Patent ID: 6612395
Filing Date: 2003-09-02
Classification: B62D

Abstract:
A steering system for a vehicle, said system comprising:a steering handle actuated by a driver of a vehicle, wherein the steering handle can be set at an angle; at least one steerable vehicle wheel, wherein said at least one vehicle wheel is set at angles which are a function of actuations of the steering handle; a control system for operating said steering system on a steer-by-wire level and on a fall-back level wherein said control system controllably switches from the steer-by-wire level to the fall-back level at least during an emergency; an electrical coupling device for coupling the steering handle to the steerable vehicle wheel on the steer-by-wire level; at least one of a hydraulic and mechanical coupling device for coupling the steering handle to the steerable vehicle wheel on the fall-back level wherein the coupling between the steering handle and the steerable vehicle wheel is preformed as a function of at least one first coupling coefficient (k1) on the steer-by-wire level and as a function of at least one second coupling coefficient (k11) on the fall-back level with each of said first and second coupling coefficients being formed as functions of at least one operating parameter (p) of the vehicle or the steering system with the functions of said at least one operating parameter being formed in such a way that a difference between said first and second coupling coefficients is smaller than a limiting difference (A) for all values of the operating parameter (p) greater than a limiting value (pa).