In this study, a wheel-type robot tractor was developed in order to reduce agricultural labor. An RTK-GPS (real-time kinematic global positioning system) and an IMU (inertial measurement unit) were used as position and attitude sensors for the navigation system. A path-following navigation algorithm and an algorithm for turning at headland were designed in this study. Tuning of the auto-steering system to improve the navigation accuracy was done. Applications of the robot tractor including tillage, spraying and weeding were tested in real farms. The RMS (root mean square) of lateral error was less than 0.05 m for all of the applications. The results of the tests revealed that the robot tractor has high and stable navigation accuracy for the tested operations.

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An analytical and experimental study is performed in this study to evaluate the discharge rate of grain flow from different discharge gates of a grain seeder. Three different apertures (circular, rectangular, and square with approximately the same area) are considered in the experiments. Based on the results obtained in this study, discharge rate of the circular aperture is the maximum. In contrast, the square aperture has a minimum discharge rate. It is also found that, with increasing the grain height in the tank, the discharge rate does not change significantly. Regarding the non-uniform and oscillating discharge from a square aperture, it is not recommended to be used for discharging grain materials from a reservoir, grain drills, storage tanks, or silos.

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This study observed soil condition in a tsunami-damaged field. An on-the-go soil sensor mounted on rice transplanter was employed for field monitoring. Topsoil depth (TD) and soil fertility value (SFV) were used for field evaluation. A dataset of 17,017 samples for tsunami-damaged and 33,716 samples from on-damaged field were evaluated in this study. Results indicated that standard deviation of TD between tsunami and non-damaged fields showed very little differences. However, average SFV in the tsunami field was greater than three times higher than that of non-damaged field. Especially, high SFV (i.e. 1.2 mS/cm) was observed around the edge of field due to the salt removal operation by using mole drain.

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This study describes the process of applying the proximity sensor technology to measure grain flow during harvest in real fields. The results of the present study can eventually lead to the accurate prediction of harvest. In the experimental combine, the grains flowed through an elevating screw into the grain tank. The flow was monitored for the amount of grain via the attached proximity sensors. The results show a high correlation (R² = 0.996) between the signal detection time and the feed amount. The high correlation of the equation obtained in the present study proves the feasibility of the system and demonstrates its potential in terms of making a considerable contribution to precision in agriculture practice.

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The postharvest quality and storage life of vegetables are controlled by maturity due to their cells still alive after harvest and continue their physiological activity. The objective of this study was to monitoring physico–chemical quality parameters of intact tomato (Lycopersicum esculentum) during storage (18 °C, 85% RH) for 12 days, based upon visible/near-infrared (VIS/NIR) absorbance spectroscopy from 350 nm to 1050 nm. Partial least squares regression (PLSR) was applied to estimate soluble solids content (SSC), Titratable acidity (TA), and lycopene content of the tomatoes. The PLSR calibration model with SSC at 12 days storage, gave the highest coefficient of determination (R²) = 0.91, root mean squared error of prediction (RMSEP) = 0.285 and bias = −0.003. While the lowest R² with lycopene (0.73) and bias of −0.002 at harvesting day. Changes of sweetness index (SI), SSC, TA and lycopene content varied from 7.16 to 11.39, 4.25 to 5.51 °Brix, 0.5936 to 0.4837% and 8.65–42.69 mg/kg fresh tomato, respectively. While, Hunter colour values L*, a*, and b* were changed from 60.5 to 38.86, −2.85 to 36.59 and 37.07 to 30.92, respectively. The results showed that physico–chemical quality parameters changes significantly during storage of turning maturity tomatoes and have potential application in the field of post-harvesting.

