• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.1-10
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• 2014

Purpose: This research was conducted to evaluate feasibility of a crank-type walking cultivators for weeding in furrowed upland. Methods: A walking cultivator developed by RDA was selected and evaluated with its working speed (S), cultivation depth (CD) and weeding performance (WP). The evaluation was performed in upland field on July and August, 2012. Also kinematic analysis of the machine was performed to draw out design improvements. Results: S in flat, uphill and downhill were about 0.11 m $s^{-1}$, 0.11 m $s^{-1}$, and 0.13 m $s^{-1}$ respectively. It was found that S had a low relevance with user conditions. The CD was 35 ~ 40 mm which was satisfied with the RDA guide for weeding machine. A wide variation was observed in values of WP depending on the growth stages of weeds and field conditions. The cultivator showed low performance in eliminating the well-grown weeds. Kinematic simulation revealed that high forward speed caused a high ratio of un-weeded area. Conclusions: The weeding performance of the cultivator was satisfactory for weeds in early growth stage but it showed difficulties in handling on up-slope and in entering up-land. Specifically, the weight of the cultivator was judged as overweight for female workers. The crank-hoe type cultivator was judged as unsuitable for small walking type machine due to weight of the four-bar linkage system. Kinematic analysis revealed that the ratio of crank speed to the ground speed must be 850 rpm s $m^{-1}$ (255 rpm based on 0.3 m $s^{-1}$) or greater to avoid uncultivated area. Selection of forward speed is a decisive factor in designing the weeding cultivator.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1027-1037
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• 2021

This study aims to evaluate the performance of an electric multi-purpose cultivator through a simulation analysis. The simulation model was developed using commercial software, Simulation X, by applying the specifications of certain parts, such as an electric motor, a battery, and so on. The input parameter of the simulation was the engine load data according to the rotary tillage level using a conventional multi-purpose cultivator. The data were collected by configuring a load measurement system, and the load cycle was developed by repeating the data collection process under the most severe conditions. The average output engine torque values of conventional multi-purpose cultivator were 10.7, 13.0, 9.4, and 11.2 Nm in the D1P1, D1P2, D2P1, and D2P2 conditions, respectively. As a result of the simulation, the maximum values of the motor torque, rotational speed, and power of the electric multi-purpose cultivator were 16.8 Nm, 2,033.3 rpm, and 3.3 kW, respectively, and the motor was driven in sections within 70, 68, and 45% of the maximum output range. The rate of decrease of the battery state of charge (SOC) level per minute was approximately 0.6%, and it was possible to supply electric power to the motor for 9,550 sec. In the future study, research to verify and improve simulation models of electric multi-purpose cultivators should be conducted.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.274-282
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• 2014

Purpose: In this study, a hybrid power system was developed for agricultural machines with a 20-KW output capacity, and it was attached to a multi-purpose cultivator to improve the performance of the cultivator, which was evaluated using output tests. Methods: The hybrid system combined heterogeneous sources: an internal-combustion engine and an electric power motor. In addition, a power splitter was developed to simplify the power transmission structure. The cultivator using the hybrid system was designed to have increased fuel efficiency and output power and reduced exhaust gas emissions, while maintaining the functions of existing cultivators. Results: The fuel consumption for driving the cultivator in the hybrid engine vehicle (HEV) mode was 341 g/KWh, which was 36% less than the consumption in the engine (ENG) mode for the same load. The maximum power take off output of the hybrid power system was 12.7 KW, which was 38% more than the output of the internal-combustion engine. In the HEV mode, harmful exhaust gas emissions were reduced; i.e., CO emissions were reduced by 36~41% and NOx emissions were reduced by 27~51% compared to the corresponding emissions in the ENG mode. Conclusions: The hybrid power system improved the fuel efficiency and reduced exhaust gas emissions in agricultural machinery. Lower exhaust gas emissions of the hybrid system have considerable advantages in closed work environments such as crop production facilities; therefore, agricultural machinery with less exhaust gas emissions should be commercialized. However, the high manufacturing cost and complexity of the proposed system are challenges which need to be solved in the future.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.447-452
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• 2015

A hybrid power system was developed for agricultural machines with a 20kW output capacity, and it was attached to a multi-purpose cultivator to improve the performance of the cultivator. The hybrid system combined heterogeneous sources: an internal-combustion engine and an electric power motor. In addition, a power splitter was developed to simplify the power transmission structure. The cultivator using a hybrid system was designed to have increased fuel efficiency and output power and reduced exhaust gas emissions, while maintaining the functions of existing cultivators. The fuel consumption for driving the cultivator in the hybrid engine vehicle (HEV) mode was 341g/kWh, which was 36% less than the consumption in the engine (ENG) mode for the same load. The maximum power take off output of the hybrid power system was 12.7kW, which was 38% more than the output of the internal-combustion engine. In the HEV mode, harmful exhaust gas emissions were reduced; i.e., CO emissions were reduced by 36~41% and NOx emissions were reduced by 27~51% compared to the corresponding emissions in the ENG mode. The hybrid power system improved the fuel efficiency and reduced exhaust gas emissions in agricultural machinery. The hybrid system's lower exhaust gas emissions have considerable advantages in closed work environments such as crop production facilities. Therefore, agricultural machinery with less exhaust gas emissions should be commercialized.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.270-278
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• 2013

