現場計測に向けた電流注入型土中水分量・電気伝導度計測のための周波数計測回路の開発

カテゴリ: 論文誌(論文単位)

グループ名: 【E】センサ・マイクロマシン部門

発行日: 2023/05/01

タイトル(英語): Development of Frequency Measurement Circuit for Soil Moisture Content and Electric Conductivity Measurement System with Detection of Soil Transient Response Characteristics for On-Site Measurement

著者名: 瀧本　壮平（静岡大学総合科学技術研究科），重桝　竜希（静岡大学総合科学技術研究科），藤園　幹樹（静岡大学総合科学技術研究科），大多　哲史（静岡大学学術院工学領域），二川　雅登（静岡大学学術院工学領域／静岡大学創造科学技術大学院）

著者名(英語): Sohei Takimoto (Graduate School of Integrated Science and Technology, Shizuoka University), Ryuki Shigemasu (Graduate School of Integrated Science and Technology, Shizuoka University), Motoki Fujisono (Graduate School of Integrated Science and Technology, Shizuoka University), Satoshi Ota (College of Engineering, Academic Institute, Shizuoka University), Masato Futagawa (College of Engineering, Academic Institute, Shizuoka University/Graduate School of Science and Technology, Shizuoka University)

キーワード: 精密農業，土壌センサ，水分量，イオン濃度，土壌過渡応答特性，周波数カウンタ　　precision agriculture，soil sensor，water content，ion concentration，soil transient response characteristics，frequency counter

要約(英語): In agricultural field, compact sensors that can measure both water content and electric conductivity are needed. Focusing on the fact that water content and conductivity depend on soil impedance, our group has been developing a new compact and noise-resistant driving circuit that measured soil impedance by detecting transient characteristics of the voltage obtained by injecting current through the soil and converting it to frequency information. In order to realize agricultural field measurements with sensors using this new driving circuit, it had been necessary to miniaturize the part that detected the output from the driving circuit, but it hadn't been achieved in our previous work. In this research, a microcomputer-based frequency counter was developed to downsize the system for on-site measurement. In general, there are two methods of frequency measurement: direct counting and reciprocal. The direct-counting method is suited for high-frequency measurements, while the reciprocal method is suited for low-frequency measurements. The developed frequency counter could measure with an error of 0.005% over the assumed frequency range by switching between those two measurement methods according to the measured frequency. Using this driving circuit and frequency counter, we measured the model soil and succeeded in capturing changes in water content as changes in impedance.

本誌: 電気学会論文誌E（センサ・マイクロマシン部門誌） Vol.143 No.5 （2023） 特集：令和4年度センサ・マイクロマシン部門総合研究会

本誌掲載ページ: 89-95 p

原稿種別: 論文／日本語

電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejsmas/143/5/143_89/_article/-char/ja/