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In order to consider the potential for electricity supply from a biogas power generation system (BGP) located adjacent to a livestock barn, the power balance was determined by using both simulation and actual measurement. Examination of power balances at the barn and the BGP showed that a certain amount of electricity for supply could be secured based on load leveling in both tie-stall barns and free-stall barns. BGPs are a viable renewable energy (RE) power source that can produce enough electricity for system operation and maintenance as well as a significant surplus of supply for power companies and other users. BGPs have the potential to allow output control appropriate for the relevant amount of gas storage. Further, output control based on the use of a gas holder in combination with changes in the number of biogas generators could allow more efficient usage of biogas. Specifically, the range of power output adjustment can be widened through parallel operation of several biogas generators, instead of a single generator. In other words, one biogas generator uses a constant power supply, and the other uses it to control the output for the related amount of gas storage. In this way, the possibility of achieving a constant electricity output through biogas power generation system and a regulated power supply was demonstrated.

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Fuel consumption intensity in agricultural transportation tasks was examined by theoretical assessments as well as practical test runs in laboratory and on road. A theoretical model for the fuel consumption intensity was created on the basis of basic equations and the results were compared to the measured figures. The results indicated that the model was working reasonably well. However, several variables included in the model require assumptions and estimations, and thus a good feel about the related issues is needed to use the model. The overall results from the study indicated that the key factors considering the energy efficiency in transportations are the rolling resistance, engine loading and payload to dead weight -ratio. With appropriate management, the energy efficiency of an agricultural tractor can be close to that of a truck. Additionally, the accuracy of the fuel consumption data captured from the tractor CAN-bus was examined. It was concluded that it was accurate enough for purposes such as energy analysis, but not for applications that demand high absolute accuracy.

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We developed a prototypic automatic spacing-controlled movable bench system for high-density planting of tomato third-truss pinching cultivation. The bench spacing can be changed to 600, 1000, or 1400 mm according to the growth stage. Cultivation experiments using a manufactured experimental model of the movable bench system gave yields of 9.7–12.4 kg/m² over 4 months' cultivation without the need for a secondary nursery system. The yield of the experimental model was higher than that of conventional cultivation systems or other cultivation systems developed for tomato low-node cultivation. Bench spacing was controlled automatically by motors and a programmable logic controller. Multiple benches could be moved together automatically to clear a work path or change use modes; manual operation took much more time. During movement on the system's rails, acceleration in the vertical direction, the direction of travel, and the longitudinal direction was less than 1.0 m/s².

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Autoclave thermal process is an important sterilisation procedure in the food canning industry. The performance of sterilisation is determined by the heating temperature and duration and the pressure in the autoclave, as well as by product's properties. In this study, a fuzzy logic controller is developed to maintain a small steady-state temperature error (121 ± 0.5 °C) for an sterilising duration (F₀) by adapting to process deviations in the autoclave. The precise temperature control associated with on-line F₀ updation assures food stuff that can be heated at the specified temperature for an expected duration and could lead therefore to successful sterilisation. The controls are implemented on a PLC (programmable logic controller) for affordability, reliability, and robustness and the operations are supervised using a web-based SCADA (supervisory control and data acquisition) system for remotely supervisory monitoring and control.

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This paper presents a nondestructive method for evaluating changes in the moisture content and in the interaction between contents such as protein and water molecule in beef cut by using visible and near infrared spectroscopies. Spectral variations in the 450–1100 nm region were measured for a beef cut using two types of spectrometers. Bands were observed in the 540–570, 600–660 and 920–980 nm regions according to the change in moisture contents. The PLS regression of moisture contents by using the second derivative in the 920–980 nm region provided a very good predictive model with R² = 0.96 and RMSE = 0.04. Moreover a band in the 600–660 nm shifted to longer wavelength in the 0.9–1.0 of water activity range and then this band slightly shifted to shorter wavelength in the lower water activity range. This spectral behavior may reflect the appearance and oxidation of myoglobin due to dry in/on beef. Simultaneously, it is very likely that the behavior of each water state; free and bonded can describe well by that band shift. These results obtained therefore provide a fundamental chemical understanding of band behavior in the 600–660 nm region and suggested that one can evaluate the quality degradation in beef cut by using visible and NIR spectral region.

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