Electronic Interlocking System Research Articles

Communication security analysis of fully electronic interlocking systems

Communication security in fully electronic interlocking systems is one of the key factors ensuring the safe and reliable operation of the entire system. EN50159 is an important standard in the European railway communication sector, aimed at ensuring the safety, reliability, and efficiency of railway transportation. According to the communication security standards of EN50159, there are six types of security risks in closed communication: data duplication, deletion, insertion, misordering, delay, and corruption. This paper analyzes and explains the aspects of communication security that need to be considered based on the safety communication standards of China's railway signaling system and the signal safety standards in EN50159, focusing primarily on communication security and reliability.

Network Management Center for East European Railways

Railways in the world are facing increasing competition with other transport facilities like electric cars, electric buses, freight trucks and aircraft. By using digital interfaces to electromagnetic relay-based block automation section or electronic interlocking system like LZB control center from Alcatel-Cegelec, the East European Union Railways must manage the whole long-distance traffic in his whole railway network and the upgrade software program is demanding the hardware part installation.

Analog circuit fault diagnosis based on enhanced Harris Hawks optimization algorithm with RBF neutral network

AbstractCircuit faults are caused by the change of device parameters in the analog circuit. Aiming at the problems that the fault feature extraction is difficult and the fault signal cannot be effectively classified, an enhanced Harris Hawks algorithm is proposed to optimize the parameter optimization process in the RBF neural network, so as to realize the fault identification and diagnosis of the analog circuit. Based on wavelet packet analysis, the output response of the analog circuit is decomposed, and the fault feature vector is extracted. Taking the power conversion circuit in the electronic interlocking system as the research object, 500 sets of data are collected, and the EHHO‐RBF algorithm is trained and tested to realize the fault diagnosis of different faults, and compared with other neural network fault algorithms, the experimental results show the accuracy of fault diagnosis of EHHO‐RBF method is about 96.5%, which verifies the effectiveness and feasibility of the algorithm.

통합형 전자폐색제어장치의 적합성 확인을 위한 현장시험

열차를 안전하면서도 신속하게 운행하기 위해서는 항상 선행열차와 후속열차가 일정한 간격을 유지하면서 운행하여야 한다. 이를 위해 일정한 간격의 폐색구간을 설정하고, 열차의 안전운전을 위해 단일 폐색구간에는 1대의 열차만이 운행될 수 있도록 제어하는 폐색시스템이 필수적으로 요구된다. 기존의 폐색시스템은 신호기에 신호를 현시하는 계전기 방식의 자동폐색장치(ABS: Automatic Block System)로 구성되며, 이것은 연동장치를 통해 궤도회로 등선로변 장치들과 연동된다. 연동장치의 경우 국산 전자연동장치로 교체되고 있지만, 폐색장치는 여전히 아날로그 방식의 계전기 형태를 사용하고 있으며, 다른 선로변 장치들과 독립적으로 설치된다. 따라서 기존의 폐색장치는 건설과 유지보수 측면에서 많은 문제점을 가지고 있다. 또한 현재 국내 기존선에 사용되고 있는 ABS와 선로변 전자장치(LEU: Lineside Electronic Unit)는 동일한 장소에서 동일한 신호 정보에 의해 열차를 제어하고 있음에도 불구하고 별개 시스템으로 분리되어 설치되기 때문에, 각 제품의 단가 및 유지보수 비용 측면에서 효율적이지 않다. 따라서 본 논문에서는 기존 폐색장치인 ABS에 통신 및 디지털 전자 기술을 접목시킨 통합형 전자폐색제어장치(integrated electronic block system)와 그것의 현장시험 결과를 소개한다. 현장시험은 1월초부터 8월말까지 8개월간 총 8번의 주기점검을 통해 시행하였으며, 이를 통해 개발된 전자폐색장치의 유효성과 적합성을 확인하였다. For trains to run safely and quickly, the train should always follow the preceding train at a proper spacing. For this purpose, a certain distance between the stations is set for each block section. For the safe operation of trains in one block section, only one train service for an automatic block system is needed. The existing block system is composed an ABS, which is a linked track circuit and line sideway system through the interlocking system. The interlocking system is being replaced with a domestic electronic interlocking system. On the other hand, the block system still uses the relay format of an analog system, and is independently installed of the line sideway systems. Therefore, the existing block system has many problems in terms of construction and maintenance. In addition, the existing domestic line is used for ABS and LEU , which is installed separately, despite the train being controlled by the information of the same signal at the same location. This is not efficient in terms of each product price and the maintenance costs. This paper introduces an integrated electronic block system and the field test results. The field test was carried out through a periodic inspection performed eight times from January to late August.

