A gyroscopic system is designed and utilized as an actuator for the prevention of vehicle rollover. The vehicle motion before rollover and during rollover is considered in two phases: before lift-off of the wheels and after lift-off of the wheels. The lateral load transfer ratio is used to identify the time when the wheels lift off the ground. Based on the equations of motion for the vehicle on two wheels, an imminent rollover algorithm is designed to specify the rollover risk. A fuzzy controller that determines the required roll moment to stabilize the vehicle is designed. A gyroscopic package is designed to apply the corrective roll torque directly on the rolling mass of the vehicle in the opposite direction to the rollover moments. The performance of the proposed system is investigated by simulating some severe manoeuvres, and the results show that the system is able to stabilize the vehicle successfully.

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In the current work the yawing and side-slip motion of a two-mass vehicle is studied. The vehicle is divided into an upper rigid mass and a lower rigid mass pivoted on one another on a vertical axis through the centre of mass. The vehicle body constitutes the upper rigid body, and the suspension axles represent the lower rigid body. A yawing stiffness and damping package is acting between the two rigid bodies. The equations of motion of the two-body yawing vehicle are developed, and the handling behaviour of the vehicle is compared with that of a basic two-degree-of-freedom vehicle-handling model. The steady-state yaw responses of the two systems are equal but the side-slip angles are different. The results show considerable differences in the transient response properties of the two systems. With regard to the stability of motion, at situations where the two-degree-of-freedom model is stable, the three-degree-of-freedom yaw stiff model is also stable.

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