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Volume 59, Issue 4
Displaying 1-25 of 25 articles from this issue
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N. ISHIZUKA1997 Volume 59 Issue 4 Pages 1-2
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1993K) -
Formulation of Optimal Control Problems and Forward Maneuver of TractorsRyo TORISU, Ken-ichi TANAKA, Joe IMAE, Takashi ISHIKAWA1997 Volume 59 Issue 4 Pages 3-10
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWe deal with optimal time/path problems of tractors on the headland. Firstly, we show that such problems are essentially equivalent to trajectory optimization problems of nonholonomic mobile robot. Secondly, making use of Pontryagin's maximum principle we analytically explore such optimal problems. Lastly, by means of trajectory optimization techniques we computationally solve the optimal time/path problems of tractors on the headland.View full abstractDownload PDF (1175K) -
Design of Blade Shape with Frictional EnergyXue-Gang WANG, Nobutaka ITO, Kyoji MIWA, Koji KITO, Xiu-Lun WANG1997 Volume 59 Issue 4 Pages 11-19
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSFriction and impact are two factors affecting paddy hulling performance of impeller type husker. In this paper, the relation between frictional energy and blade shape was analyzed. It was hypothesized that reducing the impact as much as possible while increasing the frictional energy will increase the paddy hulling performance. Based on mathematical calculations, the amount of frictional energy almost only depends on the center angle of arch of the blade. Increasing the center angle of arch of the blade will improve the paddy hulling performance. Then, an improved impeller was made and comparative experiments were conducted using the new impeller and the commercial one mounted to both vertical and horizontal axis type husker. The test results showed that under the same hulling ratio, the broken rice ratio of the new impeller is lower than the commercial one by about 6% and 8% in the vertical and horizontal axis type husker, respectively.View full abstractDownload PDF (1264K) -
Yoshitaka MOTONAGA, Takaharu KAMEOKA, Atsushi HASHIMOTO1997 Volume 59 Issue 4 Pages 21-28
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSConsidering the surface color change in ripening of tomatoes the color appearance by the production of pigments, the purpose of this study is to examine the color appearance mechanism by measuring the surface color change, to find the relationship between the color development and the production of pigments. As the results, it was found the surface color changed from the special points upon the radial wall of the pericarp. Next, the changing rate of the chlorophyll and the lycopene were calculated by assuming that the carotene content was constant. The calculated values showed the similar tendency to the extracted values of the pigments. This result is suggested that the hue was suitable for the analysis of the production of pigments.View full abstractDownload PDF (6693K) -
Effect of Adhered Soils on Transmission of Ultraviolet Rays through FabricsNobuaki KUWABARA, Noriko OBATA, Tsuguo OKAMOTO1997 Volume 59 Issue 4 Pages 29-37
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this study, the reduction of UV exposure for farmer in agricultural work, is aimed. For the purpose, the effects of adhered soils on the transmission of ultraviolet rays through fabrics were investigated. The results obtained are as follows. 1) The variation of Hunter indices (L, a, b, and ΔE) with the amount of adhered soils were larger for the soils containing more α-Fe2O3. 2) It was found that the hue of adhered soils on fabrics is estimated from that of suspension of the soils. 3) The transmission of ultraviolet rays through fabrics was reduced by adhesion of soils. The reduction was higher for soils containing α-Fe2O3 and also for black humus. 4) It was also found that the reduction of ultraviolet rays with adhesion of soils are interrelated with the apparent absorption coefficient. This finding may suggest that the increase in the absorption coefficient is more effective than the decrease in the scattering coefficient for the reducton of exposure of ultraviolet rays. 5) The contribution of the scattering to the decrease in the transmission of ultraviolet rays for adhesion of soils on fabrics was lower than that for dyeing fabrics. The results mentioned above will be helpful for desiging of farm working clothes.View full abstractDownload PDF (1158K) -
Experiments of Locomotion in Green House by a Control System for TravelingMasahiko KANEKO, Kazuhiro NAKANO, Tokuji OKADA1997 Volume 59 Issue 4 Pages 39-46
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper describes the control system of an agricultural vehicle for autonomous traveling without utilizing special traveling targets. To travel autonomously in a green house widely, it is necessary to get such important information like the direction for steering from visual information about the size of the house, the shape of traveling road and etc. while the vehicle is traveling. The traveling control system has four hierarchies and thus the vehicle travels autonomously with processing visual information hierarchically. The traveling control system had tested out in the green house.View full abstractDownload PDF (2899K) -