Form follows vision — user-centred interface design for rail traffic controllers' workplaces

In our Rail Human Factors approach, we define the human as the starting point for our interdisciplinary research on the design of human-machine interfaces in railway systems. One key focus of this approach is on the future workplace of the rail traffic controller. In this paper, a collaboration project between human factors scientists and trained rail traffic controllers is presented. Based on the methodological background of usability engineering, an innovative interpretation of the user interface of the German electronic interlocking system (ESTW) was developed. First prototypical propositions for the design of a future interlocking system were generated in an iterative process of design and feedback phases. Here, we made use of the advantages of the domain expertise of the usability experts as well as the rail traffic controllers. The resulting design is characterized by a decluttered central display / control panel on a single monitor.

Modeling and proving functional completeness in formal verification of counting heads

The demand for safety of electronic devices is high. Especially in safety-critical systems, e.g. electronic railway interlocking systems, safety is an important issue. Nowadays these systems are tested and simulated with a manually created set of test cases. But testing is a very cost-intensive procedure and can never reach a complete coverage for large designs. Hence, an efficient way to formally verify these systems is required. In this paper we present a formal verification flow, including the modeling, for counting heads (CHs) for railways, a real-time system that is used in most electronic railway interlocking systems from SIEMENS.1 The approach shown here is based on SystemC, a powerful system description language. In this way efficient modeling and simulation-based verification of railway components and systems becomes possible. For the formal verification part bounded model checking algorithms are applied, i.e. a set of properties is formally proven to be correct. Additionally the completeness of this set is formally and efficiently determined.

Harmonisation Method of Safety Validation Systems

This paper presents methods to harmonize different safety validations, which were created at different times and by different prescriptions, with each other and with the CENELEC standards, in connection with a concrete application example, the realization of the first electronic interlocking system of the MÁV.

The safety-bag expert system in the electronic railway interlocking system elektra

Abstract The real-time expert system “Safety-Bag” is an integral part of the electronic railway interlocking system ELEKTRA. The interlockinh system contains a logic channel, which processes commands, and a safety channel, which checks the commands according to safety rules. Commands which are only allowed under certain circumstances are carried out only if the instructions generated by processing the command in the logic channel are checked and committed by the safety channel. To minimize the possibility of common errors in both channels, different programming paradigms are used. The logic channel is implemented in a procedural programming language and the Safety-Bag is implemented in PAMELA, a rule-based expert system language suitable for real-time applications. The rule-oriented programming paradigm is very well suited to the Safety-Bag because the safety requirements themselves are represented by rules. The Safety-Bag runs on a standard ALCATEL process control computer.

Safety Measures of the Electronic Interlocking System “Elektra”

Alcatel Austria is currently developing the Electronic Interlocking System ELEKTRA, of which the first installation is to be put into operation at the end of 1989 in Neumarkt-Kallham/Austria. The primary requirement of such an interlocking system is safety, which has to be combined with a high reliability under economical constraints coming from a high competitive market.This paper presents the safety measures of this system which are:– Architectural Measures (two computer channels with diverse software)– Theoretical Measures (SW-Quality assurance program)– Practical Measures (Systematic Testing)

Reliability and Safety in Electronic Interlocking

This paper discusses different system structures for use in electronic interlocking, it studies the impact of the different methods on the reliability and safety of the whole system.First in a broad sense reliability and safety are discussed, their tradeoff in electronic interlocking is shown. Then the different characteristics of the traditional relay based system and the electronic interlocking system are analysed. Based on these prerequisites the different fault and error classes of computer systems are discussed: physical faults as well as design faults in hardware and software.The main part of the paper is devoted to an analysis of the hardware and software structure of various electronic interlocking systems and the principles which are applied: fault avoidance, error detection, fault tolerance, failsafeness, hardware redundancy, software perfection versus software diversity. Furthermore important aspects such as the time behaviour of the system (outdated information), the influence of the operating system and the scope of the safety proof are discussed.

“ELEKTRA”: A System Architecture that Applies New Principles to Electronic Interlocking

This paper presents the conceptual ideas which lead to the architecture of the electronic interlocking system “ELEKTRA”. The key problem of software safety is adressed by the introduction of the so-called ‘safety bag’ method. While the convetional interlocking software is implemented using the real-time programming language ‘CHILL’ (CCITT High Level Language) the ‘safety bag’ uses a totally different programming paradigm based on AI (Artificial Intelligence) methods. Reliability is achieved by the-application of the fault-tolerant, distributed computing system ‘VOTRICS’ (Voting Triple Modular Computing System).