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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Biosystems Engineering
Journal Basic Information
Journal DOI :
Korean Society for Agricultural Machinery
Editor in Chief :
Volume & Issues
Volume 21, Issue 4 - Dec 1996
Volume 21, Issue 3 - Sep 1996
Volume 21, Issue 2 - Jun 1996
Volume 21, Issue 1 - Mar 1996
Selecting the target year
Development of a Feed Shaft Driving System for Planters Using the Fifth Wheel as a Speed Sensor
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 399~405
In order to maintain a constant speed ratio between the tractor and attached seed planter, a feedback control unit to rotate the feed shaft of the planter in proportional to the ground speed of the tractor was designed. The fifth wheel was used as a ground speed sensor for the unit. Using this control unit a feed shaft driving system was developed and tested to estimate its performance both in laboratory and fields. The test results showed that the system rotates the feed shaft proportionally to the ground speed in the range of the normal planting speed of 0.5-0.8m/s with errors less than 5%.
Development of a Control System for Uniform Application Rate on a Self-Propelled Boom Sprayer
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 406~413
A control system for a self-propelled boom sprayer to spray at uniform application rate was developed and evaluated. The ground speed of the sprayer was converted into voltage. The voltage was used as an input signal. Output signal was current of a servo motor, that controlled application pressure of the sprayer with a feedback control system. Spraying was executed at the pressure of 20~55 psi and the speed of 0.640~0.696 km/hr and 1.040-1.131 km/hr. Although the pressure and the speed of sprayer were changed continuously, application rate was tried to keep a nearly constant amount of 666.67 L/ha. This result showed that the developed control system for uniform application rate was adoptable for the self-propelled sprayer.
Development of a Prototype Automatic Sorting System for Dried Oak Mushrooms
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 414~421
Development of a Simple Autonomous Vehicle for Greenhouse Works
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 422~428
This study was conducted to developed to develop a simple battery-powered autonomous vehicle for greenhouse works. A steering method using speed difference of two independent driving motors was adopted. DC motor driving circuit, speed control circuit and controller using one-chip microcomputer were constructed. The inputs of controller are rolling of the vehicle and current speed of driving motors. Using these signals, automatic guidance system along furrow was developed. A computer simulation program by the kenematic analysis was developed to find out optimal control algorithm. The results of this study are as follows. 1. Automatic guidance system along the furrow that adopted two independent driving motors and rolling of vehicle was developed. 2. The results of simulation showed that PID control was adequate to automatic guidance system along furrow. 3. Two commercial 12V battery serially connected were able to drive the vehicle on the soil ground for five hours in continuous operation and for four hours in intermittent operation without recharging the battery. 4. The speed range was 0-0.7m/s and the rolling of vehicle could be controlled within
range. 5. From a series of tests, developed vehicle was found to be a useful tool for greenhouse works.
Design of a Wind Tunnel for Plug Seedlings Production under Artificial Light and Aerodynamic Characteristics above Plug Stand
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 429~435
A wind tunnel consisting of two air flow conditioners with polycarbonate pipes, a plant growth room, a suction fan and fan controller, and fluorescent lamps, was designed to investigate the interactions between the growth of plug seedlings under artificial light and their Physical environments. Light transmissivities in the plant growth room based on the photosynthetic photon flux density and photosynthetically active radiation was appeared to be 96.3% and 96.8%, respectively. Measurement showed a uniformity in the vertical profiles of air current speed at the middle and rear regions of plug trays in wind tunnel. This result indicated that the development of a wind tunnel based on the design criteria of the American Society of Mechanical Engineers was adequate. Air current speed inside the plug stand was significantly decreased due to the resistance by the leaves of plug seedlings and boundary layer developed over and below the plug stand. Driving force to facilitate the diffusion of gas inside the plug stand might be regarded as extremely low. Aerodynamic characteristics above the plug stand under artificial light were investigated. As the air current speed increased, zero plane displacement decreased but roughness length and frictional velocity increased. Zero plane displacement linearly increased with the average height of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on the microclimate over and inside the plug stand and to collect basic data for a large-scale plug production under artificial light in a semi-closed ecosystem.
