• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1964-1969
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• 2008

A railway is a complex system integrated with a lot of technical elements such as rolling stock, power, signal control, communications, tracks, stations, operation control systems, and so on. As a mass transportation system, a railway could contain potential risks that may result in a high death rate and property losses. Accordingly, Railroad Safety Technology R&D Corps. is adopting the plan of the construction of Railway Safety Test Facilities as a part of the Railway Total Safety Project to enhance the railway safety, and carrying out researches on effective project management methods with Systems Engineering techniques. To support that, we propose the more effectual management method of constructing the Railway Safety Test Facilities applying the model-based systems engineering tool to the research.

• International Journal of Railway
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• v.5 no.2
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• pp.77-83
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• 2012

Railroad signaling systems are to control intervals and routes of trains. There are ATS, ATP, ATO and ATC system. Trains are operated in the section which is met on the signaling system because various signaling systems are used in Korea. Hence, trains are not operated in the section which is used in the other signaling system. To solve this problem, recently combined on-board system has been developed. The combined on-board system designed by doubling the ATS, ATP and ATC system to ensure the safety of system. The inductance of antenna is change and in return the resonance frequency of antenna is varied by the electromagnetic induction. Therefore, the information signal is not received exactly in the combined on-board system and in return accidents between trains occur. In this paper, electric model of the combined on-board system for considering the ATS and ATP antenna is presented. Moreover, the mutual inductance including the distance between the ATS and ATP antenna is calculated. As a result of the frequency response of the antennas, the mutual inductance met on operation range of resonance frequency is defined.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1108-1114
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• 2011

In general, railway system uses wheels so detecting speed by tachometer. However, LRT(Light Rail Transits) stands out recently as alternatives transportation, and besides of that Maglev trains are emerged as an alternative means of transportation. Maglev operates above certain heights caused inability of the measurement by tachometer which used to detect speed of wheels. Velocity Detection Signal Device of Train Control System applied in "Train Control System Project of Pilot Line Construction for Urban MAGLEV Train" which is prepared ahead of opening in 2013. This paper, therefore, explains the function and operation principal of Velocity Detection Signal Device, and suggests installation method of velocity detection loop installed around the track.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.694-698
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• 2005

The operation speed improvement of the train in electric railway must pursue continuously and need the investigation of whole railway system whole. The high-speed of the train is related to not only vehicle technique but also the infrastructure, signal system, operation technique, the trolley line and catenary, economical efficiency. Specially, in case of electric railway, we have to consider a technical investigation which is current collection efficiency improvement, voltage drop countermeasure, equipment capacity, track force, signal system. In this paper, we presents the technical investigation of AT feeder system in order to achieve high speed train in exist real railroad. We proved this approach which will use the whole domestic lines in the future.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.2
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• pp.70-76
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• 2004

The purpose of interlocking system in railway is to prevent the route for a train being set up and its protecting signal cleared if there were already another, conflicting route set up and the protecting signal for that route cleared. Recently, conventional relays circuitry in industrial field is replaced to computer-based control systems according to the advance of computer and communication technology. Therefore, interlocking systems in railway field are rapidly changing from existing relay-based interlocking system to computer-based electronic ones that executes the vital interlocking logic to assure the safety train routes at trackside signaling equipment room using electronic circuits. So it is very important to verify the performance of developed electronic interlocking system by plentiful laboratory testing before actually application in the railway system. However the laboratory testing in the present state of railway signaling is preformed individually by manual, so very much test time and cost are required. To solve these problems, we are developed the simulator for automatic interlocking inspection in this research. This simulator is able to operate on general personal computer and has following beneficial functions : automatic test sheet generation for inspection, automatic inspection execution and et al. The experiments are executed to test the feasibility of the developed simulator the experimental results have good agreements with the anticipated ones.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1473-1479
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• 2009

Recently, the high speed train was operated and then the train system's reliability requirements are growing more and more. The exact prediction simulation is necessary in the design of power feeding system by the increase of railway electrification. In order to develope the AC feeding system analysis technology, real-time power simulator was manufactured. It is composed to eight channels analog input, forty channels analog output and forty-eight channels digital I/O. The size of simulator rack is 19" and the two I/O boards are installed the PXI chassis built into the real time os. The signal I/O is possible through BNC connector. The test results of manufactured simulator are obtained that the error range of analog I/O signal is below 1 % and simulation condition is set to 1 ms and the simulation output of the analog output compares the results of the simulator.

• International Journal of Railway
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• v.4 no.4
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• pp.93-96
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• 2011

The basic element of the EMS suspension is the electromagnet system, which suspends the vehicle without contact by attracting forces to the rails at the guideway. The suspension of a vehicle by attractive magnetic forces is inherently unstable and consequently it is continuously adjusted by the strength of the suspending electromagnet from rail irregularity and bending of the guideway. In order to improve reliable tracking, it needs to get feedback signals without measurement delay time. In this paper the concept of feedback control system with Kalman Filter in EMS is proposed. The input signals in the feedback control system are an air-gap and an acceleration signal. The air-gap signal with noise from the gap sensor is transformed to the filtered air-gap signal y without measurement delay time by using Kalman Filter. The filtered air-gap signal is transformed to a relative velocity and a relative acceleration signal. Then it multiplies these values by gain matrix in order to get the actuator's reference voltage value. The simulation results show that the dynamic responses of the suspension system can be improved by reducing the influence of measurement delay time of air-gap signals.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.130-136
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• 2011

This paper suggests realization method for real-time speech recognition using VoiceXML in telephony environment based on SIP for Railroad Reservation Service. In this method, voice signal incoming through PSTN or Internet is treated as dialog using VoiceXML and the transferred voice signal is processed by Speech Recognition System, and the output is returned to dialog of VoiceXML which is transferred to users. VASR system is constituted of dialog server which processes dialog, APP server for processing voice signal, and Speech Recognition System to process speech recognition. This realizes transfer method to Speech Recognition System in which voice signal is recorded using Record Tag function of VoiceXML to process voice signal in telephony environment and it is played in real time.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.3
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• pp.138-142
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• 2015

Most of the existing studies on functional safety testing for the railway signaling system software have focused on verifying the functional safety through the monitoring of internal memory embedded railway signaling system. However, the railway signaling system is one of the typical embedded control system in the railway sector, and the embedded software has a characteristic of generating an appropriate outputs through the combination of internal processing in consideration of the current internal status and external input. Therefore, the test approach of using the interface communication channel can be effective way for the functional testing for railway signaling system software in consideration of these characteristic. Since a communication interface specification of the railway signal system has a the properties of the sequence input and output signals, test-case for software testing is the most effective methodology by MSC (Message Sequence Chart) language, one of the graphic language. The MSC-based test-case generating methodology for signaling system software was proposed in this paper.

• 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.