不同CACC渗透率条件下的混合交通流稳定性分析

摘要

未来协同自适应巡航控制(Cooperative Adaptive Cruise Control,CACC)车辆和传统车辆混合交通流的稳定性决定了CACC技术对交通拥堵、能耗排放的改善程度.鉴于此,研究不同CACC渗透率时这种混合交通流的稳定性.应用基于轨迹数据标定的IDM(Intelligent Driver Model,IDM)模型和由加州伯克利PATH实验室实车测试验证的CACC模型分别作为传统车辆跟驰模型和CACC车辆跟驰模型.依据传统车辆在扰动下的稳定性,确定高稳态速度和低稳态速度,并考虑两种车型相对数量、相对位置的随机性,设计数值仿真实验.实验结果表明,在高稳态速度下,不同CACC渗透率时混合车队均整体稳定;在低稳态速度下,当CACC渗透率较小时,车队整体不稳定,CACC渗透率需达到50%以上时,才有可能使得混合车队由不稳定转变为稳定.%The string stability of future traffic flow mixed with cooperative adaptive cruise control (CACC) and traditional vehicles will determine the improvement of CACC on traffic capacity and fuel consumptions. Therefore, this paper focuses on string stability of this mixed traffic flow for different CACC penetration ranges. Intelligent driver model (IDM) calibrated using trajectory data and CACC model validated using real vehicles by PATH laboratory of Berkeley are employed to be traditional vehicle car-following model and CACC car-following model respectively. Higher and lower equilibrium velocities are determined based on traditional vehicle stability under small perturbation and numerical simulations are designed considering the randomness of the relative quantity and positions of the two kinds of vehicles. Experimental results show that mixed traffic flow is stable under higher equilibrium velocities for different CACC penetration ranges. However, the mixed traffic flow is unstable under lower equilibrium velocities and lower CACC market penetration. CACC market penetration needs to reach at least 50% to guarantee that the mixed traffic flow can be stable under lower equilibrium velocities.