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This study aims to develop the integrated control system for an intelligent agricultural vehicle, which consist of several functions including self-localization, 2D/3D mapping, situation awareness, path planning, remote monitoring, and feedback control. The system was designed in accordance with the standards of automation level 3 of the guidelines for ensuring the safety of automatic driving of agricultural machinery established by the Ministry of Agriculture, Forestry and Fisheries (MAFF) in Japan. To satisfy the standards of automation level 3, agricultural machinery needs to recognize the surrounding environment and secure safety using various sensors. In addition, the operator must be able to check and control the working state of the machine using a monitoring device. The proposed system integrated with cameras, 3D-LiDAR, GNSS positioning devices, and IMU was instrumented on a commercial wheel tractor that can be controlled by drive-by-wire technology and made it a level 3 autonomous vehicle. An experiment with multi-field soil tillage and road driving between fields following the prescribed target paths were conducted using the fully autonomous tractor to evaluate the performance of the control system. A mannequin was arbitrarily installed around the experimental area to test the emergency stop function of the system when detecting obstacles. The experimental result indicated that the control system could enable the self-localization of the tractor in the agricultural environment and accurately guide it along the target paths during the soil tilling and the road driving. The average root mean square error (RMSE) of the lateral distance from the target path to the navigation point of the tractor (the center of rear axle) was about 0.05m and 0.06m for the navigations within fields and between fields, respectively. The system also could locate the mannequin at the danger area around the tractor, then performed the emergency stop and sent a warning message to a handheld device.

A robot combine harvester for beans was developed using CAN Bus network. Two sensors are connected to the CAN Bus; a RTK-GPS to locate the position, and a GPS Compass to detect the heading direction. This robot is programmed to perform autonomous operation such as moving forward, backward, and turning in right angle. When the robot was tested in harvesting soybeans on a 100m × 30m rectangular field, the deviations between the target path and the robot's traveling path was approximately 0.07m RMS, and the yaw angle error was approximately 1.82° RMS along the long side of the field. Therefore this robot can work autonomously along the target path without overlapping and shortening. In addition, this robot can unload harvested grain to adjacent transport truck during harvesting operation, which improved harvesting capacity to approximately 10%.

The objective of this research is to realize fully robot-operated farming from tillage to harvest in large-scale agriculture such as cultivation of rice, wheat and soybean in Japan. For this purpose, three types of robot have been developed; the first is robot tractor, the second are rice transplanter robots, the third are combine harvester robots. RTK-GPS and inertia measurement unit (IMU), or GPS compass, are used for navigation system. Robots have Controller Area Network (CAN) bus that all sensors and PC can be connected in common among other robots such as tractors, rice transplanters, and combine harvesters. These robots could be done autonomous operation in paddy field. In addition, moving between the fields for effective operations and safe guideline for robot system were discussed.

In this paper, development and standardization of on-vehicle control and communication data network for small size farm machinery is described. There already exist an international standard and many compliant products in the western countries. But, they are too huge and complicated for the average Japanese style of farming, which is represented by the words of small tractors and small paddy fields. In order to achieve an advancement and cost reduction in this field, enough and sufficient low cost simple electronic devices and related software were developed. The communication method adopted basically depends on the ISO 11783 standard technology, and some new features needed for the domestic agricultural conditions are considered. At the same time, a new domestic simple standard for data exchange between ECU's on tractors and attached implements are discussed. From some experiments, it became clear that the developed hardware and software together are strong tools to realize the domestic standardized devices. It can be said that standardization of data communication for lower range of farm machinery just has been started.

We have developed a new Global Positioning System (GPS) guided rice transplanter. We developed GPS and IMU guided rice transplanter in previous researches. Those were guided with GPS position data and inertia measurement unit (IMU) direction data. New one is guided with GPS position data with tilt correction during straight driving and guided with IMU direction data during turning at the headland. The GPS antenna is set to 1.5m height and 0.4m front offset from vehicle front axle. The actuator control command and data communication protocols comply with through the controller area network (CAN) bus. Steering and transmission are controlled by electrical actuators according to the location in a field. We report results of experiment.

