Vehicle and method of controlling a vehicle

Patent metadata

Field	Value
Publication number	US-9630493-B2
Application number	US-201214000393-A
Country	US
Kind code	B2
Filing date	Feb 20, 2012
Priority date	Feb 18, 2011
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A motor vehicle having: a prime mover; first and second groups of wheels; and a driveline operable by a controller to connect a torque transmission path from the prime mover to the wheels. The driveline connects the second group to the torque transmission path by an auxiliary portion including first and second releasable torque transmitting devices and a prop shaft. The controller operates the auxiliary portion to switch the driveline between first and second modes such that in the first mode the prop shaft is disconnected from both the torque transmission path and second group of wheels. The driveline transitions from the first mode to the second mode responsive to a value of a vehicle operating parameter, and when a transition to the second mode is made the vehicle is operable not to transition back to the first mode from the second mode before a disconnect delay period has expired.

First claim

The invention claimed is:

1. A motor vehicle having:
prime mover means;
at least first and second groups of one or more wheels;
control means; and
a driveline arranged to connect a torque transmission path from 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 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 arranged 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 arranged to connect a first end of the prop shaft to the torque transmission path, the second releasable torque transmitting means being arranged to connect a second end of the prop shaft to the second group of one or more wheels,
the control means being arranged 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 said second group of one or more wheels,
wherein, when the driveline is in the second mode, the control means is arranged to operate the vehicle not to transition to the first mode from the second mode unless an at least one vehicle operating parameter has no value corresponding to a condition for the second mode to be assumed during a period of time not less than a disconnect delay period,
wherein the timing of the period of time is commenced only when the driveline is in the second mode.

2. The motor vehicle of claim 1 wherein the driveline is arranged to transition from the first mode to the second mode when the condition is met that the value of one said at least one vehicle operating parameter is less than or greater than a first threshold value,
the vehicle being arranged subsequently to transition from the second mode to the first mode when the condition is met that the value of said at least one vehicle operating parameter is greater than or less than the first threshold value and has been for a period of time not less than the disconnect delay period.

3. The motor vehicle of claim 1 wherein the driveline is arranged to transition from the first mode to the second mode when the magnitude of the value of the at least one vehicle operating parameter is less than or greater than a corresponding first threshold value of said at last one parameter,
the driveline being arranged subsequently to transition from the second mode to the first mode when the magnitude of the value of said vehicle operating parameter is greater than or less than a corresponding second threshold value of said at last one parameter and has been for a period of time not less than the disconnect delay period, the second threshold value having a value different from the first threshold value.

4. The motor vehicle of claim 1 wherein the transition back to the first mode may be made only when one or more conditions in respect of one or more further operating parameters are met in addition to the requirement in respect of any operating parameter triggering the transition from the first mode to the second mode.

5. The motor vehicle of claim 1 wherein timing of the disconnect delay period by the control means begins at the moment the second mode is assumed.

6. The motor vehicle of claim 1 wherein timing of the disconnect delay period by the control means begins again each time a value of a vehicle operating parameter changes from a value that does not correspond to a condition for the second mode to be assumed to a value that does correspond to a condition for the second mode to be assumed.

7. The motor vehicle of claim 1 wherein when the driveline is in the second mode, timing of the disconnect delay period by the control means begins when the condition is met that none of the operating parameters have a value requiring the second mode to be assumed.

8. The motor vehicle of claim 2 wherein when the vehicle is in the second mode, timing of the disconnect delay period by the control means begins when the condition is met that the value of said at least one vehicle operating parameter is less than or greater than the first threshold value.

9. The motor vehicle of claim 8 wherein when the vehicle is in the second mode timing of the disconnect delay period begins when the condition is met that the value of said at least one vehicle operating parameter is greater than or less than the second threshold value.

10. The motor vehicle of claim 1 wherein the length of the disconnect delay period is dependent on a value of at least one vehicle operating parameter.

11. The motor vehicle of claim 1 wherein the length of the disconnect delay period to be timed by the control means is dependent on the identity of the operating parameter that triggered the transition from the first mode to the second mode of operation.

12. The motor vehicle of claim 2 wherein the disconnect delay period is responsive to the difference between the first threshold value and the value of the operating parameter triggering the transition to the second mode at the time the transition to the second mode is made.

13. The motor vehicle of claim 1 wherein the disconnect delay period is responsive to the rate of connection by the driveline of the second group of one or more wheels when the transition to the second mode is made.

14. The motor vehicle of claim 13 wherein the rate of connection is responsive to at least one selected from amongst the value of at least one operating parameter and the identity of the operating parameter triggering the transition to the second mode.

15. The motor vehicle of claim 13 wherein the disconnect delay period is arranged to increase as a function of increasing rate of connection.

16. The motor vehicle of claim 14 wherein the disconnect delay period is arranged to decrease as a function of increasing rate of connection.

17. The motor vehicle of claim 1 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.

18. The motor vehicle of claim 17 wherein the output of the drive style evaluator is responsive to at least one selected from amongst:
(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 eval

Assignees

• Stares Pete
• Clare David
• Jaguar Land Rover Ltd

Inventors

• Stares Pete
• Clare David

Classifications

• B60K2023/0883

  manually actuated · CPC title

• B60W30/182

  Selecting between different operative modes, e.g. comfort and performance modes · CPC title

• F16H2300/14

  Selecting a state of operation, e.g. depending on two wheel or four wheel drive mode · CPC title

• B60K17/3515

  with a clutch adjacent to traction wheel, e.g. automatic wheel hub · CPC title

• B60Y2400/82

  Four wheel drive systems · CPC title