Kang-Mi Lee

Development of verification and conformance testing tools for a railway signaling communication protocol

Verification and conformance testing for protocol specification, the key part of the protocol development process, are complementary technologies employed to increase confidence that a system will function as stated in its specifications. In this paper, we verify the safety and liveness of the protocol specified for the Labeled Transition System (LTS) by using a model-checking method and implementing the testing tool, which experimentally demonstrates the presence of deadlock and reachability from the initial state to a random state. Implementing the testing tool can use modal mu-calculus to assess whether protocol model properties, presented by modal logic, meet protocol specifications. In addition, we propose a conformance testing tool to check correct implementation of sequences that have been derived by the UIO method from the specification of the protocol being verified. This generating tool uses the C++ language in the Microsoft Windows NT environment.

Analysis of Return Current for Rolling Stock Operation on Electrical Railroads

Electrical Railroads provide electric power, which can operate vehicles, via feeder wires. And the supplied current returns to the transformer substation through lines and ground net. The return current, related to signal, power and power line, and track circuit systems, is one of the most important components in the electric railway. Therefore, to prevent system faults and breakdown according to unbalance and overcurrent of the return current, various and detailed analyses for the return current are needed. In the paper, we present measurement and analysis manners in real environment and evaluate its safety. For analysis, we utilize the measured values of return currents measured in track circuits in electric railway. we expect that this research plays a key role to the related fields.

A study on the on-board centered train control system to enhance efficiency of low-density railway line

In the low-density branch line section of domestic railway, the necessity for development of new concept on-board centered train control system which can control the trackside equipment directly from the on-board of train is on the rise since it is problematic in the aspect of efficiency because of its operation in deficits, etc. in accordance with the operation of high-priced wayside equipment being applied to main lines. Accordingly, this paper proposed an on-board control system which can minimize wayside equipment and replace the existing system with it simultaneously by grafting the advanced domestic Information & Communication Technology(ICT), and presented contents of performing confirmation of function through results of concept and detailed design and by building model test environments.

Study on the Speed Control Code Design for Fixed Block TCS

Kyung-Bu High Speed Railway is operated in train control system(tcs) of fixed block operated in a way of dividing track circuits into several blocks in accordance with operation circumstances such as rolling stocks, grade, curves and facilities. The TCS of fixed block system refers to a continuous train control system, which transfers operational information such as entry and exit speed, distance-to-go, and deceleration etc. into on-board train control equipment on the basis of block occupancy of a preceding train. It guarantees a safe operation of trains by giving an emergency braking order, in case that a train exceeds an entry and exit speed of a corresponding block. In this paper, we analyze the speed control code deducing in accordance with maximum operation speed and characteristics of rolling stocks by analyzing principles of generation of speed control code allocated in blocks for safe operation, then train operational efficiency was analyzed by means of analysis of operation headway in accordance with the deduced speed control code. This study will be used to design in case of getting an increase in speed for existing high speed line or new high speed line TCS.

The Study on Centralization & Electronic for Maintenance Efficiency of Ground Signaling System

The train control system used in Gyeongbu-line is classified in ATC, IXL and CTC. Domestic railway signaling systems are being developed by electrification. In these systems the electrification of interlocking reaches 57% and the safety equipments of railway crossings in trackside devices have completed their development into an integrated system. Block systems of all the existing sections have not yet electrified and integrated so that they need a number of complement in terms of construction and maintenance. For ABS currently used in existing domestic lines, and LEU being installed in Gyeongbu and Honam lines, although a train is controlled by the signaling information of the same train in the same location, the system is separately installed so that the same information is separately divided and transmitted at the each distinct system. Therefore, in the conventional ABS and LEU, there are a lot of duplicate installed compartments such as lamp detection and a power supply unit. Hence, we have a lot of problems: for maintenance, a lot of manpower and costs need to be invested and the overall manufacturing costs get higher, as well as the construction costs by duplicate. Therefore, this paper suggest design to develop an integrated electronic Block Control Unit by the integration of the currently used ABS, and communication and electronic technology. We are to monitor and manage the block systems in the corresponding station by integrating. And we are to transmit information together with LEU, which is an ATS wayside transmitter.

Train control simulator design for Korean Radio-based Train Control System

The primary function of train control system prevents train collisions with speed restriction and applying brakes. To improve practical usability in the business area, the safety analysis and evaluation of train control system are needed. In this paper, we design train control simulator of Korean Radio-based Train Control System for evaluation of the design of train control and operation. The paper presents the system configuration of the simulator, and designed modules and those operations.

Simulator design for communication based train control system

The primary function of train control system prevents train collisions by keeping the safe interval with the preceding train. The train control system is consisted of wayside and onboard equipment. The wayside train control system generates control information necessary for train operation, and the onboard train control system controls operational conditions of vehicle and train speeds through information transmitted from the wayside. To improve practical usability in the business area, the safety analysis and evaluation of train control system are needed. In this paper, we design train control simulator for communication based train control system to evaluate the design of train control and operation. The paper presents the simulation configuration, and designed modules and those operations.

ATP Functional Procedure of the Train Control System for an Automated Train Coupling/Decoupling Operation

A train coupling/decoupling technology is essential not only for a usual operation for a formation building of the train, but also for an operation with variable formation according to the change in transportation demand within the same line and for an equalization of the allocation interval of the main and branch lines. However, there are problems of long time required and frequent occurrence of accidents due to the human error since the existing train coupling/decoupling operation is completely accomplished by intervention of the operator. Therefore, an automated train coupling/decoupling system is required. This paper presents an ATP (Automatic Train Protection) functional procedure to develop a train control system which enables an automated coupling/decoupling operation of the train.

Software black-box testing tool for railway signaling system by real interface

The railway signaling system is being converted to the computer system from the exiting electrical equipment, and then the dependency on software is being increased. So far, the software validation has been mainly dependent profess, the these methodology is just depended to software experts as a tester. So it is our situation where not only validation of the document on safety activities being required, but also another automatci testing tool for vital railway signaling software. There were difficult to take advantage at the existing software black-box testing tool like usage of internal memory access of target system. This paper have proposed a new black-box testing tools with enhanced usability and the represents the design and prototype result for proposed tool.

The Design and Analysis of Recognition Structure for Absolute Train Positioning System of High-speed Maglev Train System

For the train positioning system currently applied in high-speed MAGLEV train systems, it is classified into absolute positioning systems which discontinuously detect train positions, and relative positioning systems which continuously detect train positions. In this paper we analyze the configuration model and the numerical model of the absolute positioning system applied in TRANSRAPID which is a representative high-speed MAGLEV train, and design the two configuration models specific to the recognition structures of absolute positioning systems. We also verify the compatibility of the design models of absolute positioning system through simulation using MATLAB and propose the optimal configuration model of absolute positioning systems for high-speed MAGLEV train system.