交通事件下快速路网匝道控制与路线诱导的集成控制

本文建立了交通事件影响下匝道控制与路线诱导相结合的完全集成控制模型,即建立了一个以节点分流比例与匝道调节率为控制变量的非线性最优控制模型,模型中考虑了突发交通事件后快速路的交通特点,基于粒子群算法设计了模型的求解算法.以一个简单的小型路网为例,讨论了突发事件后采用不同控制策略对系统的全局影响,仿真表明,匝道控制与路线诱导相结合的集成控制有效地降低了事件的影响.     

高速公路网入口流量控制的双层规划模型及算法

建立双层规划模型用于解决高速公路网的入口流量控制问题。提出了一种结合遗传算法和Aloplex算法的新算法——GAA算法来求解双层规划问题。实验结果表示，GAA算法在求解双层规划问题上优于遗传算法；分车型测算得出进入路网的流量使上层目标函数值更小（相对于单车型情况），并且使路网利用程度得到进一步的提高。     

基于多agent和分层递阶结构的城市快速路网多模控制*

提出了基于多agent和分层递阶智能结构的城市快速路网多模控制策略。执行级agent采用单点积分反馈控制策略,协调级agent采用多匝道协调控制策略,组织级agent采用路线诱导与匝道控制相集成的控制策略。仿真表明,多模控制能灵活有效地适应路网中各种状况的实时变化,控制效果良好。     

城市过饱和路网的偏好多目标相容优化控制

针对城市过饱和路网的交通信号控制问题,提出将总延误分为主线路段延误和次线路段延误的划分方法,将控制问题描述为冲突的多目标控制。针对冲突多目标控制问题中最优解不唯一,而传统优化方法中一次运行只能得到一个最优解的问题,提出了一种基于偏好的相容优化控制算法：利用偏好信息动态指引寻优的方向,在偏好区域内获得更多有价值的解;提出基于偏好的目标选择函数,保证控制解在偏好区域内的稳定性。在仿真环境中对一个11个交叉口的城市过饱和路网进行实时控制,结果表明,提出的偏好相容控制算法的效果优于定时控制方案。     

基于遗传算法的城市混合型路网优化设计研究

城市路网设计问题就是研究如何用定量的方法在已有交通网络上添加或扩容某些路段的问题。本文提出一种基于遗传算法的城市混合型路网设计的双层优化模型,可求出最优的用于道路网新建或改善的交通建设投资决策方案,并利用一个算例进行仿真试验,结果表明,该模型和算法是可行的,可为城市路网设计提供借鉴。     

城市快速路交通诱导和匝道控制集成仿真模型

为缓解城市快速道路网络交通网络拥挤问题,将网络交通流模型、匝道控制模型、基于可变信息标志（VMS）的路径选择模型等整合为一体,建立了城市快速路交通诱导和匝道控制集成仿真模型。与各种边界条件相结合,测试了匝道控制和路径诱导的控制效果。结果表明城市快速路集成控制方法有助于在空间和时间上均衡交通负荷,提高交通系统整体运行效率。     

多目标规划模型的研究

优化问题是数学建模中的一类大问题,在历年全国大学生数学建模竞赛赛题中几乎离不开优化方法。多目标规划是大规模优化问题中最常见的一种,在现实的决策过程中,决策者面临的往往是一些具有多个目标的决策问题。多目标规划恰恰就是解决这类问题的理想方法,因而有着广泛的应用前景。本文从多目标规划的意义,发展现状,研究内容,技术难点,关键技术,研究方法,市场前景及社会效益等方面进行论述,使多目标规划模型在应用上更具有普遍性。     

城市路网和快速公路交通流的分散协调控制

利用模糊理论对城市路网和快速公路交通进行实时分散协调控制。把路网和快速公路作为一个大系统,子系统为路网中的各个交叉口,每个子系统有一个控制器,该控制器根据它自己和相邻子系统的交通流信息来动态管理绿灯相位及绿灯时间。控制器有三个模块组成：相序选择模块,绿灯判断模块和相位切换模块。控制器的控制目标是保持快速公路主线密度均衡和路网内各车辆平均延误时间最短。仿真研究表明该方法控制效果较好。     

