• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.139-142
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• 2005

High speed railway, KTX has started commercial service last you and passengers is increasing. To secure the safety and reliability of high speed railway, it is necessary to inspect and maintain the rail regularities. Several methods of measuring track irregularities are developed in other railway advanced countries. In this paper, we introduce foreign track Inspection methods and application scheme to Koreans.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1378-1387
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• 2011

Seoul Metropolitan Rapid Transit Corporation - which is operating the subway lines No. 5, 6, 7 and 8 of Seoul's subway - has been operating a variety of motor cars and rail inspection vehicles to transport workers and materials into the tunnel at night after the daily revenue service for the maintenance of tunnel structure and track. However, the air quality in tunnels has been contaminated due to the operation of diesel engine cars, and rail inspection vehicles are now having higher chances of risks since the lightweight vehicles made with aluminum bogie became too obsolete. In this study, MRT type eco-friendly electric multi-inspection car has been elaborated for the purpose of improvement of tunnel environment and replacement of motor cars and rail inspection vehicles.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1656-1664
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• 2007

본 논문에서는 고속선에 사용 중인 UM71C 궤도회로의 결함진단을 위한 개선방안을 연구하였다. 고속선 궤도회로는 구간이 길어 유지보수자에 의한 점검 시 많은 시간과 노력이 소요된다. 따라서 주기적으로 검측차를 운행하고 있다. 그러나, 궤도회로 결함 시 차상검측데이터의 변화를 정확히 알 수 없으므로 실제, 고속선 운행선상의 샘플개소를 선정하여 환경에 따른 선로정수를 구하고 전송라인의 특성임피던스와 전파정수를 반영시켜 단락전류에 대한 시뮬레이션을 수행하였으며, 임의의 지점에 결함을 발생시켜 측정한 결과와 시뮬레이션 수행한 결과를 비교하였다. 이렇게 검증된 시뮬레이션 프로그램을 이용하여 보상콘덴서의 기능저하 수량 및 용량변경에 따른 차상검측데이터를 예측하였다. 이것은 보상콘덴서의 기능저하를 사전 예측하여 열차의 안전운행을 확보하기 위해 필요하다. 또한 차상검측시스템에서 얻어진 검측데이터와의 비교를 통해 유지보수에 활용 가능한 활용지침 및 분석기준을 작성하기 위해 필요하다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1720-1721
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• 2007

This paper presents a Fuzzy+PID control method for a Bridge Inspection Robot(BIR) system. The BIR has been developed with the aim of checking the safety status of a real bridge, gathering accurate data and performing maintenance. The developed robot system is composed of the specially designed car for bridge inspection, the guide rail and the inspection robot. The proposed Fuzzy+PID controllers are used to track speed reference signal of X axis and position reference signal of Z axis. Experimental results verify that the proposed Fuzz+PID control design method can achieve favorable control performance with regard to external disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.464-465
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• 2008

This paper proposed a robust controller in order to handle the boom vibration of inspection robot. While a inspection robot moves on boom with vibration by weight occurs. Therefore, Boom as structure like cantilever beam appears vibration by weight of inspection robot. The Z axis of inspection robot operates with Sliding structure. inspection robot is used "Fuzzy Controller" for position control with Z axis. The developed robot system is composed of the specially designed car for inspection robot. The proposed Fuzzy Controllers are used to track position reference signal of Z axis. A Experiment verify that the proposed Fuzzy Controller design method can achieve favorable control performance with regard to external disturbance.

• 전기학회논문지
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• 제65권7호
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• pp.1303-1310
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• 2016

The track circuit carries out a train detection using a electrical closed loop, and incidentally it detects the rail rupture using the track circuit current flowing rail. However, in the case of the axle counter or the Radio based train control system, it requires a new way for detecting the rail rupture because of not using the track circuit. To solve this problem, it periodically checks non-steady state of rail by the track inspection car. but real-time detection of the rail rupture is impossible. Therefore, this paper analyzed feasibility to realize a real-time detection of rail rupture by using the return current.

• Structural Monitoring and Maintenance
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• 제1권1호
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• pp.131-157
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• 2014

