• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.443-444
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• 2013

This paper deals with development of 35hp Electric Tractor. First, Motor and inverter are designed and manufactured suitable for the 35hp diesel tractor. Then these are apply to electric tractor. Also, We confirm performance of electric tractor as driving and field operating test.

• 드라이브 ㆍ 컨트롤
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• 제17권2호
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• pp.19-27
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• 2020

The purpose of this study was to suggest design criteria for the HMT (hydro-mechanical transmission) of a 55 kW-class agricultural tractor, develop a simulation model, and evaluate its performance such as axle rotational speed, tractor speed, and power transmission efficiency. In this study, the HMT comprised a compound planetary gear and a HSU (hydro-static unit), and the compound planetary gear comprised two planetary gear sets. The HMT has three gear stages, and the maximum tractor speed was selected as 40 km/h. The simulation time was set at 2736 hours considering the lifetime of the tractor, and the simulation was performed for each gear stage at the engine-rated power conditions. As a result of the simulation, the axle rotational speeds for each gear stage were 39, 77, and 158 rpm, respectively. The range of tractor speed for each gear stage were 1.05-10.22 km/h, 10.74-20.17 km/h, and 20.70-41.40 km/h, respectively. The APE (absolute percentage gear) for the tractor's maximum speed between target value and simulation results were 2.20%, 0.85%, and 3.50%, respectively. Also, the power transmission efficiency for each gear stage were 0-75%, 72-81%, and 69-81%, respectively. The simulation results for the power transmission efficiency of the HMT were similar with the results of the previous research. This was a basic study on the development of the HMT for an agricultural tractor. In future studies, it is necessary to develop a tractor platform and evaluate the performance. The comparison between the simulation model and the HMT tractor should be performed.

• Journal of Biosystems Engineering
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• 제25권4호
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• pp.301-310
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• 2000

An autonomous tractor system was developed and its performance was evaluated. The system consisted of a tractor system of and a remote control station. The tractor and the remote control station communicated each other via wireless modems. The tractor had a DGPS(differential global positioning system), sensors, a controller and a modem. The DGPS collected position data and the tractor status was estimated. The information of tractor status and sensors was transferred to the remote control station. Then, the control station determined the control data such as steering angles using a fuzzy controller. The fuzzy controller used the information from the DGPS, sensors, and GIS(geographic information system) data. The control data were obtained by remote signal processing at the control station The control data for autonomous operation were transferred to the tractor controller. The performances of an autonomous tractor were evaluated for various speeds, different initial positions and different initial headings. About 1.3 seconds of time lag was occurred in transferring the tractor status data and the control data. Compensation the time lag, about 27cm deviation was observed at the speed of 0.5m/s and 37cm at the speed of 1m/s. Error caused mainly by the time lag and it would be reduced by developing a full-duplex radio module for controlling the remote tractor.

• Journal of Biosystems Engineering
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• 제38권3호
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• pp.208-214
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• 2013

Purpose: Performances of a tractor diesel engine fueled by three different animal fats biodiesels were evaluated comparing with light oil tractor in terms of power, fuel consumption rate, exhaust gases, particulate matter amount and field work capacity. Methods: Animal fats based on pig biodiesel were manufactured manually and tested for its engine performance in the tractor diesel engine and fuel adoptability in the field works. Four different fuels, three different content of biodiesel (BD20, BD50, BD100) and light oil, were prepared and tested in the four strokes diesel engine. Power output, fuel consumption rate and exhaust gases of the four fuels in the diesel engine were compared and discussed. Results: Power output of light oil engine was the greatest showing 5.3% difference between light oil and BD100, but 0.37% better power than BD20 engine power. Less exhaust gases of $CO_2$, CO, $NO_X$ and THC were produced from animal fats biodiesel than light oil, which confirmed that biodiesel is environmental friendly fuel. For fuel adoptability in the tractor, biodiesel engine tractor showed its fuel competitiveness comparing with light oil for tractor works in the faddy field. Conclusions: With four different fuel types of animal-fats biodiesel, performances of a four cylinder diesel engine for tractor were evaluated in terms of power, exhaust gases, particulate matters (PM) and field work capacity. No significant differences observed in the engine performances including power output and exhaust gases emission rate. No significant power difference observed between the various fuels including light oil on the engine running, however, amounts of noxious exhaust gases including $CO_2$ and $NO_X$ decreased as biodiesel content increased in the fuels. Field performances of animal-fats biodiesel tractor were investigated by conducting plowing and rotary operation in the field. Tilling and rotary performance of light oil tractor and BD20 tractor in the field were compared, in which about 10% travelling speed difference on both operations were monitored that showed light oil tractor was superior to BD20 tractor by 10%. Animal-fats can be an alternative fuel source replacing light oil for agricultural machinery and an environmental friendly fuel to nature.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.506-512
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• 2000

Performance of a four- wheel tractor fabricated by Tongyang Moolsan Co., Ltd, Korea was tested in Thailand during May-June 2000. Wheel slip and field capacity were measured in three fields using different traction devices and implements. The tractor worked satisfactorily in the test conditions. Wheel slip of 26.05-33.63 % and the field capacity of 0.17 - 0.20 ha/hr were observed during plowing operation. Further tractive performance tests using a three-point linkage configuration are recommended in Thailand field conditions. Different designs of cage wheels are recommended to be tested to optimize the tractive performance.