基于免疫算法的多匝道MF-AILC控制方法

针对高速公路交通系统的重复性和周期性,提出基于免疫算法的高速公路多匝道无模型自适应迭代学习控制（MF—AILC）联合协调控制,以高速公路最大流量、全局最小行程时间和入口平均等待时间三者为目标函数,用免疫算法对多匝道协调迭代学习控制器进行优化。仿真结果表明,与无控制情况下进行比较,该控制方法具有良好的控制效果和较强的鲁棒性。     

基于信号控制的城市路网旅行时间计算模型

交通控制信号对交通流的影响是干扰实时交通数据计算准确性的重要因素。为此,提出一种基于信号控制的城市路网旅行时间计算模型。将城市道路的旅行时间分为2个部分,即路链有效旅行时间和路口延误时间,设计改进的信号控制延误模型用于计算路口延误时长,并给出路链合并算法。实验结果表明,该模型起点到终点的旅行时间误差率能降低5%~15%。     

基于蚁群算法的城市快速路优化控制

根据城市快速路交通流的特性,以宏观稳态交通流Macro模型为基础,将快速路虚拟划分为多个路段,将车辆在快速路系统内总的服务流量最大及入口匝道车辆平均等待时间最小作为优化控制目标,设计快速路多匝道联合控制模型,并采用蚁群优化算法对设计的控制模型进行求解计算,以确定各匝道最优调节率。模拟实验结果表明,通过多匝道联合控制,能够提高城市快速路系统的运行效率,减少交通事故及交通拥堵的发生概率。     

Distributed Model Predictive Control Method for Optimal Coordination of Signal Splits in Urban Traffic Networks

Coordination and control approaches based on model predictive control (MPC) have been widely investigated for traffic signal control in urban traffic networks. However, due to the complex non‐linear characters of traffic flows and the large scale of traffic networks, a basic challenge faced by these approaches is the high online computational complexity. In this paper, to reduce the computational complexity and improve the applicability of traffic signal control approaches based on MPC in practice, we propose a distributed MPC approach (DCA‐MPC) to coordinate and optimize the signal splits. Instead of describing the dynamics of traffic flow within each link of the traffic network with a simplified linear model, we present an improved nonlinear traffic model. Based on the nonlinear model, an MPC optimization framework for the signal splits control is developed, whereby the interactions between subsystems are accurately modeled by employing two interconnecting constraints. In addition, by designing a novel dual decomposition strategy, a distributed coordination algorithm is proposed. Finally, with a benchmark traffic network, experimental results are given to illustrate the effectiveness of the proposed method.     

工业控制网络安全模型研究

为了减少产品费用和提高生产效率,更多的专用网络被连入IT网络,或更多的IT技术被应用到工业控制网络系统中,网络安全成为一个重要的问题。工业控制网络系统作为国家基础设施的重要组成,一旦受到攻击和破坏,其影响将是灾难性的。因此,保护工业控制网络系统的安全、防御各种攻击和破坏是关系到国家安全的重要内容。本论文结合中国第一个工业以太网标准《用于测量与控制系统的EPA通信标准》,建立了一般的工业控制网络体系结构,研究分析了它的安全威胁,提出工业控制网络的安全要求,构建了基于区域安全的DMZ模型,最后用UML描述了该模型。     

Cost Effective Smart System for Water Pollution Control with Underwater Wireless Sensor Networks: A Simulation Study

The underwater sensor network is a rapidly developing area of research with a wide range of applications such as data collection in the ocean, pollution monitoring, and ocean sampling. One of the most researched areas is the coverage of underwater sensor networks, which are the basis of many applications. The coverage is usually related to how effectively a network is monitored by the sensor. There are major problems in the ocean or marine region, especially in water pollution. Underwater pollution generally causes acidification, plastic residues, and toxins. Today, the determination of this pollution is carried out through a human surveillance monitoring process. Therefore, there is a need for an automatic and intelligent monitoring system to identify the formation of pollution. The proposed simulation model defines the intelligent sensor-based monitoring system that identifies and alarms the formation of underwater pollution. Aloha was chosen as the medium access protocol for the cost-effective system in which we designed the simulation model. The efficiency of the system has been shown to be more stable, cost-effective and manageable than the monitoring process involving the existing human surveillance by testing with the simulation model.     

