基于元胞自动机模型的交通流混沌仿真研究

研究一维元胞自动机模型——Nagel-Schreckenberg(NS)模型的交通流混沌问题。用Matlab程序产生交通流时间序列,在一定参数组合情况下,仿真研究了交通流车队中前后车辆之间车头间距的变化过程,并在此基础上讨论了车辆密度和车辆减速概率的变化对交通流运动状态的影响。结果表明,当车流密度超过某一值时,NS模型仿真出的交通流会产生混沌现象;而交通流混沌产生的根本原因在于交通流的内在随机性,其中车辆不规则的加速、减速是这种内在随机性的主要因素。

Simulation study on chaos in traffic flow based on cellular automaton model

The chaos in traffic flow is studied based on the one-dimensional cellular automaton mode(Nagel-Schreckenberg Model).The time series of the traffic flow are generated using Matlab program.The changing processes of headway of the front vehicle and the following vehicle in the traffic flow were studied under the parameters combinations.The influence of the density and brake probability of vehicles on the movement of the traffic flow is discussed.The result shows that when the density of vehicles is bigger than a critical value,chaos in the traffic flow will appear.Moreover,the basic reason of chaos phenomenon is the intrinsic randomness of the traffic flow,among which the brake probability of the vehicles is the main factor.