Impact-by-impact Sensing of Grain Flow on Jidatsu Combine

To enhance the accuracy of an impact-based yield sensor installed inside the grain tank of a combine, we measured the individual impacts of intermittent grain flow accelerated by an auger blade. Non-linear calibration was modeled to relate each impulse received by the sensor to the weight of grain released at a single rotation of the auger blade, taking into account the rotational speed of the auger. The parameters were optimized through pairs of signal recording and grain weight at harvest in situ. The relative error of calibration was less than 2%. The proposed instrumentation and signal processing showed robustness to the flow rate of grain, and the maximum relative error of validation was 3.5%.