Vehicle and method of controlling a vehicle

Patent metadata

Field	Value
Publication number	US-9365111-B2
Application number	US-201214000378-A
Country	US
Kind code	B2
Filing date	Feb 20, 2012
Priority date	Feb 18, 2011
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A vehicle having a prime mover and a driveline to connect the prime mover to first and second groups of wheels such that the first group is driven by the prime mover when the driveline is in a first mode, and the first and second groups are driven when the driveline is in a second mode. The driveline comprises an auxiliary portion comprising first and second releasable torque transmitting mechanisms and a prop shaft. The first and second torque transmitting mechanisms are respectively operable to connect the prop shaft to the prime mover and to the second group of wheels. The driveline is operable to transition to the second mode when a second condition is met that includes a vehicle operating parameter exceeding a first threshold, and to transition to the first mode when a first condition is met that includes the operating parameter being less than a second threshold.

First claim

The invention claimed is:

1. A motor vehicle having:
a prime mover;
at least first and second groups of one or more wheels; and
a driveline operable by means of a controller to connect a torque transmission path from the prime mover 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 the torque transmission path 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 the torque transmission path when the driveline is in a second mode of operation,
the driveline being operable to connect the second group to the torque transmission path by means of an 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, 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 controller being operable to control the auxiliary portion 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 and the second group of one or more wheels,
the driveline being operable to transition from the first mode to the second mode when a second mode trigger condition is met, the second mode trigger condition including the requirement that a magnitude of a value of a vehicle operating parameter of a first set of one or more vehicle operating parameters is less than or greater than a first threshold value,
the driveline being further operable subsequently to transition from the second mode to the first mode when a first mode trigger condition is met, the first mode trigger condition including the requirement that the magnitude of the value of the vehicle operating parameter of the first set is greater than or less than a second threshold value, the second threshold value having a value different from the first threshold value.

2. The motor vehicle as claimed in claim 1 wherein the first set of one or more vehicle parameters comprises a plurality of vehicle parameters and the second mode trigger condition includes the requirement that the magnitude of the value of any one of the first set of operating parameters is less than or greater than a respective first threshold value of that operating parameter,
the first mode trigger condition including the requirement that the magnitude of the value of each vehicle operating parameter of the first set is greater than or less than a corresponding second threshold value of each operating parameter.

3. The motor vehicle as claimed in claim 1 wherein the vehicle is operable to transition from the second mode to the first mode only when a further requirement is met in respect of one or more further operating parameters not being parameters of the first set.

4. The motor vehicle as claimed in claim 1 wherein the transition to the first mode may only be made when a disconnect delay period has elapsed.

5. The motor vehicle as claimed in claim 4 wherein the transition to the first mode may only be made when the second mode trigger condition has not been met for a time period that is greater than the disconnect delay period.

6. The motor vehicle as claimed in claim 4 wherein the transition to the first mode may only be made when the first mode trigger condition has been met for a time period that is greater than the disconnect delay period.

7. The motor vehicle as claimed in claim 4 wherein a length of the disconnect delay period is dependent on a value of at least one vehicle operating parameter.

8. The motor vehicle as claimed in claim 4 wherein a length of the disconnect delay period is dependent on an identity of the operating parameter of the first set of one or more operating parameters that triggered the transition from the first mode to the second mode of operation.

9. The motor vehicle as claimed in claim 4 wherein the disconnect delay period is responsive to a difference between the first threshold value and the magnitude of the value of the operating parameter triggering the transition to the second mode at a time the transition to the second mode was made.

10. The motor vehicle as claimed in claim 4 wherein a rate of connection by the driveline of the second group of one or more wheels to the prime mover when the transition to the second mode is responsive to a value of at least one operating parameter, the disconnect delay period being dependent on the rate of connection by the driveline of the second group of one or more wheels when the second group of one or more wheels was last connected.

11. The motor vehicle as claimed in claim 4 wherein a rate of connection by the driveline of the second group of one or more wheels to the prime mover when the transition to the second mode is responsive to the identity of the operating parameter triggering the transition to the second mode, the disconnect delay period being dependent on the rate of connection by the driveline of the second group of one or more wheels when the transition to the second mode was made.

12. The motor vehicle as claimed in claim 10 wherein the disconnect delay period is arranged to increase as a function of increasing rate of connection.

13. The motor vehicle as claimed in claim 10 wherein the disconnect delay period is arranged to decrease as a function of increasing rate of connection.

14. The motor vehicle as claimed in claim 4 wherein the disconnect delay period is dependent on an output of a drive style evaluator, the drive style evaluator being arranged to provide an output responsive to a driving style of a user over an evaluation time period.

15. The motor vehicle as claimed in claim 14 wherein the output of the drive style evaluator is responsive to at least one of:
(a) an average rate of acceleration and/or deceleration of the vehicle over the evaluation time period,
(b) a peak value of rate of acceleration and/or deceleration over the evaluation time period,
(c) an instantaneous value of rate of acceleration and/or deceleration,
(d) an average value of rate of change of steering wheel position over the evaluation time period,
(e) a peak value of rate of change of steering position over the evaluation time period,
(f) an instantaneous value of rate of change of steering wheel position,
(g) an average value of rate of change of throttle position over the evaluation time period,
(h) a peak value of rate of change of throttle position over the evaluation time period,
(i) an instantaneous value of rate of change of throttle position,
(j) an average value of torque transmitted to the second group of wheels over the evaluation time period,
(k) a peak value of torque transmitted to the second group of wheels over the evaluation time period and
(l) an instantaneous value of torque transmitted to the second group of wheels.

16. The motor vehicle as claimed in claim 4 wherein the vehicle has a plurality of driver selectable vehicle programs operable to control a performance of the vehicle, the disconnect delay period being responsive to an identity of the driver selected vehicle program.

17. The motor vehicle as claimed in claim 4 wherein the disconnect delay period is responsive to at least one environmental condition parameter.

18. The motor vehicle as claimed in claim 17 wherein the at least one environmental co

Assignees

• Stares Pete
• Jaguar Land Rover Ltd

Inventors

• Stares Pete

Classifications

• B60K23/08 Primary

  for changing number of driven wheels {, for switching from driving one axle to driving two or more axles (B60K17/3515 takes precedence)} · CPC title

• B60W10/14

  Central differentials for dividing torque between front and rear axles · CPC title

• B60W2710/023

  Clutch engagement rate · CPC title

• B60W10/16

  Axle differentials, e.g. for dividing torque between left and right wheels · CPC title

• B60W10/119 Primary

  including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle (B60W10/14 takes precedence) · CPC title