Multi-agent model predictive control of signaling split in urban traffic networks

The operation of large dynamic systems such as urban traffic networks remains a challenge in control engineering to a great extent due to their sheer size, intrinsic complexity, and nonlinear behavior. Recently, control engineers have looked for unconventional means for modeling and control of complex dynamic systems, in particular the technology of multi-agent systems whose appeal stems from their composite nature, flexibility, and scalability. This paper contributes to this evolving technology by proposing a framework for multi-agent control of linear dynamic systems, which decomposes a centralized model predictive control problem into a network of coupled, but small sub-problems that are solved by the distributed agents. Theoretical results ensure convergence of the distributed iterations to a globally optimal solution. The framework is applied to the signaling split control of traffic networks. Experiments conducted with simulation software indicate that the multi-agent framework attains performance comparable to conventional control. The main advantages of the multi-agent framework are its graceful extension and localized reconfiguration, which require adjustments only in the control strategies of the agents in the vicinity.     

高速公路交通标志最小明视距离算法研究

文章基于认知心理学原理,结合人体工程学、交通安全和交通心理学知识,提出了高速公路交通标志最小明视距离算法,为高速公路交通标志最小明视距离的计算提供了量化手段。     

高速公路突发事件快速响应与决策平台构建

针对高速公路突发事件应急响应滞后、处置效率不高的问题,从突发事件的自动发现、影响评估、预案生成、资源配置、效果评估等多维角度进行系统全面的研究,推动建立跨区域跨部门应急联动救援机制。采用GIS地图技术、Electron框架技术等方法构建基于分布协作的高速公路重大突发事件快速响应与决策支持平台,实现对突发事件发现、响应、处置、救援及事后分析等环节的全流程管理,提升应急处置效能和效率。     

“互联网+”交通信号辅助优化机制探索

为优化城市道路交通信号控制方法,本文结合交通信号控制系统建设发展现状,分析当前各大城市交通信号控制系统普遍存在的问题,立足于互联网环境下的浮动车数据,提出基于互联网平台大数据的交通信号控制辅助优化机制。研究发现可利用互联网路口拥堵报警数据及时有效发现问题路口,利用路段拥堵指数及路口交通流参数变化趋势辅助评估配时方案的优化效果,并通过成都市应用实例证明该机制适用于当前交通控制场景需求,可有效辅助交通信号优化工作,是传统交通模式向真正智能交通模式过渡的阶梯。     

铁路清算分析系统模拟环境数据库性能的调整

在铁道部清算分析系统模拟环境中,根据其应用特点,针对其搭建、安装和运行数据库过程中的问题,对Oracle数据库性能进行调整并提出具体可行的措施.     

胶济线分散自律调度集中系统综合组网方案

主要介绍胶济线分散自律调度集中系统综合网络方案,重点描述分散自律调度集中广域网组网方案及利用GSM-R铁路专用全球移动通信系统解决分散自律调度集中系统无线通信相关问题.     

北京局集团公司铁路专用线发展对策探讨

铁路专用线作为大宗货物运输"最后一公里"的起讫点承担着铁路和企业的纽带作用.从专用线分布情况及专用线到发运量方面分析北京局集团公司专用线现状,阐述影响专用线发展的因素,研究提出专用线功能由"为企业服务"向"为社会服务"转变、利用市场机制优化专用线改扩建手续、引导企业完成专用线扩能改造、对无运量专用线进行分类管理、建设现...     

重点违法行为导致交通事故的数据分析

超速行驶、酒后驾驶、违法超车等重点交通违法行为是导致交通事故的主要原因,每年都造成大量的人员伤亡和财产损失．本文对近十年来上述重点违法行为所导致的交通事故的数据进行了系统的分析,对各种重点违法行为的特征和趋势进行了研究,并对不同驾龄、不同车型驾驶人的违法肇事规律进行了归纳．分析结果表明：上述重点违法行为每年导致的交通死亡人数占总死亡人数的40％,特别是超速行车导致死亡人数近年来大幅上升;同时,低驾龄驾驶员每年导致的事故死亡人数占总死亡人数的44％,而大客车驾驶人因上述违法行为导致的死亡人数是小客车的5.2倍,大货车是小货车的2．9倍．     

基于组件式GIS的道路交通安全管理集成系统

2004年以来,我国已有200多个城市编制了道路交通安全管理规划,规划涉及大量的数据搜集与处理,交通安全现状的分析与评价以及未来安全状况发展预测等内容,这些都要求有一个计算机软件系统辅助完成以提高规划的效率与科学程度。本文对国内外交通安全软件进行了分析,提出了集辅助规划、管理、研究于一体的道路交通安全管理集成软件系统的开发原则和开发阶段,设计了基于组件式GIS技术的系统开发的总体框架,并对系统数据库进行了重点研究和设计。     

Accounting for scale heterogeneity within and between pooled data sources

There is growing interest in incorporating both preference heterogeneity and scale heterogeneity in choice models, as a way of capturing an increasing number of sources of utility amongst a set of alternatives. The extension of mixed logit to incorporate scale heterogeneity in a generalised mixed logit (GMXL) model provides a way to accommodate these sources of influence, observed and unobserved. The small but growing number of applications of the GMXL model have parameterized scale heterogeneity as a single estimate; however it is often the case that analysts pool data from more than one source, be it revealed preference (RP) and stated preference (SP) sources, or multiple SP sources, inducing the potential for differences in the scale factor between the data sources. Existing practice has developed ways of accommodating scale differences between data sources by adopting a scale homogeneity assumption within each data source (e.g., the nested logit trick) that varies between data sources. This paper extends the state of the art by incorporating data-source specific scale differences in scale heterogeneity setting across pooled RP and SP data set. An example of choice amongst RP and SP transport modes (including two ‘new’ SP modes) is used to obtain values of travel time savings that vary significantly between a model that accounts for scale heterogeneity differences within pooled RP and SP data, and the other where differences in scale heterogeneity is also accommodated between RP and SP data.