Introduction of Researches on Data-driven Agriculture in Japan

( Takashi Okayasu ) 한국농업기계학회 2023 한국농업기계학회 학술발표논문집 Vol.28 No.2

Development of Monorail-type Mobile Robot for Field Environment and Plant Status Monitoring

( Takashi Okayasu ),( Daisaku Arita ),( Takashi Yoshinaga ),( Rin-ichiro Taniguchi Eiji Inoue ),( Yasumar Hirai ),( Muneshi Mitsuoka ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Field environmental and plant growth status monitoring is very important task to establish smart agriculture. Field monitoring device is usually installed only into the representative location in the field because of the management cost and complexity. Thus, their spatial distribution and time variation are not well grasped in actual cultivation. On the other hand, comprehensive analysis on the spatiotemporal field environmental and plant growth information is required in phenotyping researches. Various high-throughput plant phenotyping systems have been studied well and developed mainly in Europe and the US countries up to present. However, their systems are very expensive. Development of the low-price system is also required to create new cultivar and advanced agricultural production system. In this study, a monorail-type mobile robot for collecting field environment and plant status information was developed by using affordable devices such as a card-size microcomputer, sensors, and camera. Many of the robot frames were printed by 3D printer. The robot is driven by using two servo motors. The performance was verified by several conditions and then the spatiotemporal data measured was also evaluated.

Early Disease Detection of Bacterial Leaf Blight on Rice Plant by using Hyperspectral Imaging

( M Naufal Rauf Ibrahim ),( Takashi Okayasu ),( Atsushi Yoshimura ),( Yoshiyuki Yamagata ),( Naruto Furuya ),( Eiji Inoue ),( Yasumaru Hirai ),( Muneshi Mitsuoka ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

In Southeast Asia, bacterial leaf blight (BLB) is one of the significant rice diseases that potentially causes productivity loss up to 50%. The early stage disease detection contributes to prevent the serious crop damage due to the disease outbreak. The hyperspectral imaging provides an extension of our vision by capturing the near infrared (NIR) region at 700-1000 nm which is the outside of visible light (VIS) region at 400-700 nm. In this study, the possibility of early stage disease detection method of BLB on rice plant was investigated in captured hyperspectral images with 40-50 cm from the top of rice plant. For early disease setting, the hyperspectral images for both the healthy and infected single leaf of the rice plants, both were taken from 2 days post-inoculation when the symptom had not been shown yet. The possible sensitive bands were explored from VIS to NIR and chosen by applying the principal component analysis (PCA) on reflectance value of the healthy and infected leaves using 400-850 nm. The PCA result provided that there several ranges of wavelength have high correlation with the disease development on early stage and found that the ratio of orange-red color (605-640 nm) and red edge (690-720 nm) has the highest possibility to detect the BLB.

Time-Dependent Elastoplastic Constitutive Model

Hashiguchi, Koichi,Wu, Xianan,Okayasu, Takashi,Tsutsumi, Seiichiro 대한금속재료학회(대한금속학회) 1998 METALS AND MATERIALS International Vol.4 No.3

The subloading surface model does not premise that the stress exists on the yield surface and thus describes a plastic deformation even when the stress exists inside the yield surface. The measure describing the degree that the stress approaches the yield surface or goes out from the surface is involved in this model. It is extended so as to describe the time-dependent deformation behavior of materials by allowing the stress to go out from the yield surface and considering the fact that a plastic deformation requires time to occur, although an elastic deformation is induced momentarily. Further, based on it, the constitutive equation of soils is formulated by taking the secondary consolidation phenomenon into account.

