Patent ID: 7434654

Claim:
A method for controlling a resistance to turning steerable wheels of a vehicle including a controller, a steering wheel angle sensor responsive to rotation of a steering wheel, a speed sensor, and a coil for varying stiffness of a valve, said method comprising the steps of: turning the wheels of the vehicle in response to rotation of the steering wheel; sensing a signal corresponding to an angle of the steering wheel; sensing a signal corresponding to a speed of the vehicle; inputting the sensed signals for the angle of the steering wheel and the speed of the vehicle into the controller; determining a lateral acceleration based on the sensed signals; determining a recommended current rate of the coil based upon the lateral acceleration; determining an adjustment to the recommended current rate of the coil based upon the sensed signal for the speed of the vehicle; multiplying the recommended current rate of the coil and the adjustment to the recommended current rate of the coil to produce a modified current rate of the coil; and applying the modified current rate of the coil to energize the coil and vary the stiffness of the valve to vary the resistance to turning the steerable wheels.