• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.63-68
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• 2017

Although automated metro subway systems have the advantage of operating a train without a train driver, it is difficult to detect an immediate fault condition and take countermeasures when an unusual situation occurs. Therefore, it is important to construct a maintenance information system (MIS) that detects the vehicle failure/status information in real time and maintains it efficiently in the depot of the railway's vehicles. This paper proposes a conceptual design method that realizes the interface between the train control system (TCS), the operation control center train control monitoring system (OCC-TCMS) console, and the MIS using wireless communication network in real-time. To transmit a large amount of information on 800,000 occurrences per day during operation, data was collected in a 56 byte data table using a data processing algorithm. This state information was classified into 4 hexadecimal codes and transmitted to the MIS by mapping the status and the fault information on the vehicle during the main line operation. Furthermore, the transmission and reception data were examined in real time between the TCS and MIS, and the implementation of the failure information screen was then displayed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.109-110
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• 2011

Because contemporary rolling stock system is complex and highly advanced, and it builds mutual interface, it is necessary to manage maintenance of rolling stock systematically. This study present a case, which shows how to adopt and apply RTD(Remote Transmission Device) integrated to train information collection device. After the train service is complete and the train enters the main subway station, various kinds of information collected from TCMS(Train Control Monitoring System) is transmitted to train depot information collection device through RTD. This study suggests that RTD integrated to train information collection device helps build an effective rolling stock maintenance system by improving reliability of data transmission and cutting maintenance costs.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.55-63
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• 2022

In recent years, with the rapid development of large and medium-sized urban rail transit in China, the total operating mileage of high-speed railway and the total number of EMUs(Electric Multiple Units) are rising. The system complexity of high-speed EMU is constantly increasing, which puts forward higher requirements for the safety of equipment and the efficiency of maintenance.At present, the maintenance mode of high-speed EMU in China still adopts the post maintenance method based on planned maintenance and fault maintenance, which leads to insufficient or excessive maintenance, reduces the efficiency of equipment fault handling, and increases the maintenance cost. Based on the intelligent operation and maintenance technology of PHM(prognostics and health management). This thesis builds an integrated PHM platform of "vehicle system-communication system-ground system" by integrating multi-source heterogeneous data of different scenarios of high-speed EMU, and combines the equipment fault mechanism with artificial intelligence algorithms to build a fault prediction model for traction motors of high-speed EMU.Reliable fault prediction and accurate maintenance shall be carried out in advance to ensure safe and efficient operation of high-speed EMU.

• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.189-195
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• 2013

Recent trains have broadband train communication networks to improve train operation safety and to provide passengers with multimedia services. Compared to glass optical fiber, plastic optical fiber (POF) has a large diameter; it also provides the good durability and maintainability necessary to railway applications. This paper suggests an All-IP broadband train communication network that connects all devices in the train through a POF interface. Performance tests according to Korean railroad standards shows that this POF interface is usable in the range of vibration and temperature conditions encountered in trains. A dedicated Layer-2 switch with the POF interface is developed for the construction of the All-IP train communication network. A prototype 1Gbps train communication network was set up in a trial-run of train on a metro line using the developed Layer-2 switch and POF. On-track tests indicated the feasibility of the POF train communication network. POF has an additional advantage of economic feasibility, and it is expected to start a trend toward broadband train communication networks using POF.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.16-24
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• 2009

In this study, fatigue crack growth rate of a cracked railway bogie frame under variable amplitude loading is predicted by applying linear elastic fracture mechanics. For this purpose, we find the critical points by reference surveying on cracked railway bogie frames. And we make an effective load history by synthesizing the dynamic load measured from the critical points of railway bogie frame during commercial line operation and the static load calculated from structural analysis. Crack growth analyses are performed at the 3 critical points under the commercial operation loading condition by assuming an initial crack size as 40 mm. and the results are compared with the experimental results from Japanese railway bogie frame crack growth case. From the analysis results, we find that around 500,000 km operating distance is necessary to bring crack growth from the initial crack to unstable crack. And it takes around 3.8 normal operating years. We conclude that it is enough time to detect the crack between normal maintenance period.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1177-1178
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• 2007

