Stabilizing Vehicle Lateral Dynamics with Considerations of State Delay of AFS for Electric Vehicles via Robust Gain-Scheduling Control

This paper presents a robust gain-scheduled H controller to improve lateral stability and handling of four-wheel-independent-drive electric vehicles possessing active front steering system with considerations of state delay. The time delay for the state is assumed as uncertain time-invariant but has a known constant bound. By considering the tyre cornering stiffness represented by the norm-bounded uncertainty and the time-varying longitudinal velocity described by a polytope with finite vertices, and the vehicle lateral dynamics model is converted into the uncertain vehicle linear parameter-varying (LPV) state-delayed system. The resulting delay-dependent robust gain-scheduling state feedback H controller is finally designed utilizing the constructed Lyapunov-Krakovskii functional, and solved via a set of delay-dependent linear matrix inequalities (LMIs). Simulations for various driving scenarios are implemented using MATLAB/SIMULINK-CARSIM. The simulation results show the effectiveness of the proposed controller.