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1.
基于应急疏散交通特征的车辆跟驰模型 总被引：1，自引：0，他引：1
提出了一个应急交通疏散车辆跟驰模型（EECM）,模型首次在车辆最小安全间距的动力学推导过程中纳入驾驶员心理行为影响因素,使得跟驰过程更客观地反映在紧急疏散状态下的交通流和疏散驾驶行为特性．通过文献研究分析传统跟驰理论与应急交通疏散跟驰特性的区别,并进一步进行驾驶员问卷调查对应急交通疏散条件下的驾驶心理行为特性进行统计分析,提炼出驾驶员行为差异分布系数和经验判断系数2个参数,并将其纳入车辆安全间距的动力学推导过程,建立了基于驾驶行为特性和最小安全间距的应急交通疏散车辆跟驰模型,应用GPS技术对北京东三环劲松路段高峰小时交通流跟驰数据,对EECM进行了比较验证,结论有力地支持了EECM模型及问卷量化分析的合理性． 相似文献
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INTRODUCTION For the past few decades, many researchers have made studies of modelling driver behavior to repro- duce the observed features of traffic flow. Recently Kerner and Rehborn (1997) observed that there are three distinct dynamic phases on highways: free traf- fic flow, coexisting traffic flow and traffic jams. The occurrence of traffic jams without obvious reasons had been explained in terms of the conventional phase transition (Nagatani, 1998). Various traffic flow models, suc… 相似文献
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The Car-following models is a kind of microscopic simulation model for vehicular traffic, which describe the one-by-one following
behaviors of vehicles in the same traffic lane. As a common traffic phenomenon, following behavior is of great importance
in the micro-study of intelligent traffic control. Compared with other traffic-flow models, car-following model embodies the
human factors and reflects the real traffic situation in a better way. This paper gives a systematic review of the development
and actuality of car-following models by introducing and analyzing in detail the advantages and disadvantages of GHR model,
OV model, CA model and fuzzy-logic model. In addition, local stability and asymptotic stability of car-following models are
discussed in this paper. 相似文献
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For automated vehicles,comfortable driving will improve passengers’ satisfaction.Reducing fuel consumption brings economic profits for car owners,decreases the impact on the environment and increases energy sustainability.In addition to comfort and fuel-economy,automated vehicles also have the basic requirements of safety and car-following.For this purpose,an adaptive cruise control (ACC) algorithm with multi-objectives is proposed based on a model predictive control (MPC) framework.In the proposed ACC algorithm,safety is guaranteed by constraining the inter-distance within a safe range; the requirements of comfort and car-following are considered to be the performance criteria and some optimal reference trajectories are introduced to increase fuel-economy.The performances of the proposed ACC algorithm are simulated and analyzed in five representative traffic scenarios and multiple experiments.The results show that not only are safety and car-following objectives satisfied,but also driving comfort and fuel-economy are improved significantly. 相似文献
