VEHICLE, AND METHOD AND SYSTEM OF CONTROLLING THE DRIVELINE OF A VEHICLE

Embodiments of the present invention provide a motor vehicle having: prime mover means; at least first and second groups of one or more wheels; and a driveline operable to connect the prime mover means to the first and second groups of one or more wheels such that the first group of one or more wheels and not the second group is coupled to a torque transmission path from the prime mover means when the driveline is in a first mode of operation and both the first and second groups of one or more wheels are coupled to a torque transmission path from the prime mover means when the driveline is in a second mode of operation, the driveline including an auxiliary portion for connecting the second group to the torque transmission path from the prime mover means, the auxiliary portion comprising first and second releasable torque transmitting means and a prop shaft, the first releasable torque transmitting means being operable to connect a first end of the prop shaft to the torque transmission path from the prime mover means, the second releasable torque transmitting means being operable to connect a second end of the prop shaft to the second group of one or more wheels, the vehicle further comprising control means operable to control the first and second torque transmitting means to switch the driveline between the first and second modes of operation such that in the first mode the prop shaft is disconnected from both the torque transmission path from the prime mover means and said second group of one or more wheels, wherein when in the first mode the vehicle is operable to control the driveline to switch from first mode to the second mode responsive to a speed of the vehicle. Des modes de réalisation de la présente invention concernent un véhicule motorisé ayant : des moyens moteurs principaux; au moins des premier et second groupes d'une ou de plusieurs roues; et une transmission servant à des fins de connexion des moyens moteurs principaux avec les premier et second groupes d'une ou de plusieurs roues de sorte que le premier groupe d'une ou de plusieurs roues mais pas le second groupe est accouplé à un chemin de transmission de couple depuis les moyens moteurs principaux quand le dispositif de transmission est dans un premier mode de fonctionnement et qu'à la fois le premier et le second groupes d'une ou de plusieurs roues sont accouplés à un chemin de transmission de couple depuis les moyens moteurs principaux quand la transmission est dans un second mode de f