Using the Lateral Tire Force to Maneuverability Increment of a Three-wheeled Vehicle During Critical Conditions

In this paper, yaw stability increment of a three-wheeled vehicle has been considered using a new control system. Therefore, a nonlinear dynamic model with twelve-degrees-of-freedom to simulate lateral dynamics of the three-wheeled vehicle has been developed and dynamic model validation is done by means of CarSim software during a standard maneuver. The degrees of freedom are the longitudinal, lateral and vertical velocity and the roll, pitch and yaw angle of the sprung mass, three degrees of freedom for the vertical displacement and three degrees of freedom for rotational movement of the unspring masses. Moreover, to improve handling and lateral stability increment, an active steering control system based on the lateral tire forces has been designed. In the control system, the yaw rate and the lateral velocity of the dynamic model are studied as control states in which must track their desired values. Then, to avoid yaw instability during severe maneuvers, linear quadratic control system (LQR) has been used. Furthermore, to evaluate the performance of the developed control system, an active steering control system has been proposed employing linearization feedback control method. Then, the performance of the dynamic model has been evaluated during without control and controlled conditions. The simulation results show that the LQR control system improves maneuverability and lateral stability during critical maneuver by elimination the error between the yaw rate and its desired value and the lateral velocity restriction.