There is a possibility of saying that the accident of urban transit vehice or deficit operation is caused by the m.aintenance. urban transit vehice where the efficiency is good though does the time passes and it becomes old anger and does not display that efficiency not only the cause of formation accident does becomes. The breakdown about under occurring before getting up an accident, appropriately shifting the parts is to a maintenance very the pending question fact which is important is a possibility of doing. From there is by an urban transit vehice, Mauntenance in reliability base grudge is a tool of confirms an improvement point and the place where it judges. From the research which it sees will present about technical development plan of Maintenance.

• Journal of Information Technology Applications and Management
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• v.29 no.6
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• pp.63-80
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• 2022

In this paper, we study structural changes and performance gains in condition-based maintenance process redesign when mobile IoT technology is embedded into urban railway rolling stock. We first develop condition-based maintenance To-Be process model in accordance with the IoT deployment scheme. Secondly, we draw upon theoretical framework of redesign process analysis to develop performance evaluation method suitable to predictive maintenance shift from As-Is ordinary maintenance practice. Subsequently, To-Be process performance evaluations are conducted adopting both the quantitative and qualitative method for time, cost, and dependability dimensions. The results ascertain the considerable benefits captured through detection abnormality prior to actual rolling stock failure occurrence, and details of performance improvements and enhancement of standardization level is revealed. The procedures and results presented in this paper offers useful insights in the fields of IoT economic analysis, condition based maintenance, and business process redesign.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1099-1107
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• 2013

This study proposes a weight reduction design for urban transit, specifically, a Korean EMU carbody made of aluminum extrusion profiles, according to size optimization and useful material changes. First, the thickness of the under-frame, side-panels, and end-panels were optimized by the size optimization process, and then, the weight of the Korean EMU carbody could be reduced to approximately 14.8%. Second, the under-frame of the optimized carbody was substituted with a frame-type structure made of SMA 570, and then, the weight of the hybrid-type carbody was 3.8% lighter than that of the initial K-EMU. Finally, the under-frame and the roof-panel were substituted with a composite material sandwich to obtain an ultralight hybrid-type carbody. The weight of the ultralight hybrid-type carbody was 30% lighter than that of the initial K-EMU. All the resulting carbody models satisfied the design regulations of the domestic Performance Test Standard for Electrical Multiple Unit.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.7-18
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• 2005

Over the past twenty years, the maintenance system has been developed and its importance has been increased. For the effective maintenance of the urban transit, we have developed the maintenance system based on the concept of RCM(Reliability Centered Maintenance). RCM analysis is a systematic approach to developing a cost-effective maintenance strategy based on the various components's reliability of the system in question. It is performed according to process that includes the following steps; definition of function and functional failures of the systems, construction of RB D(Reliability Block Diagram), performance of FMEA(Failure Modes & Effects Analysis) and calculation of the reliability index. The final process of RCM is to determine appropriate failure maintenance strategies. This paper aims to define the procedure of maintenace based on the concept of RCM for urban transit. The key for a successful maintenance system is an automated scheduling to the maximum extent possible and timely executions. The developed system issues maintenance plan and repair request based on analyzed data and maintenance experience.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.261-269
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• 2015

To overcome the weaknesses of viaduct bridges and the non-economic efficiency of underground LRT, the study of near-surface railway systems is in progress. To apply a box structure to the low depth transit, a connection joint to precast modules are very important when applying precast modular structures to replace temporary structures. In this study, wall to wall connections were applied in diverse cases such as rebar connections, guiding structures that were used to fit the verticality of precast walls during construction, and non-reinforcement structures used only for waterstop. Experimental performance verification was carried out for the bending, shear and splitting of the wall to wall connection. Precision of construction joints between wall to wall was identified as a factor that influenced the structural performance of the precast wall. A structure that can serve as a guide during the vertical insertion of a wall is confirmed for the most suitable case, but it will be necessary to modify this structure for detailed cases.