Development of a Boom-Height Detection Device Using Position-Sensitive Detectors

──Evaluation of Detection Accuracy for Four Major Field Crops in Hokkaido──

Abstract

　In this study, we examined the accuracy of a boom-height detection device equipped with three position-sensitive detectors for the major field crops grown in Hokkaido—potatoes, soybeans, sugar beets, and wheat. A traveling device, moving at a constant velocity, was used to measure the boom height from the detection device to the crop. The average detection error was within ±4 cm of the actual measurements for all crops except wheat. For wheat, detection occurred 11.6 cm farther from the crop than the actual value. Although correction for wheat is needed after the heading stage because of ear length, the system proved effective in automatically controlling the boom of sprayers used in Hokkaido.