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在一维元胞自动机交通流WWH模型和SDNaSch模型的基础上,建立了一种考虑驾驶员特性的元胞自动机交通流模型(Driver-SDNaSch模型).该模型将驾驶员分为激进型、保守型和中立型三类,根据其不同的驾驶特性制定了各自的演化规则,并以此对其进行状态更新;同时考虑了前车速度为0的情况,引入安全减速概率.通过计算机对Driver-SDNaSch模型进行模拟,给出了由三类驾驶员按不同比例组成的混合交通流的速度-密度图和流量-密度图,并对此类混合交通流的特性进行了分析和讨论.与NaSch模型和SDNaSch模
关键词:
交通流
元胞自动机
驾驶员特性
计算机数值模拟 相似文献
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在考虑自适应巡航(adaptive cruise control, ACC)车辆的交通流模型的基础上, 建立了考虑ACC车辆影响的上匝道系统混合交通流模型, 研究ACC车辆引入对上匝道交通系统交通流的影响. 为了描述ACC车辆和手动驾驶车辆在交通流运行中的差异, 分别构建了基于常车头时距原则的ACC 车辆跟驰子模型和手动驾驶车辆MCD元胞自动机子模型; 基于上匝道车辆合流驶入主线的需求, 建立了换道子模型, 引入了表征驾驶员换道心理的参数λ. 通过对混合交通流模型进行数值模拟发现, ACC车辆的混入可以有效改善上匝道系统交通流的运行, 降低合流等事件对于交通流运行的影响, 抑制交通拥堵的时空范围及拥堵强度, 提高交通流的平均速度和流量. 此外在混合交通流模型中, ACC车辆期望车头时距Hd的减小与换道心理参数λ 的增大均可以提高混合交通流运行的速度和流量, 而合流区长度lw对混合交通流影响则因上匝道车辆驶入概率的不同而存在差异. 相似文献
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基于智能交通诱导信息,提出一种改进的耦合映射跟驰模型,用于描述单车道的交通流动力学特性及其拥堵控制.利用反馈控制理论,给出了在头车速度发生变化时交通流保持稳定的条件.分析结果表明,考虑前方更多车辆的信息对交通流有致稳作用,亦即稳定性条件明显减弱.数值模拟证实了理论分析的正确性,通过与他人相关工作的比较得知,考虑智能交通诱导信息能够更有效地抑制交通拥堵.
关键词:
交通流
智能交通系统
耦合映射跟驰模型
交通拥堵控制 相似文献
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通过对现有换道模型进行改进,提出了一种考虑换道实施过程的模型,并对模型中的关键参数进行了标定.由于该模型考虑了换道实施过程中车辆换道对交通流的影响,新模型的模拟结果与实测值更为符合.运用新模型对不同车道数的道路交通流进行模拟,发现不同车道数的平均每车道通行能力及其交通流特性存在显著差异.
关键词:
换道模型
换道时间
车道数
道路通行能力 相似文献
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The optimal velocity model of traffic is extended to take
the relative velocity into account. The traffic behavior is investigated
numerically and analytically with this model. It is shown that the car
interaction with the relative velocity can effect the stability of the
traffic flow and raise critical density. The jamming transition between
the freely moving and jamming phases is investigated with the linear
stability analysis and nonlinear perturbation methods. The traffic jam is
described by the kink solution of the modified Korteweg--de Vries equation.
The theoretical result is in good agreement with the simulation. 相似文献
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The optimal velocity model of traffc is extended to take the relative velocity into account. The traffcbehavior is investigated numerically and analytically with this model. It is shown that the car interaction with therelative velocity can effect the stability of the traffic flow and raise critical density. The jamming transition between thefreely moving and jamming phases is investigated with the linear stability analysis and nonlinear perturbation methods.The traffic jam is described by the kink solution of the modified Korteweg-de Vries equation. The theoretical result isin good agreement with the simulation. 相似文献
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In this paper, the optimal velocity model of traffic is extended to take into account the relative velocity. The stability and density waves for traffic flow are investigated analytically with the perturbation method. The stability criterion is derived by the linear stability analysis. It is shown that the triangular shock wave, soliton wave and kink wave appear respectively in our model for density waves in the three regions: stable, metastable and unstable regions. These correspond to the solutions of the Burgers equation, Korteweg-de Vries equation and modified Korteweg-de Vries equation. The analytical results are confirmed to be in good agreement with those of numerical simulation. All the results indicate that the interaction of a car with relative velocity can affect the stability of the traffic flow and raise critical density. 相似文献
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从研究微观个体车辆行为出发,考虑车辆加速过程的不确定性,提出了随机计及相对速度的 交通流跟驰模型(SR-OV模型).对随机相对速度的跟驰模型的动力学方程进行稳定性分析,得 到与Bando跟驰模型不同的稳定性判据,其稳定性优于Bando模型.运用摄动理论分析交通过 程中密度波的变化,结果表明,在发生交通阻塞相变时,交通密度波以mKdV方程描述的扭结 -反扭结波演化.对随机相对速度跟驰模型进行数值模拟和分析,结果发现车流速度的变化小 于Bando模型的速度变化,而且与随机概率有关,当随机考虑相对速度的概率增大时,初始 的小扰动不会放大对车流产生影响,甚至长时间就消失,这与Bando模型完全不同.数值模拟 所得到的相图与解析解相符合,而且交通流稳定区域大于Bando模型.从车间距-速度演化图上 ,随着随机概率的增大,SR-OV模型在初始时存在的滞后现象,随着时间的增长,趋于稳定 状态后,滞后曲线收敛于一小区域,滞后效应被削弱.这完全不同于Bando模型,在Bando模 型中,滞后曲线由一点向外扩散,滞后曲线区域越来越大,车流趋于不稳定状态.
