理想诱导环境下的网联车与网联自动驾驶车混合交通流建模研究

Modeling a mixed traffic flow of connected vehicles and connected autonomous vehicles in an ideal induction environment

智能网联车辆通过先进的无线通信技术能够实现车辆间信息传递,然而通信环境中不可避免的存在干扰信号,当干扰信号达到一定的强度时,车辆间的通信会被迫中断,等效于交通流中车辆的通信拓扑发生了切换,通信拓扑切换必然会对交通流造成影响。基于此,本文在由网联车(connected vehicle,CV)和网联自动驾驶车(connected autonomous vehicle,CAV)构成的混合交通流中,研究了理想诱导环境下通信拓扑结构切换和CAV不同空间分布对混合交通流动态性能的影响。首先提出一种结合图论和概率论的通信拓扑表征方法,对混合交通流中的通信拓扑进行表征。然后考虑CV与CAV在决策行为上的特点,结合通信拓扑提出一个通用车辆跟驰模型,并使用约化摄动法推导出通用车辆跟驰模型的稳定性条件。最后设计数值仿真实验,在不同的CAV渗透率下,研究理想诱导环境下通信拓扑结构切换和不同CAV空间分布对混合交通流动态性能的影响。通信拓扑结构切换数值仿真结果表明,稳定的通信连接将有利于混合交通流动态性能的平滑性。不同CAV渗透率下数值仿真结果表明,当理想诱导环境中不存在干扰信号时,CAV渗透率越高,混合交通流动态性能的平滑性越好;当理想诱导环境中存在干扰信号并导致通信拓扑切换时,CAV渗透率为40%且空间分布为集中分布时的抗干扰能力最强。不同CAV空间分布下数值仿真结果表明,当理想诱导环境中不存在干扰信号时,CAV集中分布下混合交通流动态性能的平滑性最好;当理想诱导环境中存在干扰信号并导致通信拓扑切换时,CAV集中分布的抗干扰能力强于CAV均匀分布和随机分布的抗干扰能力。

Intelligently connected vehicles exchange information using advanced wireless communication technology.However,interference signals are inevitable in the communication environment.An interference signal of sufficient strength interrupts the communication between vehicles,an effect equivalent to the switching of the communication topology(CT)displayed by vehicles in a traffic flow.Such CT switching inevitably affects the traffic flow.This study therefore considers a mixed traffic flow composed of connected vehicles(CV)and connected autonomous vehicles(CAV)to investigate the effects of CT switching and different spatial CAV distributions on the dynamic performance of the mixed traffic flow in an ideal induction environment.First,a method combining graph and probability theories is proposed to characterize the CT of the mixed traffic flow.Then,by considering the feature between CVs and CAVs in decision-making behavior,a general car-following(CF)model is proposedand combined with CT.The stability conditions of the general CF model are then deduced using the perturbation method.Finally,a numerical simulation experiment is designed to study the effects of CT switching and of different CAV spatial distributions on the dynamic performance of mixed traffic flows for different CAV penetration ratesin an ideal induction environment.The CT switching simulations show that a stable communication connection improves the smoothness of the dynamic performance of the mixed traffic flow.The simulations using different CAV penetration rates show that,in the absence of an interference signal in the ideal induction environment,the smoothness is also enhanced with increasing CAV penetration rate.When an interference signal in the ideal induction environment produces CT switching,the anti-interference ability is strongest for a CAV penetration rate of 40%and when the spatial distribution is centralized.The simulations with different CAV spatial distributions show that the dynamic performance of the mixed traffic flow with a centralized CAV distribution is smoother in the absence of an interference signal in the ideal induction environment.In the presence of an interference signal producing CT switching in the ideal induction environment,the anti-interference ability of the centralized CAV distribution is stronger than that of the uniform and randomCAV distributions.