All issues
Volume 50, Issue 6
Displaying 1-17 of 17 articles from this issue
- |<
- <
- 1
- >
- >|
-
Leaf TobaccoY. MIYAKE1988 Volume 50 Issue 6 Pages 1-2
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (1786K) -
Effect of Lug Angle on Soil ReactionHiroshi NAKASHIMA, Takashi TANAKA1988 Volume 50 Issue 6 Pages 3-10
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a serial study on soil-lug system interactions, effect of lug angle on soil reaction was experimentally studied and the following results are obtained. When lug angle becomes large, the average lift by lug also increases but the average thrust decreases except for the case of 13.8% wheel slippage, as for which case clear effect of lug angle cannot be identified. Wheel thrust efficiency tends to increase with the decrement of lug angle and clear tendency on effect of lug angle is found at 28.8% wheel slippage. The value of the efficiency for the case of small lug angle becomes maximum when the wheel slippage condition is 28.8%. But strong effect of variation in slippage condition cannot be seen for the case of large lug angle.View full abstractDownload PDF (970K) -
Lug Elements and Motion Analyses of WheelsJun SAKAI, Tadashi KISHIMOTO, Surin PHONGSUPASAMIT1988 Volume 50 Issue 6 Pages 11-18
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIt is considered that the interactions between agricultural wheels and soil surface have to be analyzed carefully for the purpose of deriving design equations for the wheels, especially for deciding the rational shape of wheel lugs.
The objective of this study is to derive design equations for deciding a wheel lug shape. In the first stage to derive them, authors' group observed lug shapes and considered them to be composed of four elements decided by five points in conventional lug shapes. Moreover, the equations for locus curves of these points were derived as the result of the motion analyses of a wheel axle center with “lift reduction” proposed by the authors and “travel reduction”.
These equations are indispensable to the motion analyses of wheel lugs, and thought to be the bases of designing a rational lug shape. The design equations for deciding a rational lug shape obtained from wheel motion analyses will be reported in subsequent papers.View full abstractDownload PDF (1045K) -
Measurent of soil stresses and displacements under pressureSatoshi YONEKAWA, Osamu KITANI, Tsuguo OKAMOTO, Naoki SAKAI1988 Volume 50 Issue 6 Pages 19-26
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn an attempt to get data for analyzing a soil-tillage tool interaction, this paper describes development and validation of the measuring system mainly consisted of the miniature soil stress/soil displacement sensor and the soil bin with soil processing equipments. This sensor was consisted of attached subminiature pressure gages to detect soil stresses and light sources transmitted by optical fibers which blink through the front glass wall of the soil bin that was used to search soil displacements by image processing. Distributions of soil stresses and strains under pressure can be estimated with several couples of these sensors, and the soil at a certain condition can be prepared in this soil bin with processing equipments.View full abstractDownload PDF (2878K) -
Takaaki MATSUO, Koichi HASHIGUCHI, Jun SAKAI1988 Volume 50 Issue 6 Pages 27-34
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA farm land generally consists of soft soil and hard subsoil pan. In other words it has two-layered structure. Since sinkage of farm vehicles would mainly depend on the bearing capacity of tilth, sinkage characteristics on farm land remarkably differ from on a homogeneous semi-infinite ground.
As a first step of theoretical study on the sinkage of farm vehicles, bearing capacity-sinkage relation is analyzed by the slip-line method, idealizing rigid pan such that a rigid plate penetrates into soil. The calculated results are shown in Fig. 9, where q is a dimensionless bearing capacity devided by cohesion, W is the width of rigid plate, D is the depth of tilth and S is sinkage. On the other hand, test results on the Masa-do (sandy clay loam) are shown in Fig. 11, where the theoretical curves are also shown. The theory could express the general trends of the experimental results.View full abstractDownload PDF (2123K) -
A Machine Manufactured for Trial and Its BehaviorIsao TAJIRI, Kunio SATO, Osamu KITANI1988 Volume 50 Issue 6 Pages 35-44
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSBy remodeling an existing tractor, a tractor for sloping ground was manufactured for trial. A suspension of the front wheels was composed of parallel links. The trailing arm type suspensions serving as the final drive unit were used for the rear wheels. On the rear part of the tractor, a parallel link was installed, to which a three-point link hitch was attached. As the sensors for attitude control, three sensing devices were taken up. These are a pendulum accompanied by a damper, compound pendulums and all hydraulic servo valve operated by acceleration. We carried out the attitude control test, and the response of inclination compensation of the tractor was examined. Since the natural frequency of the pendulum with a damper is low, the sawtooth shape of swing angle owing to attitude control was observed. Compound pendulums were particularly effective for unsteady running such as sudden start-up and running over obstacles. Since the servo valve sensor has the high natural frequency, insufficient flow rate was apt to occur, and the phase was lagged, bus it accomplished a smooth control, and showed avery high stability in unsteady running.View full abstractDownload PDF (5290K) -
Formulation and evaluation for steering control system based on linear muti-variable control theorySatoshi OKE, Haruhiko MURASE, Yoshiaki NAKAMURA1988 Volume 50 Issue 6 Pages 45-52
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to develop an automatic steering control system of articulated vehicles, adaptability of the linear multi-variable control theory based on the state space approach to the steering control was studied. The numerical model study showed a strong possibility of application of linear multi-variable control theory to the automatic steering system.
