Development of Boom Height Measurement Module with PSD Sensor = Development of Boom Height Measurement Module with PSD Sensor

다국어 초록 (Multilingual Abstract)

As the scale of farming continues to expand, the boom length and tank capacity of sprayers have increased. Because both ends of a long boom are subject to violent upward and downward movement with even slight rolling of the tractor, chemical spraying tends to be irregular. Even an experienced operator must pay close attention when adjusting the boom height manually. Although boom height is typically measured using an ultrasonic sensor, we present a system that controls the boom height using optical position sensors that are available at a much lower price than the commonly used ultrasonic sensors. In this paper, we report that the developed boom height measurement module and data collection system can be used to control the boom height. Because a position-sensitive detector (PSD) irradiates a target with an LED spot size smaller than the measurement range of ultrasonic waves, we assumed that the spotlight would, at times, pass through the top of a crop and measure the leaves and ground instead. For this reason, we designed the module with three PSD sensors improved for outdoor use by attaching infrared transmission filters. The measurements were performed in two fields to obtain data under different conditions; one field contained unharvested potato and the other contained germinated wheat. We tested two simple algorithms to calculate the appropriate boom height from the measured data; the Minimum-mode for the potato and Median-mode for the wheat. The analysis showed that the PSD module measured a height similar to that by the ultrasonic sensor by changing the algorithm according to the state of the stems and leaves.