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This paper focuses mainly on the stability analysis of two-lane traffic flow with lateral friction, which may be caused by irregular driving behavior or poorly visible road markings, and also attempts to reveal the formation mechanism of traffic jams. Firstly, a two-lane optimal velocity (OV) model without control signals is proposed and its stability condition is obtained from the viewpoint of control theory. Then delayed-feedback control signals composed of distance headway information from both lanes are added to each vehicle and a vehicular control system is designed to suppress the traffic jams. Lane change behaviors are also incorporated into the two-lane OV model and the corresponding information about distance headway and feedback signals is revised. Finally, the results of numerical experiments are shown to verify that when the stability condition is not met, the position disturbances and resulting lane change behaviors do indeed deteriorate traffic performance and cause serious traffic jams. However, once the proper delayed-feedback control signals are implemented, the traffic jams can be suppressed efficiently. 相似文献
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In this paper, a prediction model is developed that combines a Gaussian mixture model (GMM) and a Kalman filter for online forecasting of traffic safety on expressways. Raw time-to-collision (TTC) samples are divided into two categories: those representing vehicles in risky situations and those in safe situations. Then, the GMM is used to model the bimodal distribution of the TTC samples, and the maximum likelihood (ML) estimation parameters of the TTC distribution are obtained using the expectation-maximization (EM) algorithm. We propose a new traffic safety indicator, named the proportion of exposure to traffic conflicts (PETTC), for assessing the risk and predicting the safety of expressway traffic. A Kalman filter is applied to forecast the short-term safety indicator, PETTC, and solves the online safety prediction problem. A dataset collected from four different expressway locations is used for performance estimation. The test results demonstrate the precision and robustness of the prediction model under different traffic conditions and using different datasets. These results could help decision-makers to improve their online traffic safety forecasting and enable the optimal operation of expressway traffic management systems. 相似文献
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刘炳全 《渭南师范学院学报》2012,(2):41-43
以UE均衡分配为前提,根据个别路段出现突发性交通堵塞的程度来发布诱导信息,并以此为依据分析出行者新的路径选择行为,从而建立路径流量转移模型,通过堵塞路径的流量转移来获取最优的交通分配新模式. 相似文献
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为研究混合非机动车道上快速行驶的电动自行车想要超越前方低速行驶车辆而进行鸣笛换道的现象,在分析经典Nasch模型的基础上,运用元胞自动机理论提出一种混合非机动车换道模型。首先,将混合非机动车换道过程分为两部分,即换道需求分析与换道操作过程|其次,在换道过程中引入鸣笛效应的概念,通过对基本换道模型的改进,建立混合非机动车的一般换道与鸣笛换道模型,并给出相应换道规则|最后,在改变交通流密度的情况下,对两种不同换道模型进行仿真对比分析。结果表明,当交通密度较低或较高时,鸣笛换道模型与一般换道模型得到的车辆平均速度及交通量几乎没有差别,但在中等密度范围内,鸣笛换道模型得到的车辆平均速度及交通量明显高于一般换道模型。说明在中等密度范围内,鸣笛换道行为有利于提高道路通行效率,但当密度较低或较高时,鸣笛换道行为对提高道路通行效率几乎不起作用。 相似文献
9.
通过对城市单交叉路口进行交通流分析,提出以车辆平均延误为性能指标的4相位交通信号控制模型,并将改进的遗传算法应用于此模型。在Matlab 7.0环境下对实际交叉路口中较为复杂的4相位控制方式下轻度、中度和重度交通流模式进行仿真。结果表明,该方案优于普通的遗传算法和传统的定时控制。 相似文献
10.
城市道路间断交通流综合拥挤指标分析(英文) 总被引：1，自引：0，他引：1
为了研究城市道路间断交通流的交通拥堵特性,提出了一种综合评价方法.首先,采用相关分析的方法研究了调查所得的间断交通流参数之间的关系,并将交通流参数分为基础参数和运行参数2类,进而采用多项式回归的方法拟合了运行参数与基础参数的非线性关系.然后,提出了一个综合考虑运行特性和流量特性的综合拥挤模型,该模型以基础参数为输入,0~1之间的无量纲拥挤度值为输出.最后,通过实例分析,对提出的综合评价方法和现有拥挤评价方法进行了对比.结果表明,相比现有评价方法,所提出的评价指标能够同时表征运行参数和基础参数的变化对交通拥挤的影响,能够更加均衡地评价交通拥堵. 相似文献
11.
用神经网络方法对高速公路交通流控制模型中的参数进行辨识 总被引：11，自引：1，他引：11
从高速公路交通流的宏观、动态特征出发，首先给出了交通流控制和仿真中常用的宏观、动态、确定性交通流模型，并利用神经网络的方法对模型中的参数进行辨识．从而获得能比较准确描述交通流真实行为的模型，以此来解决高速公路交通的最优控制问题． 相似文献
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13.