The results obtained from the numerical experiment for the step-function response of the control system were reported in this installment. Since the actual control object is always associated with disturbances and parameter fluctuations, the effect of the constant disturbance and the white noise for the control system was discussed in terms of the response characteristics and stability of the system. In the following installment, the entire process of determination of mechanical parameters (moment of inartia of vehicle, cornering power of vehicle, etc.) and control parameters (gain vector, etc.) using an experimental vehicle will be discussed.View full abstractDownload PDF (974K) -
In case of tractors and related vehiclesNobutaka ITO, Atsushi UTVNO1988 Volume 50 Issue 6 Pages 53-60
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs one of the factors for improving the operation efficiency, the improvement of turnabillity of the farm use vehicle can be considered. There can be listed three methods of improving the turnability of the agricultural vehicles.
In this paper, the test result of the turnabilty of the wheel type vehicle equipped with turn table turning function was discussed in comparison with the conventional commercial machine and the operation efficiency was evaluated.View full abstractDownload PDF (2776K) -
Measurement of Velocity Distributions in the Layer of Grains Flowing in an Inclined Open ChannelEiichiro SAKAGUCHI, Senkichiro HAYAKAWA1988 Volume 50 Issue 6 Pages 61-68
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIt is necessary to know the flow characteristics of grains in order to prevent troubles occurred in the facilities and plants where grains are handled and processed and to develop the new techniques to handle and process grains. In respect of powders and granular materials like grains, however, the mechanism of the flow is complex and it is difficult to measure the state of the flow, so we have not being able to even quantitatively describe the condition of the flow. Therefore, the aim of this study is to clarify the flow characteristics by considering the velocity distributions in the layer of grains flowing in an inclined open channel, that is a basic gravity flow. In this paper, by correlation techniques and using optical fibers for sending and receiving light, we developed the on-line instrument system by which the velocity distributions at the bottom and the side in the layer of grains flowing in an inclined open channel could be measured in one flowing, with high accuracy, in short time and at maximum 31 points almost without disturbing the flow.View full abstractDownload PDF (1168K) -
Measuring SystemHaruhiko MURASE, Satoshi OKE, Sakae SHIBUSAWA, Yoshiaki NAKAMURA1988 Volume 50 Issue 6 Pages 69-76
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the first installment, the application of the finite element inverse analysis to parameter estimation of mechanical properties of agricultural materials has been reported. The main system that will be developed for this parameter estimation research consists of two systems. One is an analysing system. The other is a measuring system. It was confirmed based on a numerical experiment that the installation of the finite element program in the analysing system was effective.
In this paper, the measuring system developed was discussed. The measuring system generates data which will be fed into the analysing system. The main performance of the measuring system is to digitize shapes of specimen deformed by compression as image data. The hard ware of the measuring system consists of a specially designed small compression testing device, a microscope, a CCD video camera and an image processing device. The verification of the main system performance was made by test runs using actual vegetative materials. The Young's moduli and the Poisson's ratios with tomato fruit and green pepper were determined without difficulties unlike traditional methods.View full abstractDownload PDF (2526K) -
Dynamic Young's Modulus and Poisson's RatioMakoto HOKI1988 Volume 50 Issue 6 Pages 77-82
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe ultrasonic measurements of soybeans proved to be an effective means to determine physical and mechanical properties of soybeans at various moisture contents. Measurements of volocity of propagation on the slendar bar specimen, called bar velocity, of soybean established values of the dynamic Young's modulus. Velocity of propagation on the thick cylinder shaped specimen, called dilatation velocity, were different from bar velocity. The differnce caused by the different boudary conditions of the two types of soybean specimen were used to determine the dynamic Poisson's ratios. The dynamic Young's modulus decreased with the increase of moisture content. The values of Poisson's ratio of soyban were ranged 0.321 to 0.253 depending upon moisture content.View full abstractDownload PDF (4996K) -
Effectiveness of the Most Suitable Wavelength Bands in the fieldNaoshi KONDO, Shunzo ENDO1988 Volume 50 Issue 6 Pages 83-89
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the part II of this series of study, it was reported that the most suitable wavelength bands for discrimination between fruits and leaves were selected. It was possible to discriminate even unripe fruits from their leaves in the laboratory which were not able to be distinguished by R, G, B filters. But there are many other objects than fruits and leaves under various conditions in the field. Therefore, it is desirable that the most suitable wavelength bands be used in order to make it easy to discriminate fruits, not only from leaves but also from other objects.