Rice plants are known to accumulate starch in leaf sheaths and culms, and in some cultivars significant amounts of starch are present at the mature stage. This can be considered as potential feedstock for the recovery of fermentable sugars. We isolated starches from the culms of cultivars Yumeaoba, Koshihikari, and Leafstar to investigate their structural and physical features. Yumeaoba culm starch contained 20.2% amylose, whereas Koshihikari and Leafstar contained 25.8% and 25.2%. Yumeaoba culm starch was found by chain-length distribution analysis to contain higher amounts of short chains, resulting in lower gelatinization temperature by 7 degrees C, as compared to Koshihikari and Leafstar. Consequently, the rate of enzymatic hydrolysis of Yumeaoba culm starches reached maximum at a lower temperature than Leafstar. Rice culm starch, with a lower gelatinization temperature, can provide an advantageous material for feedstock for bioethanol production in terms of energy conservation.

We monitored rice plant growth over a region in order to define a cropping system that could produce higher-quality paddy rice. Plant growth information is more useful when collected for a large area. Information on a production region can aid in realizing uniform, high-quality rice production with the competitive ability of a regional strain. We used an unmanned aerial vehicle (UAV) to monitor plant growth in paddies. The UAV was considered more effective than an unmanned helicopter for monitoring a wide area, and easier and more flexible to use than a piloted airplane or satellite. The vehicle carried a commercial digital camera for true-color images and a plant cover ratio camera for to acquire near-infrared images. Two paddy field sites (composed of 33 and 55 individual fields) were monitored near Myoko, Japan, when rice plants were at the panicle-forming stage. The ground area captured in each image measured about 410 m x 280 m. Both red-green-blue (RGB) and near-infrared images were analyzed using commercial image processing software. Several indices were calculated for each field, including the degree of greenness and the normalized difference vegetation index. Growth variability between fields was quantified, and suggestions for how to improve cropping systems were presented at meeting with local farmers. On the basis of our results, fertilizer use will be decreased with the intended benefit of producing a higher-quality rice crop. The monitoring method using a UAV was easier and cheaper than other remote sensing methods, and the acquired information was useful to local farmers. Further study is needed to optimize the monitoring period and image-analysis methods. Effects of the new cropping system implemented by farmers must also be investigated in a controlled trial.

飼料イネ収穫・調製作業において収穫と同時に収穫物に乳酸菌溶液等を添加する際に，溶液の噴霧を適切・自動的に断続できる乳酸菌散布装置を開発した．1）本装置では，複数のセンサを組み合わせて簡易な自動化回路を構成したことにより，オペレータが頻繁なスイッチ操作をすることなく自動的に薬液の散布が断続できる．2）大区画圃場における実証試験から，停止中や旋回中等の無駄な散布を容易に抑制することができ，薬液の節減効果は最大37%となった．3）制御回路の異常時には直ちにバイパス回路に切り替えて従来法と同等の作業が保証されるなど，高い有用性が確認された．

フレール型の専用収穫機と自走式ベールラッパ各1台による作業体系を想定して簡易なシミュレーションモデルを開発し，飼料イネのダイレクト収穫における作業時間の短縮・効率化の方策を検討した．1） 開発したモデルは，作業経路シミュレーションと作業時間シミュレーションの2つのモジュールで構成され，圃場区画や作物密度，作業経路等の条件設定値を変えた様々なシミュレーションが可能となった．2）実作業の作業時間解析を行い作業機の固有作業能率等のデータ収集を行った．この結果を用いて，圃場内でのロールベール運搬に関する両機の分担・連携条件と作業の効率化について解析が可能となった．3） 開発した本モデルは，表計算ワークシートとマクロプログラムで構成されるため，解析の目的に応じてモデルの改良・拡張が容易である．

The major carbohydrates of rice straw samples were determined in order to evaluate the potential of using rice straw as a feedstock for ethanol production in Japan. Straw samples were harvested by cutting the plants at ground level when the grain was mature and immediately heating or chilling the samples. In all cases, significant amounts (62–303 g kg−1) of soft carbohydrates defined as consisting of glucose, fructose, sucrose, starch and β-1,3-1,4-glucan were detected, in addition to structural carbohydrates (cellulose and xylan). These results indicate that rice straw is a rich source of fermentable sugars from both soft carbohydrates and lignocellulosic portions of the cell wall.