Patent ID: 7809484

Claim:
A method for active front wheel steering control for a vehicle having steerable front wheels and fixed rear wheels, comprising: generating a steering wheel angle signal corresponding to a steering wheel angle; controlling the steerable front wheels based upon a steering control signal comprising a combination of an open-loop steering control signal and a closed-loop steering control signal; estimating vehicle dynamics parameters based upon signal inputs from vehicle sensors; providing the open-loop steering control signal corresponding to the steering wheel angle signal; providing the closed-loop steering control signal based upon the estimated vehicle dynamics parameters; providing an original yaw rate feedback angle signal; and providing a corrected yaw rate feedback angle signal based on the estimated vehicle dynamics parameters; wherein the corrected yaw rate feedback angle signal is provided in accordance with the relationship: δ RP = K RP o ⁡ ( V x ) · ( Ω c - Ω ) + ( Δ ⁢ ⁢ K RP Δ ⁢ ⁢ T  o ⁢ Δ ⁢ ⁢ T ⁡ ( V x ) + Δ ⁢ ⁢ K RP Δ ⁢ ⁢ D F  o ⁢ Δ ⁢ ⁢ D F + Δ ⁢ ⁢ K RP Δ ⁢ ⁢ D R  o ⁢ Δ ⁢ ⁢ D R ) · ( Ω c - Ω ) where, Ω is a yaw rate; Ω 2 is a yaw rate command; K 0 RP (V x ) is a nominal yaw rate feedback gain table as a function of a vehicle speed; ΔD F is a change in a front cornering compliance; ΔD R is a change in a rear cornering compliance; ΔT is a deviation in an open-loop gain; and Δ ⁢ ⁢ K RP Δ ⁢ ⁢ T  o , Δ ⁢ ⁢ K RP Δ ⁢ ⁢ D F  o ; Δ ⁢ ⁢ K RP Δ ⁢ ⁢ D R  o is a yaw rate P-gain sensitivity to the open-loop gain, the front cornering compliance, and the rear cornering compliance, respectively.