城市高速公路交通的神经网络建模与控制

从城市高速公路交通流的宏观、动态特性出发 ,分析了交通流控制中常用的宏观、动态、确定性模型 在此基础上 ,利用人工神经网络技术建立了城市高速公路的神经网络模型 ,并提出了入口匝道放行和路段速度相结合的多变量神经网络控制策略 利用该控制策略建立的自适应神经网络控制器 ,可以使高速公路上的交通密度维持在理想的密度值附近 .进一步分析可以得到 ,该控制器是一个状态和控制作用均可跟踪的伺服系统 .以杭州某高架高速公路为背景的仿真结果表明 :该控制器具有较强的鲁帮性 ,控制效果令人满意 .     

城市交通网络正系统模型与稳态信号控制

城市路网内车流分布不均衡为交通拥堵原因之一,且交通控制系统为典型正系统．为此,本文采用Compartment正系统对网络交通流演化建模,以网络均衡为控制目标,提出稳态信号控制方法．首先,建立网络交通流Compartment正系统模型,可描述具有任意控制结构网络的过饱和特征;进一步,给定网络车流输入,由非负矩阵理论可得网络存在唯一稳定平衡点,给出平衡点解析计算公式．由此,提出网络稳态信号控制律,为路段状态反馈控制律．最后,以北京市奥林匹克公园区域拓扑路网为例,在VISSIM软件中建立仿真环境,比较稳态信号控制方法与定时控制方法,仿真结果表明在高需求网络条件下,稳态信号控制方法可改善网络整体性能和缓解局部拥堵．     

基于模糊神经网络的模型参考自适应控制

用模糊神经网络作为控制器,依靠参考模型产生理想的控制系统闭环响应,从而随时得到控制系统的输出误差.用梯度法实时修正模糊控制器的输入和输出隶属度参数,得到一种在线模糊自适应控制的新方法.通过倒立摆的仿真实验表明,该方法是可行的并能适应对象特性的大范围变化.     

Autonomous Vehicle Platoons In Urban Road Networks: A Joint Distributed Reinforcement Learning and Model Predictive Control Approach

In this paper, platoons of autonomous vehicles operating in urban road networks are considered. From a methodological point of view, the problem of interest consists of formally characterizing vehicle state trajectory tubes by means of routing decisions complying with traffic congestion criteria. To this end, a novel distributed control architecture is conceived by taking advantage of two methodologies: deep reinforcement learning and model predictive control. On one hand, the routing decisions are obtained by using a distributed reinforcement learning algorithm that exploits available traffic data at each road junction. On the other hand, a bank of model predictive controllers is in charge of computing the more adequate control action for each involved vehicle. Such tasks are here combined into a single framework: the deep reinforcement learning output (action) is translated into a set-point to be tracked by the model predictive controller; conversely, the current vehicle position, resulting from the application of the control move, is exploited by the deep reinforcement learning unit for improving its reliability. The main novelty of the proposed solution lies in its hybrid nature: on one hand it fully exploits deep reinforcement learning capabilities for decision-making purposes; on the other hand, time-varying hard constraints are always satisfied during the dynamical platoon evolution imposed by the computed routing decisions. To efficiently evaluate the performance of the proposed control architecture, a co-design procedure, involving the SUMO and MATLAB platforms, is implemented so that complex operating environments can be used, and the information coming from road maps (links, junctions, obstacles, semaphores, etc.) and vehicle state trajectories can be shared and exchanged. Finally by considering as operating scenario a real entire city block and a platoon of eleven vehicles described by double-integrator models, several simulations have been performed with the aim to put in light the main features of the proposed approach. Moreover, it is important to underline that in different operating scenarios the proposed reinforcement learning scheme is capable of significantly reducing traffic congestion phenomena when compared with well-reputed competitors.