宏观交通网络拥堵区边界最优控制

Optimal Control for Traffic Congested Area Boundary in Macroscopic Traffic Network

为了缓解交通拥堵,解决拥堵状态下区域交通控制问题,提出了宏观交通网络拥堵区边界最优控制方法。首先,基于同质性路网宏观基本图特性固定划分控制子区,通过分析子区之间的车辆流入、流出关系,建立了宏观网络车流平衡方程;其次,以路网旅行车辆完成率最高,同时子区边界处受阻车辆数最低为优化目标建立了拥堵区边界最优控制模型,根据最优控制确定子区边界输入、输出最佳交通流量,进而以饱和度高的边界交叉口饱和度快速降低为优化目标,提出了子区边界交叉口流量分配及信号配时参数优化方法;最后,以合肥市一环路以内的路网为测试对象,通过微观仿真分析,比较了无区域边界控制、拥堵区入口Bang-Bang边界控制、拥堵区出口与入口BangBang边界控制和最优控制4种控制方案。结果表明:最优控制条件下宏观路网运行效益比前3种方法分别提高49.17%、30.19%、71.99%,车辆行程延误分别降低21.65%、3.74%、1.94%;最优控制可有效改善拥堵区内外交通密度的均衡性;宏观路网拥堵区的边界控制可有效降低高峰期间拥堵区的拥塞程度,提高整个路网的疏散能力。

In order to alleviate traffic congestion and solve problem of regional traffic control under traffic congestion,an optimal control method for the macroscopic congested area boundary was put forwarded. Firstly,the control sub-regions were fixedly divided based on the characteristic of the macroscopic fundamental diagram（MFD）of the homogeneous network,and by analyzing the relationship of the traffic inflow and outflow between the sub-regions,the equilibrium equation of the macroscopic network traffic flow was established.Next,the optimal control model for congested are a boundary was set up which regarded the highest completion rate of travel vehicles in road network and the minimum blocked vehicles in boundary of sub-regions as the optimal objective.Meanwhile,according to the optimal control to determine the input and output optimal flow of sub-region boundary,a method was proposed to optimize the traffic assignment and signal timing parameters of the intersections on the boundary of sub-regions,and the optimal objective of it was to rapidly reduce the high saturation of the boundary intersections.Finally,the first-ring road network in Hefei was used as the test object,by microscopic simulation and analysis,four different control schemes including no regional boundary control,Bang-Bang boundary control at the congestion area entrance,Bang-Bang boundary control both at the congestion area entrance and exit,and optimal control were compared.The results show that optimal boundary control could improve the operation efficiency of the macro network by49.17%,30.19%,and 71.99%,and reduce the vehicle travel delay by 21.65%,3.74%,and1.94%,compared with first three methods respectively;optimal boundary control could improve the homogeneity of traffic density inside and outside the congestion area effectively;boundary control in macroscopic network could availably reduce the congestion degree in peak period and improve the evacuation ability of the whole network effectively.