Header height control for a harvesting head

1. A header for an agricultural vehicle, the header comprising:

a center section extending from a first end to a second end;

a wing section movably attached to the first end of the center section, the wing section being movable relative to the center section through a range of motion comprising a lower operating range including a lowest operating position, a higher operating range including a highest operating position, and a median operating range between the lower operating range and the higher operating range;

a displacement sensor configured to indicate a position of the wing section within the range of movement;

an inboard height sensor located between a centerline of the center section and a distal end of the wing section;

an outboard height sensor located between the inboard height sensor and the distal end of the wing section; and

a signal conditioning unit operatively connected to the displacement sensor, the inboard height sensor and the outboard height sensor, and configured to:

receive a displacement sensor signal from the displacement sensor;

receive an inboard height sensor signal from the inboard height sensor;

receive an outboard height sensor signal from the outboard height sensor;

determine from the displacement sensor signal whether the wing section is in the median operating range and, upon determining that the wing section is in the median operating range: apply an inboard correction factor to the inboard height sensor signal to generate an inboard control signal, and apply an outboard correction factor to the outboard height sensor signal to generate an outboard control signal, with the inboard correction factor being greater in magnitude than the outboard correction factor; and

determine from the displacement sensor signal whether the wing section is in the higher operating range and, upon determining that the wing section is in the higher operating range: apply an inboard correction factor to the inboard height sensor signal to generate an inboard control signal, and apply an outboard correction factor to the outboard height sensor signal to generate an outboard control signal, with the outboard correction factor being greater in magnitude than the inboard correction factor.

2. The header of claim 1 , wherein the inboard height sensor is located on the center section, and the outboard height sensor is located on the wing section proximal to the distal end of the wing section.

3. The header of claim 1 , wherein the wing section is movably attached to the center section by one or more pivots.

4. The header of claim 1 , wherein the displacement sensor comprises one or more potentiometers, gyroscopes or optical sensors, and the inboard height sensor and the outboard height sensor each comprise one or more radar rangefinders, optical rangefinders, ultrasonic rangefinders, drag wheels or drag arms.

5. The header of claim 1 , wherein, upon determining that the wing section is in the higher operating range, the outboard correction factor increases as a function of proximity to the highest operating position.

6. The header of claim 5 , wherein, upon determining that the wing section is in the higher operating range, the outboard correction factor increases exponentially as a function of proximity to the highest operating position.

7. The header of claim 5 , wherein the outboard correction factor has a maximum magnitude when the wing section is in the highest operating position.

8. The header of claim 1 , wherein the signal conditioning unit is further configured to determine from the displacement sensor signal whether the wing section is in the lower operating range and, upon determining that the wing section is in the lower operating range: apply an inboard correction factor to the inboard height sensor signal to generate an inboard control signal, and apply an outboard correction factor to the outboard height sensor signal to generate an outboard control signal, with the outboard correction factor being greater in magnitude than the inboard correction factor.

9. The header of claim 8 , wherein, upon determining that the wing section is in the lower operating range, the outboard correction factor increases as a function of proximity to the lowest operating position.

10. The header of claim 9 , wherein, upon determining that the wing section is in the lower operating range, the outboard correction factor increases exponentially as a function of proximity to the lowest operating position.

11. The header of claim 9 , wherein the outboard correction factor has a maximum magnitude when the wing section is in the lowest operating position.

12. An agricultural combine comprising:

a chassis;

a header movably connected to the chassis by a movable mount;

a combine control system configured to operate the movable mount to change an orientation of the header relative to the chassis;

wherein the header comprises:

a center section extending from a first end to a second end;

a first wing section movably attached to the first end of the center section, the first wing section being movable relative to the center section through a respective range of motion comprising a lower operating range including a lowest operating position, a higher operating range including a highest operating position, and a median operating range between the lower operating range and the higher operating range;

a first displacement sensor configured to indicate a position of the first wing section within the respective range of movement;

a first inboard height sensor located between a centerline of the center section and a distal end of the first wing section;

a first outboard height sensor located between the first inboard height sensor and the distal end of the first wing section; and

a signal conditioning unit operatively connected to the combine control system, the first displacement sensor, the first inboard height sensor and the first outboard height sensor, and configured to:

receive a first displacement sensor signal from the first displacement sensor;

receive a first inboard height sensor signal from the first inboard height sensor;

receive a first outboard height sensor signal from the first outboard height sensor;

determine from the first displacement sensor signal whether the first wing section is in its respective median operating range and, upon determining that the first wing section is in its respective median operating range: apply a first inboard correction factor to the first inboard height sensor signal to generate a first inboard control signal, apply a first outboard correction factor to the first outboard height sensor signal to generate a first outboard control signal, with the first inboard correction factor being greater in magnitude than the first outboard correction factor, and send the first inboard control signal and the first outboard control signal to the combine control system; and

determine from the first displacement sensor signal whether the first wing section is in its respective higher operating range and, upon determining that the first wing section is in its respective higher operating range: apply a first inboard correction factor to the first inboard height sensor signal to generate a first inboard control signal, apply a first outboard correction factor to the first outboard height sensor signal to generate a first outboard control signal, with the first outboard correction factor being greater in magnitude than the first inboard correction factor, and send the first inboard control signal and the first outboard control signal to the combine control system.

