Research On Overtaking Control Strategy Of Autonomous Vehicles

With the continuous development of automobile technology,autonomous driving has become a research focus in the field of vehicle engineering.Overtaking is one of the contents of automatic driving,which is of great significance for ensuring the safe driving of cars.This thesis studies the overtaking control strategy and technology in autonomous driving,the main contents include:(1)Taking traditional fuel vehicles as the research object,a vehicle inverse longitudinal dynamics model reflecting the dynamic characteristics of the system is established according to the driving/braking conditions,and the acceleration/brake switching control strategy is designed.(2)Imitating the decision-making process of a human driver when overtaking,the overtaking behavior is divided into four sub-behaviors: following,left lane changing,overtaking,and right lane changing.The transfer relationship between states is analyzed and established by finite state machine The decision model of overtaking behavior is improved,which reduces the difficulty of system decision-making.(3)On the premise of avoiding collisions,combined with legal requirements,a longitudinal safety distance model based on the time of the workshop and the minimum safety distance for lane change are determined,and the safe lane change area is determined.At the same time,the fifth-degree polynomial lane change path and the constant velocity migration-sine function superimposed lane change path are analyzed,and the constant velocity migration-sine function superimposed lane change path is selected as the lane-changing overtaking reference path.(4)Decoupling of vehicle motion control.A vertical hierarchical control architecture and horizontal PID controller are designed.A joint simulation platform was built to verify the path tracking performance of the control system at different vehicle speeds and different road adhesion coefficients.The simulation results show that the tracking effect of the lane-changing path is better,the system responds quickly,and the stability is high.(5)Based on CarSim and Simulink software,a joint simulation platform was built,and the proposed control strategy was simulated and verified under typical operating conditions.The simulation results show that the overtaking control strategy proposed in this paper has a better control effect on the realization of automatic driving vehicles changing lanes and overtaking.