• The Magazine of the IEIE
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• v.39 no.12
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• pp.62-66
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• 2012

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.779-785
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• 2006

This paper introduces a result of internal signal modeling for a defect diagnosis of the UM-71C track circuit using on HSL. Actually, We fixed a sample area within operating section on HSL and performed the simulations for short circuit current that is reflected characteristic impedance and propagation factor. We compared the measuring data with the result of the simulation. These modeling can be used as the basic data for secure of the safety. Also, It need to make a criteria of analysis for the maintenance through comparison simulation data and inspection data.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.701-704
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• 2006

The catenaries must guarantee the constant electricity to the trains, so that the safety and the estimate of fatigue degree and the inspection of abrasion degree should be done rapidly. This thesis proposes the system that can manage the performance/failure of the catenaries using the image process as the solution for the weak points of the existing inspection such as the decrease of immediateness and the lack of constancy in the human resources. This study simulates the ALD using VHSV (Virture HSV) which is the unreal HSV images, not getting the real HSV in ages to the image processing technique that repeats the erosion and the expansion of the images as the methods that can monitor the slight/critical defects of the catenaries as dealing with the result of the catenaries inspection images. The final ALD (Abnormal Line Detection) system is designed based on this simulation. I have demonstrated it with the VHSV (Virture HSV) virtual images as the materials of the test and inspected it through testing the defects of the catenaries for the thesis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.139-142
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• 2005

High speed railway, KTX has started commercial service last you and passengers is increasing. To secure the safety and reliability of high speed railway, it is necessary to inspect and maintain the rail regularities. Several methods of measuring track irregularities are developed in other railway advanced countries. In this paper, we introduce foreign track Inspection methods and application scheme to Koreans.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.377-388
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• 2006

Most structures experience deterioration after construction. A routine inspection and maintenance must be accomplished for the efficient use of the structures. The routine inspection will play a major role on the determination of maintenance period and method. This study aims development of an automated tunnel inspection system based upon a 3 dimensional laser scanner. As for the initial stage of the project, a prototype tunnel scanner has been developed. The development of a tunnel scanner prototype follows comparison between image scanning and laser scanning system and investigation on the applicability and adaptivity of the scanners to the railway tunnel scanner. The applicability of the laser scanner on the railway tunnel has been confirmed from the pilot test by using commercialized general purpose close range laser scanner and applicability of a laser scanner as a railway tunnel scanner has been checked. From the result, a prototype of railway tunnel scanner has been built and the calibration of the system was carried out. Finally the developed tunnel laser scanner has been applied to different shapes and sizes of tunnels in use.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1020-1026
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• 2011

In this paper, we propose a method that measures the height and stagger of an catenary using the laser profile images. One line laser and area scanner CCD cameras are used. To quickly and accurately extract, from a photographed image, the area of the overhead line on which the line laser is shone, we consider the established fact that the catenary is the lowest among the electric wires. Here we are solving the the distance to the catenary if we know the distance the camera is from the ground and the angle of the catenary in the field of view. The angle will be related to the number of pixels in the image. This pixels per degree is a constant for the camera. Also, because of the different pixel resolution of the camera according to the overhead line position, we compensate the measurement result through camera calibration.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.1
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• pp.18-24
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• 2015

Train positioning detection information is fundamental for high-speed railroad inspection, making it possible to simultaneously determine the status and evaluate the integrity of railroad equipment. This paper presents the results of measurements and an analysis of an inertial measurement unit (IMU) used as a positioning detection sensors. Acceleration and angular rate measurements from the IMU were analyzed in the amplitude and frequency domains, with a discussion on vibration and train motions. Using these results and GPS information, the positioning detection of a Korean tilting train express was performed from Naju station to Illo station on the Honam-line. The results of a synchronized analysis of sensor measurements and train motion can help in the design of a train location detection system and improve the positioning detection performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.312-320
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• 2020

3D scanning began in the field of manufacturing. In the construction field, a BIM (Building Information Modeling)-based 3D modeling environment was developed and used for the overall construction, such as factory prefabrication, structure construction inspection, plant facility, bridge, tunnel structure inspection using 3D scanning technology. LiDARs have higher accuracy and density than mobile scanners but require longer registration times and data processing. On the other hand, in interior building space management, relatively high accuracy is not needed, and the user can conveniently move with a mobile scan system. This study derives considerations for the development of Simultaneous Localization and Mapping (SLAM)-based Scan Backpack systems that move freely and support real-time point cloud registration. This paper proposes the mobile scan system, framework, and component structure to derive the considerations and improve scan productivity. Prototype development was carried out in two stages, SLAM and ScanBackpack, to derive the considerations and analyze the results.

• Journal of the Korean Society for Railway
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• v.11 no.6
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• pp.569-574
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• 2008

Catenary and Pantograph are used to transmit electrical energy to electric railways. Catenary (Overhead Contact Lines) should be installed precisely and managed for stable train operations. But external factors such as weather, temperature, etc., or aging affect catenary geometry. Changed catenary stagger and height cause high voltage spark or instant electric contact loss. Big spark derived from contact loss can damage the pantograph carbon strip and overhead contact lines that might interrupt the train operations. Therefore, to prevent a big scale spark or electric contact loss, catenary maintenance are required catenary geometry measurement systems with catenary maintenance capability. In this paper, we describe the development of catenary height and stagger measurement system. The catenary height and stagger measurement system uses Acuity company's AR4000 Laser Range Finder for distance measurement and AccuRange Line Scanner for degree measurement. This system detects suspicious overhead line sections with excessive stagger and height stagger variance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.581-582
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• 2006