Radio frequency grain mass and constituent measurement systems for combine harvesters

1. A radio frequency (RF) grain mass and constituent measurement system utilized onboard a combine harvester, the RF grain mass and constituent measurement system comprising:

an RF sensor subsystem configured to capture RF sensor readings of a currently-harvested grain within an area of the combine harvester containing the currently-harvested grain;

a memory storing an RF characteristic database, the RF characteristic database containing RF characteristic testing data observed for tested grain samples over one or more tested frequency ranges; and

a controller operably coupled to the RF sensor subsystem and to the memory, the controller configured to:

receive the RF sensor readings from the RF sensor subsystem;

identify a grain type of the currently-harvested grain;

recall selected RF characteristics from the RF characteristic database corresponding to the identified grain type;

determine grain mass and a first constituent content of the currently-harvested grain based, at least in part, on the RF sensor readings as compared to the RF characteristic testing data and utilizing the selected RF characteristics; and

perform at least one action, including display or storing values associated with, or adjusting a component of the combine harvester, in response to determining the grain mass and the first constituent content of the currently-harvested grain.

2. The RF grain mass and constituent measurement system of claim 1 , wherein the RF sensor subsystem comprises:

a first RF sensor configured to capture RF sensor readings of the currently-harvested grain at a first frequency or frequency range; and

a second RF sensor configured to capture RF sensor readings of the currently-harvested grain at a second frequency or frequency range different than the first frequency or frequency range.

3. The RF grain mass and constituent measurement system of claim 2 , wherein the first frequency or frequency range is between 1 and 300 Gigahertz (GHz); and

wherein the second frequency or frequency range is between 1 and 300 GHz, while being different than the first frequency or frequency range.

4. The RF grain mass and constituent measurement system of claim 2 , wherein the combine harvester includes a clean grain flow path extending from a grain cleaning section to a grain storage tank;

wherein the first RF sensor is positioned to capture RF sensor readings of the currently-harvested grain at a first location along the clean grain flow path; and

wherein the second RF sensor is positioned to capture RF sensor readings of the currently-harvested grain at a second location along the clean grain flow path downstream of the first location.

5. The RF grain mass and constituent measurement system of claim 4 , wherein the first RF sensor and second RF sensor capture concurrent RF sensor readings of the currently-harvested grain without removal of the currently-harvested grain from the clean grain flow path.

6. The RF grain mass and constituent measurement system of claim 4 , wherein the combine harvester includes a clean grain elevator through which the clean grain flow path extends;

wherein the first RF sensor is positioned to capture RF sensor readings of the currently-harvested grain when supported by a paddle of the clean grain elevator; and

wherein the second RF sensor is positioned to capture RF sensor readings of the currently-harvested grain when discharged through an outlet of the clean grain elevator.

7. The RF grain mass and constituent measurement system of claim 1 , wherein the controller is further configured to:

recall, from RF characteristic testing data, RF characteristics for tested grain samples having varying moisture contents; and

estimate a moisture content of the currently-harvested grain based, at least in part, on the moisture content of at least one the RF characteristics identified as corresponding to the RF sensor readings.

8. The RF grain mass and constituent measurement system of claim 1 , wherein the first constituent content of the currently-harvested grain, as determined by the controller, is selected from the group consisting of an oil content, a protein content, a cellulose content, and a starch content.

9. The RF grain mass and constituent measurement system of claim 1 , wherein at least a subset of the RF sensor readings captured by the RF sensor subsystem measure a phase shift of RF energy when impinged against the currently-harvested grain; and

wherein the RF characteristic testing data includes testing data correlating observed RF energy phase shift over a tested frequency range.

10. The RF grain mass and constituent measurement system of claim 1 , wherein at least a subset of the RF sensor readings captured by the RF sensor subsystem measure attenuation of RF energy when impinged against the currently-harvested grain; and

wherein the RF characteristic testing data includes testing data correlating observed RF energy attenuation over a tested frequency range.

