Construction and Tests of Gain Flow and Water Content Sensors for Full-feed Type Mid-sized Multipurpose Combines

摘要

Precision agriculture analyzes the spatial variability according to the characteristics of an optimum setting of agricultural materials. Market for full feed type combine harvesters is recently growing in many countries including Republic of Korea. Yield monitoring system is one of the recent trends of the combines, and the major components consist of a positioning system, grain flow and water content sensors, ground speed and cutting width sensors. Objective of the paper was to design and constructgrain flow and water content sensors for full-feed type mid-sized multi-purpose combines, as a part of a yield monitoring system, targeting row-planted and broadcasted rice, barley, wheat and soybean. The principle of the flow sensor was that quantity ofthe cereal grains after threshing was measured below the concave sieve with optical sensing modules. For grain water content, a capacitive sensing module was attached under the horizontal transportation auger. Basic performances of the flow sensor and water content sensor unit were validated by predetermined data. The first tests were conducted from 0.1 to 1.0 kg mass flow with a 0.1 kg interval. Then, test was conducted 50, 150 and 300 g grain weight for water content. In the first experiment, array sensor and ultrasound sensor produced high R2 values of 0.97 and 0.92, respectively. Next, in the moisture content measurement experiment, the sensor value was not affected by the shape of an auger, and the scope of moisture content to measure was wide when rice and bean were 300g and barley was 150g. Results of the study showed a good potential of the fabricated flow and water content sensor. Future study would include installation of the sensors on the test combine and evaluation of the performance under field operational conditions.