• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1624-1633
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• 2009

Brake system in railway train operates to reduce the speed of the train or to stop the train via changing the kinematic energy into heat energy for emission and so brake system makes an important rule to transport passenger and cargo for safety operation. Recently operators have a matter of grave concern for the verification of performance in brake system. To verify the exact performance of brake system, most of brake test has been carried out on real operating track condition. Therefore we will determine the braked weight of indirect brake system applied in Iran DMU(Diesel Multiple Unit) in accordance with mc leaflet 544-1, which is to enable Iran DMU to achieve the required braking distances in defined situation.

• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.319-326
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• 2018

The safety interval to prevent collision between trains in a train control system is based on the braking distance according to the emergency braking of the train. The evaluation of the braking performance is based on the longitudinal train dynamics or the commissioning test in the test track, but since the conditions such as the weakening of the adhesion coefficient between the wheel and rail can not all be considered, these conventional methods are not sufficient to design of the train control systems. Therefore, in this study, the Monte Carlo Method (MCM) which can consider various environments is used to analyze braking performance and limitations. The braking model is based on the air braking used in the emergency braking and is modeled to take into account the braking pressure, efficiency, friction coefficient, adhesion condition, and vehicle mass distribution. It is confirmed that braking performance can be improved by controlling the quality of braking device. In addition, the change of the braking performance was confirmed according to the vehicle constituting the train. The results of this study are expected to be used as basic information for designing safety clearance for the train control systems and as a basis for improving the braking performance of railway vehicles.

• Journal of IKEEE
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• v.21 no.3
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• pp.174-184
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• 2017

This paper proposes a torque predictive control for dynamic performance improvement of clamping force in electro-mechanical brake (EMB) for railroad cars. In general, pneumatic braking system (PBS) is used for railroad cars. It is sensitive depending on environmental changes and it has increasing idle running time because of slow dynamic response. Additionally, the PBS has low braking efficiency in case braking torque more than standard value is applied to the brake system such as emergency braking. In order to overcome these disadvantages of the PBS, the EMB is used for the railroad cars. The EMB for railroad cars has advantages that increasing the fuel efficiency and design flexibility because it is able to decrease vehicle weight of railroad cars and secure space for design. In this paper, control method for dynamic performance improvement of clamping force in EMB for railroad car is proposed. The effectiveness of the proposed control method is verified by the simulation results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.887-895
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• 2018

This paper presents a braking model that can be used to design the safety distance of a train control system and a train braking system to increase the volume of traffic. For the braking model, a train set (electric multiple unit composed 6 cars) was tested. The factors that can affect the braking characteristics include the friction coefficient, braking pressure, and regenerative braking. The braking pressure was classified into service and emergency braking and reflected the characteristics of the vehicle. The external force acting on the running railway car was tested in accordance with KS R 9217, and the running resistance of the train is presented in the form of a polynomial. The dynamic behavior of the train running on a straight flat line was simulated using UM 8.3. The results were validated with experimental data, and the results were reasonable. With the validated model, a stopping distance was determined according to the initial braking speed and compared with the deceleration braking model. In addition, a safety distance for the train control system could be changed according to the frictional coefficient limits. These results are expected to be useful for analyzing the dynamic behavior of trains, and for analyzing various railway environments and improving the braking performance.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1576-1578
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• 2005

기존 국내의 간선 철도와 도시철도에서는 궤도회로에 기반한 고정폐색방식에 의한 열차제어시스템을 사용하고 있으나, 세계적인 추세가 유지보수 비용을 줄이고 선로 용량을 증가시킬 수 있는 무선통신을 이용한 이동폐색방식에 의한 새로운 통신기반 열차 제어 시스템(CBTC(Communication Based Train Control) system)에 대한 연구가 활발히 진행되고 있으며, 특히 도시철도의 경우 이에 대한 실용화가 이루어지고 있는 실정이다. 현재 국내에서도 한국철도공사에서는 분당선 구간에 CBTC 시스템의 시범적응을 진행하고 있으며, 또한 한국철도기술연구원에서도 건설교통부가 추진하고 있는 도시철도 표준화 사업의 한 분야로 도시철도 신호시스템에 대한 향후의 표준화 방향을 CBTC 시스템으로 선정하고, 이에 대한 표준화 및 국산화 연구개발이 진행되고 있다. 또한 유럽에서 진행되고 있는 ERTMS/ETCS 시스템의 레벨 2와 3에서는 앞의 방식하고는 다른 GSM-R의 무선방식을 사용하고 있지만 이 또한 무선통신에 의한 열차제어시스템을 적용하고 있다. 본 연구에서는 이러한 무선통신을 이용한 열차제어시스템에 있어서의 안전제동모델에 대해 연구하였으며 그 결과를 소개하고자 한다.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.368-376
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• 2011

An Electric railway system has the characteristics. The train powered by substations generates regenerative power when it runs on railway of various slope. A regenerative braking is an ideal system on account of reducing mechanical braking as well as recycling the energy. This study dealt with the line gradient review, train running records and power data out of substations in a bid to establish the efficient regenerative energy storage system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.578-585
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• 2018

This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.426-438
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• 2015

Train speed controlling systems are now changing from wayside systems to onboard signaling systems. Locomotive engineers refer to wayside markers to decide on a braking point when the train speed appears to be lower than the current speed. However, in the onboard signaling systems that have been installed recently, the braking point is not determined by the wayside signal but by an onboard value. In this paper, we studied braking points and methods for deciding on such points by engineers using the onboard systems. An optimized braking point is proposed via simulation of decelerating velocity to control the velocity in the signaling system through a predefined point; Gaussian distributions are used to simulate the actual situation. We estimated and demonstrated how to obtain braking parameters in order to satisfy the interval of permitted error.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.85-90
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• 2011

To maintain the safety and efficiency of railroad vehicles, it is important to understand the working of the brake system with anti-skid control unit (ASCU) for rolling stocks. In this paper, a HILS (Hardware In-the Loop Simulations) system with ASCU hardware (for logic) and a DSP board (for dynamics) is developed to analyze skidding of the Hanvit-200 train during the process of braking. Experimental results are presented for the case that the skid on one of the four wheels is artificially generated using a Simulink model. A convenient GUI is prepared using ControlDesk of dSPACE.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.545-551
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• 2016

In this study, we evaluate the braking performance of an urban railway vehicle to verify its basic safety condition. The braking performance evaluation methods, deceleration measurement and braked weight percentage, were compared for trains with different numbers of cars, in order to assess the advantages of each method and their compatibility. With a probabilistic braking model, the effect of the adhesion coefficient distribution was analyzed in accordance with the train composition. A train with many cars has a narrower deceleration distribution width than one with few cars. The braked weight percentage method is expected to be useful in the design of train signal systems, because it allows the braking distance to be calculated for various initial brake velocities. The deceleration distribution model and its results are expected to be useful as a basis for precise train signal design.