Yield monitoring of potato is cruicial because it could provide total yield and income information instantly. In this study, the potentials sensors were evaluated in a small-sized potato harvester. Mass-based (i.e., load cell) and volume-based (i.e., CCD camera) sensors were selected and tested under laboratory conditions. For mass-based sensing, the potatoes discharged from the transportation part struck the spring loaded plate before they are stored to the collecting bag. Load cell signals by the impact force were calibrated to the mass of the potatoes. Effects of potato dropping height on load cell were investigated for single potato and multiple potatoes. For volume-based sensing, a CCD camera was installed above the transportation part so that the top and side images of the potatoes were captured. Area and volume were obtained from the original images and calibrated to the mass of potatoes. The calibration tests of potato showed linear calibrations with R2 of 0.98 for potatoes dropped from a height of 30 cm for the mass-based and 0.37 for volume-based approaches. This study showed the effectiveness of real-time potato yield monitoring. Further study is necessary to investigate the effects of vibration and harvester inclination on data acquisition during field application.
Figures & Tables
Fig. 1. Test bench of the potato yield monitoring system showing arrangement and locations of the sensors.