Motor vehicle controller and method

Patent metadata

Field	Value
Publication number	US-10328942-B2
Application number	US-201515120088-A
Country	US
Kind code	B2
Filing date	Feb 12, 2015
Priority date	Feb 19, 2014
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A motor vehicle controller configured to: receive a drive demand signal indicating an amount of net drive to be applied to one or more driving wheels of a vehicle, estimate a value of a parameter indicative of a surface coefficient of friction between one or more driving wheels and a driving surface, and apply a net torque to one or more wheels of a vehicle. The amount of net torque applied is determined in dependence at least in part on the received drive demand signal. The controller is configured to increase an amount of net torque applied to one or more driving wheels independently of the drive demand signal and to update an estimate of the parameter in dependence on a change in speed of the at least one driving wheel when the amount of net torque applied to the at least one driving wheel is increased.

First claim

The invention claimed is:

1. A motor vehicle controller, the controller being configured to:
receive a drive demand signal indicative of an amount of net drive to be applied to one or more driving wheels of a vehicle;
estimate a value of a parameter indicative of a surface coefficient of friction between one or more driving wheels and a driving surface, surface_friction; and
cause the application of a net torque to one or more wheels of a vehicle, an amount of net torque applied being determined in dependence at least in part on the received drive demand signal, the net torque being a difference between a positive drive torque and a negative brake torque applied to the or each wheel,
the controller being configured automatically to increase momentarily an amount of net torque applied to a driving wheel independently of the drive demand signal and to update an estimate of parameter surface_friction in dependence at least in part on a change in speed of said driving wheel when the amount of net torque applied to said at least one driving wheel is increased,
wherein increasing momentarily an amount of drive torque applied to the driving wheel and updating an estimate of parameter surface_friction comprises:
causing the application of positive drive torque and negative brake torque to the driving wheel substantially simultaneously;
increasing momentarily an a amount of net positive torque applied by momentarily reducing the amount of brake torque applied to the driving wheel;
measuring the speed of the driving wheel when the amount of brake torque applied to the driving wheel is reduced; and
updating said estimate of parameter surface_friction based at least in part on the measured speed of the driving wheel.

2. A method of controlling a motor vehicle comprising:
receiving a drive demand signal indicative of an amount of net drive to be applied to one or more driving wheels of a vehicle;
estimating a value of a parameter indicative of a surface coefficient of friction between one or more driving wheels and a driving surface, surface_friction; and
applying a net torque to one or more wheels of a vehicle, an amount of net torque applied being determined in dependence at least in part on the received drive demand signal, the net torque being a difference between a positive drive torque and a negative brake torque applied to the or each wheel,
the method comprising automatically increasing momentarily an amount of net torque applied to a driving wheel independently of the drive demand signal and updating an estimate of parameter surface_friction in dependence at least in part on a change in speed of said driving wheel when the amount of net torque applied to said driving wheel is increased,
wherein increasing momentarily an amount of net torque applied to the driving wheel and updating an estimate of parameter surface_friction comprises:
causing application of positive drive torque and negative brake torque to the driving wheel substantially simultaneously;
increasing momentarily an amount of net positive torque applied by momentarily reducing the amount of brake torque applied to the driving wheel;
measuring the speed of the driving wheel when the amount of brake torque applied to the driving wheel is reduced; and
updating said estimate of parameter surface_friction based at least in part on the measured speed of the driving wheel.

3. A controller according to claim 1 wherein the controller is configured to cause the application of a net torque to one or more wheels of a vehicle by controlling an amount of torque coupling between first and second axles of a vehicle, the controller being configured automatically to increase momentarily an amount of net torque applied to a driving wheel of a second axle at least in part by momentarily reducing an amount of torque coupling between the first and second axles of the vehicle.

4. A controller according to claim 1 wherein the controller is configured to cause the application of a net torque to one or more wheels of a vehicle by controlling an amount of torque coupling between respective wheels of an axle of a vehicle, the controller being configured automatically to increase momentarily an amount of net torque applied to a driving wheel of an axle at least in part by momentarily adjusting an amount of torque coupling between respective wheels of an axle.

5. A controller according to claim 1 configured to determine the amount of net torque to be applied to one or more driving wheels in dependence at least in part on the drive demand signal and the value of surface_friction.

6. A controller according to claim 5 configured to determine the amount of net torque to be applied to one or more driving wheels such that an amount of slip of one or more driving wheels is substantially equal to a predetermined amount.

7. A controller according to claim 6 wherein the predetermined amount is determined in dependence at least in part on the value of surface_friction and a speed of a vehicle.

8. A control system comprising a controller according to claim 1 .

9. A control system according to claim 8 configured to determine the amount of net torque to be applied to one or more driving wheels in dependence at least in part on information indicative of a terrain over which a vehicle is driving.

10. A control system according to claim 9 configured to receive information indicative of a terrain over which a vehicle is driving by receiving a signal indicative of the identity of an operating mode in which a vehicle is operating, the operating mode being selected from a plurality of operating modes.

11. A control system according claim 10 wherein the operating modes are control modes of at least one subsystem of a vehicle, the control system having a subsystem controller for initiating control of a vehicle subsystem in the selected one of the plurality of subsystem control modes, each one of the operating modes corresponding to one or more different driving conditions for a vehicle.

12. A control system according to claim 11 wherein the system comprises a processor configured to evaluate one or more driving condition indicators to determine the extent to which each of the subsystem control modes is appropriate.

13. A control system according to claim 12 operable in an automatic operating mode selection condition in which the system is configured automatically to control the subsystem controller to initiate control of the or each subsystem in the subsystem control mode which is most appropriate.

14. A control system according to claim 11 wherein in each operating mode the system is configured to cause each one of a plurality of vehicle subsystems to be operated in a subsystem configuration mode appropriate to the driving condition.

15. A control system according to claim 14 wherein the operating modes include one or more control modes selected from the following:
control modes of at least one vehicle subsystem selected from amongst an engine management system, a transmission system, a steering system, a brakes system and a suspension system;
control modes of a suspension system and the plurality of subsystem configuration modes comprise a plurality of ride heights;
control modes of a fluid suspension system in which fluid interconnection can be made between suspensions for wheels on opposite sides of the vehicle, and wherein said plurality of subsystem configuration modes provide different levels of said interconnection;
control modes of a steering system which can provide steering assistance, and wherein said plurality of subsystem configuration modes provide different levels of

Assignees

• Jaguar Land Rover Ltd

Inventors

• Kelly James
• Bean Alex
• Beever Paul
• Brockley Nick
• Parr Jon
• Prins Jan
• Fairgrieve Andrew
• Woolliscroft Daniel
• Cooke Charlotte

Classifications

• B60T8/172 Primary

  Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters {(B60T8/17551 takes precedence)} · CPC title

• B60W40/068

  Road friction coefficient · CPC title

• B60G2400/82

  Ground surface · CPC title

• B60W2520/26

  Wheel slip · CPC title

• B60W2520/10

  Longitudinal speed · CPC title