Research On Vertical Automatic Parking System Based On Path Planning And Tracking Control

In recent years,with the development of intelligent driving technology,the automatic parking system has become the research focus in the intelligent driving assistance system.The automatic parking system acquires parking space information through sensors and controls the vehicle to enter the target parking space after detecting the parking space.This greatly reduces the driver's burden during the parking driving operation,while also ensuring the safety and efficiency of the parking process.According to the development experience of the automatic parking system and some problems existing in the current research,this paper studies the parking space detection,path planning and path tracking control algorithms of the vertical automatic parking system.The main work contents are as follows:Firstly,for the parking space detection of vertical parking,this paper proposes a parking space detection scheme based on ultrasonic radar ranging technology,and briefly introduces the principle and main characteristics of ultrasonic radar.Based on the characteristics of vertical parking,the basic characteristics and overall detection ideas of parking space recognition in three typical working conditions are proposed.The structural framework and logic algorithm of parking space detection scheme are established.The effectiveness of the parking space recognition algorithm is verified in the co-simulation platform of Prescan and Matlab-simulink.Secondly,for the vertical automatic parking path planning algorithm,the parking kinematics constraint based on the Ackermann steering geometry principle is obtained,and the safety avoidance constraint is established based on the vertical parking environment analysis.Different vertical parking path planning schemes are proposed for different parking initial areas.At the same time,the process of reversing into the warehouse is considered to continuously turn to the non-stop problem,and the fifth-order polynomial is used for the first stage of the storage curve to fit and optimize.Finally,a target path that satisfies the constraints of vehicle motion characteristics,safe collision constraints,and continuous curvature is obtained.Based on the vehicle kinematics model,the feasibility of the path planning algorithm is verified in Matlab.Finally,based on the target vehicle's path tracking algorithm for research and analysis,a control strategy based on the combination of lateral preview direction control and target speed vertical control is proposed.The vertical automatic parking simulation experiment platform and algorithm simulation model based on Prescan/Simulink are built.The effectiveness of the path tracking algorithm is verified by the one-step and multi-step modified parking modes.Furthermore,the simulation experiment of the complete parking process is carried out for the initial position lateral distance,parking space type and parking orientation related factors,and the feasibility and effectiveness of the proposed vertical automatic parking system algorithm are verified.