<i>Design and development of a particle flow yield monitor for combine harvesters</i>

Abstract

Abstract. Crop yield maps have become the standard tool for building agricultural production plans for future crop years. Yield monitoring systems must be accurate to ensure validity of producer decisions. The objective of this research was to propose a yield monitoring system that maintains accuracy with limited calibration requirements. Maintaining accuracy of the system requires moving to a fundamental system of yield measurement. Impact-based yield monitoring relies upon regression of a calibration curve to fit the mass flow sensor response signal to the actual mass flow rate of grain. The system is built upon a foundation of factor dependent analysis and error is induced when conditions are experienced that do not directly fit into the model. Volumetric grain flow was selected as the measurement method for determining crop yield. A camera was selected as a sensor to measure velocity of grain as it traveled through the fountain auger and into the grain tank on a commercial combine. Velocity was obtained through measurement of grain displacement between image frames. The particle flow yield monitor was used to quantify the volumetric flow rate of grain passing through the combine and the accuracy of this system in different harvesting conditions. Yield estimation and sensor response had positive, linear relationships with load size and flow rate intake of the combine. The initial performance of the particle flow yield monitor showed great potential for a future yield monitoring solution, although future designs should reflect the issues observed with velocity profile of the grain and maintenance of a grain cavity area.