Distinction of Ripeness Using Image ProcessingMasaru TOKUDA, Tsuneo KAWAMURA, Hiroaki YAMAMOTO, Hisashi HORIO1997 Volume 59 Issue 4 Pages 47-52
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe aim of this research is to develop a visual system for a watermelon harvesting robot. At present farmers commonly harvest the fruit counting the number of days from fruit-bearing day. In this study, the distinction of ripeness of the underripe, ripe, or overripe fruit was investigated by image processing. Ripe, overripe and underripe fruit was used as a sample of image data and only the part of the green skin stripe was abstracted from that images and checked for colors. The image was changed to HSI from RGB. The result demonstrated that (the number of peaks)/(the number of the right side of peaks) of the hue histogram decreases as sugar content increases and that the saturation average of the image decreases linearly as sugar content increases.View full abstractDownload PDF (834K) -
Binarization of Fruit Pictures Taken from Apple OrchardsMing SUN, Teruo TAKAHASHI, Eiji BEKKI1997 Volume 59 Issue 4 Pages 53-60
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis study intends to develop a vision sensor detecting system necessary for robotics of apple harvesting. In this paper, an image processing algorithm using color was investigated as a target such that the rate of fruit pixels segmented correctly (RFPSC) was obtainable above 80% in binary images. The binarization was treated with the threshold value which was selected by analyzing the individual histogram of fruits and leaves and others in color TV pictures taken from apple orchards during harvesting period. The results showed that the RFPSC above target of 80% was obtained by applying -5 in threshold value of chrominance G-Y for red apples in front light, but it was difficult to obtain the level in back light because of low brightness of apples. The RFPSC for yellow-green apples was over 80% by applying 30 in threshold value of difference between two original colors R-B when the brightness of apples exceeded 110, but it was not usually easy to reach the level in back light and discriminate fruits from leaves according to the reflection of sunshine onto leaves.View full abstractDownload PDF (6069K) -
Soil-bin Test on a SliderP.A.S. RADITE, Kiyoshi NAMIKAWA, Michihisa IIDA1997 Volume 59 Issue 4 Pages 61-70
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper presents the results of soil-bin tests on electro-osmotic lubrication to reduce friction force on a slider. This study also developed a mixed friction model to explain the relationship among parameters related to electro-osmotic lubrication. Soil bin tests were conducted using a steel slider on silt loam and sandy loam soils at several speeds up to the maximum of 62.0cm/s. The slider was used as anode and the wire net at the bottom of soil-bin was used as cathode. Direct current (DC) electricity was applied between anode and cathode at maximum voltage of 120V. The electro-osmotic lubrication brought about draft reductions not only by 33.7% for silt loam soil with 27.2% db moisture content at 9.6kPa normal pressure and 61.1cm/s sliding speed, but also by 16.5% for sandy loam soil with 28.1% db moisture content at 9.6kPa normal pressure and 26.4cm/s sliding speed.View full abstractDownload PDF (2944K) -
Water·Heat Balance and Energy Efficiency for Various Static Pressures in Drying ChamberMitsuhiko KATAHIRA, Eiji BEKKI1997 Volume 59 Issue 4 Pages 71-77
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSExperiments with positive, negative and zero static pressures were carried out to determine the static pressure suitable for heated air drying of garlic bulb in an air-bag type drying chamber. Under positive pressure the air current was in turbulent state and was partly pushed outside through lower part of air-bag wall. The thermal efficiency was 30.5%, and the energy efficiency was 142.6MJ/kg. Under negative pressure the air current was in a stable state and sucked in ambient air. The thermal efficiency was 8.4%, and the energy efficiency was 128.6MJ/kg. Under zero static pressure the air current was in the most stable state with minimal air leak. Thermal efficiency was 12.2% and the energy efficency was 198.4MJ/kg. It was concluded that heated air drying of raw garlic bulb using an air-bag type is suitable under negative static pressure because it produces stable air current and low energy consumption. Then water and heat balance equations were represented under three static pressures to express the characteristics of air-bag type dryer.View full abstractDownload PDF (1136K) -
Influence of Tilt of a Tractor on Yaw Angle Measurement with a 1-axis GyroscopeKenji IMOU, Mitsuyoshi ISHIDA, Atsushi OKADO, Hiroshi TAKENAGA, Yukino ...1997 Volume 59 Issue 4 Pages 79-86
