• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.239-245
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• 2015

In order to control the hybrid power system efficiently, the knowledge for the required load of the system is important. The agricultural tractor performs various farm works such as plow, rotary, and baler. When it performs rotary tillage and baler operation, the generated work load is analyzed. To analyze trend of work load, moving average technique is applied to the measurement data. Optimal control inputs for the two works are obtained from simulation using the dynamic programming. The novel fundamental control strategy for parallel hybrid tractor called Max. SOC is proposed.

• Journal of Biosystems Engineering
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• v.25 no.5
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• pp.341-350
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• 2000

This study was conducted to develop a control unit for a tying device of a variable chamber round baler. The work process of the tying device was thoroughly analyzed and the control sequence was established according to the work process. Based on this control sequence, a control unit using an 8 bit microprocessor AT 89C52 as a CPU was developed. The driving circuit to control the actuator motion was developed and the PWM method was used to regulate the velocity of the actuator. On the front panel of the control unit, indicators were also installed to show the operations being conducted. A prototype of the developed control unit was manufactured and tested. A total of 50 complete cycles of the control sequence was repeated and no failure was observed. It was evaluated that the developed control unit has an excellent performance and can be used practically for variable chamber round balers.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.613-627
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• 2019

The purpose of this study was to design a powertrain for a 78 kW AWD (all wheel drive) electric tractor by analyzing the combination of various reduction gear ratios on a commercial motor using data from actual agricultural work and driving conditions. A load measurement system was constructed to collect data using wheel torque meters, proximity sensors, and a data acquisition system. Field experiments for measuring load data were performed for two environmental driving conditions (on asphalt and soil) and four agricultural operations (plow tillage, rotary tillage, loader operation, and baler operation). The attached implements and gear stages were selected through farmer surveys. The range of the reduction ratio was determined by selecting the minimum reduction ratio needed to satisfy the torque condition required for agricultural operations and the maximum reduction gear ratio to satisfy the maximum travel speed. The minimum reduction gear ratio selected was 57 in consideration of the working load condition and the maximum reduction gear ratio selected was 62 considering the maximum running speed. In the range of the reduction gear ratio 57 - 62, the selected motor satisfied all working torque conditions. As a result, the combination of the selected motor and reduction gear ratio was applicable for satisfying the loads required during agricultural operation and driving operation.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.223-227
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• 2013

Purpose: The objectives of this study were to develop a general purpose baler system that is appropriate for the domestic forage cultivation environment and operated by the medium size tractor for production of bale silage made of green forage crops, and to test its performance. Methods: In a first experiment, the time of formation per one bale and densities of bales that are produced from bale system, were measured. In a second experiment, power requirement was measured by a power measurement system manufactured during bale system work. Results: The power measurement system was constructed with strain-gage sensors to measure torque of a PTO axle and proximity sensor to measure rotating speed of a PTO axle. Thus, the power requirement was calculated by PTO torque and PTO rotating speed. For evaluation of bale quality, the samples of bales were analyzed for contents of moisture, ADF, NDF and TDN. Conclusions: If the results of this study will be utilized, the coefficient of utilization of agricultural machinery will be increased by the operation of a medium size tractor that is a major disseminated tractor in farm, and it will contribute tremendously to make a forage production base for livestock farms.