Takashi Okayasu

Precise measurement of soil deformation and fluctuation in drawbar pull for steel and rubber-coated rigid wheels

The travelling performance of rigid wheels on sand stratum is measured using two kinds of surface material, i.e. steel and steel coated with rubber. A new method for measuring the displacement of soil beneath the wheel has been developed using small polyester film markers. The trajectories of soil particles beneath the wheels are approximated by an exponential function and the fluctuations in the drawbar pull are represented by a sinusoidal function. The amplitude and basic wavelength of the fluctuation in the drawbar pull are discussed for both types of wheels.

Study on Knowledge Management Platform about the Field of Agricultural Infomatization

In the region of Japan, broadband network and informatization have spread. However the field of agriculture has not come willingly. The infrastructure that has not been enough in mountainous areas, but various initiatives of computerization are being started using production and distribution as the subjects. Since this began in reality, there are still insufficient matters that have been resolved in regards to the technical validations and cost effectiveness. Therefore necessitates pouring in a tremendous amount of expertise, possibility is ICT and its related technologies of sensors. In our research and developments, we create demo hardware for the experiment using in the farm collected data. On the other hand, making study group with farmers for accumulation of data and experience. That visualized information configure to the platform of knowledge management.

Development of a remote environmental monitoring and control framework for tropical horticulture and verification of its validity under unstable network connection in rural area

Display Omitted Remote monitoring and control framework under unstable network connection.The framework consists of local and global management subsystem.Evaluated on tropical horticulture monitoring and soil moisture content control. This study focuses on the development and evaluation of a remote field environmental monitoring and control framework, implementing a local-global management strategy to overcome the unstable network connection in the rural area. The framework consists of environmental monitoring and control node as the local management subsystem (LMS), and the web data providing and system management as the global management subsystem (GMS) to establish a simple and flexible remote environmental monitoring and control based on a cloud platform. The supporting features are online and offline environmental monitoring, synchronization of system configuration, actuation, and offline management. Two field tests were conducted to verify its performances and functionalities, (1) environmental monitoring on tropical horticulture cultivation in Yogyakarta, Indonesia, and (2) implementation of the monitoring and control for automatic drip irrigation control based on soil moisture content for tomato. As the result of the first test, the developed framework could help to maintain the sustainability of environmental monitoring under unstable network connection over 80% availability of the data with local offline measurement up to 24% of the total entries. From the second test result, the framework could support the real-time monitoring and control of soil moisture content as well as increase the system flexibility in the adjustment of the system configuration remotely. The control system has 0.78% error (E) and 99.2% in-range soil moisture content (L

Development of Actuation Framework for Agricultural Informatization Supporting System

Abstract Agriculture faces many challenges in the production system, such as climate and weather, field conditions, crop types, soils types and conditions, and so on. Farmers consider many aspects to optimize the “on-farm” process by their long-term experiences. Various informatization agricultural supporting systems have been developed using ICT (Information and Communication Technologies) to improve agricultural productivity. Authors have developed the ICT-based agricultural supporting system called the “Agri-eye” in which a field monitoring, crop growth and quality evaluation, work recording, and online data offering and sharing sub-systems were incorporated. On the other hand, an actuation sub-system for controlling and managing agricultural facilities in a greenhouse such as a heater, water pumps, circulation fans, a CO 2 generator, etc. has been introduced. In this study, an actuation framework is developed as a useful method for monitoring and controlling local facilities and machineries. The method can be used for controlling particular device with adjusting parameter from Agri-eye server to meet the cultivation requirement. Furthermore, the validity of the developed framework was verified to monitor and control air temperature in laboratory test box.

Turbulent Flow Characteristics of the Cleaning Wind in Combine Harvester

Abstract The flight of separated straws is thought to affect the cleaning wind of a combine harvester. To comprehend the turbulent flow characteristics of the cleaning wind and its passage through the grains, the cleaning wind velocity is measured by particle image velocimetry and laser Doppler velocimetry. The flow of the cleaning wind is blocked by the grains, and therefore the distribution of wind velocity changes. It is found that the energy loss of the cleaning wind is not a result of turbulent flow. The wall friction and the pressure change observed as a result of the shape and the friction loss in the grains are the main considerations while calculating the energy loss of the cleaning wind in combine harvester.

