共查询到19条相似文献,搜索用时 46 毫秒
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交通流问题的有限元分析和模拟(Ⅰ) 总被引:1,自引:1,他引:0
采用交通流问题流体动力学模型,通过权余方法建立了相应的有限元弱解变分形式,利用一般的有限元方法进行了交通流问题的数值计算和数值模拟试验,并对数值结果进行了讨论和分析。 相似文献
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在一维元胞自动机交通流WWH模型和SDNS模型的基础上,建立了考虑驾驶方式改变的元胞自动机模型(Change-CA模型).具体描述为驾驶员可根据交通环境选择不同的驾驶方式在道路上驾车行驶,以各自的演化规则进行状态更新,同时定义了驾驶方式更新原则.通过计算机数值模拟,发现驾驶方式可变时,模型模拟得到的混合交通流流量较大;保守型驾驶方式对交通流变化的影响随改变概率增大而减少.并且在演化过程中,驾驶方式改变频率的变化趋势与改变概率、安全概率密切相关.与NS模型和SDNS模型相比,Change-CA模型减少了车流
关键词:
交通流
元胞自动机
驾驶方式
计算机数值模拟 相似文献
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在一维交通流格子模型的基础上,分别提出考虑最近邻车和次近邻车以及考虑前、后近邻车相互作用进行车流优化的一维交通流格子模型.应用线性稳定性理论和非线性理论进行分析,得出车流的稳定性条件,并导出了描述交通阻塞相变的mKdV方程.用数值模拟验证了mKdV方程的解,数值模拟结果表明考虑最近邻车和次近邻车的优化车流能够增强车流稳定性,而考虑前、后近邻车的优化车流将使稳定性减小.
关键词:
交通流
交通相变
稳定判据
mKdV方程 相似文献
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In this paper,we further analyze our cellular automaton(CA)traffic flow model.By changing some parameters,the characteristics of our model can be significantly varied,ranging from the features of phase transitions to the number of traffic phases.We also review the other CA models based on Kerner’s three-phase traffic theory.By comparisons,we find that the core concepts for modeling the synchronized flow in these models are similar.Our model can be a good candidate for modeling the synchronized flow,since there is enough flexibility in our framework. 相似文献
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建立交通流短时预测状态空间模型, 研究混合状态下城市快速路交通流短时预测. 结合城市快速路自由流状态、拥挤流状态和阻塞流状态下交通流参数的时间和空间分布特性, 基于交通流守恒方程和速度动态模型, 借鉴偏微分方程组求解时空离散的思想, 建立三种状态下交通流短时预测模型; 同时考虑进出口匝道、车道数变更以及道路坡度等因素的影响, 将交通流短时预测模型转化为交通流短时预测状态空间模型, 实现混合状态下交通流短时预测. 研究表明, 该方法能够实现混合状态下道路网内的交通流短时预测, 预测精度可达90.23%. 相同条件下, 经典自回归滑动平均模型的预测精度仅为81%.
关键词:
交通流短时预测
自由流状态
拥挤流状态
阻塞流状态 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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A speed bump reduces traffic noise levels during the deceleration phase and increases them during the acceleration phase. The net effect of a speed bump on noise from a light vehicle is assessed by means of the concept of noise energy density, S. This is a function of the instantaneous distance between the vehicle and the bump, S(x). To determine the function S(x) explicitly, five measurements of the sound exposure level, for each vehicle, are needed. It is assumed that the noise from each vehicle is generated by a single non-directional point source and propagates without vertical-surface reflections. An example prediction is presented based on measurements of sound exposure levels due to passenger cars. 相似文献
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In this paper,a new lattice hydrodynamic model based on Nagatani’s model [Nagatani T 1998 Physica A 261 599] is presented by introducing the flow difference effect.The stability condition for the new model is obtained by using the linear stability theory.The result shows that considering the flow difference effect leads to stabilization of the system compared with the original lattice hydrodynamic model.The jamming transitions among the freely moving phase,the coexisting phase,and the uniform congested phase are studied by nonlinear analysis.The modified KdV equation near the critical point is derived to describe the traffic jam,and kink-antikink soliton solutions related to the traffic density waves are obtained.The simulation results are consistent with the theoretical analysis for the new model. 相似文献
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Since ramps are an important composition of traffic systems and there often exist multi ramps in a traffic system,the number of ramps can have great effects on main road traffic and produce some complex phenomena.In this paper,we employ the model presented by Tang et al.[2009 Communications in Theoretical Physics 51(1) 71] to further study the effects of the number of on-ramps on the stability of traffic flow on a ring road.The numerical results show that this model can reproduce some complex traffic phenomena resulting from multi on-ramps on the ring road and the effects of the number of on-ramps on traffic flow,but the phenomena and the effects are both related to the initial density of the main road. 相似文献