Patent ID: 8775048

Claim:
A method of determining a reference velocity, the method performed by a controller and comprising the steps of: determining a first reference velocity from a first front wheel speed signal, a second front wheel speed signal and a drive speed signal, the drive speed signal comprises one of an axle speed signal or a driveshaft speed signal and is representative of a drive speed; determining a first updated vehicle velocity using the first reference velocity and a longitudinal acceleration; determining whether the vehicle is accelerating or decelerating; when the vehicle is accelerating, setting a second reference velocity as a highest undriven wheel speed selected from the first front wheel speed signal, the second from wheel speed signal and the drive speed signal, and determining the updated vehicle velocity in response to the second reference velocity and a longitudinal acceleration; when the vehicle is decelerating, determining whether the first and second front wheel speed signals are potentially unreliable or reliable; when the vehicle is decelerating, the wheel speed signals are potentially unreliable, and the updated vehicle velocity is less than the first reference velocity and drive speed signal is greater than the first reference velocity, setting the second reference velocity as a maximum of the updated vehicle velocity, the drive speed signal, the first front wheel speed signal or the second front wheel speed signal; when the vehicle is decelerating, the wheel speed signals are potentially unreliable, and the drive speed signal is greater than the first reference velocity, setting the second reference velocity as a maximum of the updated vehicle velocity, the first front wheel speed signal or the second front wheel speed signal; when the vehicle is decelerating, the wheel speeds are reliable, and one of the front wheel speed signals is greater than the drive speed signal, setting the second reference velocity as a maximum of the first front wheel speed signal or the second front wheel speed signal; and when the vehicle is decelerating, the wheel speeds are reliable and the drive speed is less than the first reference velocity, setting the second reference velocity as the drive speed.