Decoupling Driveline and Steering Systems for 4 × 4 SUV Lateral Dynamics

This paper is concerned with the coupled effects of a vehicle's driveline and steering system. The interaction of the tire longitudinal forces, characterized by the driveline system, on the lateral dynamics of the vehicle is analyzed in terms of the impact on steering accuracy and potential for lateral skid. A concept for a hybrid electric power transmitting unit utilizing a planetary gear set and eddy current brake to provide a variable gear ratio is considered for controlling the front/rear split of longitudinal forces to decouple and make interactive the dynamics of the driveline and steering systems. Computer simulations are performed for a 4x4 small Sport Utility vehicle (SUV) with and without the hybrid electric device to compare the difference in the lateral behavior.