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWhen a 1-axis gyroscope is used to determine the azimuth angle (yaw angle) of an autonomous vehicle, an error will be introduced from a tilt of the body. For the purpose of finding the characteristics of the error, the relationship between the detected rotation angle about the vertical axis of the body and the yaw angle is theoretically investigated. And experiments with driving a tractor on horizontal forage farm were carried out to measure the tilt angles owing to the field roughness and the centrifugal force during turns. From the obtained data, the influence of tilt upon the yaw angle measurement was investigated. The results showed that the difference between the yaw angle and the rotation angle about the vertical axis of the body was mainly caused during turns, and the higher turning speed, the angular difference would be larger. It was also found that the detected rotation angle about the vertical axis would be smaller than the change in yaw angle during a turn.View full abstractDownload PDF (1154K) -
Unmanned Application SystemKoichi TOSAKI, Sumihiko MIYAHARA, Tomohiko ICHIKAWA, Yoshiharu MIZUKUR ...1997 Volume 59 Issue 4 Pages 87-96
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA microcomputer controlled driverless air blast sprayer which equipped with unmanned application system was developed. The sprayer travels and applies automatically along the guiding cable which is set on the working course in orchard garden. The unmanned application system consists of the unmanned traveling system, which was stated in the Part 1 of this paper, and the control systems for application and safety devices. The application control system controls: automatic stops of applying and traveling when the liquid chemical tank becomes empty, or when the sprayer arrives at the end point of application work; remote control operations for start and stop of traveling, blowing or spraying; and the automatic stop of outward spray during turning. The control system of safety devices controls the automatic stop of the sprayer when there is an obstacle on the working course, when the sprayer swerves from the course, or when the guiding cable is snapped. The sprayer worked smoothly along the experimental working course, and it was considered that the working efficiency of the sprayer was equal to or higher than that of ordinary manned air blast sprayers.View full abstractDownload PDF (1725K) -
Differences in Fissuring Behavior of Selected Japonica and Indica VarietiesRustico C. BAUTISTA, Eiji BEKKI1997 Volume 59 Issue 4 Pages 97-108
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe fissuring behavior of seven selected rough rice varieties of the japonica and indica types was compared using a single-grain layer model dryer. The physicochemical properties of the grain influenced fissure variation. Japonica varieties were more sensitive to drying rate which produced more fissures at similar drying rates than indica varieties. Serious fissuring started at a drying rate of 4%/h in indica, 1%/h and 1.5%/h in nonwaxy and waxy japonica, respectively. The recommended drying rates are: 0.8%/h for nonwaxy japonica (var. Mutsuhomare), 1.2%/h for waxy japonica (var. Yukimimochi), For the indica varieties: 3.9%/h for IR 20, 5.0%/h for IR 30, 3.5%/h for IR 58, 3.6%/h for IR 64 and 3.2%/h for IR 65. Recommended air drying temperature and relative humidity for each variety were also determined.View full abstractDownload PDF (1627K) -
Measurement of a Sound and its Applications (Part 2)Takahisa NISHIZU1997 Volume 59 Issue 4 Pages 109-112
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Measurement of a Sound and its Applications (Part 2)Setsuo HAYASHI1997 Volume 59 Issue 4 Pages 112-115
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Measurement of a Sound and its Applications (Part 2)Masami ASHIMORI, Hiroyuki KUSANO1997 Volume 59 Issue 4 Pages 115-118
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Kohei TASAKA1997 Volume 59 Issue 4 Pages 120-123
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Tatsuya KONISHI1997 Volume 59 Issue 4 Pages 123-127
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Koichiro OKAZAKI1997 Volume 59 Issue 4 Pages 128-131
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Paddy Management Works by Riding MachineTakashi GOTO1997 Volume 59 Issue 4 Pages 131-135
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Paddy Management Works by Radio-controlled helicopterMinoru MIHARA1997 Volume 59 Issue 4 Pages 136-140
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Takao SUGIYAMA1997 Volume 59 Issue 4 Pages 140-145
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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M. OZOE1997 Volume 59 Issue 4 Pages 147-148
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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Y. NAKAO, S. INOUE1997 Volume 59 Issue 4 Pages 149-150
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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M. SUGITA, A. SUZUKI, A. SATOH1997 Volume 59 Issue 4 Pages 151-152
Published: July 01, 1997
Released on J-STAGE: April 30, 2010
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