Research On Location And Path Tracking Error Of Driverless Vehicle Under Snowfall Conditions

As an inevitable trend of vehicle development,driverless vehicle has become one of the hot issues in recent years.In order to achieve driverless vehicle,vehicle location and path tracking become two basic research directions of driverless vehicle safety driving.In order to realize the safe driving of driverless vehicles,the accuracy of positioning system,the continuity of positioning system and the real-time of positioning system are required;in the case of driverless vehicles driving safely in the lane,the accuracy of path tracking is required.To solve these two problems with reasonable and efficient methods is a subject worthy of further study and discussion.In terms of vehicle positioning.The satellite positioning system will be affected by many factors when it works in the complex urban environment.This paper looks for a breakthrough from the most basic positioning principles and methods,compares the positioning accuracy of conventional RTK and network RTK and its influencing factors on the positioning accuracy,and adopts a fusion algorithm based on CORS Network RTK differential positioning,inertial measurement unit and track inference algorithm To improve the positioning accuracy of driverless vehicles.In order to improve the positioning accuracy of the whole path,this paper analyzes how to improve the positioning accuracy of the point by integrating various kinds of positioning equipment.By using two different RTK Positioning Methods and static positioning and dynamic positioning on snowy days(troposphere change)and sunny days respectively,the positioning accuracy errors under different conditions are analyzed in detail,and an overall scheme more suitable for the positioning accuracy requirements of driverless vehicles is sought to provide a more stable and high positioning accuracy for driverless vehicles At the same time,it can provide high-precision positioning information for path tracking control and reduce the error of path tracking as much as possible.In the aspect of path tracking control.This paper mainly studies the lateral control and longitudinal control according to the motion law of the vehicle,and applies a preview point tracking method based on the positioning point to develop the overall path tracking scheme of the driverless vehicle.In the point tracking algorithm,the selection of the positioning point is based on the preview principle;the preview point is selected and the preview distance is determined according to the current vehicle speed,vehicle attitude,path curvature and other information.The path tracking system uses the incremental PID control vehicle longitudinal tracking and preview point tracking principle to control vehicle lateral tracking.Finally,based on the vehicle kinematics model,the parameters of the whole vehicle are set in the CarSim software,the overall control model is built in the MATLAB/Simulink software,the overall path tracking model is built in the joint simulation platform,the normal road surface and snow road are simulated by setting different road adhesion coefficient,and the joint simulation is carried out under the conditions of different speeds and different paths The path tracking error of driverless vehicle is analyzed.