AI 中文总结
本研究提出CC与ACC的统一动力学模型，通过sigmoid函数插值两种模式，设计最优切换阈值可提升通行能力、降低速度振荡，缓解商用ACC车辆对交通流的负面影响。
AI 中文摘要
自适应巡航控制（Adaptive Cruise Control, ACC）车辆是第一代自动化车辆。尽管人们期望全自动车辆能改善交通流，但现场实验表明，商用ACC车辆反而可能通过降低 string 稳定性和道路通行能力来恶化交通流。为缓解这些影响，现有研究调整ACC控制算法或引入额外控制输入；然而，鲜有研究在不修改ACC控制算法本身的情况下考察巡航控制（Cruise Control, CC）与ACC模式之间的过渡，导致对ACC车辆的影响理解不完整。为解决这一缺口，我们提出了CC与ACC的统一动力学模型，通过sigmoid权重函数在两种模式间连续插值，并通过设计模式切换来改善交通流。基于该新模型，我们对车队进行了平衡态与string稳定性分析，揭示了安全性、通行能力与string稳定性之间的权衡关系。在通行能力优先和安全性优先准则下设计了最优切换阈值，并与商用ACC车辆采用的阈值进行了对比。数值实验表明，与商用基线相比，采用合理设计的切换阈值时，通行能力最多提升58.6%，作为速度振荡衡量指标的平均速度变化最多降低39.7%。我们得出结论，商用ACC车辆过大的切换阈值可能是其对交通流产生负面影响的原因，通过适当降低阈值至更安全、更具string稳定性的区间，可缓解该影响。
英文摘要
Adaptive cruise control (ACC) vehicles are the first generation of automated vehicles. While fully automated vehicles are expected to benefit traffic flow, field experiments have shown that commercially available ACC vehicles may instead degrade it by reducing string stability and roadway throughput. To mitigate these effects, existing studies adjust the ACC control algorithm or introduce additional control inputs; however, few have examined the transition between the cruise control (CC) and ACC modes without modifying the ACC control algorithm itself, leaving the impacts of ACC vehicles incompletely understood. To address this gap, we propose a unified dynamical model of CC and ACC that interpolates continuously between the two modes through a sigmoid weighting function, and improve traffic flow by designing the mode switching. Based on this new model, we conduct an equilibrium and string stability analysis of the platoon, revealing the trade-off among safety, throughput, and string stability. The optimal switching threshold is designed under throughput-priority and safety-priority criteria, and compared against the threshold adopted by commercially available ACC vehicles. Numerical experiments show that, with a properly designed switching threshold, the throughput increases by up to 58.6% and the average speed variation, a measure of speed oscillations, decreases by up to 39.7% relative to the commercial baseline. We conclude that the excessively large switching threshold of commercially available ACC vehicles is a likely cause of their negative impact on traffic flow, and that this impact can be mitigated by properly reducing the threshold toward a safer and more string-stable regime.
