速度差影响下混合驾驶交通流动态特性分析

Dynamic characteristics of mixed vehicular traffic flow under the influence of velocity difference

为分析自动驾驶车辆(AV)与人工驾驶车辆(HV)之间存在速度差时对混合驾驶交通流动态特性的影响,选取智能驾驶员模型(IDM)和协同自适应巡航控制(CACC)模型分别对HV和AV跟驰行为进行建模,采用MOBIL换道模型对换道行为进行建模.以单向两车道路段为场景,仿真分析了不同AV渗透率下速度差对混合驾驶环境交通流基本图的影响,进一步从通行效率、交通安全、燃油消耗、舒适度4个方面探究速度差和渗透率对交通流动态特性的影响.研究结果表明:渗透率与速度差的增大都可以提高道路通行能力,但速度差增大所带来的影响低于渗透率;速度差主要影响低、中密度混合交通流动态特性,随速度差的增大,通行效率可以得到提升,燃油消耗会有所下降,但同时会降低交通安全性和舒适度.此外,速度差对4项指标的影响程度与渗透率紧密联系,高渗透率条件下受影响程度会显著增加.

In order to analyze the influence of speed difference between automated vehicles(AVs) and human-driving vehicles(HVs) on the dynamic characteristics of mixed vehicular traffic flow, the intelligent driver model(IDM) and the cooperative adaptive cruise control(CACC) model are selected to model the car-following behavior of HVs and AVs, respectively, and the MOBIL(minimizing overall braking induced by lane change) model is used to model the lane change behavior. In a one-way two-lane road numerical experiment scenario, the effects of velocity difference on the fundamental diagram of traffic in the mixed driving environment under different AV penetration rates are analyzed, and the effects of velocity difference and penetration rate on the dynamic characteristics of traffic flow are further analyzed from four aspects, including traffic efficiency, traffic safety, fuel consumption, and comfort. The simulation results show that the increase of both penetration rate and velocity difference can improve the road capacity, but the improvement effect of velocity difference is lower than that of penetration rate. Velocity difference mainly affects the dynamic characteristics of low and medium density mixed traffic flow. With the increase of velocity difference, traffic efficiency is improved and fuel consumption is reduced, but traffic safety and comfort are reduced. In addition, the degree of impact of velocity difference on the four indicators is closely related to the penetration rate, and the degree of impact will increase significantly under high penetration conditions.