Patent ID: 7493201
Filing Date: 2009-02-17
Classification: B62D

Abstract:
1. A method for providing an active front steering for a vehicle, said method comprising: providing a vehicle speed signal of the vehicle; providing an actual yaw rate signal of the actual yaw rate of the vehicle; providing a steering command signal indicative of the vehicle operator's desired steering direction; providing a lateral acceleration signal of the lateral acceleration of the vehicle; determining a yaw rate command signal based on the steering command signal and the vehicle speed signal; determining a yaw rate error signal as the difference between the yaw rate command signal and the actual yaw rate signal; determining a derivative of the yaw rate error signal; determining an understeer and oversteer condition of the vehicle based on the steering command signal, the actual yaw rate signal, the vehicle speed signal and the lateral acceleration signal; determining an understeer flag and an oversteer flag based on the understeer and oversteer behavior condition; determining a vehicle understeer control and a vehicle oversteer control based on the understeer and oversteer flags; determining a front steering feedback control signal based on the understeer control and the oversteer control; combining the front steering feedback control signal and the steering command signal to provide the active front steering; and determining dead bands where the method does not provide the feedback control signal if the yaw rate error signal is below a predetermined threshold.