基于元胞自动机的城市混合非机动车流特性模拟研究

Urban Mixed Non-motor Vehicle Flow Character Simulation Based on Cellular Automata

我国大城市交通非机动车流主要由普通自行车与电动自行车构成,二者具有异质性,主要体现在速度、横向位移意愿以及随机扰动引起的减速状态的差异,并具体表现为车辆影响域、横向位移倾向值、随机慢化概率的不同。采用多车道元胞自动机(Cellular Automata,CA)模型对混合非机动车流进行模拟研究。基于此分析了车辆构成比例对速度-密度、流量-密度及可实现的横向位移行为的影响。模拟结果显示:电动自行车的构成比例与前二者关系紧密;实现的横向位移数目,即横向位移率随密度的增长呈现先增后减趋势,且上升阶段会出现驻点,该点的产生表明低密度条件下出现了明显的偏析现象。

In China, especially in some big cities, mixed non-motor bicycle flow consists of bicycles and electric bicycles, the differences they have can be described as influence range, degree of the desire to do lateral movement and velocity randomization probability, which represent the actual effects caused by differences of speed, aspiration to change lane, and velocity decreasing in uncertain circumstances respectively. Multi-lane cellular automaton model is used to simulate the flow of mixed non-motor vehicles. On this basis, the influence of the proportion of vehicle constitution on volume-density, speed-density and achieved lateral movement are analyzed respectively. The simulation result shows that （1） the proportion of electric bicycle has a great impact on the first two relations mentioned above; （2） the number of achieved lateral movement grows firstly and decreases after that by density＇s keeping arise. The function has a stagnation point when it is at the rising phase, which shows that the mixed non-motor vehicle flow displayed apparent segregation behavior in the low-density environment.