• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.216-220
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• 2022

This paper proposes an inspection robot that can operate on a single square rail. Various inspection robots have been developed to identify emergency situations in industrial environments, such as those involving fires or individuals with cardiac arrest. Because the robots must operate in wide areas and long tunnels, they are designed to move along a rail installed on the ceiling. Double rail track are typically used to ensure the stability of robot movement. However, the cost for installing a double rail track is nearly two times that for a single rail track. Moreover, it is challenging to install double rail tracks while ensuring the same curvature and interval between the two rails. Therefore, in this study, an inspection robot that operate on a single square rail track is developed. To ensure stable movement in the longitudinal and lateral directions, two passive guide parts are used, and the main active wheel is allowed to move on the upper side of the square rail. The prototype was manufactured, and experiments were performed for different robot velocities.

• 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.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.107-111
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• 2008

This paper presented a literature review and investigation analysis results of total 19 present guide book and provisions of maintenance and management system in existing railway bridges to development of urban maglev track structures inspection manual. This research carried out a cooperated research subject 3-1, development a design code and maintenance and management inspection manual for urban maglev track structures, of the Center for Urban Maglev Program. Three types of track structures were includes as a major analytical parameter together with railroad, high speed railroad, subway and light rail transit. Bridges were analyzed a general rules, investigation, evaluation, repair and strengthen method as a key aspect. And rail were analyzed examination and maintenance also. This analysis results show that the track structures evaluation are based on the test and examination results, and repaired or strengthened consideration of deterioration, track irregularity and materials according to provision requirements.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.278-282
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• 2007

The riding comfort and the durability of train are effected by the rail irregularities such as track gauge, superelevation, alignment, longitudinal level, twist, cant and cross level. Inspection and estimation of irregularities are very important to maintain the rail condition. Generally, the EM120 has been utilized to measure the rail irregularities once a month in Korea. However, the EM120 can be operated at night time only, because the inspection speed of EM120 is much slower than the speed of high-speed trains. Also, the EM120 is too slow to inspect effectively for the whole commercial line. Therefore, we have mounted the track inspection system on the High-Speed Rolling Stock 350 eXperimental (HSR350X) and measured the rail irregularities to confirm the condition of a rail while running 300km/h. In this paper, the track inspection system mounted on HSR350X is mainly considered, and the measured results through test run are introduced.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.768-773
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• 2003

The inspection of track irregularity, which is the most important index for the evaluation of the dynamic safety of the rolling stock, is performed by setting up the testing train set. The self-diagnosis for the various rolling stocks and railways can be obtained if it is possible to take the simultaneous inspection of track irregularity for the commercial vehicle while it is running and to build up a dynamic safety evaluation system. It is expected to have some good effects, such as preventing accident with the low dynamic safety, cutting cost for the testing train set and evaluating the exact influence on the rolling stock and railway. In this study, innertial measuring method, which allows us to directly measure the track irregularity from the commercial vehicle, will be considered and some overseas cases will be explored as well.

• Nuclear Engineering and Technology
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• v.38 no.4
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• pp.353-358
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• 2006

Alpha track analysis for the determination of the trace amount of alpha emitting nuclides in a very small particle was performed as an efficient and powerful technique during safeguard inspection. Metal particles with well-defined spherical shape, size and isotopic compositions as a reference material were used to correlate the number of tracks or track diameter with an isotopic composition eventually to identify the uranium enrichment in the environmental swipe samples. Slopes in the number of tracks versus the exposure time curve provide a simple insight into the uranium enrichment of an unknown particle. Low enriched uranium metal particles result in slopes still steeper than the depleted or natural uranium metal particles. In addition, a linear relationship between track diameter and particle size Is thought to be a useful first stage analytical tool as an efficient and convenient inspection guide. The significance of the simple linear model was also judged using the usual statistical tests.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.777-784
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• 2006

The lateral dynamic behaviours of a track inspection vehicle with laterally guided system are studied for the safety and comfort. A 10-DOF dynamic model is proposed counting for lateral and yaw motions. The equations for motions of the vehicle running on curved tracks at a constant speed are presented. It is shown by simulation that lateral guiding forces applied to the guiding wheels on the inner side of the track increase in a larger scale in comparison with those on the outer side when the vehicle passes through curved tracks with cant, and the front guiding spring forces is larger than the rears. Lateral vibrations due to yaw motions of the vehicle take place when the vehicle runs through curved tracks. Finally, effect of the lateral guidance on the vehicle dynamics is also examined and advantages of such a guiding system are discussed in some details. An optimal guided control is applied to restrain the lateral and yaw motions. The comparisons between the active and passive guidance explain the effect of the active control approaches.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.86-93
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• 2010

The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.6_spc
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• pp.644-650
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• 2016

Track maintenance works based on track geometry recordings are essential to enhance the safety and comfort of railway transportation. Usually, the track irregularity has been measured by a special inspection trains which all were imported from abroad. Because the inspection train speed is limited under 160 km/h, it takes a long time to inspect railways and there is difficulty in daytime operation. To solve this problem, we started to develop a track geometry measuring system (TGMS) with measurement speed up to 300 km/h which can be installed in commercial vehicles such as HEMU-430X. In this paper, we introduce a newly developed inertial TGMS and propose two inertial navigation system (INS) algorithms (method A, B) for measuring track geometry. In order to investigate advantage and disadvantage of each algorithm, we performed vibration test of the TGMS, which was simulated by 6-axis shaking table. Through the vibration test, we analyzed the influence of vehicle vibration on the TGMS which will be installed on bogie frame. To the vibration test, two methods satisfied the required accuracy of track geometry measurement under the level of the actual vehicle vibration of HEMU-430X train. Theoretically, method A is sensitive to vehicle vibration than method B. However, HEMU-430X's bogie vibration frequency range is out of interest range of measurement system. Therefore, method A can also apply the HEMU-430X train.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1656-1664
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• 2007

This paper introduces a study of improvement for a defect diagnosis of the UM71C track circuit using on HSL. The track circuit on HSL has long operation section. Therefore, when the worker maintain, many times and efforts are spent. So, periodically, we have operated a inspection car. However, we don't know exactly the state changed of the inspection data when track circuit has defect. Actually, We fixed a sample area within operation 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. Using verified simulation program, we estimated inspection data as the malfunction number and the change of capacity of compensation capacitor. These study need to secure of the safety as the train operation. Also, It needs to make a criteria of analysis for the maintenance through comparison simulation data and inspection data.