Research On Lane-changing Trajectory Planning Method For Autonomous Vehicles

In order to reduce the occurrence of traffic accidents caused by the improper behavior or wrong operation of traffic participants,as a new technological revolution of automobile manufacturing and transportation,the research on automatic driving vehicles has been paid great attention by traffic researchers and many scholars for a long time.And lane change is the most common behavior in the research of automatic driving vehicles,which greatly affects the flow of the road,so the fast and safe lane change operation has a strong practical significance to reduce traffic accidents.Therefore,it is of great significance to plan and study the lane changing trajectory of automatic driving vehicles to improve the efficiency of lane changing,reduce traffic accidents and promote the development of automatic driving vehicle technology.Firstly,the scene of lane changing of automatic driving vehicles is analyzed,which is divided into forced lane changing and free lane changing.The characteristics of lane changing are analyzed,the whole process of lane changing of automatic driving vehicles is studied,the safety distance model of lane changing of automatic driving vehicles is constructed,and the vehicle kinematics and dynamics models are established to study the lane changing trajectory planning of automatic driving vehicles The research is to pave the way for the early stage.Secondly,the smooth vehicle trajectory data is obtained by processing and analyzing the vehicle trajectory data of expressway;the lane changing trajectory in the process of vehicle lane changing is extracted,and the space-time diagram of lane changing trajectory is drawn,and the basic lane changing information such as vehicle speed,acceleration and headway in the process of vehicle lane changing is analyzed.Thirdly,the six basic models of vehicle lane changing trajectory are analyzed,and the basic characteristics of each model are described in detail.At the same time,the six lane changing trajectory models are compared.Considering that the polynomial lane changing trajectory model can be derived many times,the curvature is continuous,and the initial acceleration value starts from zero,the polynomial lane changing trajectory model is selected as the basic model of this paper;Based on the vehicle anti-collision algorithm and avoid roll-over algorithm,the safety constraints of the automatic driving vehicle model are established,the objective function is established to find the optimal vehicle lane changing trajectory,and the generated automatic driving vehicle lane changing trajectory is verified to ensure the safety and practicability of the lane changing model.Finally,considering the vehicle’s own operating environment,external roads and traffic scenes,the detailed simulation models of vehicle model,road model and event model are built for the automatic driving vehicle,and the lane changing of the automatic driving vehicle is simulated by using Matlab/Simulink and Car Sim software;combined with the lane changing trajectory data information and lane changing trajectory planning model information,the calculation results are imported into Car Sim software for verification The simulation analysis of four different scenarios of automatic driving vehicle lane changing is carried out,and the error information f simulation trajectory and planning trajectory is compared,which proves the effectiveness of the method of automatic driving vehicle lane changing designed in this paper.