetcar if we still use the common traffic signal control method. The transportation environment of China is also different from the one of Europe and America such as more bicycles, short instance between intersections and so on, so there exists the limitation of external traffic signal control system in Chinese cities. How to solve the problem of intersection signal control priority of streetcar based on the driving characteristics of the streetcar and transportation environment of China is an important issue.
This dissertation has a research on the signal control priority method of streetcar at the intersection based on the analysis of the driving characteristics of the streetcar and transportation environment of China. The main purpose of this dissertation is to provide priority at the intersection to streetcar by the means of traffic signal control to prove the service level of streetcar and consider the benefit of the background vehicles at the same time. The research is focused on the calculation of intersection signal control elements, isolated independent signal priority control of streetcar, coordinated signal priority control of streetcar.
First, the dissertation has an analysis of the driving characteristics of the streetcar and transportation environment of China, the relationship between it and signal control priority logistics and elements. Then this dissertation builds the map of driving characteristics and environment to the issues which were affected by it, defines the research object and contents, lay the foundation of the later research.
Then, the calculation method of the basic elements of intersection signal control is proposed which included amber time and inter green time. The method suggested considers both the driving characteristics and transportation environment of streetcar. On the basic of results above, the intersection cycle length calculation model is suggested. The objective function of the model is minimal of the vehicle delay of the intersection, short distance intersections, capacity, driving demand of streetcar are considered in the constraint conditions.
After that, the dissertation has a research on isolated independent control priority of streetcar. The model is based on the prediction of the arriving time window of streetcar, the objective is the maximum of passenger benefit, with the consideration of streetcar lateness, energy cost and ride comfortable, background vehicle benefit and so on. This model can provide the priority to streetcar and don’t affect the background vehicle significantly at the same time. The priority measure included streetcar green phase extension, red phase reduction and green phase insertion.
Then the outline coordinated signal priority control method of streetcar model is proposed. The objective function of the model is the maximum of green band widths of background vehicles with the constraint of the green band width of streetcar. If the control plan can’t satisfy the green band width of streetcar, the objective function will be modified to the maximum of green band width of streetcar, and the model will be solved again. Finally, two methods of online coordinated signal priority control way of streetcar are suggested on the basic of outline coordinated signal priority control: the combination of isolated independent signal priority control and outline coordinated signal priority control, the combination of dynamic streetcar holding control and speed guidance control.
Key Words:modern streetcar, signal priority control, control elements, isolated independent control, coordinated control
