• Title/Summary/Keyword: Tractor

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Turning Behavior of Tractor-Trailer System by Computer Simulation (컴퓨터 시뮬레이션에 의한 트랙터와 트레일러의 선회운동)

  • Kim, J.H.;Choi, C.H.
    • Journal of Biosystems Engineering
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    • v.16 no.4
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    • pp.346-354
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    • 1991
  • Turning behavior of tractor-trailer system was studied to guide the tractor and trailer. Based upon kinematic relationship between the tractor and the trailer, a mathematical model was developed and analyzed by computer simulation. A field test was carried out to verify the mathematical model. Following conclusions were drawn from this study. 1. A mathematical model and a simulation program for turning behavior of tractor-trailer system were developed. 2. The results of the field tests showed that the RMS errors were less than 0.33m and the mathematical model based upon kinematic relationship can be used for mapping guidance system for tractor and trailer. 3. As the steering angle was increased, the turning radius was decreased. When the tractor travelled at the low speed, the travel speed of the tractor did not affect turning radius but did affect running time and stability for steering. 4. When the tractor travelled under the critical velocity, the towed trailer followed smoothly. When the the tractor travelled faster than the critical velocity, the towed trailer oscillated. The critical velocity was determined from the specification of the tractor and the trailer.

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Development of an Autonomous Tractor System Using Remote Information Processing (원격 정보처리를 이용한 자율주행 트랙터 시스템의 개발)

  • 조도연;조성인
    • Journal of Biosystems Engineering
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    • v.25 no.4
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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.

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Effects of Tread, Wheelbase and Axle Load Distribution on Tractor Vibrations (윤거, 축거, 차축 하중 분포가 트랙터 진동에 미치는 영향)

  • 조춘환;김경욱
    • Journal of Biosystems Engineering
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    • v.21 no.3
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    • pp.293-305
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    • 1996
  • Effects on the tractor vibrations of tread, wheelbase and axle load distribution were analyzed by using mathematical models of tractor and random road surface. A 4 degrees of freedom tractor model was developed to predict the bounce, pitch and roll motions of tractor. The front axle which is constrained to roll with respect to tractor body was also included in the model. A random road profile was generated and used as an excitation input to the tractor. Output vibrations of the model were predicted and analyzed by a computer simulation method. In general, longer tread tends to reduce rolling and longer wheelbase does bouncing and pitching motions. Tractor vibrations were minimum when the ratio of front to rear axle loads was in the range of 30:70-35:65. Sensitivity analysis showed that rolling and pitching motions most sensitively varied with changes in tread and wheelbase while bouncing motion did with the location of mass center.

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Tractive Performance Comparison Between Wheel-Drive Tractors and A Rubber Belt Crawler Tractor

  • Nikoli, I.R.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • pp.1196-1201
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    • 1993
  • Test of Caterpillar Challenger 65 tractor which has rubber tracks, and articulated four wheel drive tractor with dual wheels and a mechanical front wheel drive tractor were conducted on an unplowed and plouwed wheat stubble field. The following parameters were analyzed : tractive efficiency (ηv), net tractive coefficient ($\phi$n), slip ($\sigma$) , drawbar pull(Fv), drawbar power (Pv) and forward velocity(v). The maximum net tractive coefficient was established at the tractive efficiency of 0.60 on the unplowed wheat stubble field : for the Challenger 65 tractor 0.855 ; 4WD 0.624 and MFWD 0.534 and on the plowed wheat stubble field with the tractive efficiency of 0.40 for the Challenger 65 tractor 0.82 : 4WD 0.57 and for tractor MFWD 0.48.

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Analysis of Power Shuttle Characteristics of Agricultural Tractor (농업용 트랙터의 전후진 파워시프트 변속 특성 해석)

  • 김대철;이호상;정병학;김경욱
    • Journal of Biosystems Engineering
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    • v.27 no.6
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    • pp.479-490
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    • 2002
  • A dynamic model of a power shuttle transmission was developed and its validity was verified using the experimental data obtained from a transmission test bench. A 40㎾, 4WD tractor was also modeled using an application software EASY5 to investigate parameters and their effects on the power shifting performance. For a tractor model, the manual reverse gear was replaced by a power shuttle transmission. The tractor model also included an engine, main-gears for transmission, wheels, differentials and planet gears. Using the tractor model, the effects of the parameters such as modulating pressure and time, engine speed, tractor speed. tractor weight. reverse to forward speed ratio and torsional damper on the transient characteristics at starting and shuttle shifting were investigated by the computer simulation. The transient characteristics were represented by variations in clutch pressure, torque transmitted to input shaft and driving wheels, and power transmission capacity of the clutch. It was found that the modulating pressure and time affected most significantly the torque transmission and shifting time. The input torque, axle torque, power transmission capacity of the clutch and transmission time all increased with increase in engine speed, tractor speed. tractor weight and ratio of reverse to forward speeds. However, the axle torque decreased with tractor speed. Both the axle torque and power transmission capacity of the clutch also decreased with the ratio of reverse to forward speeds.