关键词:
交通流
跟驰模型
稳定性判据
相对速度 相似文献
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Usually there are multi-lane on the main road of the on-ramp system. The drivers may decelerate for more safety when they are near the on-ramp. In addition, the car velocity may be restricted according to the traffic regulation. In this paper, we study phenomenon using the cellular automata traffic flow model. We find that: (i) the phase diagram of the two-lane on-ramp system appears a new region, in which the traffic of the on-ramp reaches maximum flow. (ii) The introduction of restricted velocity region will decrease capacity of the on-ramp, but reduce the drastic velocity fluctuation near the on-ramp. 相似文献
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在全速度差(Full Velocity Difference, FVD)模型的基础上,提出了一个扩展模型——多速度差(Multiple Velocity Difference, MVD)模型. 在MVD模型中,尝试利用多辆前车信息以提高交通流的稳定性,除了考虑前车与本车的速度差外,进一步利用了多辆前车间的速度差信息. 通过线性稳定性分析,对两个模型进行比较,发现在MVD模型中,自由流稳定的敏感系数临界值变小,稳定区域有明显增加. 数值仿真结果表明,MVD模型能有效地抑制交通流堵塞.
关键词:
交通流
稳定性分析
速度差
节能 相似文献
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The velocity of a particle detector in granular flow can be regarded as the combination of rolling and sliding velocities. The study of the contribution of rolling velocity and sliding velocity provides a new explanation to the relative motion between the detector and the local granular flow. In this study, a spherical detector using embedded inertial navigation technology is placed in the chute granular flow to study the movement of the detector relative to the granular flow. It is shown by particle image velocimetry (PIV) that the velocity of chute granular flow conforms to Silbert's formula. And the velocity of the detector is greater than that of the granular flow around it. By decomposing the velocity into sliding and rolling velocity, it is indicated that the movement of the detector relative to the granular flow is mainly caused by rolling. The rolling detail shown by DEM simulation leads to two potential mechanisms based on the position and drive of the detector. 相似文献
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In real urban traffic, roadways are usually multilane and are divided into fast, medium and slow lanes according to different velocity restrictions. Microscopic modelling of single lane has been studied widely using discrete cellular automata and continuous optimal velocity models. In this paper, we extend the continuous single-lane models (OV model and FVD model) to simulate the lane-changing behaviour on an urban roadway that consists of three lanes. Considering headway difference, velocity difference, safety distance, and the probability of lane-changing intention, a comprehensive lane-changing rule set is constructed. We analyse the fundamental diagram and reveal the “faster-is-slower” effect in urban traffic induced by lane-changing behaviour. We also investigate the effect of lane-changing behaviour on the distribution of vehicles, velocity, flow and headway. Asymmetrical phenomenon with symmetrical rules on urban roadway and density inversion on the slow lane were also found. The simulation results indicate that lane-changing behaviour is not advisable on crowded urban roadway. It is hoped that information from this study may be useful for traffic control and individual moving strategy on urban roadway. 相似文献
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Based on the velocity gradient model, an extended continuum model with consideration of the mean-field velocity difference is proposed in this paper. By using the linear stability theory, the linear stability criterion of the new model is gained, which proved that mean-field velocity difference has significant influence on stability of traffic flow. The KdV–Burgers equation is derived by using non-linear analysis method and the evolution of density wave near the neutral stability line is explored. Numerical simulations are carried out how mean-field velocity difference affect the stability of traffic flow, and energy consumption is also studied for this new macro model. At the same time, complicated traffic phenomena such as local cluster effects, shock waves and rarefaction waves can be reproduced in the new model by numerical simulation. Numerical results are consistent with the theoretical analysis, which indicates that the mean-field velocity difference not only suppresses traffic jam, but also depresses energy consumption. 相似文献