• Journal of Biosystems Engineering
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• 제39권4호
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• pp.290-298
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• 2014

Purpose: To ascertain the increase of the farm income that predominantly relies on human resources by mechanizing Welsh onion harvesting, a tractor-mounted Welsh onion harvester was developed in this study. Method: An experiment for evaluating harvesting performance was performed for the developed Welsh onion harvester in an actual Welsh onion farm. The harvest performance was evaluated at the tractor running speeds of 5.0 cm/s, 11.4 cm/s and 15.8 cm/s, by comparing the operating efficiency, harvest rate, and damage rate of the Welsh onion harvester. Results: The performance of the harvester was rated as very good, with a 100% harvest rate, regardless of tractor running speed. Furthermore, it is shown that work efficiency of the harvester is expected to increase as the running speed increases. Nonetheless, the damage rate of the harvested Welsh onions at running speeds 5.0 cm/s, 11.4 cm/s, and 15.8 cm/s, increased correspondingly and proportionally to speeds from 4.55% to 6.53% and to 11.29%. The residual amount of soil on the harvested Welsh onions was about 0.24% of their weight showing excellent soil-removal performance of the harvester. Conclusion: The developed Welsh onion harvester is believed to improve the labor productivity and cultivation environment of Welsh onion farmhouses by the mechanization of the harvesting process that is currently associated with the largest amount of labor hours.

• 한국농공학회지
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• 제15권1호
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• pp.2925-2933
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• 1973

For the efficient utilization of farm machines on the inclined uqland, work performance in plowing, harrowing and terracing and critical workable gradients were tested on three farm machines which are 47 ps-farm tractor, 8 ps-power tiller and 5 ps-power tiller. The results of this study are summarized as follows; 1) The steeper the slope of the upland was the more inefficient the work performance of all machines was. 2) The critical workable gradients of the machines were proved as 14 for 47 ps-farm tractor, 12 for 8 ps-power tiller and 10 for 5ps-power tiller. 3) Plowing in the way of turning the furrow slices against the slope in order to build up terraces, the critical workable gradients were 8 for 47 ps-farm tractor and 8 ps-power tiller and 6 for 5 ps-power tiller. 4) Two-way plow is recommended for plowing with farm tractor on inclined upland, and high lug of tire would be good to prevent the slippage, and side valance-weight should be attached to power tiller for preventing its overturning.

• 한국기계가공학회지
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• 제20권11호
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• pp.92-99
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• 2021

Agricultural tractors drive and operate both off-road and on-road. Tire-road interaction significantly affects the tractive performance of a tractor, which is difficult to predict numerically. Many empirical models have been developed to predict the tractive performance of tractors using the cone index, which can be measured through simple tests. However, a magic formula model that can determine the tractive performance without a cone index can be used instead of traditional empirical models as the cone index cannot be measured on asphalt roads. The aim of this study was to predict the tractive performance of a tractor using the magic formula tire model. The traction force of the tires on an asphalt road was measured using an agricultural tractor. The dynamic wheel load was calculated to derive the coefficients of the traction-slip curve using the measured static wheel load and drawbar pull of the tractor. Curve fitting was performed to fit the experimental data using the magic formula. The parameters of the magic formula tire model were well identified, and the model successfully determined the coefficient of traction of the tractor.

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.133-140
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• 2020

Traction performance of a tractor varies depending on soil conditions. Sinkage and slip of the driving wheel for tractor frequently occur in a reclaimed land. The objective of this study was to develop a tractor suitable for a reclaimed land. Traction performance was evaluated according to soil conditions of reclaimed land and paddy field. Field experiments were conducted at two test sites (Fields A: paddy field; and Field B: reclaimed land). The tractor load measurement system was composed of an axle rotation speed sensor, a torque meter, a six-component load cell, GPS, and a DAQ (Data Acquisition System). Soil properties including soil texture, water content, cone index, and electrical conductivity (EC) were measured. Referring to previous researches, the tractor traveling speed was set to B3 (7.05 km/h), which was frequently used in ridge plow tillage. Soil moisture contents were 33.2% and 48.6% in fields A and B, respectively. Cone index was 2.1 times higher in field A than in field B. When working in the reclaimed land, slip ratios were about 10.5% and 33.1% for fields A and B, respectively. The engine load was used almost 100% of all tractors under the two field conditions. Traction powers were 31.9 kW and 24.2 kW for fields A and B, respectively. Tractive efficiencies were 83.3% and 54.4% for fields A and B, respectively. As soil moisture increased by 16.4%, the tractive efficiency was lowered by about 28.9%. Traction performance of tractor was significantly different according to soil conditions of fields A and B. Therefore, it is necessary to improve the traction performance of tractor for smooth operations in all soil conditions including a reclaimed land by reflecting data of this study.

• 농업과학연구
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• 제37권1호
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• pp.113-121
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• 2010

Land consolidation ratio for rice paddy fields reached to 64.7% as of 2008 in Korea, and this also accelerated automation of field machinery. Especially, research on autonomous tractors has been continuously conducted. Tillage is one of the labor-, energy-, and time-consuming field operations. Most important requirements for autonomous tractors would be travelling path planning and electronic system to control the tractor to follow the path. The instruction of computer was required to conduct the tillage operation in field with unmanned traveling tractor. This instruction was coincidently used in the control of the traveling path and the motion of tractor. The objectives of the study were 1) to characterize and model tillage operating sequence, turning pattern, and 2) to develop tillage path formation programs for autonomous tractor and evaluate the performance.