Differential lock control system and associated method

• US 7,650,961 B2
• Filed: 12/08/2006
• Issued: 01/26/2010
• Est. Priority Date: 12/08/2006
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Smith, Brent A., Breiner, Scott J., Kelly, Andrew W.
• Primary Examiner(s): Dickson; Paul N
• Assistant Examiner(s): Coker; Robert A
• Application Number:
  US11/608,687
• Publication Number:
  US 20080135322A1
• Time in Patent Office: 1,145 Days
• Field of Search: 180/338, 475/84, 475/86, 701/50, 701/51
• US Class Current: 180/338
• CPC Class Codes: B60K 23/04 for differential gearing
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: F16H 48/30 using externally-actuatable means

Abstract

A differential lock control system for controlling a differential lock of a work vehicle is adapted to determine if the work vehicle is oriented to travel in a generally straight direction, and, if the work vehicle is so oriented, automatically command activation of the differential lock. An associated method is disclosed.

Claims

1. A method for controlling a differential lock of a work vehicle, comprising:

receiving at least one turn angle signal,

determining if the work vehicle is oriented to travel in a generally straight direction based on the at least one turn angle signal, and

if the work vehicle is so oriented, automatically commanding activation of the differential lock, wherein;

the at least one turn angle signal comprises a single articulation angle signal representative of an articulation angle between articulated front and rear sections of the work vehicle and a single steering angle signal representative of a steering angle of a ground-engaging traction element of the work vehicle, and

the determining comprises determining if the work vehicle is oriented to travel in a generally straight direction based on the articulation angle signal and the steering angle signal.

2. The method of claim 1, wherein the determining comprises calculating a turn angle (θ

)of the work vehicle by summing the articulation angle (α

) and the steering angle (β

) (i.e., θ

=α

+β

).

3. The method of claim 2, wherein the determining comprises determining if the turn angle is within a predetermined tolerance about a zero turn angle.

4. A differential lock control system for controlling a differential lock of a work vehicle, comprising:

a single articulation angle sensor configured to sense an articulation angle between articulated front and rear sections of the work vehicle,

a single steering angle sensor configured to sense a steering angle of a ground-engaging traction element of the work vehicle, and

a controller configured to receive an articulation angle signal representative of the articulation angle and a steering angle signal representative of the steering angle and determine if the work vehicle is oriented to travel in a generally straight direction based on the articulation angle signal and the steering angle signal.

5. The differential lock control system of claim 4, wherein the controller is configured to calculate a turn angle (θ

) of the work vehicle by summing the articulation angle (α

) and the steering angle (β

) (i.e., θ

=α

+β

).

6. The differential lock control system of claim 5, wherein the controller is configured to compare the turn angle to predetermined turn criteria.

7. The differential lock control system of claim 5, wherein the controller is configured to determine if the turn angle is within a predetermined tolerance about a zero turn angle.

8. A work vehicle, comprising:

articulated front and rear sections,

a ground-engaging traction element,

a differential,

a differential lock, and

a differential lock control system configured to control the differential lock, wherein the differential lock control system comprises a single articulation angle sensor configured to sense an articulation angle between the front and rear sections, a single steering angle sensor configured to sense a steering angle of the ground-engaging traction element, and a controller configured to receive an articulation angle signal representative of the articulation angle and a steering angle signal representative of the steering angle, determine if the work vehicle is oriented to travel in a generally straight direction based on the articulation angle signal and the steering angle signal, and, if the work vehicle is so oriented, automatically command activation of the differential lock.

9. The work vehicle of claim 8, wherein the controller is configured to calculate a turn angle (θ

) of the work vehicle by summing the articulation angle (α

) and the steering angle (β

) (i.e., θ

=α

+β

), and determine if the turn angle is within a predetermined tolerance about a zero turn angle.

10. The work vehicle of claim 9, wherein the work vehicle is a motor grader.

11. The work vehicle of claim 8, wherein the controller is configured to calculate a turn angle (θ

) of the work vehicle by summing the articulation angle and the steering angle (β

) (i.e., θ

=α

+β

).

12. The work vehicle of claim 11, wherein the controller is configured to determine if the turn angle is within a predetermined tolerance about a zero turn angle.