“大路口”交通信号的优化控制

Optimal control of traffic signal in "big unit"

针对城市交通网络里传统的交通信号最小控制单元模型的不足,提出了“大路口”的概念,给出了“大路口”的几何模型和相位划分,在此基础上,建立了以整个“大路口”车辆平均延误最小为目标的优化模型,得到了目标函数及其约束条件,采取遗传算法进行优化,获得了“大路口”各个相位的绿信比.计算机仿真表明,引入“大路口”比不引入“大路口”情况下支路方向交通流量基本维持不变,而主干路方向的交通流量有明显改善,且总的车辆平均延误明显减少.

To overcome the shortcomings of the traditional least traffic signal control unit model in the urban traffic network, the definition of ＂big unit＂ is presented and its geometry model, as well as its phase partition, is also given in this paper. Based on the optimal model of the ＂big unit＂ for minimizing the vehicles average delay, the objective function and its constraints are obtained. Then the splits of all phases of ＂big unit＂ can be achieved through optimizing the objective function by using genetic algorithm （GA）. The computer simulation shows that after introducing the ＂big unit＂, the traffic flows in main road direction are improved obviously, while the traffic flows in the secondary road direction change to only a small degree, and the total vehicles average delay decreases more in comparison with that without introducing ＂big unit＂.