Design Parameter Optimization for Tillage Blade of Crank-type Rotavators considering Strength and Weight

Nam, Ju-Seok,Moon, Sang-Gon,Park, Sang-Hun,Inoue, Eiji,Okayasu, Takashi,Kim, Dae-Cheol FACULTY OF AGRIC PUBLICATIONS-KYUSHU UNIV 2016 Journal of the Faculty of Agriculture, Kyushu Univ Vol.61 No.1

<P>This study conducted design parameter optimization for tillage blade of a crank-type rotavator (45 kW rated power, eight blades). Load, stress, and mass of the blade were obtained from field tests and a commercial program, and design parameter optimization was carried out with them. Selected design parameters were the heights. of front and rear ribs, and thickness of the blade. And objective function was minimizing the mass of the blade. Optimization for the nominal tillage blade was conducted considering two different cases of thickness profile: constant thickness of tillage blade in the length direction and inclined thickness. In addition, it was conducted in two different cases of safety factor to consider the changes of tillage load depending on the soil characteristics: higher safety factor on the stress than the nominal tillage blade and lower safety factor. From the results of the optimization for the nominal tillage blade, the mass of the blade reduced by 3.2% under the same safety factor condition. And results of the optimizations with various conditions showed that higher safety factor increased the mass of the blade. The inclined blade also increased the mass of the blade to have the same safety factor. The results of the sensitivity analysis provided that the design parameter affected most on the stress and mass of the blade was thickness of the blade. Therefore, determining appropriate safety factor and thickness of the blade is important in designing the tillage blade. Design parameters of this study do not affect on the surface area of the blade, which is the important influence factor for the tillage performance. Thus, the process used in this study will contribute to the design of tillage blade in minimizing the mass while having similar tillage performance. Further studies on optimization of the shape of the frame and optimization of geometrical structure of the blade will be needed.</P>

Analysis of the Separating Performance of Peanut Harvester Sorting System

Kim, Bong-Jin,Kang, Young-Sun,Kim, Hong-Gon,Inoue, Eiji,Okayasu, Takashi,Kim, Dae-Cheol FACULTY OF AGRIC PUBLICATIONS-KYUSHU UNIV 2015 Journal of the Faculty of Agriculture, Kyushu Univ Vol. No.

Development of Plant Motion Monitoring System to Study the Circadian Rhythms based on Leaf Motion Implementing the Optical Flow Method

( Andri Prima Nugroho ),( Lilik Sutiarso ),( Rudiati Evi Masithoh ),( Takashi Okayasu ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Circadian rhythm is a biological process that repeats according to environmental conditions and occurs due to the change of light and temperature. Plants are triggered by biological clocks to help adapt to dark and light changing times in accordance with the presence of light and environmental temperature conditions. The objective of this study was to develop an automatic plant monitoring system to measure the motion rhythmic in plant based on leaf motion. The proposed system allows continuous, high-resolution time-lapse imaging, independent of the presence of visible light, and based on the open-source platform. The system utilized an infrared (IR) camera positioned above and side of the plant as top view projection and side view projection respectively. As the motion tracking, the Optical Flow method was adopted, implementing the Lucas-Kanade technique combined with Shi-Tomasi corner detection. Optical flow is one of the motion detection methods to analyze the motion between two consecutive images by differentiating the constraint. Average of the displacement distance (V) was used as a parameter for representing the motion. As the result, the proposed system could be used to monitor the plant motion resembles the diurnal circadian rhythm. Further investigation of the rhythmic motion and its relation to environmental treatment will be in the future works.

Relationships between Mass and Porosity of Rough Rice Piled in a Combine Grain Tank

( Ryuichi Yoshizaki ),( Yasumaru Hirai ),( Muneshi Mitsuoka ),( Shio Inagaki ),( Eiji Inoue ),( Takashi Okayasu ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Percentage of ripened grains (PRG) is an important indicator to evaluate soil and crop management in rice production and is used to estimate weight of ripened brown rice by which economic returns are determined in Japan. This study focused on estimating PRG using bulk density of rough rice piled in the grain tank of a combine harvester. Our former study has showed that linear relationships between bulk density and particle density (an indicator of PRG) of rough rice piled in a vertical cylinder were dependent on the filling conditions of the rough rice. This finding required to clarify the filling conditions of the rough rice piled in a grain tank to estimate PRG using bulk density. Porosity is an indicator to evaluate the filling conditions. Thus, the objective of this study was to clarify factors affecting the porosity of rough rice piled in a grain tank. Relationships between mass and porosity of rough rice piled in a grain tank was measured through the field tests and the indoor experiments using a 6-row and a 4-row head feeding combine harvester, respectively. In addition, relationships between pressure at the bottom part in the grain tanks and porosity were compared between the field tests and the indoor experiments. The determination coefficients (R²) of regression lines between mass and porosity were high: 0.96 in the field tests and 0.88 in the indoor experiments. These relationships showed that mass is a major factor affecting porosity of rough rice piled in a grain tank. For the relationships between pressure at the bottom part of a grain tank and porosity, the field tests (moisture content: 23-29 %) showed 6 % larger porosity at around 2.5 kPa of pressure than the indoor experiments (moisture content: 15 %). Lowered fluidity of rough rice at higher moisture content is a possible cause of this larger porosity in the field tests. In addition, the magnitude of the slope of the regression line for relationships between the pressure and porosity was higher in the field tests (2.74) than in the indoor experiments (0.83). This result suggested that shaking of the combine during harvest, which involved only in the field tests, affected the porosity.

