【作者】 魏巍；

【导师】 曲昭伟；

【作者基本信息】 吉林大学 ， 交通信息工程及控制， 2019， 博士

【摘要】 在城市道路路段及交叉口范围内,行人过街时往往会伴随着与机动车和非机动车等交通工具争夺时空资源的现象发生。长期以来,我国的交通规划重视机动车而忽略包括步行等其他交通方式的思想根深蒂固。近年来,一部分城市开始重新重视行人交通,将城市交通资源向其倾斜,布设相对完善的交通设施。根据我国相关法律的要求,城市道路上通行的机动车应当让行更弱势的行人。但是现实情况却与理想相去甚远,由于行人违规横穿马路以及机动车不礼让行人等现象的发生,导致行人与机动车为主的其他交通方式并未从时间、空间上彻底分离,过街行人的安全依然没有得到足够的保障。因此,有必要针对我国复杂的交通环境,在深入分析行人交通特性的基础上,结合机动车运行情况,建立能够提高行人过街效率,减少行人等待时间的行人过街信号优化控制方法,并设计实现能够集成上述功能的软件系统。论文主要包括两个方面:控制方法研究和系统实现。控制方法研究是系统实现的理论基础,系统实现是控制方法的实际应用。控制研究主要包括基于视频的行人数量估计方法、行人交通特性分析与建模和行人优化控制研究三部分。通过对包含不同交通情况的视频图像进行处理,去除可能外界干扰。之后利用图像特征间的因果关系建立贝叶斯网,并根据贝叶斯网进行行人数量的推理,最终得到较为准确的行人数量检测值。而后主要针对包括行人过街的速度特性、心理特性(等待时间)、人群过街轨迹的时空特性、人群的密度特性以及过街时双向行人的阻滞特性等行人群进行研究。同时,基于之前得到的行人数量检测值,建立行人过街时间与行人数量的关系模型,为信号优化控制方法的研究提供理论依据。基于路段行人过街特征的相位模型构建,提出了定时控制和协调控制两种针对不同交通环境的行人人群过街控制系统。路段行人过街的定时控制系统和路段与交叉口信号协调的行人过街系统,并结合实际交叉口与路段的交通环境给出相应的案例分析。从时间资源的角度分析,根据相邻路口的不同交通状态对行人的通行相位进行联动优化,结合行人检测算法,建立了路段行人过街优化模型,判断上下游协调相位的绿波带给出行人过街相位时长。从空间资源的角度分析,针对某些地点的人行横道较长,为了保证行人人群安全通过路段条件下,对较长的人行横道设置行人安全岛。采取二次过街的方式,并对设置分段通过路段后的人行横道相位与相邻交叉口进行联动优化控制,实现路段人行横道设置相位期间延误最低。并通过VISSIM仿真软件和COM接口搭建行人过街模型进行对比,证明了控制方法的有效性。在系统实现方面主要通过软件及硬件设计集成待过街行人检测设备。其中软件部分为待过街行人视频检测设备算法和行人过街时间算法的嵌入式软件。硬件部分从图像处理系统、视频采集系统、视频输出系统、通讯系统、片设内存芯片和电源设计六个方面分别阐释了具体的芯片选取和相关电路设计。综上所述,论文通过基于行人视频的过街优化控制方法的研究,首先设计了可以较为准确估计过街行人数量的视频检测设备;其次,基于估计得到的过街行人数建立了过街特性与行人数量的关系模型;最后,提出了针对不同的交通情况设计了定时控制与协调控制两种优化配时方案,并通过仿真的方法证明了优化控制方法的有效性。更多还原

【Abstract】 In urban road sections and intersections,pedestrian crossings are often accompanied by the competition for time and space resources with other transports such as motor vehicles and non-motor vehicles.For many years,in urban transportation planning of China,the thought of emphasizing motor vehicles and ignoring non-motor vehicles,including walking and other modes of transport,has been deeply rooted.In recent years,some cities have paid more attention to pedestrian traffic.Some design agencies are starting to tilt more resources for pedestrians.According to the requirements of relevant laws of China,the motor vehicles should yield to the vulnerable pedestrians.But the situation is still pessimistic,the safety of pedestrians crossing on the street is not guaranteed.Large amount of disorder walkers and vehicles conflicts together that is caused by the uncivilized behaviors.These include scrambling for roads,jaywalk,nonobservance of traffic lights and other behaviors of walkers.Therefore,to increase operation efficiency and reduce waiting time of pedestrians,it is necessary to establish a pedestrian crossing signal optimization control method for the complex traffic environment in China,which based on the comprehensive study of pedestrian traffic characteristics and the operation of motor vehicles.The design implements a software system that integrates the above functions.This paper mainly includes two aspects: control method research and system implementation.Control method research is the theoretical basis of system implementation.On the other hand,system implementation is the practical application of control method.The experimental results show that the theoretical research is correct.The research of control method mainly includes three parts: Pedestrian Count Estimation Method;pedestrian traffic characteristics analysis and modeling and study on pedestrian optimal control.To reduce the possible external disturbance,video images containing different traffic conditions are processed.After this,based on using the causality between image features,a Bayesian network is established to infer the number of pedestrians,and finally a more accurate detection value of pedestrians is obtained.Then it mainly studies the pedestrian traffic characteristics,including the speed characteristics,psychological characteristics(waiting time),space-time characteristics of pedestrian trajectories,the density characteristics of the crowd and the retardation effect of two-way pedestrians crossing the street.At the same time,based on the previous pedestrian detection values,the relationship model between pedestrian crossing time and pedestrian number is established,which provides a theoretical basis for the study of signal optimization control method.Based on the phase model of pedestrian crossing characteristics,two pedestrian crossing control systems,timing control method for road section and coordinated control method for section to intersections,are proposed for different traffic environments,with the corresponding case analysis of actual traffic environment of intersections and sections.From the aspect of time resources,according to the different traffic conditions of adjacent intersections,coordinated control method of pedestrian phase is carried out.Combining with pedestrian detection algorithm,an optimization model of pedestrian crossing is established to determine the length of green wave of upstream and downstream coordinated phase and pedestrian crossing phase.From the aspect of space resources,in order to ensure the safety of pedestrians passing through the wide section,the pedestrian safety island is set up on the long pedestrian crossing to achieve twice crossing.The coordinated optimal control of the first crosswalk and adjacent intersections achieve the minimum delay.By comparing different pedestrian crossing models with VISSIM simulation software and COM interface,the effectiveness of the proposed control method is proved.In the aspect of system implementation,the pedestrian detection equipment is integrated through software and hardware design.The software part is embedded software for the algorithm of pedestrian video detection equipment and pedestrian crossing time algorithm.The hardware part includes six parts: image processing system,video acquisition system,video output system,communication system,chip memory chip and power supply design.All parts have specific chip selection and circuit design.The major tentative conclusions of this study can be summarized as follows:(1)a video detection device which can accurately estimate the number of pedestrians crossing the street is designed.(2)Based on the estimated number of pedestrians,a relationship model between the characteristics of pedestrians and the number of pedestrians is established.(3)For different traffic situations,two optimizing timing schemes,timing control method and coordinated control method,are proposed.The effectiveness of the optimal timing control method is proved by simulation.更多还原