Control system for a front and rear wheel steering vehicle

Abstract

In a control system for a front and rear wheel steering vehicle which steers the rear wheels so as to cancel a deviation of an actual yaw rate from a standard yaw rate which can be computed from the steering input, the vehicle speed and other parameters, there is provided a feature to automatically and manually cancel the yaw rate feedback control. If the actual yaw rate continues to exceed a threshold level for more than a certain time period, the yaw rate feedback is canceled gradually so as not to cause any abrupt change in the handling of the vehicle. Alternatively, if the vehicle operator wishes to operate the vehicle under extreme conditions, he may manually cancel the yaw rate feedback control so as to avoid undesirable interference or conflict between the manual steering effort and the yaw rate feedback control action. Thus, the maneuverability of the vehicle under extreme conditions can be improved without losing the benefits of the yaw rate feedback control.