Research On Coordinated Control Of Intelligent Vehicle Lateral Stability Based On State Estimation And Path Tracking

With the continuous development and popularization of intelligent vehicles,research on vehicle driving stability becomes particularly important.Lateral stability can determine the driving stability of a vehicle on the one hand,ensuring the safe driving process of the vehicle;On the other hand,the control of lateral stability parameters ensures maneuverability and ride comfort.This article conducts research on a coordinated control method for lateral stability of intelligent vehicles based on state estimation and path tracking.The following are the main research contents and achievements of this article:(1)Given the importance of real-time vehicle state parameters for lateral stability control,this paper first designs an EKF observer based on a three degree of freedom vehicle model and extended Kalman filtering theory to estimate important vehicle state parameters;Then,in order to increase the universality of observer usage scenarios,a tire model was added on the basis of three degrees of freedom,and a CKF observer was constructed using Cubature Kalman filtering theory to estimate state parameters,providing accurate and real-time vehicle state parameters for path tracking and lateral stability coordination control in the following text.(2)A vehicle preview path tracking model based on lateral position error and heading angle error is established,and combined with the characteristics of sliding mode control,such as fast response,insensitivity to parameter changes and disturbances,an intelligent vehicle path tracking sliding mode controller based on improved reaching law is designed,which effectively reduces the chattering problem caused by sliding mode control and achieves better path tracking effect.The Carsim/Simulink joint simulation platform was used to verify the vehicle path tracking performance in three scenarios: vehicle speed uncertainty,changes in road adhesion coefficient,and changes in vehicle parameters.The path tracking accuracy and strong robustness of the proposed control method were demonstrated,and its effectiveness in controlling vehicle lateral stability was also verified.(3)A coordinated control strategy for lateral stability of intelligent vehicles based on AFS and DYC coordinated control is proposed to address the limitations of active front wheel steering(AFS)and direct yaw moment control(DYC)when they act alone.The weighted fusion of yaw rate deviation and sideslip angle deviation of the center of mass is used as the sliding mode control variable,and the direct yaw moment sliding mode controller is designed based on the new reaching law;Based on the β-ω phase plane theory and combined with a two degree of freedom model fitting,the critical front wheel angle of the vehicle under critical instability conditions is obtained.Then,in order to ensure the vehicle’s handling stability during DYC intervention in coordinated control,a switching function is designed to determine the intervention timing of the control system and the allocation weights of AFS and DYC in the coordinated control process,ensuring the lateral stability performance of the vehicle during various driving conditions.(4)Based on the CarSim-Simulink joint simulation platform,two extreme driving scenarios of high-speed double lane change and low road adhesion coefficient FHWA were built to verify the effectiveness and robustness of the lateral stability coordination control method.The simulation results demonstrate that the designed intelligent vehicle lateral stability coordinated control method based on state estimation and path tracking has better vehicle stability performance,improved path tracking accuracy,stronger robustness,and ensured passenger comfort compared to AFS and DYC control alone.