说明：  模型考虑了车辆的长度,并将传统模型中的期望间距转换为期望车头时距,反映了后车 速度对跟车状态的影响
(The model takes into consideration the length of the vehicle and converts the expected pitch in the traditional model to the desired headway, which reflects the influence of the rear vehicle speed on the condition of the car following)