A System Design On Lane Keeping Assistance System Based On PreScan

With the popularization of on-board sensors and the development of high-precision maps,Advanced Driving Assistance System(ADAS),one of the key technologies of driverless vehicles,has gradually come into people’s vision.on-board sensors and highprecision maps were applied in Advanced Driving Assistance System to analyzing and calculating real-time environmental information while driving,and early warning or active control of vehicles were adopted to ensure the driving safety,which has become a research hit of major universities,automobile companies,and parts suppliers.Researches on Advanced Driving Assistant System not only conform to the trend of automobile development,but also effectively correct drivers’ misoperation and improve the comfortableness and safety of driving.This paper mainly studies the lane keeping assist system,which is a subsystem of advanced driving assistant system.Firstly,the kinematics model and dynamic model of vehicle monorail were built,and then the tire model of vehicle was built according to Pacejka magic formula.In addition,with the dynamic model,the path tracking algorithm based on optimal preview theory and the velocity tracking algorithm based on PreView were developed.What’s more,an algorithm test platform based on PreScan/Carsim/ Simulink was constructed.The test results show that the vehicle can track the target trajectory well in straight or small curvature sections,while the vehicle cannot track the target trajectory well,even press the lane lines of sides or deviate from the lane when the vehicle is too high in speed or passes through the section with larger curvature.In order to improve the applicability of preview algorithm and solve the problem of inadequate applicability of traditional fixed preview time preview algorithm in large curvature section and high-speed section,Based on the experimental data of Korea Automobile Research Institute,the preview distance matched with vehicle speed and road curvature is given by interpolation fitting method.Through the test of the joint simulation platform,the target trajectory can be well tracked by the improved preview tracking algorithm at no matter what speed and with no matter what pipeline curvature.Finally,in order to verify whether the improved preview algorithm can run in hardware,in this paper,hardware-in-the-loop test platform was designed in which PreScan scenario was run on the PC,dynamic model CarsimRT was run on the lower computer dSPACE,and preview algorithm on the MSC controller.The results of hardware-in-the-loop test show that,whatever the road curvature and vehicle speed is,the communication delay of the improved preview algorithm in hardware is controlled within 0.1s,and he target trajectory can be well tracked by the embedded preview algorithm in hardware,neither deviating from the lane nor pressing the lane lines of sides.