SPEED CONTROL SYSTEM AND METHOD FOR OPERATING THE SAME

• US 20150210282A1
• Filed: 08/13/2013
• Published: 07/30/2015
• Est. Priority Date: 08/16/2012
• Status: Active Grant

• Current Assignee: Jaguar Land Rover Limited (TATA Motors Limited)
• Original Assignee: Jaguar Land Rover Limited (TATA Motors Limited)
• Inventors: Fairgrieve, Andrew, Kelly, James, Woolliscroft, Daniel
• Granted Patent: US 10,399,566 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60T 2201/04 Hill descent control
• CPC Class Codes: B60T 2210/14 Rough roads, bad roads, gravel roads
• CPC Class Codes: B60T 2210/16 Off-road driving conditions
• CPC Class Codes: B60T 2220/04 Pedal travel sensor, stroke sensor; Sensing brake request
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60W 2552/05 Type of road, e.g. motorways, local streets, paved or unpaved roads
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/12 Lateral speed
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/146 Speed limiting
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60Y 2200/20 Off-Road Vehicles
• CPC Class Codes: F16H 2061/0234 Adapting the ratios to special vehicle conditions
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

A method for operating a speed control system of a vehicle is provided. The method comprises identifying a torque required to achieve a desired operating parameter of the vehicle. The method further assessing whether the required torque exceeds a predetermined torque limit, and when it does, determining if it is appropriate to increase the torque limit. When it is determined that it is appropriate to do so, the method further comprises increasing the predetermined torque limit. A speed control system of a vehicle comprising an electronic control unit configured to: determine a torque required to achieve a desired operating parameter of the vehicle, assess whether the required torque exceeds a predetermined torque limit; when the torque exceeds the torque limit, determine if it is appropriate to increase the torque limit; and when it is determined that it is appropriate to do so, increase the torque limit, is also provided.

Claims

1. A method for operating a speed control system of a vehicle, comprising:

identifying a torque required to achieve a desired operating parameter of the vehicle;

assessing whether the required torque exceeds a predetermined maximum positive torque limit of the speed control system;

when the required torque exceeds the predetermined maximum positive torque limit, determining if it is appropriate to increase the predetermined maximum positive torque limit; and

when it is determined that it is appropriate to do so, increasing the predetermined maximum positive torque limit.

2. The method of claim 1, wherein determining if it is appropriate to increase the torque limit comprises evaluating one or more criteria, and when at least certain of the one or more criteria are met, determining that it is appropriate to increase the torque limit.

3. The method of claim 2, wherein the one or more criteria comprise one or more of:

the current speed of the vehicle is less than a desired speed;

the current powertrain output torque is at the predetermined maximum positive torque limit;

the speed control system has been active with the powertrain output torque at the predetermined maximum positive torque limit for a predetermined period of time or a number of revolutions of the vehicle powertrain;

no user intervention to reduce the speed of the vehicle or the powertrain output torque is present;

no system for limiting movement of the vehicle is active;

the steering angle is below a predetermined threshold;

the vehicle is not traveling down a gradient and sufficient negative torque cannot be applied to maintain vehicle composure;

the brake system is operating correctly and has been primed;

the vehicle is traveling over a particular type of terrain; and

the vehicle is wading in water.

4. The method of claim 1, further comprising:

displaying a user notification that the required torque exceeds the predetermined maximum positive torque limit, and

prompting the user to confirm that torque limit should be increased, wherein the torque limit is increased only in response to a user indication to do so.

5. The method of claim 1, wherein when it is determined that it is not appropriate to increase the predetermined maximum positive torque limit, the method comprises:

displaying a user notification that the desired operating parameter cannot be met; and

prompting the user to indicate whether the speed control system should be deactivated.

6. The method of claim 1, wherein when the predetermined maximum positive torque limit has been increased, the method comprises:

monitoring one or more operating parameters of the vehicle; and

adjusting the increased torque limit based on the monitored parameter(s).

7. The method of claim 6, wherein one or more operating parameters comprises monitoring the rate of acceleration of the vehicle, and the adjusting step comprises reducing the increased torque limit when the rate of acceleration of the vehicle exceeds a predetermined threshold.

