Research On Parallel Parking Path Planning And Tracking Control

With the continuous increase of car ownership,the problem of "parking difficulty"becomes more and more prominent,and the limited parking space brings great challenges to the parking space.An effective parking system can not only help drivers complete parking operations quickly,but also reduce traffic accidents.Therefore,it is of practical significance to study the path planning and tracking control in the automatic parking system for improving the intellectualization of vehicles and alleviating the pressure of drivers.In the process of parallel parking,the vehicle always travels at a low speed.In this process,the vehicle will not have wheel sliding and lateral movement.According to the characteristics of the vehicle,the mathematical model of vehicle kinematics is established by using The Ackerman steering principle.In the aspect of path planning,the minimum radius method is adopted to carry out the path planning for the parking scene of vehicles in a simple environment.By analyzing the anti-collision constraint conditions,steering Angle constraint conditions,minimum parking space constraint conditions and initial position constraint conditions of the minimum radius method in parallel parking,the initial range of vehicle parking was determined,and the feasibility of the minimum radius method was verified by simulation experiments based on different initial positions.A parallel parking path planning method based on minimum radius and artificial potential field is proposed for the vehicle parking scene in complex environment.Considering that the traditional artificial potential field method has the problem that the excessive gravitational field may cause the collision between the target vehicle and the obstacle vehicle,this method takes the path planned by the minimum radius method as the initial path.When the vehicle moves into the influence range of the obstacle vehicle,the artificial potential field method is used to modify the initial path.The simulation results show that the path planned by the minimum-radius artificial potential field method can dump the vehicle into the garage and avoid collision with the obstacle vehicle.In the aspect of path tracking control,a path tracking controller based on fuzzy PID is designed.The simulation experiment platform of MATLAB and Carsim was built to study the effect of path tracking control.The simulation results show that the fuzzy PID control has better tracking effect than the traditional PID control,and can better realize the track control of vehicle in simple environment and complex environment.