• Journal of Biosystems Engineering
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• 제26권5호
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• pp.409-414
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• 2001

This paper reports a technique for measuring a three-dimensional soil deformation and a simplified method to determine the three-dimensional contact area of agricultural tires in a soil bin. A Pirelli 12.4R28 radial-ply tire was used on soft soil. Effects of dynamic load and inflation pressure were determined using the equipment for measuring soil deformation on the soil surface. Soil deformation measurements were made under three conditions of over-load (59kPa-14.2kN), rated-load (108kPa-11.8kN) and under-load (157kPa-9.3kN) in the combinations of the inflation pressures (kPa) and the tire load (kN). The results from three conditions were shown that the contact area of the over-load increased considerably bigger than those of the rated-load and the under-load. Therefore, to regulate soil deformation, the inflation pressure and the tire load should be set according to the soil conditions.

• 한국전자통신학회논문지
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• 제7권6호
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• pp.1327-1335
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• 2012

타이어 파손으로 인한 사고를 사전에 방지하기 위해 개발된 TPMS(Tire Pressure Monitoring System)는 타이어에 장착된 센서부로부터 전송된 데이터를 기반으로 타이어의 이상 유무를 디스플레이 장치에 표시하고 운전자가 실시간으로 타이어의 온도, 압력 등의 정보를 수시로 파악하여 최적의 주행조건을 유지시켜주기 위한 안전보조시스템이다. 무선통신을 사용하는 TPMS는 측정된 데이터의 송수신 시 간섭이나 잡음으로 인해 데이터 전송 시 수신 오류가 발생할 수 있다. 이러한 문제점을 해결하기 위해 스위칭(Switching), MVDR(Minimum-Variance Distortionless-Response), GSC(Generalized Sidelobe Canceler) 빔형성기(Beamformer) 등과 같은 간섭제거에 효율적인 대표적인 빔형성 기술들을 사용한다. 본 논문에서는 이 세 가지 빔형성기의 복잡도를 계산하여, 복잡도 성능 비교에 대한 수학적 근거를 제시한다. 컴퓨터 시뮬레이션을 통하여 본 논문에서 고려된 세 가지 빔형성기의 복잡도 성능을 확인한다.

• Journal of Biosystems Engineering
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• 제23권1호
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• pp.1-12
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• 1998

This study was intended to investigate experimentally the effect of inflation pressure on tractive performance of bias-ply tires for agricultural tractors. Traction tests were conducted at the three velocities of 3, 4, and 5.5km/h under few different surface conditions using a 13.6-28 6PR bias-ply tire as driving wheel of the test tractor. When the inflation pressure was reduced from 250kPa to 40kPa by a decrement of either 30 or 50kPa depending upon the test surface conditions, some of the test results showed that the tractive coefficient and efficiency were increased maximally by 40% and 17％, respectively, at 20% slippage. However, it was failed to derive any consistent rules depicting the effect of inflation pressure of bias ply tires on the tractive performance of tractors.

• Journal of Biosystems Engineering
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• 제36권5호
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• pp.303-313
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• 2011

This study was conducted to investigate the effects of axle weight distribution and inflation pressure of tire on the fuel economy of tractors as well as operational range of tractor engine in terms of engine speed and power when a 4WD tractor of 38.2 kW rated power at 2500 rpm is used for plowing and flooded-field rotavating in paddy fields. (1) Plowing operation required an average engine power of 9.6~13.5 kW which equals 25~35% of rated PTO power. Engine speed ranged from 1,320.4 to 1,737.4 rpm, work velocity from 3.4 to 4.8 km/h, and fuel consumption from 3.2 to 4.2 L/h, respectively. (2) Flooded-field rotavating required an average engine power of 11.5~18.5 kW which equals 30~48.4% of rated PTO power. Out of this 6.2~12.2 kW was used for PTO power. Engine speed ranged from 1,557 to 2,067 rpm, work velocity from 2.5~5.4 km/h and fuel consumption from 3.2~5.5 L/h, respectively. (3) Axle weight distribution, inflation pressure of tire and moisture content of soil did not affect significantly the specific volumetric fuel consumption but affected significantly the fuel consumption per unit area of operation. Fuel savings amounted to 65% in plowing operation and 20% in flooded-field rotavating when the axle weight distribution and inflation pressure of tire were optimally adjusted. (4) Optimal adjustment of axle weight distribution and inflation pressure of tire are expected to save fuel consumption by 10~65% per unit area of operation in plowing and 10~20% in flooded-field rotavating.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.601-606
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• 1993

The natural frequency measurement of passenger car tire under the load and rotation are studied. In order to obtain theoretical natural frequency and mode shape, the plane vibration of a tire is modeled to that of circular beam. By using the Tickling method based on Hamilton's principle, theoretical results are determined by considering tension force due to tire inflation pressure, rotational velocity and tangential, radial stiffness. Modal parameters varying the inflation pressure, load, rotational velocity are determined experimentally by using frequency response function method. The results show that experimental conditions are parameter for shifting of natural frequency.

• 대한기계학회논문집A
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• 제20권1호
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• pp.1-13
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• 1996

The measurement of radial directional natural frequency ina passenger car tire rotating under the load is studied. In order to obtain theoretical matural frequency and mode shape, the ploane vibration of a tire is modeled to that of circular beam. By esing the Tieking method based on Hamiltons's principle, theoretical results are determined by considering tension horce due to tire inflation pressure, retational velocity and tangential, radial stiffness. Radial directional modal parameters varying with the inflation pressure, load, rotational velocity are experimentally determined by using frequency response function method. The results show that experimental conditions canbe considered as the parameters which shift the natural frequency.

• 오토저널
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• 제15권2호
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• pp.76-83
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• 1993

The vibration characteristics of radial tire are studied. In order to obtain theoretical natural frequency and mode shape, the plane vibration of a tire is modeled to that of circular beam. By using the Tielking method based on Hamilton's principle, theoretical results are determined by considering tension force due to tire inflation pressure, rotational velocity and tangential, radial stiffness. Modal parameters varying the inflation pressure are determined experimentally by using the transfer function method. Results show that material property and wear are parameter for shifting of natural frequency and damping.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1317-1318
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• 2011

• EDISON SW 활용 경진대회 논문집
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• 제6회(2017년)
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• pp.204-215
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• 2017

비공기압 타이어(Non-Pneumatic Tire)는 공기압 타이어(Pneumatic Tire)와는 다르게 스포크(Spoke)를 이용하여 공기압을 대체하는 타이어이다. 비공기압 타이어는 기존 공기압 타이어가 가지고 있는 펑크 발생이 없고, 공기압을 유지할 필요도 없다. 또한, 온도가 급격하게 변하는 우주에서도 사용이 가능하다. 이런 점에서 비공기압 타이어는 차세대 바퀴로써 주목 받고 있다. 하중이 가해지는 Honeycomb구조를 Edison을 이용하여 유한요소 해석을 진행하고, 각각의 결과를 비교하여 최적의 허니콤 구조를 찾았다.

• 한국기계가공학회지
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• 제8권2호
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• pp.40-45
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• 2009

This study is analyzed by stress contour of automotive tire at contact on road surface. Maximum equivalent stress as 61200Pa is shown on the lower mid part in case of tire contacted on road surface. As the air pressure of tire increases, maximum total deformation as 5mm is shown on the side part of tire. It can be shown that the side part of tire is unstabilized. There is no load effect on tire at its upper and lower directions. When the moment applied on the side of tire is increased 1.4 times as its value, the value of maximum principal stress is increased 1.4 times. The stress at the tire is in proportion to the moment applied on the its side. The tire tends to incline toward its side by this moment.