Improved Mass Flow Sensing for Yield Monitoring in Grain Combines

Abstract

Yield monitors have become an indispensable part of many precision agriculture systems because of their ability to quickly and efficiently measure the yield variability within a field. The current technology of measuring grain yields with sensors mounted in the clean grain elevator is error prone due to mass flow variations caused by the threshing and separating operations. To reduce the effect of combine dynamic errors, a new yield sensing technology is being developed. This new sensor measures the tension on the feed conveyor drive chain, as it is believed the tension on this chain is related to the flow of biomass through the feeder housing. The initial field tests were conducted in 160 m strips of corn that were broken into six blocks of varying grain volumes. An analysis of the data indicated the chain tension sensor could detect differences between the blocks of varying grain volumes. Additional tests, under normal field conditions, were also conducted under varying biomass volumes controlled by selecting each of the three possible stripper plate settings on the combine corn head. The chain tension sensor could detect differences between the different stripper plate widths, as the greatest chain tensions were recorded at the narrowest stripping plate width. Results from both field trials were compared to yield data collected from an impact style mass-flow sensor located in the clean grain elevator. The results indicated biomass flow sensing at the feeder housing may compliment existing technologies to improve yield monitor data quality.