基于交通路网的TASEP模型的扩展研究

完全非对称的简单排它过程(Totally Asymmetric Simple Exclusion Process,TASEP)模型是一种描述一维晶格上粒子运输的一种经典模型,其主要考虑了粒子之间的体积排斥效应,已被广泛应用到生物、交通等领域。文中主要对传统的TASEP模型进行了扩展研究,结合实际交通网络的结构和特性对TASEP模型进行了如下改进:1)粒子在各条边上的跳跃率是异质的,即设置各条边上的跳跃率不同且符合泊松分布;2)在交叉路口的粒子在选择下一个路段时是非随机的。具体地,设计了一种实时路径策略,结合各个时刻各条边上的流量值与粒子数得到对应边上粒子的平均移动“速度”;在此基础上引入“理性”参数α来控制粒子的路径选择:α的值越大,粒子越倾向于运动到平均速度越快的连边上。结果显示,随着参数α值的增大,网络中粒子的整体运动得到了优化,使得系统的流量有较大的提升,从而可以缓解网络拥塞。文中通过结合复杂网络的概念和方法,对传统TASEP模型做出了两点改进:1)设计出粒子在交叉口处的路径策略优化其行驶路径;2)为研究城市交通流模型提供了新的思路和方向。

Study of TASEP Model Based on Road Networks

TASEP is a classic model for describing the particle transportation on one-dimension lattices,which considers the vo-lume exclusion effect of real matters.It has been widely applied in the area of biology and public transportation.In this paper,based on the real properties of the traffic network,a modified TASEP model was proposed.The TASEP model is improved as follows,considering the heterogeneity of the hopping rate of particles on each edge,i.e.setting different hopping rates on each edge and conforming to Poisson distribution,and considering that the particles at the intersection are non-random in choosing the next section.Specifically,a real-time path strategy was proposed.Combining the traffic flow and the number of particles on a road,an average moving velocity is obtained for each link.Then a parameterαis introduced to make the movements of the particles at the intersections more rational.The larger the value ofα,the more likely the particles are to move to the edge of the larger average velocity.Experimental results show that with the increase ofα,the flow of the system will be greatly improved,which alleviates the congestions to a certain extent.By extending the traditional TASEP model,this paper provides a new insight and direction for the study of urban traffic system.