• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1185_1186
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• 2009

철도신호시스템은 열차들의 운행간격과 열차진로를 제어하는 기능을 담당함으로써 열차를 안전하고 효율적으로 운영하는 데 있어 핵심적인 역할을 수행한다. 철도신호시스템의 고장은 열차운행중지를 비롯하여 열차충돌이나 탈선등과 같은 치명적인 사고로 직결될 수 있기 때문에 시스템의 신뢰성과 안전성이 매우 중요하다. 현재까지 철도신호시스템에서는 지존의 지상신호방식이 많이 사용되어 왔으나 지상에 설치된 신호기 현시상태를 기관사가 확인하여 열차속도를 제어함으로써 기관사의 인적 오류 등의 사고 위험이 있다. 아울러 시스템의 수명이 다 되어 시스템절체의 필요성이 있다. 이에 따라 최근에는 컴퓨터 및 통신기술을 이용하여 열차속도제어 정보를 차상으로 송신하고, 차량에서 열차속도를 제어하는 차상신호방식이 도입 적용 되어 효과를 보고 있다. 따라서 수명이 다된 신호시스템을 교체하기 위하여 승객을 위한 운행서비스를 하면서 새로운 방식으로 절체 하는 것이 필요하다. 이에 본 논문에서는 시스템 절체과정의 절차와 시스템검증을 위한 일련의 과정중 간섭의 문제점을 시험평가를 통해 확인하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.507-512
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• 2003

The railroad is a means of large transportation which has many latents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of high speed rail, such as to treat a measuring wheelset, its finite element analysis, adhesion of strain gauges and static toad test, running test result of main line.

• Journal of the Korean Society for Railway
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• v.4 no.3
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• pp.116-122
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• 2001

As freight traffic becomes heavier, the high speed of existing freight cars is essential, instead of the construction of a new railway. The high speed can be achieved by the modifications of freight bogie design. In this paper, an analytical model of freight bogie is developed to decide the critical speed. The dynamic responses of the analytical model are compared with the experimental data from a running test of freight bogie and showed good agreements between them. The analytical model is used to find the design of freight bogie. The parameter studies show that the reduction of wheelset mass ratio and the increase of the axle distance of freight bogie can increase the critical speed, but the primary lateral stiffness has little effects on the critical speed. And this study also shows that smaller wheel conicity deteriorates the running safety of freight car, which means that the overhauling of the wheel of freight bogie should be done regularly.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.993-1001
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• 2007

An analysis model has been developed to assess running safety of railway vehicle passing curves. By using ADAMS/Rail, a computer analysis has been conducted by changing various parameters according to the track conditions. Analysis results show as follows: A derailment coefficient of left wheel was increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A unload rate of left wheel was also increased according to increase of cant at low speed, while it was decreased as increase of cant at high speed. A wear number of left wheel was increased according to increase of cant at all speed, but only at 35 m/s, it was decreased as increase of cant. A friction coefficient of left wheel was Increased according to increase of cant at all speed, but only at 35 m/s. it was decreased as increase of cant.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.443-445
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• 1999

본 연구에서는 고도의 전문가 수준에서 역구내 상황을 고려하여 실시간 전자연동처리전략을 수립함으로써 열차운행을 안전하고 정확하게 제어 열차충돌이나 탈선 등의 사고를 사전에 방지함으로써 보다 높은 안전도가 보장될 수 있도록 지원하는 전문가 시스템이 제안된다. 전문가 시스템은 열차의 역구내 운행시 신호기, 전철기 궤도회로 등의 입력정보로부터 연동 지식베이스에 근거하여 신호설비들간의 연쇄관계를 확인, 실시간 연동전략을 수립하며, 연동규칙을 정확하고 효과적으로 표시할 수 있도록 규칙기반 시스템으로 구현된다. 특히, 제어실패시 논리적 추론기능과 협조하여 합리적인 진로를 제시함으로써 비상시 역무원이 당황하지 않고 신속하고 안전하게 연동업무를 처리할 수 있도록 한다.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.745-750
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• 2004

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, wheelset manufacturing for test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 80km/h for estimating the curving performance and running safety of Gwangju EMU. As the test results, could confirm the curving performance and running safety of Gwangju EMU from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.8, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1301-1309
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• 2008

The curved portion fur each section running safety evaluation interpretation according to the track condition for improving the curved portion passage rate of a vehicle by using the multibody analysis model of the Saemaeul train was carried out. As a result, The excess of cant reaches the bad effect to the running safety in case the radius of curvature is small. In case the radius of curvature was large, we could confirm that the deficiency of cant reached the bad effect to the running safety. In the curved portion, the circular curve section most badly showed the running safety. The deficiency of curve length reaches the bad to the running safety. In the curved portion, the circular curve section most badly showed the running safety. Therefore the track condition(cant, transition curve length, etc) can reach the bad effect to the running safety of a vehicle, the exact design is required.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.295-299
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• 2011

According to the national railway safety plan 1 billion US$ have been invested in railway industry every year. As a result, railway accident rate has been reduce to half recent 6 years. Currently, Korea has 3 kinds of national railway safety target, which are accident fatalities, train accident rate, and passenger fatality per passenger kilometer. Increase of railway passengers and train operating companies force to set up new safety target. Current safety target cannot reflect train operator's safety activities because they include suicide and trespass related accidents, which are hard to be controlled by the operators. In order to reflect to the national railway safety plan, new safety targets are proposed in this study.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.526-538
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• 2016

The government of South Korea has made great efforts in the area of railway safety management by means of a railway safety law and an integrated railway safety plan established in 2004 after the Daegu subway fire accident. However, after certain railway incidents, a reactive railway safety management system has been implemented that has led to fatal accidents caused by the collision, derailment, and fire every year. Hence, this study is intended to propose a framework that integrates data from distributed detection devices into a real-time railway safety monitoring and control system for proactive safety management. Furthermore, we will provide a future development direction for safety performance monitoring indicators to determine whether the railway safety monitoring and control system works effectively. The proposed framework is expected to be a cornerstone for the real-time railway safety monitoring and control system to be implemented in the future.

• Journal of the Korean Society for Railway
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• v.14 no.5
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• pp.433-441
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• 2011

It is a fact that the straightening of track alignment is one of the undoubted ways to improve the train speed on conventional lines, while that requires huge investment resources. Therefore, the operation of a tilting train as well as the minimum improvement of track is suggested as an effective and economical alternative way for the speed-up of conventional lines. Since a driving mechanism of tilting train is different from those of existing trains, in order to make sure its operation safety and stability on conventional line, the performance of track and roadbed must be preferentially evaluated on the conventional line. Furthermore, it is necessary to estimate the tilting-train-induced roadbed response in detail since the roadbed settlement can lead to the track deformation and even derailment. In this research, the patterns of wheel load and lateral force were monitored and analyzed through the field tests, and the derailment coefficient and degree of wheel off-loading were calculated in order to evaluate the tilting train running safety depending on the running speeds (120km~180km) on the conventional line. Moreover, roadbed pressure, settlement and acceleration were also observed as tilting-train-induced roadbed responses in order to estimate the roadbed stability depending on the running speeds. Consequently, the measured derailment coefficient and degree of wheel off-loading were satisfied with their own required limits, and all of the roadbed responses were less than those of existing high-speed train (KTX) over an entire running speed range considered in this study. As a result of this study, the tilting train which will be operated in combination with existing trains is expected to give no adverse impact on the conventional line even with its improved running speed.