Special track systems used to divert a train to other directions or other tracks are generally called 'railway turnout'. A traditional turnout system consists of steel rails, switches, crossings, steel plates, fasteners, screw spikes, timber bearers, ballast and formation. The wheel rail contact over the crossing transfer zone has a dip-like shape and can often cause detrimental impact loads on the railway track and its components. The large impact also emits disturbing noises (either impact or ground-borne noise) to railway neighbors. In a brown-field railway track where an existing aged infrastructure requires renewal or maintenance, some physical constraints and construction complexities may dominate the choice of track forms or certain components. With the difficulty to seek for high-quality timbers with dimensional stability, a methodology to replace aged timber bearers in harsh dynamic environments is to adopt an alternative material that could mimic responses and characteristics of timber in both static and dynamic loading conditions. A critical review has suggested an application of an alternative material called fibre-reinforced foamed urethane (FFU). The full-scale capacity design makes use of its comparable engineering characteristics to timber, high-impact attenuation, high damping property, and a longer service life. A field trial to investigate in-situ behaviours of a turnout grillage system using an alternative material, 'fibre-reinforced foamed urethane (FFU)' bearers, has been carried out at a complex turnout junction under heavy mixed traffics at Hornsby, New South Wales, Australia. The turnout junction was renewed using the FFU bearers altogether with new special track components. Influences of the FFU bearers on track geometry (recorded by track inspection vehicle 'AK Car'), track settlement (based on survey data), track dynamics, and acoustic characteristics have been measured. Operational train pass-by measurements have been analysed to evaluate the effectiveness of the replacement methodology. Comparative studies show that the use of FFU bearers generates higher rail and sleeper accelerations but the damping capacity of the FFU help suppress vibration transferring onto other track components. The survey data analysis suggests a small vertical settlement and negligible lateral movement of the turnout system. The static and dynamic behaviours of FFU bearers appear to equate that of natural timber but its service life is superior.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8516-8524
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• 2015

궤도틀림은 직접 궤도검측을 통해서도 평가가 가능하지만, 차체 진동가속도의 계측을 통해서도 간접적으로 관리상태를 파악할 수 있으며, 최근 이에 대한 연구가 활발히 진행되고 있다. 이러한 간접적인 방법을 통해 국내 경부고속철도 자갈궤도의 유지보수 수준을 조사하고 평가하기 위하여, 국내 경부고속철도와 프랑스 고속철도(TGV)의 차체 진동가속도 계측을 수행하고 UIC518 규격에 제시된 방법에 따라 차체 진동가속도 계측 데이터에 대한 신호처리를 수행하였다. 차체 진동가속도는 차량의 주행속도에 따라서도 영향을 많이 받으므로, 신호처리된 계측결과를 속도대역별로 구분하여 상하방향 차체가속도 및 좌우방향 차체가속도의 크기에 따른 빈도분포를 계산하였다. 이렇게 계산된 빈도분포로부터 차량 주행속도에 따른 차체 진동가속도의 분포특성을 조사하고 UIC518에 제시된 기준과 비교하였다. 또한, 경부고속철도와 프랑스 고속철도의 상하방향 및 좌우방향 차체가속도의 빈도분포에 대한 정량적 비교분석을 수행하고, 국내 경부고속철도 자갈궤도 구간의 궤도틀림 관리수준을 평가하였다.

• International Journal of Railway
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• 제2권2호
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• pp.43-49
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• 2009

Wear and rolling contact fatigue (RCF) defects are most important causes of rail damage, and often interaction competitive at present railway track. Head check is one of rolling contact fatigue (RCF) defects, and generally occurs in mild circular curves and transition curves that are set at both ends of sharp circular curves. Wear tends to limit the crack growth of head checks by removing the material from the RCF surface. In order to clarify the conditions of the occurrence and growth of head checks, the authors measured the interacting forces between wheels and rails and the angle of attack of wheelset, and carried out contact analyses using the actual profile data of wheels and rails. The effects of the lateral force, the contact geometry, and the wear rate at rail gauge comer on the formation of head checks were also analyzed by using the worn profiles of actual wheels and rails and the data obtained by a track inspection car. Some specific range of wear rate at the gauge comer was identified as having close relation with occurrence of head checks.

• 한국철도학회논문집
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• 제18권5호
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• pp.401-409
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• 2015

철도에서 차량의 가이드 역할을 하는 레일에 결함이 발생할 경우 빠르게 진전하는 특성이 있으며 차량의 탈선과 같은 대형사고로 이어질 수 있어 레일 결함 탐상 기술은 매우 중요하다. 본 연구에서는 증속에 따른 누설자속기반 철도레일 결함탐상 기술의 적용성 검토를 위해 증속이 가능한 레일 탐상 시험 장치 제작 및 결함 레일 시편에 대한 탐상 시험을 수행하였다. 이를 위해, 철도레일 형상에 맞는 센서부 및 자화부를 설계하였고 인공결함을 갖는 결함 레일 시편을 제작하였다. 제작된 시험 장치를 이용해 4km/h에서 12km/h까지 속도를 증가시키며 결함에 의해 생성되는 누설자속을 측정하였고 원 신호의 미분을 통한 가시성 향상으로 결함 판별 및 결함 위치를 성공적으로 확인하였다. 향후 리프트 오프 유지 등 고속화에 필요한 점을 보완할 경우 고속 검측차에도 적용가능 할 것으로 생각된다.