13. The agricultural combine of claim 12 , wherein, upon determining that the first wing section is in the higher operating range, the first outboard correction factor has a magnitude that increases as a function of proximity to the respective highest operating position of the first wing section.

14. The agricultural combine of claim 12 , further comprising:

a second wing section movably attached to the second end of the center section, the second wing section being movable relative to the center section through a respective range of motion comprising a lower operating range including a lowest operating position, a higher operating range including a highest operating position, and a median operating range between the lower operating range and the higher operating range;

a second displacement sensor configured to indicate a position of the second wing section within the respective range of movement;

a second inboard height sensor located between the centerline of the center section and a distal end of the second wing section;

a second outboard height sensor located between the second inboard height sensor and the distal end of the second wing section; and

wherein the signal conditioning unit is operatively connected to the second displacement sensor, the second inboard height sensor and the second outboard height sensor, and configured to:

receive a second displacement sensor signal from the second displacement sensor;

receive a second inboard height sensor signal from the second inboard height sensor;

receive a second outboard height sensor signal from the outboard height sensor;

determine from the second displacement sensor signal whether the second wing section is in its respective median operating range and, upon determining that the second wing section is in its respective median operating range: apply a second inboard correction factor to the second inboard height sensor signal to generate a second inboard control signal, apply a second outboard correction factor to the second outboard height sensor signal to generate a second outboard control signal, with the second inboard correction factor being greater in magnitude than the second outboard correction factor, and send the second inboard control signal and the second outboard control signal to the combine control system; and

determine from the second displacement sensor signal whether the second wing section is in its respective higher operating range and, upon determining that the second wing section is in its respective higher operating range: apply a second inboard correction factor to the second inboard height sensor signal to generate a second inboard control signal, apply a second outboard correction factor to the second outboard height sensor signal to generate a second outboard control signal, with the second outboard correction factor being greater in magnitude than the second inboard correction factor, and send the second inboard control signal and the second outboard control signal to the combine control system.

15. The agricultural combine of claim 14 , wherein, upon determining that the second wing section is in the higher operating range, the second outboard correction factor has a magnitude that increases as a function of proximity to the respective highest operating position of the second wing section.

16. The agricultural combine of claim 14 , wherein the signal conditioning unit is further configured to:

determine from the first displacement sensor signal whether the first wing section is in its respective lower operating range and, upon determining that the first wing section is in its respective lower operating range: apply a first inboard correction factor to the first inboard height sensor signal to generate a first inboard control signal, apply a first outboard correction factor to the first outboard height sensor signal to generate a first outboard control signal, with the first outboard correction factor being greater in magnitude than the first inboard correction factor, and send the first inboard control signal and the first outboard control signal to the combine control system; and

determine from the second displacement sensor signal whether the second wing section is in its respective lower operating range and, upon determining that the second wing section is in its respective lower operating range: apply a second inboard correction factor to the second inboard height sensor signal to generate a second inboard control signal, apply a second outboard correction factor to the second outboard height sensor signal to generate a second outboard control signal, with the second outboard correction factor being greater in magnitude than the second inboard correction factor, and send the second inboard control signal and the second outboard control signal to the combine control system.

17. The agricultural combine of claim 12 , wherein upon receiving the first inboard control signal and the first outboard control signal, the combine control system is configured to determine an average value of the respective magnitudes of the first inboard control signal and the first outboard control signal, and operate the movable mount to change the orientation of the header relative to the chassis to a new vertical or angular orientation.

18. A method for operating a header on an agricultural combine located on a surface, the method comprising:

measuring a displacement of an outboard portion of the header relative to an inboard portion of the header;

receiving a first measured distance between the inboard portion and the surface, and a second measured distance between the outboard portion and the surface, the first measured distance and the second measured distance comprising a height data set;

determining whether the displacement indicates a relatively low degree of displacement of the outboard portion relative to the inboard portion or a relatively high degree of displacement of the outboard portion relative to the inboard portion;

upon determining that the displacement indicates a relatively low degree of displacement, generating from the height data set a first control signal comprising a respective inboard height signal and a respective outboard height signal in which the magnitude of the inboard height signal is increased relative to the magnitude of the outboard height signal; and

upon determining that the displacement indicates a relatively high degree of displacement, generating from the height data set a second control signal comprising a respective inboard height signal and a respective outboard height signal in which the magnitude of the outboard height signal is increased relative to the magnitude of the inboard height signal.

19. The method of claim 18 , further comprising:

determining a proximity of the displacement to a predetermined maximum operation displacement value, and

in the step of generating the second control signal, a magnitude of the outboard height signal increases as a function of the proximity.

20. The method of claim 19 , wherein the magnitude of the outboard height signal increases as an exponential function of the proximity.