Research On Trajectory Planning And Tracking Control Of Intelligent Vehicle Active Lane Change

The intelligent vehicle with autopilot function has attracted more and more attention to improve the safety of the traffic and alleviate the driver’s burden,and one of the core technologies of the intelligent vehicle is the active lane change technology.To achieve the safe and stable lane changing in the complex traffic environment,the active lanechanging trajectory planning and trajectory tracking control of intelligent vehicles are studied in this paper.Firstly,the research status of domestic and foreign on the vehicle active lane changing system is introduced,and the research content of this paper is determined by studying relevant literature.The corresponding vehicle dynamics model,vehicle-to-road position relationship model,and safety distance model are established,which make a good preparation for further research on lane change trajectory planning and trajectory tracking control.In view of the sudden change of front vehicle movement state during lane change,a dynamic trajectory planning method based on the idea of scrolling window optimization is proposed.The initial lane-changing track is planned in the method of quintic polynomial trajectory plan.On this basis,considering collision avoidance constraints and stability constraints during lane changing,the lane changing trajectory is planned online in real time,and the transit position is set to prevent the planned trajectory from exceeding the boundary of the target lane.To keep the intelligent vehicle on the planned trajectory,a lateral controller in the method of the model predictive control and a longitudinal speed controller based on the vehicle inverse longitudinal dynamic model is designed.And the joint simulation of Car Sim/ Simulink is used to verify the effectiveness of the dynamic trajectory planning algorithm and the controller.For the complex traffic scene where there are traffic vehicles in the target lane,considering that the change of the motion state of the front vehicle and rear vehicle in the target lane have an impact on the lane changing of intelligent vehicle,the lane-changing trajectory correction strategy and lane changing return strategy are respectively designed.For adjusting the lane-changing track more flexible,the lane-changing trajectory is replanned horizontally based on the quintic polynomial,and the improved cosine acceleration model is used for longitudinal replanning.Simulation analysis is used to prove that the rescheduling method is effective.Finally,experiment on the hardware-in-the-loop experimental platform is used to prove that the designed lane-changing trajectory planning algorithm and tracking control algorithm is effective,and the effectiveness of the planning algorithm and the tracking algorithm in this paper is verified by the result of the experiment.