共查询到20条相似文献,搜索用时 93 毫秒
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在Nagel-Schreckenberg(NS)模型的基础上,提出一种可应用智能交通系统(ITS)信息的新的交通流元胞自动机模型. 其中考虑了有效间距及刹车灯的作用,并引入了可变安全间距的新概念. 数值模拟表明:对于这种改进的ITS元胞自动机模型,道路交通量有了显著提高,体现了智能交通的优越性——有效地扩大交通流量,减少阻塞生成. 当考虑快车和慢车的混合交通流时,发现即使少量的慢车也会导致交通流量大幅度下降,说明了严格实施快慢道行驶的必要性.
关键词:
交通流
智能交通系统(ITS)
元胞自动机模型
刹车灯
可变安全间距 相似文献
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在分析应急车辆对城市道路交通流影响的基础上, 引入让行状态参数、警笛影响区域和强制换道安全距离等特征变量, 修改换道规则, 建立了多车道元胞自动机模型, 并进行数值模拟. 结果表明, 车道数量和混合车辆比例系数在低密度范围内影响车辆速度及换道次数, 警笛影响区域参数改变了一定范围内车辆的换道次数, 应急车辆强制换道安全距离参数主要影响应急车辆的速度及换道次数.研究发现, 应急车辆对低密度交通流的扰动现象明显, 其与社会车辆相互作用参数的设置使得交通流元胞自动机模型更接近应急条件下实际交通运行.
关键词:
交通流
元胞自动机
应急车辆 相似文献
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在一种改进的Nagel-Schrekenberg元胞自动机交通流模型的基础上,提出一个高速公路双车 道元胞自动机模型来模拟开放性边界条件下的车流运动,并考虑两车道之间左边界开放程度 的比例系数α及车辆加减速概率p的影响.计算机数值模拟结果表明,在车流状态的演化过程 中,通过确定车道耦合系数b来控制车流量,不同的b值车流量不同,对车辆运动出现堵塞项 的相变点有影响.
关键词:
元胞自动机
交通流模型
耦合效应 相似文献
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在交通流NS模型的基础上,考虑混合车辆之间存在的速度差异,不同车辆的驾驶员在对前车的敏感驾驶随机减速行为过程中其延迟概率是不同的,从而提出了一维多速混合车辆敏感驾驶元胞自动机交通流模型. 通过计算机数值模拟得到了混合车辆在不同参数下的 基本图.结果表明,与NS模型、SDNS模型相比,道路交通流量有较大的提高,而且还展现出 了亚稳态、相分离等复杂的实际交通行为现象.结合实际情况,对混合交通的特性进行了分析和讨论.
关键词:
元胞自动机
混合交通流模型
亚稳态
相分离
计算机模 拟 相似文献
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本文以右转机动车和直行自行车为对象研究交叉口混合交通流特性.基于交叉口机非干扰特性,将机动车元胞模型和自行车元胞模型进行了耦合,建立了考虑自行车穿越机动车延时、机动车穿越自行车间隙和冲突区占据处置等规则的交叉口混合交通流元胞自动机模型(NS-BCA).对右转机动车与直行自行车混合交通流进行了仿真,从流量-车辆到达率关系、交通流相位相变、交通流相位-到达率-混合交通流状态等方面研究了交叉口混合交通流的机非干扰机理. 相似文献
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考虑两车道耦合效应的影响和换道效应,提出了改进的两车道交通流耦合格子模型.同时,改进了换道时的流量转移率,这样更符合实际交通情况.通过线性稳定性分析,得到了改进模型的稳定性条件.数值模拟结果也表明,模型通过考虑耦合作用信息,更好地再现了换道情况,同时也表明两车道间的耦合效应对两车道交通流存在不可忽视的影响. 相似文献
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Continuum modeling for two-lane traffic flow with consideration of the traffic interruption probability 下载免费PDF全文
Considering the effects that the probability of traffic interruption and the friction between two lanes have on the car-following behaviour,this paper establishes a new two-lane microscopic car-following model.Based on this microscopic model,a new macroscopic model was deduced by the relevance relation of microscopic and macroscopic scale parameters for the two-lane traffic flow.Terms related to lane change are added into the continuity equations and velocity dynamic equations to investigate the lane change rate.Numerical results verify that the proposed model can be efficiently used to reflect the effect of the probability of traffic interruption on the shock,rarefaction wave and lane change behaviour on two-lane freeways.The model has also been applied in reproducing some complex traffic phenomena caused by traffic accident interruption. 相似文献
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We study the fundamental diagram for traffic flow of vehicular mixture on a multi-lane highway. We present the car-following model of multi-lane traffic in which slow and fast vehicles flow with changing lanes. We investigate the traffic states of the vehicular mixture under the periodic boundary. Two values of the current appear at a density and two current curves are obtained. Vehicles move with changing lanes in the traffic state of high current, while vehicles move without changing lanes in the traffic state of low current. They depend on the density, the fraction of slow vehicles, and the initial condition. In the high-current curve, the jamming transition between the free flow and the jammed state occurs at a low density. The fundamental diagrams (current-density diagrams) are shown for the single-lane, two-lane, three-lane, and four-lane traffics. 相似文献
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This paper introduces a new two-lane high-order continuum model
by embedding the two delay time scales continuum traffic model presented by
Xue (2003 Phys. Rev. E 68 066123) into the multi-lane model proposed
by Daganzo (1997 Transpn. Res. B 31 83) with the consideration of
the coupling effect between the vehicles of two lanes in
instantaneous traffic situation and lane-change effect. In the novel model,
the coupling effect of two lanes and phenomena of lane change, which were
not discussed in Daganzo's model and Xue's model, are taken into account.
