• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.9
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• pp.545-551
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• 2004

CBTC(Communication Based Train Control) System can improve train operation efficiency by realizing moving block system which makes a continuous train interval control in accordance with the position and speed of train. Adopting radio transmission to make a continuous detection of train position and transmit the control data from the ground to a train, CBTC needs dedicated train operation and control algorithm which should be quite different from the conventional track-circuit-based train control system. This paper provides a train operation display and control algorithm for CBTC system in making train interval control, train route control and train supervision. Signalling pattern diagram is devised to analyze the train interval control mechanism of moving block system, and interlocking logic is devised to represent the train route control mechanism of moving block system. For train supervision, train occupation status on railway are displayed by using the segment which virtually divide the whole railway. The proposed method has been successfully applied to the development of CBTC system for the standardized AGT(automatic guided transit) which is under construction now in Korea, and also can be applied to any other CBTC system.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.105-110
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• 2015

This paper presents a $4{\times}1$ beam-forming reader antenna system for a new type of RFID based train position detection technology. The required beamwidth of the reader antenna is analytically expressed for different train speeds. The proposed antenna system consists of four rectangular patch elements and two switching couplers which are designed, without any impedance matching networks, for two different antenna modes. The switching coupler is a rectangular quadrature coupler with Pin diodes connecting its center line and the ground plane. The beamwidth of the antenna when the diodes are off and on is $18^{\circ}$ and $39^{\circ}$, respectively. The proposed antenna system will be used for a real train test in the near future.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.671-679
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• 2011

Now, for the continuous location detection of train, The method which the moving distance and speed of vehicles are detected using an odometer mounted within railway vehicle, is used in railway domain generally. There are some problems that the train's positioning errors are accumulated as the moving distances increase. To solve this problems, The Train-borne Positioning System is being developed at Korea Railroad Research Institute. It is required to evaluate exactly a positioning performance of The Train-borne Positioning System for improvement of performance. Therefore, in this paper, we review the CDGPS methods to acquire reference position for performance evaluation of Train-borne Positioning System and verify the accuracy of the reference position through the static test and the vehicle test.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.346-348
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• 1997

This paper presents microprocessor-based real-time speed and position detection by inductive radio loop in new transportation system, such as magnetically levitated train system, rubber tyred train, and linear-motor car. The constant elapsed time method is used in this study for high accurate detection over a wide speed range. And for reliability and safety of the system, it is duplicated and data-bus level comparison is performed by fail-safe comparator.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1729-1734
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• 2007

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. Nowadays, position data inputs to pulse signal from wheel. Perfect position measurement was limited to slip and slide of vehicle. This measurement makes up for the weak points, Position Detection System using GPS develops. By using the system, Korean High Speed Train is capable of accurate fault position detection.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.237-242
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• 2017

This paper presents development of the transponder system which provides an accurate train position, especially for supporting 400km/h high speed train. Here, we analyzed an operating frequency band of the transponder system which can be interoperable with the Eurobalise system already installed in Korea railroad as to be used for the automatic train protection (ATP). By investigating the power frequency band and its data frequency band of the transponder system, we presents the adoptable frequency band for the developed transponder system. Additionally, through the real testbed using HEMU-430X, we evaluate its performance requirement and shows interoperable operation with the Eurobalise system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5534-5540
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• 2015

This In the railway signaling system, applications of axle counter in addition to track circuit goes on increasing for detecting train position. Consequently, this paper compares sensor methods of axle counter with between geo-magnetism method and proximity sensor method. And it presents differences and results, to improve reliabilities of train detection and axle counting. Also, this article presents an applied result which is based on field experience, with regard to installation, considering attachment condition of sensor part for accurate axle counting. This study acquires expandability that is able to perform not only axle counting function but also various other functions (direction detection of train, speed detection of train, and so on). It was a result of a change of design in order to judge phase difference of sensors, to improve reliability of axle counting. Furthermore, it does not subordinate to characteristics (type, weight of train). And it is confirmed that the omission of axle counting was not occurred in 350km/h. This was the result of Lab test after the construction of transfer equipment of trial axle and Test Bed for axle counting. Both of them are self-productions. Through this, it prepares foundation which is able to apply not only to train detection but also to speed of passing trains, formation number of trains, detector locking condition - when the train passes the section of switch point, and level crossing devices. Furthermore, it would be judged to contribute safety train operation if proximity sensor method applies to the whole railway signaling system from now on.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.10
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• pp.3608-3626
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• 2021

The detection of bolts is an important task in high-speed train inspection systems, and it is frequently performed to ensure the safety of trains. The difficulty of the vision-based bolt inspection system lies in small sample defect detection, which makes the end-to-end network ineffective. In this paper, the problem is resolved in two stages, which includes the detection network and cascaded classification networks. For small bolt detection, all bolts including defective bolts and normal bolts are put together for conducting annotation training, a new loss function and a new boundingbox selection based on the smallest axis-aligned convex set are proposed. These allow YOLOv3 network to obtain the accurate position and bounding box of the various bolts. The average precision has been greatly improved on PASCAL VOC, MS COCO and actual data set. After that, the Siamese network is employed for estimating the status of the bolts. Using the convolutional Siamese network, we are able to get strong results on few-shot classification. Extensive experiments and comparisons on actual data set show that the system outperforms state-of-the-art algorithms in bolt inspection.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.69-74
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• 2011

In the curving detection method by using an accelerometer, the ride comfort in the first car is worse than one in the others due to spend the time to calculate the tilting command and drive the tilting mechanism after entering in the curve. In order to enhance the ride comfort in the first car, the preditive curve detection method which predicts the distance from a train to the starting point of curve by using the GPS, Tachometer, Ground balise and position DB for track. In this study, we predicted and evaluated the ride comfort for predictive curve detection method in transient curves according to the shape and dimension of transient curve and the various driving speed. Also, we predicted the improvement of the ride comfort for predictive curve detection method by comparing with the result of the ride comfort for predictive curve detection method and for curve detection method using an accelerometer in the short transient curve.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.638-640
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• 1996

This paper presents microprocessor-based Digital Position Detection Unit using the inductive radio line and the antennas in train signaling system. This comprises the Fail-Safe system due to the dual controlled system to drive with safe-side even in events of faults, and designs the FSC(failure safe comparator). And the method of Markov Modeling is described for the reliability evaluation of system.