Characteristics of Tractor PTO Power and Work Loads (트랙터 PTO 출력과 농작업 부하 특성)

  • Park, Seok-Ho;Kim, Young-Jung;Im, Dong-Hyeok;Kim, Chung-Kill;Jung, Sang-Cheol;Kim, Hyeok-Joo;Lee, Jong-Soon;Kim, Sung-Su
    • Journal of Biosystems Engineering
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    • v.35 no.1
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    • pp.15-20
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    • 2010
  • Tractor PTO output and fuel consumption rate under the korean paddy and various paddy operations were measured and analyzed, in which all the measurements were accomplished by the OECD tractor test codes and the collected information will be utilized for defining tractor energy efficiency class and its test methods. Tractor PTO performance tests were conducted under full-load, part-load and various engine RPMs with part-load at the engine laboratory, while the paddy operations were dry land plowing, wet and dry land rotary tilling and wet land preparation under various soils. As a whole, the rated tractor outputs were ranged from 17% to 100% in the various tillage and land preparation operations, however, the loads for the paddy operations of 1,700 to 2,000 rpm were very close to the OECD tractor load distribution thus it would be appropriate to adopt OECD tractor test codes to measure energy consumption efficiency of tractor.

Noise Reduction in Tractor Cabin (트랙터 운전실의 소음 저감에 관한 연구)

  • Kim, Wonjin;Eun, Myoungwoo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.4
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    • pp.380-384
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    • 2014
  • This study focused on identifying the major noise source in a tractor cabin using experimental methods. The noise levels in a tractor cabin for different engine revolution speeds were analyzed to identify the noise source. The results showed that the power steering unit (PSU) was the major noise source in a tractor cabin. The PSU was moved to the outside from the inside of the cabin in order to reduce the noise in the tractor cabin. As a result, the noise levels on the left and right sides of the operator in the tractor cabin were reduced by 6.8 and 3.9 dB, respectively. Finally, the window method was introduced to evaluate the contribution of the transmission noise. The orders of significance in the tractor noise were the front, bottom, and left area, successively.

Autonomous Tractor for Tillage Operation Using Machine Vision and Fuzzy Logic Control (기계시각과 퍼지 제어를 이용한 경운작업 트랙터의 자율주행)

  • 조성인;최낙진;강인성
    • Journal of Biosystems Engineering
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    • v.25 no.1
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    • pp.55-62
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    • 2000
  • Autonomous farm operation needs to be developed for safety, labor shortage problem, health etc. In this research, an autonomous tractor for tillage was investigated using machine vision and a fuzzy logic controller(FLC). Tractor heading and offset were determined by image processing and a geomagnetic sensor. The FLC took the tractor heading and offset as inputs and generated the steering angle for tractor guidance as output. A color CCD camera was used fro the image processing . The heading and offset were obtained using Hough transform of the G-value color images. 15 fuzzy rules were used for inferencing the tractor steering angle. The tractor was tested in the file and it was proved that the tillage operation could be done autonomously within 20 cm deviation with the machine vision and the FLC.

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The Comparative Analysis of Holding Pace and Decision Factors of Tractor in Korea and Japan (한.일 트랙터의 보유속도와 수요요인 비교)

  • 강창용;김남욱
    • Journal of Biosystems Engineering
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    • v.25 no.5
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    • pp.391-398
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    • 2000
  • This study was performed to analyze the holding pace and decision factors of tractor in Korea and Japan, which probably should be used for making master plan of agricultural mechanization. The logistic function is used for holding pace estimation of tractor, and log-log function for analysis of decision factors. The results of this study are as follows: First, the increasing rate of the total amount of holding tractor power in Korea has been over that in Japan during 1980∼、94 which is now, however, under Japan. So, it could be forecasted that the per tractor holding power in Japan will increase continuously, and will be over 30PS in the short run. Second, the most important one of decision factors to support tractor demand is agricultural income in Korea, but on the other hand Non-Agricultural Income in Japan. From these, the fast increase of total amount of holding power of tractor in Korea could not expected, because Korea Agriculture has some difficulties to increase Agricultural Income. There are differences on the holding pace and decision factors of tractor between Korea and Japan, therefore, the plan of agricultural mechanization should be made in accordance with self-features.

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Analysis of Agricultural Working Load Experiments for Reduction Gear Ratio Design of an Electric Tractor Powertrain (전기구동 파워트레인의 감속기어비 설계를 위한 농용 트랙터의 작업 부하 분석)

  • Kim, Jung-Yun;Park, Yeong-Il
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.5
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    • pp.138-144
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    • 2012
  • Recent environmental issues such as exhaust gas and greenhouse effect make the agricultural machinery market takes into account the hybrid and electric propulsion technology used in automotive engineering. Generally the agricultural machinery, particularly an agricultural tractor, needs large load capacity and long continuous operating time comparing with conventional vehicles. In case of a pure electric tractor, it is necessary for considering large capacity batteries and long charging time. Therefore we take an AER extended PHEV (All Electric Range extended Plug-in Hybrid Electric Vehicle) power transmission system in developing an electric tractor in this study. First we propose a PHEV powertrain structure in order to substitute the conventional diesel engine equipped tractor. And we performed the road tests using a conventional mechanical tractor with various load conditions, which were classified and statistically treated real agricultural works. The test results were analysed with respect to the power characteristics of the power source. Finally using the test result, we designed two-stepped reduction gear ratios in the proposed an electric tractor powertrain for carrying out typical agricultural works.