Methods, systems, and apparatus for monitoring yield and vehicle weight

1. A method for monitoring yield while harvesting grain with a harvester, the method comprising:

by using a mass flow rate sensor disposed to measure a mass flow rate of grain in the harvester, generating a flow rate signal related to a grain flow rate within the harvester;

generating a weight signal related to a weight of a grain tank of the harvester, wherein an elevator passes through a wall of said grain tank; and

while harvesting grain, correlating said flow rate signal with said weight signal in order to monitor yield.

2. The method of claim 1 , wherein said step of correlating said flow rate signal and said weight signal includes:

determining a rate of change of said weight signal; and

comparing said rate of change of said weight signal to said flow rate signal.

3. The method of claim 1 , wherein said step of correlating said flow rate signal and said weight signal includes:

integrating said flow rate signal over a recording period to obtain a flow-based weight change estimate;

determining a change in weight signal over said recording period to obtain a weight-based weight change estimate; and

comparing said flow-based weight change estimate to said weight-based weight change estimate.

4. The method of claim 1 , further including:

determining an error associated with said flow rate signal; and

correcting said flow rate signal.

5. The method of claim 1 , wherein the step of generating said weight signal includes:

providing a vehicle weight system configured to generate said weight signal, said vehicle weight system including a first weight sensor and a second weight sensor.

6. The method of claim 5 , wherein the step of generating said weight signal further includes:

carrying out a calibration routine while said harvester weight remains substantially unchanged; and

determining a first calibration factor associated with said first weight sensor and a second calibration factor associated with said second weight sensor such that said weight signal remains substantially constant during said calibration routine.

7. The method of claim 5 , wherein the step of generating said weight signal further includes:

changing a known weight of said harvester such that said weight signal changes; and

determining a first calibration factor associated with said first weight sensor and a second calibration factor associated with said second weight sensor such that a difference in said weight signal corresponds to said known weight.

8. The method of claim 1 , further including:

determining an error associated with said flow rate signal based on said weight signal;

correcting said flow rate signal using said error to generate a corrected mass flow measurement; and

displaying said corrected mass flow measurement.

9. The method of claim 1 , further including:

generating a data quality criterion associated with said weight signal;

comparing said data quality criterion to a desired range;

determining an error associated with said flow rate signal using a value of said weight signal recorded while said data quality criterion was within said desired range;

correcting said flow rate signal using said error to generate a corrected mass flow measurement; and

displaying said corrected mass flow measurement.

10. A system for monitoring yield while harvesting grain with a harvester, comprising:

a mass flow sensor configured to generate a flow rate signal corresponding to a flow rate of grain within the harvester;

a vehicle weight system comprising a weight sensor, said vehicle weight system configured to generate a weight signal corresponding to a weight of a portion of the harvester, said vehicle weight system comprising a displacement measurement device mounted to an axle of the harvester; and

processing circuitry in electrical communication with said mass flow sensor and said vehicle weight system, said processing circuitry configured to calculate an error in said flow rate signal using said weight signal.

11. The system of claim 10 , wherein said processing circuitry is further configured to calculate a corrected mass flow rate based on said error.

12. The system of claim 10 , further including:

a data quality sensor configured to generate a data quality criterion associated with said vehicle weight system, said sensor in electrical communication with said processing circuitry.

13. The system of claim 12 , wherein said data quality sensor comprises one of a gyroscope, an accelerometer, a speed sensor, an auger weight sensor, a GPS system, and a header pressure sensor.

14. The system of claim 12 , wherein said processing circuitry is further configured to compare said data quality criterion to a threshold, and wherein said processing circuitry is further configured to disregard said weight signal when said data quality criterion enters a non-desired range defined by said threshold.

15. The system of claim 10 , wherein said weight sensor comprises a load cell bearing a portion of the weight of the harvester.

16. The system of claim 10 , wherein said weight sensor is configured to measure a deformation of a load-bearing member of the harvester.

17. A method of calibrating a mass flow sensor of a harvester while harvesting grain, said method including:

intercepting a flow of grain with a mass flow sensor;

measuring a mass flow rate of said grain with said mass flow sensor to obtain a measured mass flow rate;

storing said grain in a grain tank on the harvester, wherein an elevator passes through a wall of said grain tank;

obtaining weight measurements of a portion of the harvester including said grain tank at a first time and a second time to obtain a measured change in grain weight;

comparing said measured change in grain weight to said measured mass flow rate while harvesting grain;

determining an inaccuracy in said measured mass flow rate based on said change in grain weight; and

correcting subsequent measured mass flow rates based on said inaccuracy.

18. The method of claim 17 , further including:

performing a calibration routine corresponding to a known change in vehicle weight;

comparing said measured change in grain weight to said known change in vehicle weight; and

determining a correction factor for correcting said measured change in grain weight to said known change in vehicle weight;

applying said correction factor to a subsequent weight measurement.

19. The method of claim 17 , further including:

obtaining a signal related to a reliability of said weight measurements; and

filtering said weight measurement based on said signal.

20. The method of claim 17 , further comprising:

determining a rate of change of grain weight, a cumulative sum of said mass flow rate, and a rate of change of said cumulative sum of said mass flow rate; and

comparing said rate of change of grain weight to said rate of change of said cumulative sum of said mass flow rate.