Research And Implementation Of Intelligent Vehicle Lane Changing Control Based On Predetermined Route

Intelligent vehicle is the future development direction of vehicle.Lane change control is the research hot-spot of automatic driving technology.Autonomous lane change is one of the key technologies of advanced auxiliary driving system.The research of lane change control is conducive to improving driving safety and road utilization efficiency.Lane change control is mainly divided into lane change trajectory planning and trajectory tracking.Good lane change trajectory planning can ensure the feasibility,safety and comfort of vehicle lane change,and whether the lane change trajectory can be executed efficiently and stably depends on the performance of the trajectory tracking controller.Aiming at the existing roads map,this paper designs a lane changing trajectory planning algorithm based on Bessel curve,and dynamically plans the lane changing trajectory according to the environmental information and vehicle state.Based on the classical sliding mode control,using a new reaching law to optimization control,and the fuzzy control is used to dynamically adjust the parameters to improve the performance of the trajectory tracking controller.This thesis studies the lane change control of intelligent vehicles,mainly including the following aspects:(1)Build an automatic driving vehicle platform based on the electric car.The transformation of the scooter mainly includes the chassis linear control transformation,the selection and installation of sensors,etc.The automatic driving software control platform realizes human-computer interaction and vehicle motion control,and provides an experimental platform for the research of lane change control.(2)The lane changing trajectory planning algorithm is designed based on the predetermined route.Considering the performance requirements of lane change trajectory and predetermined route condition,the Bessel curve with simple calculation and smooth curve is selected to generate lane change trajectory.And then the feasible region of lane change trajectory planning is adjusted according to lane change constraints and obstacle avoidance needs.Finally,the loss function is designed to obtain the optimal Lane change trajectory.In the MATLAB environment,the simulation experiment is designed under the two working conditions of obstacle and obstacle free ahead,which verifies that the lane change trajectory planning algorithm can obtain a good lane change trajectory at different speeds.(3)The trajectory tracking controller is designed based on sliding mode control theory.Based on the classical sliding mode control,a new reaching law and a hyperbolic tangent function are used to replace the symbolic function to improve the convergence speed of the controller and reduce the system chattering.In view of the difficulty in selecting the reaching law parameters,this thesis designs a fuzzy controller to dynamically adjust the parameters and further improve the performance of the trajectory tracking controller.Finally,Matlab simulation experiments verify that the fuzzy adaptive sliding mode controller has good trajectory tracking effect.(4)The designed algorithm is loaded to the experimental vehicle and tested on the actual road.I set up obstacle conditions and obstacle free conditions on the actual road,and analyze the driving track of the experimental vehicle under different conditions.The real vehicle test results verify the reliability of the algorithm in this thesis.