考虑前后不对称网联多车跟驰模型及数值仿真

Connected and Automated Multi-vehicle Following Model and Numerical Simulation Considering Front and Rear Asymmetry

基于车联网技术的发展,未来智能网联车的普及和应用会极大改变驾驶人的跟驰操作行为和交通流宏观特性。为研究网联自动驾驶车辆的跟驰行为以及智能跟驰决策如何合理确定前后跟驰车辆数,通过引入前后多车车头间距、多前车速度差、加速度差等信息,建立前后不对称多车信息的网联车辆跟驰模型。利用线性稳定性分析得出交通流的临界稳定条件,最后利用Matlab对模型的制动、起步和交通流演化特性进行数值仿真,定量对比分析前后多车数量对车辆速度、加速度、位置的影响。仿真结果表明:AMFR-CAV模型较MFRHVAD模型制动过程加速度平均峰谷差值减少43.32%,震荡时间提前16%,速度峰谷差值降低42.43%;起步过程平均加速度波峰值降低28.54%,波峰出现时间平均提前6.76%,速度延迟时间平均减少30.27%,第500 s第10辆跟驰车辆位置提高1.29 m;周期性边界运行条件下,减速过程交通流稳定性优于加速过程,减速过程中,当跟驰车辆引入P=2,Q=8时交通流稳定性最好,加速过程中,当跟驰车辆引入P=3,Q=7时交通流稳定性最好;当车辆信息给定时,前车数量考虑越多,交通流稳定性不一定越好,且最优跟驰状态下前后车数量具有不对称性。

Based on the development of Internet of Vehicles technology,the popularity and application of intelligent connected vehicles in the future will greatly change drivers’following operation behavior and macroscopic characteristics of traffic flow.In order to study the following behaviors and intelligent following decision of CAV how to reasonably determine the number of vehicles following,by introducing the headways of vehicles,the speed difference between the front vehicles and the acceleration difference,an Asymmetric Multi-Front-and-Rear-CAV(AMFR-CAV)model is established.The critical stability condition of traffic flow is obtained by using linear stability analysis.Finally,the numerical simulation on braking,starting and traffic flow evolution characteristics of the model is conducted by using Matlab,the influences of the number of vehicles on vehicle speed,acceleration and position are quantitatively compared and analysed.The simulation result shows that(1)Compared with MFRHVAD model,AMFR-CAV model reduced the average peak valley difference of acceleration by 43.32%,advanced the shock time by 16%,and reduced the peak valley difference of speed by 42.43%.(2)During the starting process,the peak value of average acceleration decreased by 28.54%,the peak time is 6.76%earlier,the average speed delay time decreased by 30.27%,and the position of the 10th following vehicle at the 500th s increased by 1.29 m.(3)Under the condition of periodic boundary operation,the stability of traffic flow in the deceleration process is better than that in the acceleration process.In the deceleration process,when the following vehicles are introduced P=2 and Q=8,the stability of traffic flow is the best.In the acceleration process,when the following vehicles are introduced P=3 and Q=7,the stability of traffic flow is the best.(4)When the vehicle information is given,the more the number of vehicles in front is considered,the better the stability of traffic flow may not be,and the number of vehicles in front and behind under the optimal following state is asymmetric.