【作者】 肖瑞杰；

【导师】 刘慕仁； 孔令江；

【作者基本信息】 广西师范大学 ， 理论物理， 2006， 硕士

【摘要】 交通被喻为国家的“动脉”,无论是发达国家还是发展中国家,高效的交通系统是经济增长的必要保证。城市交通与城市发展关系极为密切,随着我国经济建设的快速发展,城市交通量迅速增长,交通出现了日趋紧张的局面,城市交通拥挤问题已成为困扰社会发展的主要问题。元胞自动机模型(Cellular Automaton,简称CA)是一种时间、空间和变量均离散的数学模型,具有算法简单、灵活可调和计算效率高等特点,是研究非线性复杂系统的有效工具,在交通流理论研究方面具有广阔的应用前景。本文的工作主要是在现有元胞自动机交通流模型的基础上,提出更符合实际情况的混合车辆交通流模型。通过计算机数值模拟,呈现了交通系统中出现的各种非线性现象,并结合实际交通,对混合车辆交通的特性进行了分析和研究。本文的主要工作由三部分组成:1.针对实际交通中存在不同类型的车辆,在NaSch模型的基础上,提出了周期边界条件下的多长度多速度混合车辆单车道元胞自动机交通流模型。数值模拟发现:在单车道上,混合车辆流的流量和平均速度与混合比例系数的变化有较大关系。混合交通流的临界占用率随混合比例系数的增加而增加;当小于临界占用率时,流量随混合比例系数增加而减小,平均速度和混合比例系数无关;当大于临界占用率时,流量基本上与混合比例系数无关,平均速度随混合比例系数增加而增加。2.由于车道上的车辆数是不断变化的,因此为了更好的反映现实交通现象,研究了开放边界条件下车辆的长度和最大行驶速度对混合车辆单车道元胞自动机交通流的影响。考虑产生概率α、消失概率β、随机减速概率p、不同类型车辆产生概率α2对混合交通系统的影响,发现开放边界条件下的混合交通呈现出了一些类似亚稳态和相分离等新特点和新现象。3.在单车道元胞自动机交通流FI模型的基础上,不考虑车辆在交叉口转向和随机减速概率的情况下,采用周期性边界条件,研究了十字路口对由不同长度和不同最大行驶速度的车辆构成的混合交通流的影响。数值模拟结果表明,混合比例系数和第二车道车道占用率对两车道的流量都有比较大的影响。最后,总结了本文的工作,并指出了若干有待进一步研究的问题。更多还原

【Abstract】 For both developing and developed countries, effective transportation systems are of primary importance in the development of society and economy. The development of transportation is tie up with the development of the whole city. With the fast development of economy, urban traffic volume increases quickly, traffic congestion appears frequently and the pressure of urban traffic becomes more and more heavy. The transportation problems are always the difficulty that disturbing people of all transportation fields. Cellular Automata model is a mathematical model in which space, time and state values are discrete. It’s parallel and simple for computation, so Cellular Automata is a very good tool for simulating variable complex nonlinear phenomena and physical problems.In this dissertation, based on the existing research on Cellular Automata traffic flow model, Several models of traffic flow with mixed vehicles in accordance with real traffic in China are proposed. We present various nonlinear phenomena in traffic system by using computer numerical simulation. The characters of traffic flow in mix models are presented and analyzed. This dissertation consists of the following three main parts:Firstly, With respect to the mixed traffic in realistic life, based on the NaSch model, a cellular automaton traffic model with different maximum length and speed vehicles mixed on single lane on periodic boundary condition is proposed. By using computer numerical simulation, we find that the flux and average velocity of mixed traffic flow is much related with the variety of mixed proportion coefficient on single lane. The share critical of mixed traffic flow increases with the increase in mixed proportion coefficient; when less than share critical, traffic flow will decrease with the increase in mixed proportion coefficient and average velocity has no relationship with mixed proportion coefficient; when more than share critical, traffic flow has no relationship with mixed proportion coefficient basically and average velocity will increase with the increase in mixed proportion coefficient.Secondly, due to the constant change in the number of vehicles, we have researched on the更多还原