Numerical simulation shows that it is in accordance with real traffic flow.
This obviously indicates that the new phenomenon and behaviour are analogous
results as single lane presented by Xue, and the proposed model is more reasonable on
two lanes. Furthermore, the generation rate between two lanes is also
investigated. The results show that the formation and diffusion of traffic
shock wave can be better simulated on two lanes. 相似文献
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Analysis of the wave properties of a new two-lane continuum model with the coupling effect 下载免费PDF全文
A multilane extension of the single-lane anisotropic continuum model (GK model) developed by Gupta and Katiyar for traffic flow is discussed with the consideration of the coupling effect between the vehicles of different lanes in the instantaneous traffic situation and the lane-changing effect. The conditions for securing the linear stability of the new model are presented. The shock and the rarefaction waves, the local cluster effect and the phase transition are investigated through simulation experiments with the new model and are found to be consistent with the diverse nonlinear dynamical phenomena observed in a real traffic flow. The analysis also focuses on empirically observed two-lane phenomena, such as lane usage inversion and the density dependence of the number of lane changes. It is shown that single-lane dynamics can be extended to multilane cases without changing the basic properties of the single-lane model. The results show that the new multilane model is capable of explaining some particular traffic phenomena and is in accordance with real traffic flow. 相似文献
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In this paper, we propose a new two-lane cellular automata model in which the influence of the next-nearest neighbor vehicle is considered. The attributes of the traffic system composed of fast-lane and slow-lane are investigated by the new traffic model. The simulation results show that the proposed two-lane traffic model can reproduce some traffic phenomena observed in real traffic, and that maximum flux and critical density are close to the field measurements.Moreover, the initial density distribution of the fast-lane and slow-lane has much influence on the traffic flow states.With the ratio between the densities of slow lane and fast lane increasing the lane changing frequency increases, but maximum flux decreases. Finally, the influence of the sensitivity coefficients is discussed. 相似文献
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采用元胞自动机模型研究了具有信号灯控制的主道为双车道的入匝道系统交通流特性.将信号灯设置在入匝道口处,通过信号灯来引导主道和匝道上的车辆通行.分析了信号灯控制对主道与匝道的车流量、系统通行能力以及入匝道口处的车流平均速度的影响.通过相图比较,说明信号灯控制的双车道入匝道系统能模拟出比信号灯控制的单车道入匝道系统更加符合实际的交通流特性.与姜锐提出的模型[Jiang R 2003 J. Phys. A 36 11713]结果相比,信号灯控制下的匝道系统的交通流状态得到改善并且道路通行能力有所提
关键词:
交通流
元胞自动机
入匝道系统
信号灯 相似文献
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X. G. Li Z. Y. Gao B. Jia R. Jiang 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,54(3):385-391
Segregation effects commonly exist in granular mixtures
with difference in size, shape or density. In mixed traffic flow,
slow vehicle and fast vehicle, as two types of particles, have
different desired speed. We investigate the segregation along the
road in mixed traffic flow by using a symmetric two-lane cellular
automata model. A parameter D, which quantifies the degree of
segregation, is defined. We study the density dependency of the
parameter at different randomization probability. Simulation results
show that segregation is more obviously in free flow region. We
argue that the overtaking maneuvers have similar effect as
percolation in granular flow. 相似文献