Purpose: Using agricultural machinery was not easy in the conventional shading structure, specified as a standard facility by standard cultivation methods for ginseng. Thus, this study designed the new types of facility allowing machine access by modifying the conventional type. Methods: Two types of facility (i.e. wide roof type and long & short roof type) were designed and installed in an experimental site to evaluate its growing environments and applicability of riding-type cultivator. Results: From the results of incoming light measurement, all three types (i.e. two new types and a conventional type) of shading structures blocked the incoming light after 9:00 am. The temperature distribution inside the new types was similar with the one in the conventional type, so the growth of ginseng was in good condition in all three types of facility. The riding-type cultivator was operated well with the low speed first gear of 0.13 m/s in the new types. However, a long & short typed roof needs to be raised 18 cm height in order to use the cultivator. Conclusions: With the results of this study, the new types of roof can be used in the ginseng farm in that they satisfied the growing environments for ginseng and the needs for agricultural mechanization.

• Journal of Biosystems Engineering
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• v.21 no.1
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• pp.3-9
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• 1996

Sowing with an automatic seed metering device is increasing in popularity. Since 100% planting is not likely, a major problem is to find any place which contains no seeds between row spacings in the agricultural field. Automatic sowing technology, including the implementation of a microcomputer, appears to be an attractive alternative to the use of manual labor for accomplishing this task. Thus, the multi-purpose seeder attached to a cultivator was designed and constructed with an automatic seed metering device. This seeder proved to be a reliable system for sowing seeds in the agricultural field. Multi-purpose seeder for cultivator consists of an automatic seed metering device, a trench device, a covering device, and a press wheel

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06a
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• pp.187-191
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• 1996

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.11-20
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• 2014

Purpose: Walking type cultivator used for weeding generated excessive handle vibration as well as bouncing motion depending on the weeding speed. This research was conducted to define a design factor of the rotary weeding blades for reducing soil reaction forces as well as hand vibration. Methods: The motion and forces acting on the rotary blades were reviewed to find out the most influencing parameter on hand vibration. The installation angle (IA) of the blade was selected and analyzed to determine the condition of no reaction force less. For removing the unnecessary upward soil reaction, the design factor theory of weeding blade was suggested based on geometrics and dynamics. For evaluation of design factor theory, the experiment in situ was performed base on ISO 5349:1. The vibration $a_{hv}$ and theoretical value $X_{MF}$ were compared with two groups that one was positive group ($X_{MF}$ > 0) and the other was negative group ($X_{MF}$ < 0). Results: $X_{MF}$ was derived from rotational velocity, forward velocity, disk diameter, weeding depth, blade's width and IA of blade. Two groups had significant difference (p < 0.05). In aspect of the group mean total exposure duration, positive group was 17.53% bigger than negative group. When disk radius 100, 150 and 200 mm, minimum IAs were $4{\sim}27^{\circ}$, $3{\sim}15^{\circ}$ and $2{\sim}10^{\circ}$, respectively. A spread sheet program which calculated XMF was developed by Excel 2013. Conclusions: According to this result, minimum IA of weeding blade for soil reaction reduction could be obtained. For reduction hand-arm vibration and power consumption, minimum IA is needed.

• Journal of Drive and Control
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• v.20 no.2
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• pp.31-39
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• 2023

The aim of this study was to measure and analyze engine load factor (LF) according to working conditions (operation type and gear stage) of small agricultural multi-purpose cultivator to estimate the emission of air pollutants. To calculate LF, a torque sensor capable of collecting torque and rotational speed was installed on the engine output shaft and DAQ was used to collect data. A field test was conducted with major operation of a cultivator and tillage operations (plow tillage and rotary tillage). Engine power was calculated using engine torque and rotational speed and LF was calculated using real-time power and rated power. In addition, unified LF was calculated using the weight for each operation and the average LF for each operation. As a result, average LF values at 1.87 and 3.10 km/h by plow tillage were 0.50 and 0.69, respectively. Average LF values at 1.87 and 3.10 km/h by rotary tillage were 0.70 and 0.78, respectively. Furthermore, unified LF calculated in consideration of the weight factor showed a value of 0.65, which was 135% higher than the conventional LF (0.48). Results of this study could be used as basic information for realizing LF values in the field of agricultural machinery.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.2
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• pp.155-160
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• 1984

This study was conducted to find out the effects of soil physical properties on workability of farm machines in the paddy fields. Various soil physical properties, workability of cultivator and tractor were investigated at three different textured soils and three levels of soil moisture conditions. The results are summarized as follows: 1. Soil strength, shear and friction resistance, plate sinkage, wheel and footprint sinkage, and slippage were greatly affected by the soil texture and moisture conditions, and the workabilities were changed by the soil physical properties. 2. Cultivator workability were high values at the range of soil shear resistance $200-450g/cm^2$, and cultivator or tractor working was difficult at below $200g/cm^2$ of the shear resistance. 3. The favorable range of soil strength for tractor working was $8-12kg/cm^2$, and $6-10kg/cm^2$ for cultivator. 4. Footprint sinkage was closely related to the values obtained by testers. It's optimum range for cultivator was 1-2cm, and tractor workability was increased by decreasing the footprint sinkage.