Optimal velocity functions for car-following models 总被引：1，自引：0，他引：1
The integral part of the optimal velocity car-following models is the optimal velocity function （OVF）, which can be derived from measured velocity-spacing data. This paper discusses several characteristics of the OVF and presents regression analysis on two classical datasets, the Lincoln and Holland tunnels, with different possible OVFs. The numerical simulation of the formation of traffic congestion is conducted with three different heuristic OVFs, demonstrating that these functions give results similar to those of the famous Bando OVF （Bando et al., 1995）. Also an alternative method is present for determining the sensitivity and model parameters based on a single car driving to a fixed barrier. 相似文献
14.
通过对交叉路口交通流到达和排队延误规律的研究,提出了一种新的交通信号控制理论,并建立了以PI值最小为目标的交通信号配时优化理论模型。该信号配时方法与通常采用的单点自适应信号控制方法的区别在于不但考虑了交通延误,而且考虑了停车次数,实现了对交通延误和停车次数两指标的优化,从而保证了以车队形式到达的交通流可以不间断地通过交叉路口。由于以实时交通流的到达规律为依据进行信号优化配时,因此,该信号配时优化模型又是实时自适应交通信号控制优化模型。 相似文献
15.
为改进小波神经网络模型对短时交通流的预测效果,提出一种基于改进混合蛙跳算法的短时交通流预测模型用以优化小波神经网络。该算法使用交叉分组法对子群进行划分,再利用具有自适应因子的局部搜索策略平衡混合蛙跳算法局部与全局搜索能力,最后把得到的最优解用于优化小波神经网络模型初始值,并对短时交通流进行预测。实验结果表明,该方法对短时交通流预测精确度达到97.43%,比传统方法提高1.016 1%,均方根误差比传统方法降低了5.587 9%,具有较高的应用价值。 相似文献
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基于有效载荷大小的早期网络流量识别(英文) 总被引：1，自引：0，他引：1
为快速将网络应用的流量进行分类,以AucklandⅡ和UNIBS两个数据集的网络流量包为研究对象,选取网络应用程序流量中最初的8个有效载荷大小作为识别特征进行研究.由于这类特征可在早期流量阶段快速提取,因此效果显著.通过将早期载荷大小可视化的方式,分析了不同网络应用的行为模式.分析结果表明,多数网络应用程序可通过早期有效载荷大小显示出它们特有的行为模式,根据早期有效载荷大小的信息可对流量进行有效识别.在此基础上,选用3种典型的机器学习分类器,即朴素的贝叶斯分类器、朴素的贝叶斯树和径向基函数神经网络进行验证分析.实验结果显示,早期有效载荷大小可作为特征对流量进行有效识别. 相似文献
18.
冯苏苇 《上海大学学报(英文版)》2005,9(1):1-5
Based on two main hypotheses of traffic economical equilibrium and the relationship between traffic density and the demand, an evolution equation of traffic cost was proposed to describe the change of cost under decreasing toll. Economical explanation of the model and a numerical case were given to demonstrate the constraint between the marginal traffic demand and the flow velocity. 相似文献
19.
一种改进的交通流元胞自动机模型 总被引：1，自引：0，他引：1
A modified cellular automaton model for traffic flow was proposed. A novel concept about the changeable security gap was introduced and a parameter related to the variable security gap was determined. The fundamental diagram obtained by simulation shows that the maximum flow more approaches to the observed data than that of the NaSch model, indicating that the presented model is more reasonable and realistic. 相似文献
20.
INTRODUCTION Damage detection of structures is very importantfor ensuring and evaluating the safety of structuresystems during their lifetime. The approaches de-veloped in this field may be generally classified intodynamic identification approach using dynamic testdata and static identification approach using static testdata (Wang et al., 2001). The dynamic identificationapproach has been highly developed, although severalinherent drawbacks and problems handicap the fullutilization o… 相似文献