Research And Simulation On Control Strategy Of Automatic Emergency Braking System Based On Driving Characteristics And Road Adhesion Coefficient

With the continuous increase of car ownership,automobile traffic accidents have become an important threat to people’s life and property.Automatic Emergency Braking System(AEB),which can avoid or mitigate collision injury by making the vehicle brake automatically,has become a hot spot in active safety technology research.However,due to the driver’s personality differences and the uncertainties of the car driving conditions,the AEB control strategy with fixed parameters cannot satisfy the practical needs.To solve this problem,the following research has been done in this paper.In order to investigate driver characteristics,the real driving data set NGSIM is chosen as the driving characteristics research object in this paper.Savitzky-Golay filtering technology is used to preprocess the original data,establish the vehicle longitudinal dangerous scene standard,and extract the emergency braking time data from the vehicle history curve.From the emergency braking data,the main characteristic variables reflecting driving style are extracted.On this basis,the drivers were divided into three types using the k-means clustering algorithm,and the response time of different types of drivers was statistically analyzed.It was found that the response time of drivers with different driving styles was significantly different during the emergency braking.Secondly,based on existing classical safe distance algorithm and actual braking process of the automobile,an AEB control strategy considering driving characteristics and road surface adhesion coefficient was established,which modified the basic safety distance model by using the driving style selected by the driver and the actual road adhesion coefficient.The former determines the driver’s response time based on the choice of driving style and modifies the AEB strategy through response time.For the latter,the estimates of the road adhesion coefficient estimation model are used to modify the AEB strategy.The vehicle dynamics model and the Dugoff tire model are used to estimate the road adhesion coefficient.Using the relationship between road adhesion coefficient and vehicle dynamic parameters,an extended Kalman filter algorithm is designed to estimate road adhesion coefficient in real time.In order to control vehicle motion more precisely,a lower level controller of fuzzy PID is designed.Finally,the Carsim/Simulink Joint Simulation Platform was established and AEB function verification was performed using C-NCAP test standard.The simulation results show that the AEB control strategy based on driving characteristics and road surface adhesion coefficient designed in this paper can meet the psychological needs of drivers with different driving styles for the timing of AEB system intervention,increase the adaptability of the system,and also increase the safety of driving on the road with low adhesion coefficient.