Research On Vehicle Active Obstacle Avoidance Control System

With the continuous advancement of driving technology,driverless cars have greatly facilitated people’s work,study and life.They have promoted the development of intelligent transportation systems and have attracted widespread attention from the world.However,there are many difficulties in the research process of driverless cars because they require the support of various advanced technologies.Based on the existing research results,this paper further studies the obstacle avoidance technology of unmanned vehicles.The main research contents of this paper are:（1）This paper first introduces the more advanced obstacle avoidance technology,summarizes the research results,and makes my research more purposeful.（2）Analyze the vehicle transverse and longitudinal dynamics,kinematics and model the vehicle and tire,then linearize the tire model,and finally construct a state space expression,which is used for the subsequent vehicle active lane change obstacle avoidance control system.（3）A safety distance model based on traffic conditions is designed,and an obstacle avoidance mode conversion strategy adapted to the obstacle avoidance scene is designed.When the conditions for changing lanes and avoiding obstacles are met,the method of changing lanes is adopted to avoid obstacles in front of them;otherwise,choose braking to avoid obstacles.（4）The next step is the design of the vehicle lane-changing obstacle avoidance trajectory.The static global path planning can no longer guarantee the safety of the vehicle in the dynamic environment.This paper designs a lane-changing obstacle avoidance trajectory based on a sixth degree polynomial.When there are obstacles and obstacle vehicles on the reference path,local path planning can be carried out according to the vehicle state and the information of the surrounding environment of the vehicle to ensure the driving safety of the vehicle.（5）Vehicle longitudinal active braking obstacle avoidance is an important part of vehicle obstacle avoidance system.This paper designs vehicle active braking obstacle avoidance system based on LQR.When the vehicle does not meet the obstacle avoidance conditions for lane changing,the active braking obstacle avoidance system can control the vehicle to brake to avoid the obstacle ahead.（6）The last is the design of vehicle lane change obstacle avoidance control system.First,MPC,RMPC and Kalman filter technology are studied.On this basis,the lane change obstacle avoidance trajectory tracking based on Kalman filter robust model predictive control is designed.controller.The trajectory tracking controller can not only ensure that the self-driving car drives to the target lane according to the lane-changing trajectory designed in Chapter 4 when changing lanes to avoid obstacles,but also keeps the roll angle and yaw angle within a certain range.