Harvesting head reel-crop engagement

1. A harvesting apparatus comprising:

a harvester;

a header coupled to the harvester, the header including a rotatable reel configured to rotate at a reel rotation rate to draw crop from a crop field toward the header as the harvester moves through the crop field;

at least one crop engagement detector at least partially positioned on the rotatable reel, the at least one crop engagement detector configured to produce data indicating when at least one respective portion of the rotatable reel is engaging the crop, wherein the at least one crop engagement detector includes a light source positioned on the rotatable reel and configured to generate light and a detector positioned on the rotatable reel and configured to detect the light from the light source; and

a control system coupled to the at least one crop engagement detector, the control system configured to determine engagement of the crop by the rotatable reel from the data and the reel rotation rate.

2. The apparatus of claim 1 , wherein the control system comprises:

a detector monitor configured to receive the data indicating when at least one respective portion of the rotatable reel is engaging the crop from the at least one crop engagement detector; and

a reel position monitor configured to determine the reel rotation rate.

3. The apparatus of claim 2 , further comprising:

a reel torque monitor configured to detect torque on the rotatable reel.

4. The apparatus of claim 3 , wherein the control system is further configured to:

determine if the crop is in a standing state or a lodged state; and

adjust a height of the rotatable reel:

responsive to the data from the at least one crop engagement detector indicating when the at least one respective portion of the rotatable reel is engaging the crop when the crop is in the standing state; and

responsive to the detected torque when the crop is in the lodged state.

5. The apparatus of claim 1 , wherein the control system is further configured to:

adjust a height of the rotatable reel responsive to the data from the at least one crop engagement detector indicating when the at least one respective portion of the rotatable reel is engaging the crop.

6. The apparatus of claim 1 , further comprising:

a power source coupled to the header; and

a slip ring assembly coupled to the rotatable reel between the power source and the at least one crop engagement detector.

7. The apparatus of claim 1 , wherein the rotatable reel has an axis of rotation and wherein the at least one crop engagement detector comprises a plurality of sensors spaced in a circumferential direction around the axis of rotation.

8. A harvesting apparatus comprising:

a harvester;

a header coupled to the harvester, the header including a rotatable reel configured to rotate at a reel rotation rate to draw crop from a crop field toward the header as the harvester moves through the crop field;

at least one crop engagement detector at least partially positioned on the rotatable reel, the at least one crop engagement detector configured to produce data indicating when at least one respective portion of the rotatable reel is engaging the crop; and

a control system coupled to the at least one crop engagement detector, the control system configured to determine engagement of the crop by the rotatable reel from the data and the reel rotation rate;

wherein each of the at least one crop engagement detector includes:

a light source configured to generate light;

a reflector positioned and configured to reflect the light from the light source; and

a light detector positioned and configured to detect the reflected light, wherein detection of the reflected light indicates no reel-crop engagement and no detection of the reflected light indicates reel-crop engagement, and wherein the light source, the reflector, and the light detector are positioned on the rotatable reel.

9. A method for detecting reel-crop engagement, the method comprising:

receiving data from at least one crop engagement detector mounted on at least a portion of a rotatable reel of a harvester, wherein the at least one crop engagement detector includes a light source positioned on the rotatable reel and configured to generate light and a detector positioned on the rotatable reel and configured to detect the light from the light source;

processing the data from the at least one crop engagement detector;

detecting crop engagement from the processed data; and

adjusting a height of the rotatable reel responsive to the detected crop engagement.

10. The method of claim 9 , wherein the receiving step comprises:

wirelessly receiving the data from the at least one crop engagement detector.

11. The method of claim 9 , wherein the processing comprises:

monitoring the data received from the at least one crop engagement detector; and

monitoring rotation rate of the rotatable reel.

12. The method of claim 11 , wherein the detecting step comprises:

detecting the crop engagement from the processed data and the rotation rate.

13. The method of claim 9 , further comprising:

detecting torque of the rotatable reel.

14. The method of claim 13 , further comprising:

determining if the crop is in a standing state or a lodged state; and

adjusting the height of the rotatable reel:

responsive to the data from the at least one crop engagement detector indicating when the at least one respective portion of the rotatable reel is engaging the crop when the crop is in the standing state; and

responsive to the detected torque when the crop is in the lodged state.

15. The method of claim 9 , wherein the rotatable reel has an axis of rotation and wherein the at least one crop engagement detector comprises a plurality of sensors spaced in a circumferential direction around the axis of rotation.

16. A non-transitory computer-readable medium storing program code for use with a header of a harvester, the header including a rotatable reel configured to draw crop from a crop field toward the header as the harvester moves through the crop field, the program code, when executed, is operative to cause a computing device to perform the steps of:

receiving data from at least one crop engagement detector mounted on at least a portion of the rotatable reel, wherein the at least one crop engagement detector includes a light source positioned on the rotatable reel and configured to generate light and a detector positioned on the rotatable reel and configured to detect the light from the light source;

processing the data from the at least one crop engagement detector;

detecting crop engagement from the processed data; and

adjusting a height of the rotatable reel responsive to the detected crop engagement.