Collision Vibration Characteristics with Interspace in Knife Driving System of Combine Harvester

Abstract It is necessary to develop a design theory of the knife driving system of combine harvesters in order to derive the control parameters of the balance weights used for vibration reduction. A collision vibration model of the knife driving system that is equipped with a slider-crank mechanism was constructed in order to examine the influence of the interspace that arises at the joint of the drive knife and the end of the link arm. The simulation result revealed that the harmonic frequency components varied with an increase in the width of the interspace although the highest harmonic frequency in the simulation without the interspace was three times the crank wheel rotation frequency. However, the vibration reduction by the balance weight was not dependent on the width of the interspace.

Feasibility Study on Field Monitoring and Work Recording System in Agriculture

Simple field monitoring system for optimizing and improving agricultural production process and management is developed by the built-in mail sender data logger unit with some weather and field monitoring sensors. In this monitoring system, all the monitoring data are once transferred and stored to mail servers. Thereafter the data are transferred periodically to the agricultural information database system. The database system was fully developed using open software such as apache (web server), MySQL, PHP, Java, CMS (Contents Management System) and so on. The stability of the monitoring system was verified using more than 20 monitoring units at four test sites where weather, crop type and farm size are different. On the other hand, work recording system to manage and optimize current production process was also developed and integrated to the developed database system. A list of farming processes and schedules was arranged flexibly by a farmer thorough a web browser. All the process data were entered into the information database by using mobile device and/or PC. The availability and validity of the developed recording system were verified by feasibility studies in the real farming sites.

Time-Dependent Elastoplastic Constitutive Model

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.

Effects of different application methods of fertilizer and manure on soil chemical properties and yield in whole crop rice cultivation

ABSTRACT Whole crop rice (WCR) is expected to establish a cultivation method using manure produced from animal wastes. Meanwhile, application methods of fertilizer and manure in the WCR cultivation are affected by availability of manure, available time for its application, and field drainage, and low market price of WCR. This raises concerns about soil fertility deterioration and yield reduction in the WCR cultivation. The objectives of this study were to investigate how different application methods of fertilizer and manure affected soil chemical properties and yield in the WCR cultivation. Field surveys were conducted in 2013 and 2014 at 10 fields cultivated by five different farmers in the Itoshima region, Fukuoka Prefecture, Japan. The surveyed fields included two application methods of manure (M) alone and chemical fertilizer (CF) alone. Clay plus silt content was significantly correlated with total nitrogen (TN), total phosphorus (TP), and exchangeable potassium (Exch. K), which indicated that soil texture partly contributed to the variations of these soil chemical properties. Meanwhile, clear gaps of TN, TP, Exch. K, K saturation degree, and available N between CF and M at around 40% of clay plus silt content strongly suggested that manure application contributed to increases in the soil chemical properties. Yearly differences of available N had relatively large negative values in CF fields. This result suggested a possible decrease in mineralizable part of soil TN in the WCR cultivation with CF alone, which needs to be clarified through long-term study. Significant relationships between potential N supply and straw weight (r = 0.698, p < 0.05 for 2013; r = 0.873, p < 0.01 for 2014) or yield of whole crop (r = 0.852, p < 0.01 for 2014) indicated that N mineralized from soil, which was enhanced by manure application, increased straw weight, resulting in an increase in yield of whole crop. However, excessive amounts of manure applied in surveyed fields can cause groundwater and surface water pollution. Thus, nutrient balances in a paddy field need to be analyzed further to determine an appropriate application amount of manure.

An Easy-to-Setup 3D Phenotyping Platform for KOMATSUNA Dataset

We present a 3D phenotyping platform that measures both plant growth and environmental information in small indoor environments for plant image datasets. Our objective is to construct a compact and complete platform by using commercial devices to allow any researcher to begin plant phenotyping in their laboratory. In addition, we introduce our annotation tool to manually but effectively create leaf labels in plant images on a pixel-by-pixel basis. Finally, we show our RGB-D and multiview datasets containing images in the early growth stages of the Komatsuna with leaf annotation.