Research On Control Strategy Of Adaptive Cruise System For Pure Electric Vehicles In Urban Roads

Adaptive cruise system(ACC)is an important part of the assisted driving system.In urban roads with complex driving conditions,the vehicle adaptive cruise system can greatly reduce the driver’s burden,improve road utilization and increase vehicle driving safety.Therefore,the auxiliary role of ACC in the driving process is gradually recognized by people.Through literature research,it is found that there are few ACC researches on electric vehicles,so this paper studies the ACC control system of pure electric vehicle.The ACC control system mainly includes two parts:an environment sensing unit and a controller unit.In the environment sensing unit,the millimeter-wave radar is used to detect the environmental information of the vehicle in front of the host vehicle.For the safety spacing algorithm,the VTH algorithm is optimized by the relative speed change rate of the main vehicle and the front workshop.The optimized algorithm performs stability analysis and proves the effectiveness of the algorithm.In the controller unit,the model predictive control algorithm is introduced as the control algorithm of the ACC system,and a prediction model with first-order hysteresis is built.In addition,in order to restore the driving environment of electric vehicles and fit the driver’s driving habits as much as possible,this paper also establishes a fuzzy control algorithm model,driving and braking switching control strategy and driver intervention priority strategy for pure electric vehicle braking force distribution.Finally,a co-simulation model on Simulink and CarSim platform is built in this paper,and simulates it under the common working conditions of urban roads—cutting conditions,cutting out conditions,“walk-and-stop”conditions and following conditions.The simulation results show that the proposed model predictive control algorithm has good control effects in four working conditions,especially under the“walk-and-stop”and follow-up conditions,the acceleration is always within±1.5m/s~2,which improves the passenger’s ride comfort.The algorithm studied in this paper is compared with the control effect of fuzzy control algorithm ofACC system.The results show that the speed difference of model predictive control algorithm of the main car following the preceding car is always the smallest.which verifies the model predictive control algorithm of ACC system have good control effect.