• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.I
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• pp.31-75
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• 2000

The tractor is the most important machine for farming keeping probably this position also for feeding the future fast growing world population. Band width of power and functions continues to increase worldwide, examples are given. Regarding the high developed countries, general farming demands as well as precision farming issues require closed loop control principles for the system "driver-tractor-implement". Progress in information technologies supports this trend, but comprehensive component and system developments are necessary to make the tractor ready for automatic or semi-automatic controls. The following technical highlights are, for example, discussed for Europe: hydropneumatic front axle suspensions, 50 km/h top speed, front brakes, electronically controlled multivalve diesel engines, automatic hydrostatic power split CVTs, load sensing hydraulics with proportional valves, improved cab and working places with "operations by wire" and more electronics on board than ever before.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1999년도 동계 학술대회 논문집
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• pp.85-91
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• 1999

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.183-194
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• 1999

Using the dynamic model and simulation program TDA developed in the previous paper, effects of design parameters of an agricultural tractor-trailer system on its vertical seat vibrations were investigated. The tractor-trailer system was excited by traversing over a half-sine bump. The excitation frequencies were determined by traveling velocity of the tractor and a half-sine bump selected appropriately. TDA predicted the autospectra of the vertical seat accelerations with different values of design parameters and compared them to analyze their effects. The design parameters included positions of engine, cab, and seat mountings as well as their dynamic properties. The results of this study suggested guidelines with which an improved structure of tractor may be developed in the early stage of design for a better ride quality.

• Journal of Biosystems Engineering
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• 제39권1호
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• pp.21-33
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• 2014

Background: Significant technological development and changes happened in the tractor industries. Contrariwise, the test procedures of the major standard development organizations (SDO's) remained unchanged or with a little modification over the years, demanding new tractor test standards or improvement of existing ones for tractor performance, safety, and comfort. Purpose: This study focuses on reviewing the research trends regarding performance, safety and comfort evaluation of agricultural tractors. Based on this review, few recommendations were proposed to revise or improve the current test standards. Review: Tractor power take-off power test using the DC electric dynamometer reduced human error in the testing process and increased the accuracy of the test results. GPS signals were used to determine acceleration and converted into torque. High capacity double extended octagonal ring dynamometer has been designed to measure drawbar forces. Numerical optimization methodology has been used to design three-point hitch. Numerous technologies, driving strategies, and transmission characteristics are being considered for reducing emissions of gaseous and particulate pollutants. Engine emission control technology standards need to be revised to meet the exhaust regulations for agricultural tractors. Finite Element Analysis (FEA) program has been used to design Roll-Over Protective Structures (ROPS). Program and methodology has been presented for testing tractor brake systems. Whole-body vibration emission levels have been found to be very dependent upon the nature of field operation performed, and the test track techniques required development/adaptation to improve their suitability during standardized assessment. Emphasizes should be given to improve visibility and thermal environment inside the cab for tractor operator. Tractors need to be evaluated under electromagnetic compatibility test conditions due to large growing of electronic devices. Research trends reviewed in this paper can be considered for possible revision or improvement of tractor performance, safety, and comfort test standards.

• Structural Engineering and Mechanics
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• 제2권4호
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• pp.327-343
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• 1994

This is the second part of the paper (Rojek and Kleiber 1993) devoted to nonlinear dynamic analysis of structures consisting of rigid and deformable parts. The first part contains a theoretical formulation of nonlinear equations of motion for the coupled system as well as a solution algorithm. The second part presents the computer implementation of the equations derived in the first part with a short review of the capabilities of the computer program used and the library of finite elements. Details of material nonlinearity treatment are also given. The paper is illustrated by discussing a practical problem of a safety cab analysis for an agricultural tractor.