Calibration Equations for the Weight of Rough Rice Layers of Various Shapes Piled in a Grain Tank

Abstract

Japanese yield monitoring systems adopt a calibration equation using load cell values measured at the grain tank bottom. We evaluated the accuracy of the current calibration equation and investigated alternatives to improve the weight estimation accuracy of rough rice layers of various shapes piled in a grain tank. The root mean squared relative error of cross validation (RMSRECV) was 22 % for the current equation. The relative error was －41 % to 60 % when a 100 kg rough rice layer was piled, involving large variations of x coordinates in the center of gravity. The calibration equation using front and rear load cell values (RMSRECV: 4.4 %) was considered practical for reducing the estimation error caused by the piled shapes.