Vehicle controller for changing the number of driven wheels

Patent metadata

Field	Value
Publication number	US-9346353-B2
Application number	US-201214000394-A
Country	US
Kind code	B2
Filing date	Feb 20, 2012
Priority date	Feb 18, 2011
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A motor vehicle having: a prime mover; first and second groups of one or more wheels; and a driveline to connect the prime mover to the first and second groups of wheels such that the first group of one or more wheels is driven by the prime mover when the driveline is in a first mode of operation and the second group of one or more wheels is additionally driven by the prime mover when the driveline is in a second mode of operation, the driveline including an auxiliary driveline comprising releasable torque transmitting means operable to connect the second group of one or more wheels to the prime mover when the driveline transitions between the first mode and the second mode, wherein when in the first mode the driveline is operable to transition to the second mode responsive to an output of a reactive evaluator and a predictive evaluator.

First claim

The invention claimed is:

1. A motor vehicle having:
a 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 and not the second group of one or more wheels is driven by the prime mover means when the driveline is in a first mode of operation and the first and second groups are driven by the prime mover means when the driveline is in a second mode of operation,
the driveline including an auxiliary portion comprising releasable torque transmitting means by means of which the driveline is operable under control of a controller to connect the second group of one or more wheels to the prime mover means when the driveline transitions from the first mode to the second mode,
wherein when in the first mode the driveline is operable to transition to the second mode under the control of the controller, the controller being actuable to cause a transition of the driveline from the first mode to the second mode responsive to an output of a reactive evaluator indicative of a current need to assume the second mode,
the controller being further actuable to cause a transition from the first mode to the second mode responsive to an output of a predictive evaluator indicative of a likely need to assume the second mode within a prescribed period of time,
the output of the reactive evaluator being responsive to a determination whether an amount of wheel slip has exceeded a first prescribed threshold,
the output of the predictive evaluator being responsive to a determination whether one or more conditions in respect of one or more vehicle operating parameters are met when the amount of wheel slip is below the first prescribed threshold,
the controller being further actuable to cause a transition of the driveline from the first mode to the second mode at a rate responsive to at least one of the outputs of said reactive evaluator and said predictive evaluator, and
wherein when the predictive evaluator determines that the second mode should be assumed, the predictive evaluator is arranged to provide the output indicative of the rate at which the transition from the first mode to the second mode should be made.

2. A vehicle as claimed in claim 1 wherein the output of the predictive evaluator is further responsive to a determination that one or more conditions in respect of one or more vehicle operating parameters are met indicating that the amount of wheel slip may be about to exceed a second prescribed threshold.

3. A vehicle as claimed in claim 2 wherein the second threshold is substantially equal to the first threshold.

4. A vehicle as claimed in claim 2 wherein the second threshold is less than the first threshold.

5. A vehicle as claimed in claim 1 wherein the output of the predictive evaluator is further responsive to a determination that one or more conditions in respect of one or more vehicle operating parameters are met indicating that a passenger discomfort parameter may be about to exceed a prescribed threshold.

6. A vehicle as claimed in claim 1 wherein the amount of wheel slip includes the amount of lateral wheel slip.

7. A vehicle as claimed in claim 6 wherein the amount of wheel slip includes the amount of longitudinal wheel slip.

8. A vehicle as claimed in claim 7 wherein the amount of wheel slip is determined according to a combination of the amount of lateral wheel slip and the amount of longitudinal wheel slip.

9. A vehicle as claimed in claim 1 wherein the predictive evaluator is arranged to determine a likelihood that a transition from the first mode to the second mode will be required within a prescribed period of time based on the value of the one or more vehicle operating parameters.

10. A vehicle as claimed in claim 1 wherein the predictive evaluator is arranged to provide an output responsive to one or more historical values of the one or more parameters.

11. A vehicle as claimed in claim 1 wherein when a transition from the first mode to the second mode is made responsive to the output of the predictive evaluator the releasable torque transmitting means is arranged to connect the second group of wheels to the prime mover means at a rate in dependence on the value of the one or more vehicle operating parameters responsive to which the predictive evaluator has triggered the transition.

12. A vehicle as claimed in claim 1 wherein the output of the predictive evaluator is responsive to a plurality of vehicle operating parameters.

13. A vehicle as claimed in claim 12 wherein the releasable torque transmitting means is arranged to connect the second group of wheels to the prime mover means at a rate responsive to the identity of the one or more operating parameters responsive to which the output of the predictive evaluator triggered the vehicle to transition from the first mode to the second mode.

14. A vehicle as claimed in claim 12 wherein when the predictive evaluator provides an output indicating that the second mode of the driveline should be assumed the predictive evaluator is further configured to provide an output corresponding to the identity of the one or more operating parameters responsive to which the predictive evaluator has provided the output indicating that the second mode should be assumed.

15. A vehicle as claimed in claim 1 wherein the predictive evaluator is configured to provide an output corresponding to a required mode of operation of the driveline.

16. A vehicle as claimed in claim 1 wherein the predictive evaluator is configured to provide an output corresponding to a likelihood that a transition from the first mode to the second mode will be required.

17. A vehicle as claimed in claim 16 wherein the output comprises a probability value being a value corresponding to a probability that a transition from the second mode to the first mode will be required within a prescribed time period.

18. A vehicle as claimed in claim 1 arranged to perform the transition from the first mode to the second mode at a slower rate when the transition to the second mode is made responsive to the output of the predictive evaluator compared with a transition made responsive to the output of the reactive evaluator.

19. A vehicle as claimed in claim 1 wherein the reactive evaluator is responsive to at least one vehicle operating parameter selected from amongst:
(a) an amount of wheel slip,
(b) a yaw rate error,
(c) a determination whether an antilock braking system (ABS) is active;
(d) a determination whether a dynamic stability control (DSC) system is active; and
(e) a determination whether a traction control system (TCS) is active.

20. A vehicle as claimed in claim 1 wherein the predictive evaluator is responsive to at least one vehicle operating parameter selected from amongst:
(a) an instantaneous amount of torque being delivered through the driveline to one or more wheels,
(b) a steering wheel angle,
(c) a steerable road wheel angle,
(d) a rate of change of steerable road wheel angle,
(e) a rate of change of steering wheel,
(f) a lateral acceleration of the vehicle,
(g) a rate of change of lateral acceleration,
(h) a throttle or accelerator pedal position,
(i) a rate of change of throttle or accelerator pedal position,
(j) a driver demanded torque,
(k) a prime mover means torque,
(l) an amount of wheel slip,
(m) a vehicle acceleration,
(n) a vehicle deceleration,
(o) a yaw rate,
(p) a yaw rate error,
(q) a

Assignees

• Stares Pete
• Beverley Ian
• Wick Shaun
• Osborn Russell Percy
• Beever Paul
• Anker Sam
• Buckley Bruce
• Jaguar Land Rover Ltd

Inventors

• Stares Pete
• Beverley Ian
• Wick Shaun
• Osborn Russell Percy
• Beever Paul
• Anker Sam
• Buckley Bruce

Classifications

• B60W50/0097

  Predicting future conditions · CPC title

• B60W2050/0008

  Feedback, closed loop systems or details of feedback error signal · CPC title

• B60W10/02 Primary

  including control of driveline clutches · CPC title

• B60K28/165

  acting on elements of the vehicle drive train other than the propulsion unit and brakes, e.g. transmission, clutch, differential · CPC title

• B60W2710/021

  Clutch engagement state · CPC title