Research On Trajectory Tracking Control For Autonomous Vehicle On MPC And Preview Theory

With the gradual growth of vehicle ownership in China,the traffic environment is becoming increasingly complex,and a series of problems such as traffic accidents and environmental pollution occur.Intelligent,electric and low-carbon cars have become an important development trend,and the research on automatic driving technology and active safety technology of cars is extremely urgent.Therefore,this paper carries out an analysis and research on the trajectory following control of autonomous vehicles.Relying on the Natural Science Foundation of Zhejiang Province(Fund No.LY21E050001),this paper takes autonomous vehicles as the research object and considers the tracking accuracy and driving stability during trajectory following.The trajectory following control based on driver previewing theory and the trajectory following control method based on model prediction are studied and analyzed.The specific research contents can be summarized as follows:(1)According to the actual driving conditions of the vehicle and the driver,the corresponding hypotheses are obtained,and the vehicle monorail model and the magic tire model considering only tire lateral dynamics are established.Based on the Frenet coordinate system to study the trace tracking of autonomous vehicles,the trajectory following motion of autonomous vehicle is analyzed and studied.Car Sim was used to simulate the real vehicle and driving conditions,and the track following controller designed below was verified and analyzed by establishing Car Sim/Simulink co-simulation model.(2)Aiming at the trajectory following control problem of autonomous vehicles,a single-point pre-view trajectory following controller is designed based on the driver model.Through analyzing and improving the single-point pre-view trajectory following control,a two-point pre-view trajectory following controller based on sliding mode-fuzzy control is designed.Compared with single point preview,the tracking accuracy of two-point preview is improved greatly.(3)In view of the automatic driving vehicle at high speed or low adhesion limit working conditions is not accurate and stable trajectory follow problem,first of all,based on the model prediction theory(MPC)trajectory following controller was designed,carries on the analysis and improvement,finally put forward considering the wheel side-slip Angle constraint MPC trajectory following controller,the simulation results show that,The proposed control strategy has good stability for different vehicle speeds and road adhesion coefficient,and has high tracking accuracy when the trajectory is followed.