Four wheel steering system for motor vehicle - replaces velocity-dependent parameter by constant value when detected velocity is unreliable

摘要

The steering system uses individual steering mechanisms (A,B) for the front and rear steered wheels, coupled to an electrical steering control (D), receiving inputs from a velocity sensor (62) and from a device (61,63) for detecting the vehicle sidewards drift. The required rear wheel steering angle is calculated from the sidewards drift and a parameter related to the detected velocity, with a constant parameter value employed when the detected velocity is unreliable. Pref. the detected velocity is discounted when the velocity sensor (62) exhibits an abnormality, or when one of the wheels is blocked. ADVANTAGE - Eliminates steering errors due to inaccurate velocity measurement.