Research On Intelligent Vehicle Path Tracking Based On High-precision Combined Positioning Equipment

Intelligent driving of automobiles is the future development field and development direction of automobiles.Path tracking of intelligent vehicles is the key links of intelligent driving technology.It is of great significance for the research on intelligent and unmanned vehicles.This subject uses high-precision combined positioning equipment that combines RTK GPS and IMU inertial measurement units.Completed the collection of the location information of the test section,and based on the collected location information,established a high-precision trajectory on which the vehicle path tracking depends.By studying vehicle path tracking methods,the verification and research of vehicle path tracking is completed on a self-built communication platform.This thesis makes a detailed introduction to intelligent vehicles and hardware equipment,and the CAN bus technology,serial communication technology used.The article makes corresponding research on positioning technology and positioning products.By comparing the positioning accuracy and the rationality of the installation method,the INS550 D model of Daoyuan Electronics was selected.And use the communication technology introduced.Based on the ubuntu system,the ROS communication framework is built on the vehicle-mounted advantech industrial control computer.Relying on the ROS communication framework,the data receiving node of the combined positioning equipment is designed.According to the dbc file of vehicle bus communication,a wire-controlled vehicle communication node and a wire-controlled vehicle bottom control node are designed,and preparations for vehicle path tracking are completed.After saving the vehicle state information in real time and filtering and denoising the positioning data,the preprocessing of the positioning data is completed.Based on the positioning information,UTM coordinate projection is used to convert the latitude and longitude information into two-dimensional rectangular coordinates.The article constructs a vehicle trajectory map by curve fitting.By comprehensively comparing various path tracking methods,based on the road geometry model of Stanley method,the path tracking method in this paper is designed.Through the introduction of the path tracking method,the closest point of the vehicle trajectory,the selection of the preview point and the preview distance aredetermined,and the steering direction of the vehicle is determined.And calculate the lateral and heading deviation of the vehicle according to the designed path tracking method.By determining the control state quantity such as the required turning angle of the vehicle,it is sent to the wire-controlled vehicle control node to complete the real-time control of the intelligent vehicle.Finally,by completing the construction of the experimental environment,the path tracking method was tested and verified at the test site of Chang’an University Weishui Campus.By comparing the target trajectory with the tracking trajectory,it is verified that the path tracking method has good robustness under low-speed operating conditions.