A New Robust Strategy to Improve the Transient Dynamic of a Vehicle

In this paper for handling improvement and lateral stability increment of a four-wheeled vehicle a new robust active control system is proposed. First, to establish an accurate model of the vehicle, a fourteen-degrees-of-freedom nonlinear dynamic model is developed. model of the vehicle, a fourteen-degrees-of-freedom nonlinear dynamic model is developed. Then, the nonlinear dynamic model is validated using CarSim software in a standard maneuver. Next, a new active steering control system was designed based on a simplified two-degrees-of-freedom dynamic mode to control the lateral motion of the vehicle. Two state variables, namely the vehicle’s yaw rate and the vehicle’s lateral velocity, are controlled using the control system. Also, the sliding mode control method is used to eliminate the error between the actual response and the desired response. Moreover, a complete stability analysis is presented based on the Lyapunov theory to guarantee closed-loop stability. Simulation results show that the controller is able to increase the vehicle’s maneuverability, especially during severe double lane change maneuver in which intense instability occurs. More investigations demonstrate that the proposed control system can considerably improve the vehicle’s path tracking under uncertainties.