Sensor Comparison for Grass Growth Estimation

Kabir, Md. Shaha Nur,Chung, Sun-Ok,Kim, Yong-Joo,Lee, Geung-Joo,Yu, Seung-Hwa,Lee, Kyeong-Hwan,Okayasu, Takashi,Inoue, Eiji FACULTY OF AGRIC PUBLICATIONS-KYUSHU UNIV 2016 Journal of the Faculty of Agriculture, Kyushu Univ Vol. No.

<P>Precision agriculture has been implemented in various cultivation operations for various crops. Recently, autonomous mower tractor with variable rate fertilization has been tried. Variable rate fertilization requires quantification of grass growth level. Objective of this study was to compare the performance of potential sensors under different growth levels and sensor operation conditions. A CCD camera, an ultrasonic module, and an optical reflectance sensor (i.e., Crop Circle) were tested at fields with different grass growth levels. Effects of sensor mounting height and angle were investigated. Effects of vehicle (i.e., mower tractor) vibration and traveling were also investigated: under static, vibration and no traveling, and vibration with traveling conditions. Results showed that sensor mounting height had a little effect on the sensor performance, and grass growth level was successfully quantified. Camera angle of 90 degrees showed the best performance with less noise. The ultrasonic sensor could work with less deviation under static condition, whereas, CCD camera proved the applicability under all operating conditions. Operation condition of the optical reflectance sensor showed a little effect on the grass growth detection results. This study would provide information useful for automated grass growth mapping and variable fertilization recommendation.</P>

Development of a Parallel Hybrid System for Agricultural Tractors

Lee, Dae-Hyun,Kim, Yong-Joo,Choi, Chang-Hyun,Chung, Sun-Ok,Inoue, Eiji,Okayasu, Takashi FACULTY OF AGRIC PUBLICATIONS-KYUSHU UNIV 2017 Journal of the Faculty of Agriculture, Kyushu Univ Vol. No.

<P>The purpose of this study was to develop parallel hybrid tractor. The hybrid tractor was constructed by adding major components of a hybrid driving system on a tractor. The tractor has 71 kW engine power and the major components included an EMG (electric motor/generator), an inverter, batteries, a battery management system (BMS), and a hybrid control unit (HCU). The hybrid tractor had three control modes: idle, power assist, and battery charge and it were determined by the workload which estimated by measuring engine rotational speed. Performance of the hybrid tractor was evaluated through the field tests of plowing. Performance tests were conducted by comparing the hybrid tractor and the conventional one, and one hybrid tractor was used for the experiment. The hybrid tractor used the hybrid system for the control of EMG, and the conventional tractor was driven by the engine not using the hybrid system. Performances of the hybrid tractor and the conventional tractor were similar at M2 which is low speed condition and it could work with low load, but the performance of the hybrid tractor was better than one of the conventional tractor at higher load condition (M3, M4). Fuel efficiency of the hybrid tractor at M2 was similar with the one of the conventional tractor, but it was lower at M3 and M4 than the one of the conventional tractor by 74%. Considering all results of this study, the developed parallel hybrid tractor is feasible to improve plowing performance of the conventional tractor.</P>