Research On Path Tracking Control Algorithm For Commercial Vehicles Based On Pre-Sighting

With the continuous improvement of China’s economic level,it has driven the rapid development of the long-distance freight industry.Commercial vehicles have become an important part of the country’s traffic transportation field because of their large cargo capacity and suitability for long-distance transportation.Commercial vehicles are mainly suitable for trunk road transportation,but during long-distance transportation of goods,drivers may cause traffic accidents due to fatigue and improper operation,resulting in incalculable losses.The application of autonomous driving technology in commercial vehicles will not only help reduce driver fatigue,accident rates and fuel consumption rates,but also improve road access and driving comfort.The autonomous driving technology of commercial vehicles has become a research hotspot currently and for a period of time in the future.Path tracking control technology is one of the key technical problems that need to be solved to achieve autonomous driving.Therefore,studying the path tracking control algorithm of commercial vehicles is of great significance.The research team cooperated with a vehicle enterprise to carry out the research of commercial vehicle assisted driving technology.The main goal of this project is to build a tractor path tracking control system and achieve stable tracking of the target path by the tractor based on the built system.The specific work includes model establishment,algorithm simulation,software and hardware integration,and actual vehicle testing.The main research contents are as follows:(1)Model building: according to the motion characteristics of the tractor,the model is simplified,and a two degree of freedom vehicle dynamics model is established.Based on the preview mechanism,the preview tracking error model is established to obtain the preview error when tracking the target path,so as to ensure that the intelligent vehicle can predict the road information ahead in advance and lay the foundation for the design of the path tracking control algorithm.(2)Design and simulation of path tracing control algorithms: considering the change of vehicle position and the state of vehicle dynamics,combining the preview error model when the vehicle is running with the vehicle dynamics model,the LQR lateral path tracking control method based on preview is designed to achieve stable tracking of the target path.Secondly,the curvature feedforward control method is used to improve the control effect of path tracking.Finally,a joint simulation was conducted using Truck Sim and Matlab/Simulink to verify the effectiveness of the designed path tracking control algorithm.The simulation results show that the designed control algorithm can achieve stable tracking of the target path by the vehicle,and the maximum tracking lateral deviation in the simulation does not exceed 0.1m.(3)Path tracking control system software and hardware integration and real vehicle verification: on the tractor produced by the partner company,the software and hardware of the path tracking control system were integrated,and relevant real-world tests were conducted to verify the designed path tracking control algorithm in real vehicles.The results of the real vehicle test show that the tractor can stably track the target path at low speed,which verifies the accuracy of the control algorithm and achieves the expected goal set by the enterprise.