11. A radio frequency (RF) grain mass and constituent measurement system utilized onboard a combine harvester, the RF grain mass and constituent measurement system comprising:

an RF sensor subsystem configured to capture RF sensor readings of a currently-harvested grain within an area of the combine harvester containing the currently-harvested grain;

a memory storing an RF characteristic database, the RF characteristic database containing RF characteristic testing data observed for tested grain samples over one or more tested frequency ranges; and

a controller operably coupled to the RF sensor subsystem and to the memory, the controller configured to:

receive the RF sensor readings from the RF sensor subsystem;

determine grain mass and a first constituent content of the currently-harvested grain based, at least in part, on the RF sensor readings as compared to the RF characteristic testing data; and

perform at least one action, including display or storing values associated with, or adjusting a component of the combine harvester, in response to determining the grain mass and the first constituent content of the currently-harvested grain;

wherein the RF characteristic testing data comprises at least one RF signal response map plotting RF signal responses of the tested grain samples over a tested frequency range:

wherein the RF sensor subsystem comprises a first RF sensor configured to capture RF sensor readings of the currently-harvested grain over a frequency range overlapping with the tested frequency range; and

wherein the controller is configured to determine the grain mass and the first constituent content of the currently-harvested grain based, at least in part, on matching the RF sensor readings with a specific RF signal response included in the RF signal responses plotted on the RF signal response map.

12. A radio frequency (RF) grain mass and constituent measurement system utilized onboard a combine harvester, the RF grain mass and constituent measurement system comprising:

an RF sensor subsystem configured to capture RF sensor readings of a currently-harvested grain within an area of the combine harvester containing the currently-harvested grain;

a memory storing an RF characteristic database, the RF characteristic database containing RF characteristic testing data observed for tested grain samples over one or more tested frequency ranges; and

a controller operably coupled to the RF sensor subsystem and to the memory, the controller configured to:

receive the RF sensor readings from the RF sensor subsystem;

estimate a moisture content of the currently-harvested grain;

recall selected RF characteristics from the RF characteristic database corresponding to the estimated moisture content;

determine grain mass and a first constituent content of the currently-harvested grain based, at least in part, on the RF sensor readings as compared to the RF characteristic testing data and utilizing the selected RF characteristics; and

perform at least one action, including display or storing values associated with, or adjusting a component of the combine harvester, in response to determining the grain mass and the first constituent content of the currently-harvested grain.

13. A radio frequency (RF) grain mass and constituent measurement system utilized onboard a combine harvester, the RF grain mass and constituent measurement system comprising:

an RF sensor subsystem, comprising:

a first RF sensor configured to capture RF sensor readings of the currently-harvested grain at a first frequency or frequency range; and

a second RF sensor configured to capture RF sensor readings of the currently-harvested grain at a second frequency or frequency range different than the first frequency or frequency range;

a memory storing an RF characteristic database, the RF characteristic database containing RF characteristic testing data observed for tested grain samples over one or more tested frequency ranges; and

a controller operably coupled to the RF sensor subsystem and to the memory, the controller configured to:

receive the RF sensor readings from the RF sensor subsystem;

identify a grain type of the currently-harvested grain;

recall selected RF characteristics from the RF characteristic database corresponding to the identified grain type;

determine grain mass and a moisture content of the currently-harvested grain based, at least in part, on the RF sensor readings as compared to the RF characteristic testing data and utilizing the selected RF characteristics; and

perform at least one action in response to determining the grain mass and moisture content of the currently-harvested grain.

14. The RF grain mass and constituent measurement system of claim 13 , wherein the controller is configured to estimate the moisture content of the currently-harvested grain by:

recalling, from RF characteristic testing data, RF characteristics for tested grain samples having varying moisture contents; and

estimating the moisture content based, at least in part, on identifying a specific RF characteristic corresponding to the RF sensor readings.

15. The RF grain mass and constituent measurement system of claim 13 , wherein the controller is further configured to determine a first constituent content of the currently-harvested grain utilizing the RF sensor readings and the RF characteristic testing data.

16. The RF grain mass and constituent measurement system of claim 13 , wherein the RF sensor readings captured by the RF sensor subsystem measure at least one of phase shift and attenuation of RF energy impinged against the currently-harvested grain; and

wherein the RF characteristic testing data includes testing data correlating at least one of phase shift and attenuation over a tested frequency range for the tested grain samples.

17. The RF grain mass and constituent measurement system of claim 13 , wherein the combine harvester includes a clean grain elevator;

wherein the first RF sensor is positioned to capture RF sensor readings of the currently-harvested grain when supported by a paddle of the clean grain elevator; and

wherein the second RF sensor is positioned to capture RF sensor readings of the currently-harvested grain when discharged through an outlet of the clean grain elevator.

18. The RF grain mass and constituent measurement system of claim 15 , wherein the first RF sensor operates at a maximum frequency of f 1 ;

wherein the second RF sensor operates at a minimum frequency of f 2 ; and

wherein 1 gigahertz<f 1 ≤2f 2 <300 gigahertz.