Coordinated control strategy of AFS and DYC Based on stability category recognition

• An integrated coordinated control strategy of AFS and direct yaw moment control (DYC) system to enhance vehicle stability. • Joint simulations using CarSim/Simulink validate the effectiveness of the coordinated control strategy proposed in this paper. • Under the proposed control strategy, the peak value of yaw rate γ decreases by 12 % compared to uncontrolled conditions. Considering the issue of insufficient control capability of the active front steering (AFS) system in maintaining vehicle stability due to tire lateral characteristics, this paper proposes an integrated coordinated control strategy of AFS and direct yaw moment control (DYC) system to enhance vehicle stability. The proposed control system consists of two main parts. The first part is the system state recognition and control weight calculation module, which utilizes the K-means++ clustering algorithm to determine the stability hierarchy of the vehicle. Based on real-time vehicle states, it calculates online the control weights for AFS and DYC. The second part employs sliding mode control (SMC) to separately compute the additional yaw moment ∆M required for maintaining vehicle stability by DYC, which is transformed into additional braking torque, and the additional front wheel steering angle required by the AFS system. Actual control inputs are then derived based on the control weights and transmitted accordingly. Joint simulations using CarSim/Simulink validate the effectiveness of the coordinated control strategy proposed in this paper. In vehicle tests, under the coordinated control strategy, the peak value of yaw rate γ decreases by 12 % compared to uncontrolled conditions.