一种VANET环境下的智能交通信号控制方法

An Intelligent Traffic Signal Control Method in VANET

城市环境中车辆数量的几何式增长带来了一系列的交通问题,高效的交通信号控制方法不仅能够改善交通安全和效率,而且还能减少车辆的尾气排放.由于车流的高度动态性,现有的一些方法存在获取车辆信息不准确和实现复杂等问题.文中基于VANET的V2I通信建立了一种精确探测车辆信息的双层管道模型,并基于该模型提出了一种自适应跳跃式信号控制方法.该方法依据"按需分配"的原则为各相位分配合适的绿灯通行时间,同时在车流稀疏情况下使用一种跳跃式控制,有效避免了车辆的"空等"现象,提高了绿灯时间的使用效率.利用真实的交通流,基于Veins在两种不同相位情况下进行仿真实验,结果表明文中提出的智能交通信号控制方法能够适应车流的高度动态性,比较明显地提高了交叉路口处的行驶质量,同时有效降低了车辆的CO_2排放量.

In urban environment,geometric growth in the number of vehicles brings a series of traffic problems.Efficient traffic signal control methods not only improve traffic safety and efficiency,but also reduce vehicles＇ emissions.Due to the high dynamic of traffic flows,some existing methods are hard to acquire accurate information about vehicles,and they are difficult to be realized.Based on the V2I（Vehicle-to-Infrastructure）communications in VANET（Vehicular Ad-Hoc Network）,we set up a double-layer pipe model to detect vehicles＇ information accurately,and propose an adaptive leaping signal control method via this model.The method allocates appropriate green time for each signal phase according to ＂demand assignment＂principle,and a leaping control is utilized in the case of sparse traffic condition.The leaping control avoids＂waiting in vain＂phenomenon efficiently,and it improves the efficiency of green time.By using real traffic flows,experiments based on Veins are simulated under two different signal phase cases.Simulation results show that the intelligent traffic signal control method proposed in this paper can adapt tohighly dynamic traffic flows,and it significantly improve ride quality at the intersection.At the same time,it can reduce vehicles＇ CO_2 emissions effectively.