8. The method of claim 1, wherein the desired operating parameter comprises a desired speed of the vehicle.

9. A method for operating a speed control system of a vehicle, comprising:

monitoring the speed and powertrain output torque of the vehicle;

when the speed of the vehicle falls below a desired speed, and the powertrain output torque has met a predetermined maximum positive torque limit of the speed control system, determining if it is appropriate for the output torque to exceed the predetermined maximum positive torque limit; and

when it is determined that it is appropriate to do so, increasing the powertrain output torque to a level at which the desired vehicle speed is achieved.

10. The method of claim 9, wherein determining if it is appropriate to increase the torque limit comprises evaluating one or more criteria, and when at least certain of the one or more criteria are met, determining that it is appropriate to increase the torque limit.

11. The method of claim 10, wherein the one or more criteria comprise one or more of:

the speed control system has been active with the powertrain output torque at the predetermined maximum positive torque limit for a predetermined period of time or a number of revolutions of the vehicle engine;

no user intervention to reduce the speed of the vehicle or the powertrain output torque is present;

no system for limiting movement of the vehicle is active;

the steering angle is below a predetermined threshold;

the vehicle is not traveling down a gradient and sufficient negative torque cannot be applied to maintain vehicle composure;

the brake system is operating correctly and has been primed;

the vehicle is traveling over a particular type of terrain; and

the vehicle is wading in water.

12. A speed control system for a vehicle, comprising:

an electronic control unit, configured to;

determine a torque required to achieve a desired operating parameter of the vehicle;

assess whether the required torque exceeds a predetermined maximum positive torque limit that the speed control system may command;

when the required torque exceeds the predetermined maximum positive torque limit, determine if it is appropriate to increase the predetermined maximum positive torque limit; and

when it is determined that it is appropriate to do so, increase the predetermined maximum positive torque limit.

13. The system of claim 12, wherein the electronic control unit is configured to determine if it is appropriate to increase the torque limit by evaluating one or more criteria, and when at least certain of the one or more criteria are met, determining that it is appropriate to increase the torque limit.

14. The system of claim 13, wherein the one or more criteria comprise one or more of:

the current speed of the vehicle is less than a desired speed;

the current powertrain output torque is at the predetermined maximum positive torque limit;

the speed control system has been active with the powertrain output torque at the predetermined maximum positive torque limit for a predetermined period of time or a number of revolutions of the vehicle engine;

no user intervention to reduce the speed of the vehicle or the powertrain output torque is present;

no system for limiting movement of the vehicle is active;

the steering angle is below a predetermined threshold;

the vehicle is not traveling down a gradient and sufficient negative torque cannot be applied to maintain vehicle composure;

the brake system is operating correctly and has been primed;

the vehicle is traveling over a particular type of terrain; and

the vehicle is wading in water.

15. The system of claim 12, further comprising a display device, and wherein the electronic control unit is configured to control the display device to display a user notification thereon that the required torque exceeds the predetermined maximum positive torque limit, and prompt the user to confirm that the torque limit should be increased.

16. The system of claim 12, further comprising a display device, and wherein when it is determined that it is not appropriate to increase the predetermined maximum positive torque limit, the electronic control unit is further configured to control the display device to display a user notification that the desired operating parameter cannot be met, and prompt the user to indicate whether the speed control system should be deactivated.

17. The system of claim 12, wherein when the predetermined maximum positive torque limit has been increased, the electronic control unit is further configured to monitor one or more operating parameters of the vehicle, and adjust the increased torque limit based on the monitored parameter(s).

18. The system of claim 17, wherein the electronic control unit is configured to monitor the rate of acceleration of the vehicle, and to adjust the increased torque limit by reducing it when the rate of acceleration of the vehicle exceeds a predetermined threshold.

19. The system of claim 12, wherein the desired operating parameter comprises a desired speed of the vehicle.

20. A vehicle comprising a speed control system, said speed control system comprising an electronic control unit, configured to:

determine a torque required to achieve a desired operating parameter of the vehicle;

assess whether the required torque exceeds a predetermined maximum positive torque limit that the speed control system may command;

when the required torque exceeds the predetermined maximum positive torque limit, determine if it is appropriate to increase the predetermined maximum positive torque limit; and

when it is determined that it is appropriate to do so, increase the predetermined maximum positive torque limit.

21. (canceled)