Control of an Electronic Locking Differential

• US 20110082634A1
• Filed: 10/01/2009
• Published: 04/07/2011
• Est. Priority Date: 10/01/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Andonian, Brian J., Walega, Kenneth G., Torres, Joseph J., Povirk, Jacob M.
• Granted Patent: US 9,605,740 B2
• Time in Patent Office: Days
• US Class Current: 701/88
• CPC Class Codes: B60K 17/344 having a transfer gear
• CPC Class Codes: B60K 23/04 for differential gearing
• CPC Class Codes: B60W 2510/0604 Throttle position
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: F16H 2048/204 Control of arrangements for suppressing differential actions
• CPC Class Codes: F16H 48/08 comprising bevel gears
• CPC Class Codes: F16H 48/24 using positive clutches or brakes
• CPC Class Codes: F16H 48/30 using externally-actuatable means

Abstract

A method for controlling a locking differential of a motor vehicle includes locking the differential, if vehicle speed is less than a reference speed, and a wheel speed differential due to wheel slip is greater than a reference speed; and unlocking the differential and preventing its engagement, if vehicle speed is greater than the reference speed, and said wheel speed differential is less than a reference speed.

Claims

1. A method for controlling a locking differential of a motor vehicle, comprising the steps of:

(a) locking the differential, if vehicle speed is less than a reference speed, and a wheel speed differential due to wheel slip is greater than a reference speed; and

(b) unlocking the differential and preventing its engagement, if vehicle speed is greater than the reference speed, and said wheel speed differential is less than a reference speed.

2. The method of claim 1, wherein step (a) further comprises determining that vehicle yaw acceleration is less than the reference acceleration.

3. The method of claim 1, wherein step (a) further comprises determining that an angular displacement of a steering wheel from a centered position is less than a reference angle.

4. The method of claim 1, wherein step (a) further comprises determining that as engine throttle displacement is greater than a reference displacement.

5. The method of claim 1, wherein step (b) further comprises determining that an angular displacement of a steering wheel from a centered position is greater than a reference angle.

6. The method of claim 1, wherein step (b) further comprises determining that a lateral vehicle acceleration is greater than a reference lateral acceleration.

7. A method for controlling a locking differential of a motor vehicle, comprising the steps of:

(a) locking the differential, if vehicle speed is less than a reference speed, a wheel speed differential due to wheel slip is greater than a reference speed, and an angular displacement of a steering wheel from a centered position is less than a reference angle; and

(b) unlocking the differential and preventing its engagement, if vehicle speed is greater than the reference speed, and said wheel speed differential is less than a reference speed.

8. The method of claim 7, wherein step (a) further comprises determining that vehicle yaw rate is less than the reference acceleration.

9. The method of claim 7, wherein step (b) further comprises determining that an angular displacement of a steering wheel from a centered position is greater than a reference angle.

10. The method of claim 7, wherein step (b) further comprises determining that a lateral vehicle acceleration is greater than a reference lateral acceleration.

11. A method for controlling an locking differential of a motor vehicle, comprising the steps of:

(a) locking the differential, if vehicle speed is less than a reference speed and a wheel speed differential due to wheel slip is greater than a reference speed;

(b) unlocking the differential and preventing its engagement, if vehicle speed is greater than the reference speed, an angular displacement of a steering wheel from a centered position is greater than a reference angle, and said wheel speed differential is less than a reference speed.

12. The method of claim 11, wherein step (a) further comprises determining that vehicle yaw rate is less than the reference acceleration.

13. The method of claim 11, wherein step (a) further comprises determining that an angular displacement of a steering wheel from a centered position is less than a reference angle.

14. The method of claim 11, wherein step (a) further comprises determining that as engine throttle displacement is greater than a reference displacement.

15. The method of claim 11, wherein step (b) further comprises determining that a lateral vehicle acceleration is greater than a reference lateral acceleration.