Research On Vehicle Lane-changing Trajectory Planning And Tracking Control Considering Driving Style

With the development of the science,technology and economy,on the one hand,the vehicles have brought convenience to people’s lives,on the other hand,they are also brought a series of problems such as traffic congestion and traffic accidents.In this background,the active safety system of vehicles is regarded as an effective measure to solve these problems.However,the traditional active safety system of vehicles which based on vehicle kinematics and dynamics has been unable to meet the people’s individual driving needs.Therefore,this paper studied the trajectory planning and tracking of vehicle lane-changing from the perspective of driving style.(1)Research on driving style based on questionnaire survey analysis and driving simulator experiment.Firstly,combining domestic and international research on driving style and lane-changing,the driving style scale was designed,and 212 data were collected through a questionnaire survey on the internet.Using principal component analysis and K-means clustering analysis,the driving styles were divided into radical,common and conservative.Then the data of lane-changing behavior of different driving style under three different lane-changing conditions were collected by driving simulator experiment,which laid a foundation for the fol low-up study of lane-changing trajectory planning.(2)The lane-changing trajectory considering the driving style was planned.Firstly,the elliptic vehicle model was improved to describe the driving safety area of drivers with different styles,and the minimum safe spacing of lane-changing was constructed.Then combined with the geometric position constraint,driving comfort constrains and the average lane-changing time of different driving style,taking the shortest longitudinal displacement of lane-changing as the target.The lane-changing trajectories planning adapted to different driving styles was realized.(3)Based on linear quadratic optimal control theory,a lateral and longitudinal controller considering driving style was designed.Aiming at minimizing the state error between the actual vehicle trajectory and the desired trajectory during lane-changing,the desired trajectory and velocity can be tracked well by controlling the vehicle front wheel angle and longitudinal acceleration respectively.Through adjusting the control weight matrix of the lateral controller to adapt to different driving styles.The simulation results based on PreScan and MATLAB/Simulink show that the designed trajectory tracking controller has small tracking error and can ens ure the safety and driving comfort during lane-changing.