Performance Analysis of an Earth Tube Heat Exchanger(I) -Temperature Variation Characteristics and Heat Exchange Performance on the Mode of Continuous Operation
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 436~448
An earth tube soil air heat exchange system was designed, installed and operated as a single pass heat exchanger to utilize the geothermal energy as an natural energy source. This study was undertaken to investigate the potential of the heating and cooling, energy gain, heat exchange efficiency and coefficient of performance of the system. The system consisted of 30m in length and 30cm in diameter polyethylene pipes buried 2m deep in soil. Maximum heating and cooling performance were 2.51㎾ and 1.26㎾ at the air mass rate of 21cmm. Energy gain and coefficient of performance were the function of temperature difference between outside air and soil temperature. They were expressed as Q=0.33
+0.134(㎾) for energy gain and COP=0.44
+0.178 for coefficient of performance with correlation factor of 0.95. The mean of heat exchange efficiencies was 85.6%.
Heat Transfer Model for Soil Irradiated by Infrared
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 449~455
The temperature distributions at various soil depths were predicted by heat transfer model during and after infrared irradiation on sand loam or loam soil. At each soil depth, predicted and measured temperature distributions were compared with using the mean relative percentage deviation and standard error. The mean relative percentage deviation was less than 10% between predicted and measured temperature distributions at each soil depth. Thus, it was concluded that the temperature distribution at each soil depth could be predicted satisfactorily by heat transfer model. Also, it is expected that these predicted temperature distributions can be used as basic information for determining the working speed of weeder and the size when the real weeder is constructed.
Spraying Performance Evaluation of Spraying Nozzle Using Electrostatic Effect
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 456~466
Electrostatic spraying is needed for today's sustainable farming. An electrostatic spraying nozzle was developed and its spraying performance was evaluated. High voltages of 15㎸, 20㎸, and 25㎸ were supplied for the electrostatic electrode. Artificial and real apple targets were used for the spraying experiments. Insulated material was used around the electrode to protect the loss of electrostatic effect. Three angles (0, 45, 90 degree) of spraying direction were used for the spraying test. The performance of electrostatic spraying was improved from 204.5% upto 429.2% on the apple targets.
Use of Ultrasonic to Atomizing a Highly Viscous Bio-oil
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 467~473
Ultrasonic energy was applied for atomizing rice-bran oil which is a highly viscous bio fuel. Six different nozzles, an injection simulator, and an ultrasonic generator system were designed and constructed for the experiment. An immersion liquid method was used for the measurement of injection droplet sizes. The characteristics of injection droplets was investigated with respect to the numbers of the droplets with diameters ranging from 5
m and to the Sauter mean diameter. The results showed that the ultrasonic energy was effective for the improvement of the atomization of the injection droplets for all the factors such as type of nozzles, nozzle opening pressures, and collection distances.
Expert System for Selecting Optimized Farm Machinery in Rice Farming(I) -Program to Minimize Cost in Utilization of Farm Machinery-
Journal of Biosystems Engineering, volume 21, issue 4, 1996, Pages 474~481
Farm mechanization has been rapidly progressed in rice farming since the 1980's, in Korea. The mechanization has been achieved up to 95-97% in the year of 1995, except irrigation and drying process. However, rice production cost remains much more expensive than the cost of other rice farming countries. Since labor cost shares a major portion of the production costs, it is essential to save labor cost with automation and more sophisticated mechanization. However, it requires great capital investment which causes farm management worse. Therefore, the computer program was developed which can select machines to minimize the management and maintenance cost by analyzing available working days in different areas, machinery to purchase, farming size, total farming size in a village, number of machines and custom fee.