城市工况下汽车走—停巡航控制与仿真

Cruise control and simulation of vehicle stopping-going under urban conditions

车辆频繁的启停会导致驾驶员疲劳,从而引发交通事故。为了降低驾驶员疲劳和追尾事故的风险,建立了一套分层的车辆走—停巡航控制系统(S&G)。通过在Carsim中建立车辆动力学模型,采用车头时距法确定安全距离,根据最优控制和模糊PID控制原理分别设计上、下控制器,最后,在Simulink中构建仿真回路,在典型S&G工况下联合仿真,得到随前车行驶时自车的速度变化曲线、加速度变化曲线、相对距离变化曲线和节气门开度曲线。结果表明,所设计的S&G系统能使自车在保持适当安全距离的同时,很好地跟踪前车的速度变化,自动启停车辆,减轻驾驶员疲劳,提高车辆的主动安全性。

Frequent starting and stopping of vehicles can lead to driver fatigue and traffic accidents.In order to reduce the risk of driver fatigue and rear-end accident,a hierarchical vehicle stop-go cruise control system(S&G)is established.Vehicle dynamics model is built on Carsim,and the safe distance is determined bytheheadwaytime-distancemethod.Theupperand lowercontrollersaredesigned accordingtotheprinciple of optimal control and fuzzy PID control.Finally,a simulation loop was established in Simulink,and a joint simulation was conducted under typical S&G conditions to obtain the velocity change curve,accelera-tion change curve,relative distance change curve and throttle opening curve of the vehicle when driving with the vehicle in front.The results show that the S&G system can keep a proper safe distance while tracking the speed change of the vehicle in front,automatically start and stop the vehicle,reduce the fatigue of the driver and improve the active safety of the vehicle.