Vehicle driveline control system and method, and motor vehicle comprising such a system

Patent metadata

Field	Value
Publication number	US-9522680-B2
Application number	US-201414891642-A
Country	US
Kind code	B2
Filing date	Apr 15, 2014
Priority date	May 16, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A control system for a vehicle operable to control a driveline of a vehicle to vary and amount of torque coupling between first and second groups of one or more wheels, the control system being operable automatically to cause application of brake torque to a wheel of the first or second groups of one or more wheels in response to detection of loss of traction of one or more wheels, wherein if the amount of brake torque or brake pressure of a braking system employed to apply the brake torque exceeds a threshold value in response to the detection of loss of traction, the control system is operable to cause the driveline to reduce the amount of torque coupling between the first and second groups of wheels.

First claim

The invention claimed is:

1. A system for a vehicle, the system being operable to:
control a driveline of a vehicle to vary an amount of driveline torque coupling between first and second groups of one or more wheels; and
in response to a detection of a loss of traction of one or more wheels cause a stability control system to apply a brake torque to a wheel of the first or second groups of one or more wheels in order to induce a corrective yaw to the vehicle to maintain an intended path of travel;
wherein the system is configured such that, when the brake torque applied and/or a brake pressure of a braking system employed to apply the brake torque exceeds a non-zero threshold value, the system causes the driveline to reduce the amount of driveline torque coupling between the first and second groups of wheels.

2. A system according to claim 1 wherein the threshold value is set in dependence on the substantially instant amount of coupling between the first and second groups of wheels.

3. A system according to claim 1 wherein the driveline is configured in a first mode in which the first group of one or more wheels and not the second group is arranged to be driven by prime mover means and a second mode in which the first and second groups are coupled such that the first group and in addition the second group is arranged to be driven by the prime mover means, and wherein the system is configured such that, when the driveline is in the second mode of operation and brake torque or brake pressure of the braking system exceeds the threshold value in response to the detection of loss of traction, the system causes the driveline to assume the first mode of operation.

4. A system according to claim 1 configured to select the threshold value of brake torque or brake pressure in dependence on one or more vehicle parameters.

5. A system according to claim 4 wherein the one or more vehicle parameters include a value of surface coefficient of friction between a wheel and a driving surface.

6. A system according to claim 1 configured to operate in one of a plurality of driving modes, wherein in each driving mode the system is arranged to control one or more vehicle subsystems to operate in one of a plurality of subsystem configuration modes, the system being configured to select the threshold value of brake torque or brake pressure in dependence on the selected driving mode.

7. A system according to claim 6 configured to allow a user to select the driving mode in which the system is to operate.

8. A system according to claim 6 configured to select automatically the driving mode in which the system is to operate.

9. A motor vehicle comprising a system according to claim 1 .

10. A method of controlling a vehicle having a driveline operable to vary an amount of driveline torque coupling between first and second groups of one or more wheels,
the method comprising, in response to detection of loss of traction of one or more wheels, automatically causing a stability control system to apply brake torque to a wheel of the first or second groups of one or more wheels in order to induce a corrective yaw to the vehicle to maintain an intended path of travel,
whereby the method comprises causing the driveline to reduce the amount of driveline torque coupling between the first and second groups of wheels when an amount of brake torque or brake pressure of a braking system employed to apply brake torque exceeds a non-zero threshold value in response to the detection of loss of traction.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Richards Karl
• OWEN Simon

Classifications

• B60W2552/40

  Coefficient of friction · CPC title

• B60W30/18172 Primary

  Preventing, or responsive to skidding of wheels · CPC title

• B60T8/175

  Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control (safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16) · CPC title

• B60T8/1769

  specially adapted for vehicles having more than one driven axle, e.g. four-wheel drive vehicles · CPC title

• B60T2270/202

  for all-wheel drive vehicles · CPC title