In this paper, experiment of image input of the plant bodies was done by a visual sensor made as a trial in order to investigate if the wavelength bands selected in the previous paper were suitable or not in the field. Besides, the degree of discrimination under the various conditions of color temperature of light source, moisture content of soil and so on was investigated by computer simulation. From the results, it was found out that it was appropriate to use properly the most suitable wavelength band filters or R, G, B filters under certain circumstances.View full abstractDownload PDF (4217K) -
Shigeo UMEDA, Kentaro MOHRI1988 Volume 50 Issue 6 Pages 91-97
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSComplex utilization of natural energy was considered on a family farm and for agricultural production. The proposed system consists of a drying unit powered by solar energy and a water pumping unit powered by a wind turbine and solar cell.
The hot water was generated by solar collectors and was stored in a storage tank. In the drying season, the hot air for grain drying was transformed from stored hot water by heat exchanger. For paddy drying, hot air with a temperature of 35-45°C could be generated, and paddy drying of 600kg could be finished in two days.
Water pumping by a savonius type wind turbine and solar cell was examined. As the wind speed was small at the experiment site, pumped water by the wind turbine was less than by the solar cells. Total daily mean pumped water was 6m3 in winter and 8m3 in summer. The maintenance of this system is very easy and this system can be used for sprinkling in vegetable cultivation.View full abstractDownload PDF (869K) -
Relation between Impedance Parameters and FreshnessKoro KATO1988 Volume 50 Issue 6 Pages 99-107
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe object of this study is nondestructive electrical inspection of internal quality of fruits and vegetables the freshness of which is very important for consumers. On-line real time system which can measure vector impedance of fruits and vegetables and analyze the dielectric properties has been developed. Impedance, capacitance and resistance of fruits and complex permittivities of the sarcocarps were measured in the frequency range from 10Hz to 13MHz both nondestructively and destructively. Obvious differences in dielectric properties were distinguished between fresh and spoiled or damaged fruits in this range of frequencies. According to rot or damage, parallel equivalent resistance of fruits, impedance, series equivalent resistance and reactance decrease sharply, and series equivalent capacitance and dielectric loss factor increase. Among these impedance parameters, correlation between series equivalent resistance and freshness or maturity is the most obvious in nondestructive measurement. Thus, the freshness of fruits can be measured nondestructively and contactively by series equivalent resistance.
Next, we tried noncontacting measurement of resistance of fruit by capacitive connection. It became clear that if the fruits are spherical and same size, the freshness can be measured nondestructively and noncontactively.View full abstractDownload PDF (1485K) -
Quick Measurement Method Based on an Estimation Technique of Temprature DistributionSei-ichi OSHITA1988 Volume 50 Issue 6 Pages 109-116
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSA method was proposed to measure thermal diffusivities of a material continuously and in a short time. This method can be applied to a specimen which is considered to be an infinite flat plate and is insulated at one end surface.
Numerical experiments clarified the errors which arise in measurements due to the imperfect insulation at the boundary surface. Thermal diffusivities of acryl resin plate were determined by the proposed method and the observed value shifted by 2.5% of the one measured by the conventional periodic heating method. It was concluded that the error accompanying each value measured by the proposed method is about 5%.
This method required about 40 minutes for obtaining 5 measurements ranging from 20°C to 40°C.View full abstractDownload PDF (1022K) -
Ritsuya YAMASAHITA, Somyot CHIRNAKSORNN, Bharata KUNJARA1988 Volume 50 Issue 6 Pages 117-120
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (559K) -
Function and Valuation of Rice TransplanterTadashi FURUYA, Tatsuya KONISHI, Sumihiko MIYAHARA1988 Volume 50 Issue 6 Pages 121-125
Published: 1988
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (742K)
- |<
- <
- 1
- >
- >|