【作者】 吴可非；

【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】 随着社会经济的发展和人们生活水平的提高,交通运输问题越来越成为人们关注的焦点,也成为关系国计民生的重要因素。交通运输系统是否现代化,交通管理水平是否先进,无疑是一个国家兴旺发达的重要标志之一。尽管各国投入巨资用于交通建设,道路建设的速度仍然滞后于交通需求量的增加。随着城市汽车数量的增加,交通拥堵、交通环境污染和交通事故的频繁发生越来越严重地影响世界各国经济和社会的发展。在我国,城市人口众多、交通工具多样化加剧了交通问题的尖锐性。目前,我国城市的交通流普遍是一个由人、非机动车和机动车混合在一起构成的混合交通流。就是机动车也是多种多样,性能、大小差异很大,如有摩托车、小汽车、客车和公交车等。可以预计,由于我国人口多、经济还不发达、经济发展不平衡和居民收入差距较大,这样一种复杂的混合交通流在我国城市还会维持很长的时间,因此如何科学管理和控制混合交通流是一个必须解决的迫切问题。近年来,交通问题受到了国内外专家们的重视,提出了各种各样的交通流模型,其中,元胞自动机(Cellular Automaton,简称CA)交通流模型的研究受到了广泛的关注。元胞自动机是一种时间、空间和变量均离散的数学模型。它具有物理图象清晰、完全的并行性、无截断误差和无计算误差等优越特点,是研究非线性复杂系统的有效工具。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,再现了交通系统中出现的非线性现象,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.考虑车辆驾驶员具有其不同的驾驶特点,将驾驶员分为两类:一类为激进(aggressive )驾驶员,他们倾向于超速、超车行驶并保持较小的车间距等,通常较少刹车;另一类为谨慎(careful)驾驶员,他们通常较少超速、超车行驶并保持较大的车间距等,为了安全起见而经常刹车。论文建立了单车道开放边界条件下由元胞自动机FI模型和NS模型混合的交通流模型。通过计算机模拟,得到了混合交通流的密度、速度和流量受边界、NS型车辆的随机减速概率PNS、FI型车辆的随机减速概率PFI和NS型车辆的产生概率α′影响的结果。结果表明, PNS和α′是决定混合交通流的主要因素,它们的值越大,混合交通流的密度、速度和流量越小。受边界效应的影响,当右边界完全开放时,混合模型的密度比NS模型的小,而速度和流量比NS模型的大;当左边界完全开放时,混合模型的密度更多还原

【Abstract】 With the development of social economy and the advancement of people′s living standard, the transportation becomes the people′s focus more and more, and becomes the important factor that relates to the national economy and the people′s livelihood. No doubt, whether the transportation system is modernized, or whether the managing level of the transportation system is advanced, is one of the important signs of a country being thriving and flourishing. Though all countries have devoted huge funds to the traffic construction, the speed of the traffic construction lags the increase of the traffic demand. With the increase of the number of automobiles in the city, traffic jam, traffic environmental pollution and traffic accidents frequently happening are more and more seriously affecting the development of economy and society in countries all over the world.In our country, numerous civil population and diversiform traffic tools aggravate the acurity of traffic problems.At present, the traffic flow in our national cities is generally mixed traffic flow which consists of passersby, non-motor vehicles and motor vehicles.As for motor vehicles, they are also diversiform and they are different in capability and size. For example, there are motorcycles, cars, passenger cars and buses in them.It can be anticipated that because of numerous population, underdeveloped economy, the imbalance in the development of economy and biggish difference in dweller′s income in our country, the complicated mixed traffic flow will persist for a long time in our national cities. Therefore, how to scientifically administer and control mixed traffic flow is a problem that needs imminently to solve.In recent years, the domestic and overseas experts have attached importance to traffic problems and have presented all kinds of traffic models, in which the studies of the cellular automaton models for traffic flow have been widely concerned.Cellular automaton is a mathematical model in which time, space and variables are all discrete.It has so many predominant characteristics—for example, its clear physical pictures, being completely parallel, having no interceptive errors and having no computational errors and so on—that it is a effective tool by which to study nonlinear complicated systems.In this dissertation, based on the existing research on the cellular automata models for traffic flow, several models for traffic flow with mixed vehicles in accordance with real traffic in更多还原