Method and apparatus of controlling an automotive vehicle using brake-steer as a function of steering wheel torque

• US 7,165,644 B2
• Filed: 03/18/2004
• Issued: 01/23/2007
• Est. Priority Date: 03/18/2004
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Offerle, Timothy G., Stephan, Craig H., Tseng, Hongtei E.
• Primary Examiner(s): Morris; Lesley D.
• Assistant Examiner(s): YEAGLEY, DANIEL S
• Application Number:
  US10/708,669
• Publication Number:
  US 20050236896A1
• Time in Patent Office: 1,041 Days
• Field of Search: 180/402, 180/407, 180/244, 701/70, 701/83, 701/41, 303/139, 303/140, 303/146, 303/20, 303/153
• US Class Current: 180/244
• CPC Class Codes: B60T 2201/10 Automatic or semi-automatic parking aid systems
• CPC Class Codes: B60T 2230/06 Tractor-trailer swaying
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B62D 11/001 control systems B62D11/183 takes precedence
• CPC Class Codes: B62D 9/002 combined with means for differentially distributing power on the deflectable wheels during cornering

Abstract

A method of controlling an automotive vehicle having a turning radius includes determining a hand wheel torque and applying brake-steer as a function of hand wheel torque.

Claims

1. A method of controlling an automotive vehicle having a turning radius comprising:

determining a hand wheel torque; and

comparing the steering wheel torque to a predetermined torque and when the steering torque is greater than the predetermined torque, performing the step of applying brake-steer, and when the steering wheel torque is below the predetermined torque not applying brake-steer.

2. A method as recited in claim 1 further comprising determining a steering wheel angle, wherein applying brake-steer comprises applying brake-steer as a function of hand wheel torque and steering wheel angle.

3. A method as recited in claim 1 further comprising determining a steering wheel angle direction, wherein applying brake-steer comprises applying brake-steer as a function of hand wheel torque, steering wheel direction and steering wheel angle.

4. A method as recited in claim 3 wherein the steering wheel direction comprises a torque increasing direction and a torque decreasing direction, wherein applying brake-steer comprises applying brake-steer using a first boost curve in the torque increasing direction and applying brake-steer using a second boost curve in the torque decreasing direction wherein the first boost curve is different than the second boost curve.

5. A method as recited in claim 4 wherein the first boost curve comprises a non-linear-boost curve.

6. A method as recited in claim 4 wherein the first boost curve increases brake-steer at a first rate for a first period of time, increases brake-steer at a second rate for a second period of time, wherein the second rate is greater than the first rate and increases brake-steer at a third rate for a third period of time wherein the third rate is less than the second rate.

7. A method as recited in claim 4 wherein the second boost curve comprises a non-linear-boost curve.

8. A method as recited in claim 4 wherein the second boost curve decreases brake-steer at a first rate for a first period of time, decreases brake-steer at a second rate for a second period of time, wherein the second rate is less than the first rate.

9. A method as recited in claim 1 wherein the torque comprises an increasing torque and a decreasing torque and wherein applying brake-steer comprises applying brake-steer using a first boost curve during increasing torque and applying brake-steer using a second boost curve during decreasing torque wherein the first boost curve is different than the second boost curve.

10. A method as recited in claim 9 wherein the first boost curve comprises a non-linear-boost curve.

11. A method as recited in claim 9 wherein the first boost curve increases brake-steer at a first rate for a first period of time, increases brake-steer at a second rate for a second period of time, wherein the second rate is greater than the first rate, and increases brake-steer at third rate for a third period of time wherein the third rate is less than the second rate.

12. A method as recited in claim 9 wherein the second boost curve comprises a non-linear-boost curve.

13. A method as recited in claim 9 wherein the second boost curve decreases brake-steer at a first rate for a first period of time, decreases brake-steer at a second rate for a second period of time, wherein the second rate is less than the first rate.

14. A method as recited in claim 1 further comprising reducing the turning radius of the vehicle during applying brake-steer.

15. A method as recited in claim 1 wherein applying brake-steer comprises applying at least one brake at a first wheel to reduce a vehicle turning radius.

16. A method as recited in claim 1 wherein applying brake-steer comprises applying an increased drive torque to a second wheel.

17. A method as recited in claim 1 further comprising determining a speed wherein applying a brake-steer comprises applying brake-steer as a function of steering wheel torque and vehicle speed.

18. A control system for a vehicle comprising:

a steering torque sensor generating a steering torque signal; and

a controller applying brake-steer to a vehicle as a function of the steering torque signal, wherein said controller changes to a 4×

2 mode from a 4×

4 mode to apply brake-steer.

19. A control system as recited in claim 18 wherein said controller applies brake-steer as a function of a vehicle speed.

20. A control system as recited in claim 18 wherein said controller applies a brake to apply brake-steer.

21. A control system as recited in claim 18 wherein said controller applies a differential torque steer.