Yield monitoring apparatus, systems, and methods

1. A sensor for measuring yield harvested by a harvesting machine, the harvesting machine having a clean grain elevator with elevator flights configured to carry grain between a lower sprocket and an upper sprocket disposed within an elevator housing, whereby the elevator flights throw the grain in the direction of the sensor as the elevator flights pass over the upper sprocket, the upper sprocket and the lower sprocket defining an elevator plane, the sensor comprising:

a sensor surface having a first end and a second end disposed above the upper sprocket in a direction parallel to the elevator plane;

a support secured to the elevator housing, said support including a resilient flexible member capable of allowing said sensor surface to move upward in translational movement with respect to said elevator housing, whereby said first end and said second end of said sensor surface move a substantially equal distance in substantially parallel relation;

whereby the grain thrown by the elevator flights imparts said upward translational movement of said sensor surface.

2. The sensor of claim 1 , wherein the grain that contacts said sensor surface has a velocity component substantially parallel to the sensor surface immediately prior to contacting the sensor surface.

3. The sensor of claim 2 , wherein the grain pile has a velocity component substantially parallel to the sensor surface while contacting the sensor surface.

4. The sensor of claim 1 , further including a pre-sensor surface adjacent to the sensor surface, said pre-sensor surface configured to allow the grain to flow substantially continuously from said pre-sensor surface to said sensor surface such that a velocity component of the grain retains substantially the same direction as the grain flows from said pre-sensor surface to said sensor surface.

5. The sensor of claim 4 , wherein a distance between said pre-sensor surface and said sensor surface is vertically offset by less than ten hundredths of an inch.

6. The sensor of claim 4 , further including a post-sensor surface adjacent to the sensor surface, said post-sensor surface configured to allow the grain to flow substantially continuously from said sensor surface to said post-sensor surface such that the velocity component of the grain retains substantially the same direction as the grain flows from said sensor surface to said post-sensor surface.

7. The sensor of claim 1 , wherein the translational movement of said sensor surface is less than 10 hundredths of an inch.

8. The sensor of claim 1 , further comprising: a displacement sensor disposed to measure the translational movement of said sensor surface.

9. The sensor of claim 8 , wherein while said sensor surface is subject to translational movement due to the grain contacting said sensor surface said sensor surface remains substantially undeformed by contact with the grain.

10. The sensor of claim 1 , further comprising: a first spring; and a second spring, wherein said first spring and said second spring resiliently retain the sensor surface in a first non-translated position.

11. The sensor of claim 1 , wherein the sensor has a natural frequency greater than 400 hertz.

12. A sensor for measuring yield harvested by a harvesting machine having a clean grain elevator with elevator flights carrying grain between an upper sprocket and a lower sprocket disposed within an elevator housing, whereby the elevator flights throw the grain toward the sensor, the upper sprocket and the lower sprocket defining an elevator plane, comprising:

a sensor surface disposed above the upper sprocket, said sensor surface having a trailing surface and a leading surface, wherein the grain that contacts said sensor surface has a transition velocity component substantially parallel to the sensor surface immediately prior to contacting the sensor surface; and

wherein the grain contacts said leading surface prior to contacting said trailing surface;

wherein said sensor surface remains in a first position when no grain force acts on said sensor surface;

wherein when a grain force acts on said leading surface, said leading surface translates upward in translational movement to a second position with respect to the clean grain elevator;

wherein said trailing surface and said leading surface are equidistant from the upper sprocket in said first position; and

wherein said trailing surface translates upward in translational movement along a direction normal to said transition velocity component in said second position.

13. The sensor of claim 12 , wherein said leading surface and said trailing surface being located adjacent to the elevator plane.

14. The sensor of claim 13 , wherein the sensor surface is disposed within a hole in a clean grain elevator housing of the elevator.

15. The sensor of claim 14 , further including: a housing resiliently supporting said sensor surface, wherein said housing is disposed within said hole in said clean grain elevator housing.

16. The sensor of claim 12 , further including: a pre-sensor surface adjacent to said sensor surface, wherein a vertical offset between said pre-sensor surf ace and said sensor surface is smaller than ten hundredths of an inch.

17. The sensor of claim 12 , further including a post-sensor surface adjacent to the sensor surface, said post-sensor surface disposed to allow substantially continuous grain flow from said sensor surface to said post-sensor surface.

18. The sensor of claim 12 , wherein said upward translation movement of said sensor surface is less than 10 hundredths of an inch.

19. The sensor of claim 12 , further comprising: a displacement sensor disposed to measure said upward translation movement of said sensor surface.