Abstract:

Heavy-duty vehicles have the characteristics of large moment of inertia and slow control response. For heavy-duty commercial vehicles， a three-dimensional phase space analysis method is designed based on the sideslip angle， yaw rate and vertical load transfer coefficient to judge the real-time stability state of vehicles. For different vehicle driving conditions， AFS control and AFS /DYC hierarchical control are adopted， and the extension control method is designed based on adhesion coefficient to compensate the control output of front wheel angle and yaw moment， so as to ensure the robustness of the controller under different working conditions. The validity of the proposed method is verified by TruckSim /Simulink co-simulation and hardware in the loop experiment， with the superiority of the dynamic stability domain in phase space demonstrated in the simulation by the comparison of \beta -\dot{\psi }-LTR judgment and \beta -\dot{\psi } judgment. The simulation and experimental results show that compared with the way tooperate the vehicle only according to the driver’s intention， the designed AFS/DYC control strategy based on Extension H_{\mathrm{\infty }} method can ensure better stability of the vehicle under different working conditions， especially on the low adhesion road， and thus effectively reduce the probability of traffic accidents under extreme working conditions.

Key words: vehicle handling and stability, phase plane analysis, {\mathit{H}}_{\mathrm{\infty }} control')">output feedback robust {\mathit{H}}_{\mathrm{\infty }} control, dynamic boundary, extension decision