• Journal of the Korean Society for Railway
• /
• v.17 no.2
• /
• pp.106-113
• /
• 2014

In this study, a practical evaluation technique to detect the deterioration of railroad lines by means of train performance and track geometry measures is suggested. A train that has a specific performance and is running the straight line can make minimum travel time (ideal time). But the actual travel time will be increased by the track geometry and various speed limitations. By comparing these travel times, we can easily define the degree of line deterioration. This method does not require complex vehicle performance measures and/or specifications that exceed those of typical Train Performance Simulations (TPS). For this reason, ease of use is ensured and the results are similar to those obtained by running a TPS for practical evaluations.

• Journal of the Korean Society of Systems Engineering
• /
• v.4 no.2
• /
• pp.15-26
• /
• 2008

The Korean High-speed train was developed during 1996 to 2007. This development project consists of many sub-projects and the train-system includes a lot of sub-systems. In order to promote the project on planned cost and time effectively, we tried to apply systems engineering process during the whole life-cycle. The purpose of this paper is to introduce the systems engineering process applied to this project. Activities carried out in each phase such as pre-design, detailed-design, integration & verification are described.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.211-219
• /
• 2005

The railway industry of each country has variant technical standards and regulations unlike other industries. For this reason, it is necessary to investigate the domestic technical standards and regulations and to prepare the countermeasure of the variance for advancing the korean high-speed railroad system into foreign market. This study was designed to investigate the railway design/manufacturing, examination/inspection and safety of domestic and foreign countries subject to a world market for advancing the korean high-speed railroad system into a foreign market. Because the reliance of a railroad system is a prerequisite for the safety of railroads, it is very important to obtain the reliance data, which is based on the RMS analysis of foreign countries subject to a world market.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.486-493
• /
• 2007

In the field of maintenance of domestic high-speed railroad which has cost a great deal more than any other fields since it was opened; 1) We found out the conditions of current domestic railroad by understanding the status of track maintenance and analyzing operative processes of track maintenance. 2) The main factors in track maintenance of high-speed railroad, that is, the elements for success to help decision-support in track maintenance were derived from a research on literature about the condition of railroad R&D in these days and about the prediction of the irregular progresses of track. 3) We derived the order of priority and weights from AHP analysis which was based on the survey regarding elements for success.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.1
• /
• pp.27-31
• /
• 2014

Magnetic fields (MF) generated both on board the vehicle and along the guideway provide levitation and propulsion forces. High speed maglev trains adopt electromagnet or superconducting magnet to realize levitation and propulsion functions. However, stray fields existing in passenger compartment and regions surrounding the vehicle and guideway have effect on passengers and environment. To investigate stray magnetic field effect, model of Transrapid and MLX are studied.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.1
• /
• pp.208-213
• /
• 2016

In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. When the transponder tag receives the energizing signal from the train, it sends a telegram to the reader, which includes location information. In high-speed railway environment, this telegram can be corrupted by electromagnetic interference caused by onboard electric train power equipments or wayside devices. In order to assess the performance of transponder system under this harsh environment, we carried out field test using HEMU-430X. Field test results are briefly introduced and discussed for the evaluation of the transponder system under development.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1173-1177
• /
• 2004

The high investment is necessary for the new high speed lines. So the KRRI was interested in the possibility of upgrading the existing line in order to speed up the train in the conventional lines. The tilting train system has been developed because the reconstruction of railway for the cant compensation costs very high. The purpose of the tilting system is to compensate the centrifugal acceleration in order to reduce the lateral acceleration of the passenger at high speed on the curves.The pantograph of the tilting train is indispensable in order to supply the electrification equipments with power in safe. The dynamic interaction between the pantograph and the overhead catenary system causes the variation of the contact force and the contact force variation can cause contact losses, arcing and sparking. If the spark happens between the pantograph and the overhead catenary system, the EMI(electro magnetic interface) and noises may occur. After all, the quality of current collection is deteriorated. This paper deals with the active control of pantograph and presents the LQ-servo controller to reduce the contact force variation.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.9
• /
• pp.759-764
• /
• 2014

Lateral force of wheel is important parameter when we evaluate the safety of a railway vehicle on curved track. The lateral force of wheel is influenced by the steering performance of wheelsets. Generally, in passive type vehicles, the steering performance of wheelsets is influenced by the parameters like primary spring stiffness, wheel base, conicity of the wheel profile, etc. But, the steering performance of passive type vehicle has its limit. To overcome the limit of the steering performance of passive type vehicle, active steering technology is being developed. In this paper, we analyze the lateral force of wheel and the safety of the railway vehicle on curved track by adopting the active steering technology. As results of dynamic analysis for vehicle model equipped with active steering system, the lateral force of wheel is reduced and the safety is improved remarkably.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.6
• /
• pp.613-620
• /
• 2012

Rails are subjected to damage from rolling contact fatigue, which leads to defects such as cracks. Rolling contact fatigue damages on the surface of rail such as head check, squats are one of growing problems. Another form of rail surface damage, known as "Ballast imprint" has become apparent. This form of damage is associated with ballast particles becoming trapped between the wheel and the surface of rail. These defects are still one of the key reasons for rail maintenance and replacement. In this study, we have investigated whether the ballast imprint is an initiator of head check type cracks and effect of defect size using Finite element analysis. The FE analysis were used to investigate stresses and strains in subsurface of defects according to variation of defect size. Based on loading cycles obtained from FE analysis, fatigue analysis for each point was carried out.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.7
• /
• pp.597-602
• /
• 2015

In this paper, we studied the steering performance of wheelset with primary suspension characteristics of railway vehicle. We carry out dynamic analysis and experimental study for the vehicle models which are different primary suspension characteristics. The steering angle of a vehicle model (Case 1) operating in domestic subway lines is insufficient compared with an objective steering angle for curved track. And the steering angle of a vehicle model (Case 2) with improved self-steering performance of wheelset is a little improved compare to previous vehicle model. But also Case 2 model is still insufficient compared with an objective steering angle and has its limit in steering performance. So to overcome this limit of steering performance of passive type railway vehicle, an active steering technology is being developed. In case of vehicle model with active steering system, the steering performance is improved remarkably compared to passive type vehicle model.