Vehicle control including control over a rate of torque decrease

Patent metadata

Field	Value
Publication number	US-2016137196-A1
Application number	US-201414898408-A
Country	US
Kind code	A1
Filing date	May 22, 2014
Priority date	Jun 14, 2013
Publication date	May 19, 2016
Grant date	—

Abstract

A method of controlling a vehicle includes determining whether control over a rate of torque decrease is desired in order to improve the vehicle behavior. The rate of torque decrease is controlled to stay within a range of a selected rate of change. A vehicle control system includes a controller configured to determine whether control over a rate of torque decrease is desired. The controller is also configured to control the rate of torque decrease to stay within a range of a selected rate of change.

First claim

1 . A method of controlling a vehicle, comprising:
determining whether control over a rate of torque decrease is desired; and controlling the rate of torque decrease to stay within a range of a selected rate of change.

2 . The method of claim 1 , wherein the determining comprises determining whether the vehicle is turning.

3 . The method of claim 1 , wherein the determining comprises determining whether a friction value that is associated with a surface that vehicle wheels contact as the vehicle is moving is below a threshold.

4 . The method of claim 3 , wherein the threshold indicates wheel slip.

5 . The method of claim 3 , wherein the threshold corresponds to a limit of cornering adhesion.

6 . The method of claim 1 , wherein the determining comprises at least one of detecting or predicting a downshift in a transmission of the vehicle.

7 . The method of claim 1 , wherein the determining comprises at least one of detecting or predicting lift-off oversteer.

8 . The method claim 1 , comprising
controlling the rate of torque decrease based on at least one of a current surface friction; a current vehicle lateral acceleration; or a current vehicle speed.

9 . The method of claim 1 , wherein the selected rate of change addresses lift-off oversteer by at least one of avoiding lift-off oversteer, minimizing lift-off oversteer or reducing lift-off oversteer.

10 . The method of claim 1 , comprising
determining a plurality of different rate limits for different conditions, respectively; and utilizing different ranges surrounding the selected rate limit based on the condition.

11 . A vehicle control system, comprising:
a powertrain; and a controller configured to
determine whether control over a rate of torque decrease is desired; and
control the rate of torque decrease to stay within a range of a selected rate of change.

12 . The system of claim 11 , wherein the controller is configured to determine whether the vehicle is turning.

13 . The system of claim 11 , wherein the controller is configured to determine whether a friction value that is associated with a surface that vehicle wheels contact as the vehicle is moving is below a threshold.

14 . The system of claim 13 , wherein the threshold indicates wheel slip.

15 . The system of claim 13 , wherein the threshold corresponds to a limit of cornering adhesion.

16 . The system of claim 11 , wherein
the powertrain comprises a transmission; and the controller is configured to detect or predict a downshift in the transmission.

17 . The system of claim 11 , wherein the controller is configured to detect or predict lift-off oversteer.

18 . The system of claim 11 , wherein the controller is configured to control the rate of torque decrease based on at least one of
a current surface friction; a current vehicle lateral acceleration; or a current vehicle speed.

19 . The system of claim 11 , wherein the selected rate of change addresses lift-off oversteer by at least one of avoiding lift-off oversteer, minimizing lift-off oversteer or reducing lift-off oversteer.

20 . The system of claim 11 , wherein the controller is configured to
determine a plurality of different rate limits for different conditions, respectively; and utilize different ranges surrounding the selected rate limit based on the condition.

21 . A vehicle comprising the system of claim 11 .

22 . The vehicle of claim 21 , comprising a plurality of wheels that are driven by the powertrain and wherein the selected rate of change corresponds to at least one of the wheels having a desired frictional engagement with a surface over which the vehicle is moving.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Beever Paul

Classifications

• B60W30/045 Primary

  Improving turning performance · CPC title

• B60W30/18145

  Cornering · CPC title

• B60W2720/26

  Wheel slip · CPC title

• B60W50/0097 Primary

  Predicting future conditions · CPC title

• B60W30/02 Primary

  Control of vehicle driving stability · CPC title