Vehicle steering

Patent metadata

Field	Value
Publication number	US-9827982-B2
Application number	US-201414779180-A
Country	US
Kind code	B2
Filing date	Jan 17, 2014
Priority date	Mar 22, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A motor vehicle control system operable in a steering assist mode in which the system is configured to: detect steering angle; and control a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle.

First claim

The invention claimed is:

1. A control system for a vehicle, the control system operable in a steering assist mode in which the system is configured to:
detect a steering angle;
detect or predict a side slip event of the vehicle; and
if the detected or predicted side slip event exceeds a threshold value, control a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle, wherein the threshold value is dependent upon a terrain mode in which the vehicle is operating.

2. The system according to claim 1 operable in a first speed control mode in which the system automatically causes the vehicle to travel at a speed in dependence upon a value of a set-speed parameter corresponding to a speed the vehicle is to be intended to maintain, and the system continues to operate in the first speed control mode during the distribution of torque by said system.

3. The system according to claim 2 operable to select the steering assist mode automatically when the system assumes the first speed control mode.

4. The system according to claim 2 wherein the value of the set-speed parameter is set by a user.

5. The system according to claim 2 operable is a second alternative speed control mode in which the control a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle, causes a cancellation of the second speed control mode.

6. The system according to claim 2 wherein the first speed control mode controls the speed within a first range of set speeds and wherein the second speed control mode controls the speed of the vehicle within a second range of set speeds.

7. The system according to claim 1 operable to allow a user to select and deselect the steering assist mode.

8. The system according to claim 1 operable automatically control said distribution of torque:
in dependence on a correspondence parameter threshold between steering angle and a current rate of turn of the vehicle;
when a difference between rate of turn and expected rate of turn for a given steering angle exceeds a prescribed threshold over a prescribed threshold distance of travel; and/or
when a difference between rate of turn and expected rate of turn for a given steering angle exceeds a prescribed threshold for a prescribed threshold time period.

9. The system according to claim 8 wherein the values of said thresholds are different in the first speed control mode and in the second speed control mode, or
wherein the values of the thresholds are different in a first mode of operation in which the vehicle is configured for off-highway driving, and in a second mode of operation in which the vehicle is configured for off-highway driving.

10. The system according to claim 1 operable to control the distribution of torque in dependence on the detected steering angle:
by reducing an amount of net torque applied to an inside wheel with respect to a direction of intended turn; and/or
by reducing an amount of net torque applied to an inside trailing wheel with respect to a direction of intended turn.

11. The system according to claim 1 operable to control the distribution of torque in dependence on the detected steering angle at least in part by reducing an amount of positive drive torque applied to an inside wheel with respect to a direction of intended turn, and
the system is operable to control the distribution of torque in dependence on the detected steering angle at least in part by reducing an amount of positive drive torque applied to an inside trailing wheel.

12. The system according to claim 11 operable to control the distribution of torque in dependence on the detected steering angle at least in part by reducing the amount of positive drive torque applied to an inside wheel and applying a braking torque thereto.

13. The system according to claim 1 operable to control the distribution of torque in dependence on the detected steering angle at least in part by application of brake torque to an inside wheel, and the system is operable to control the distribution of torque in dependence on the detected steering angle at least in part by application of brake torque to an inside trailing wheel.

14. The system according to claim 1 operable to detect when a vehicle has passed the same portion of a route more than once with a steering angle exceeding a prescribed value with respect to a direction of travel of the vehicle, the system being operable to provide an indication to a driver of a location along said portion of the route at which an amount of understeer was reduced relative to other locations of said route when the vehicle previously negotiated that portion, and the system is operable to provide said indication only if the system detects that the vehicle is negotiating that portion of the route within a prescribed time period of the previous occasion.

15. A vehicle comprising the control system according to claim 1 .

16. A method of controlling a motor vehicle comprising:
detecting a steering angle;
detecting or predicting a side slip event of the vehicle; and
if the detected or predicted side slip event exceeds a threshold value, controlling, via an electronic control unit, a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle, wherein the threshold value is dependent upon a terrain mode in which the vehicle is operating.

17. The method according to claim 16 comprising:
operating the vehicle in a first speed control mode in which the vehicle is automatically controlled to travel at a speed in dependence upon a value of a set-speed parameter corresponding to a speed the vehicle is to be intended to maintain, and comprising continuing to operate in the first speed control mode during the steering angle based distribution of torque by said system.

18. The method according to claim 17 comprising operating the vehicle in a second alternative speed control mode in which the control a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle, causes a cancellation of the second speed control mode.

19. A non-transitory carrier medium carrying computer readable code for controlling a vehicle to carry out a method, comprising:
detecting a steering angle;
detecting or predicting a side slip event of the vehicle; and
if the detected or predicted side slip event exceeds a threshold value, controlling a distribution of torque to one or more wheels of the vehicle in dependence on the detected steering angle thereby to induce a turning moment in the direction of turn indicated by the steering angle, wherein the threshold value is dependent upon a terrain mode in which the vehicle is operating.

20. The method according to claim 16 , further comprising varying the threshold value in response to a detected change in the terrain mode.

Assignees

• Jaguar Land Rover Ltd

Inventors

• OWEN Simon
• Richards Karl
• Maskell Andrew

Classifications

• B60W10/20 Primary

  including control of steering systems · CPC title

• B60W30/045 Primary

  Improving turning performance · CPC title

• B60W2720/10

  Longitudinal speed · CPC title

• B60W2710/202

  Steering torque · CPC title

• B60W30/14

  {Adaptive} cruise control · CPC title