European Rail Traffic Management Research Articles

43 SCHIZOPHRENIA POLYGENIC RISK IS ASSOCIATED WITH BRAIN MATURATION IN TYPICALLY DEVELOPING YOUTH

Product and application life-cycle management (PLM/ALM) are the processes that govern a product and a software system, respectively, encompassing the creation, deployment and operation of a system from the beginning to the end of its life. As both PLM and ALM require cross-discipline collaboration and cooperation, tools integration and inter-operation are necessary to enable the efficient and effective usage of tool suites supporting the management of the entire system life-cycle and overcome the limitations of all-in-one solutions from one tool vendor. In this context, the Open Services for Life-cycle Collaboration (OSLC) initiative proposes a set of specifications to allow a seamless integration based on linked data. This paper describes the work performed within the ARTEMIS JU project CRYSTAL to develop an environment for the functional system-level testing of railway controllers, relying on OSLC to enable inter-operation with existing PLM/ALM tools. A concrete realization of the proposed architecture is described also discussing some design and implementation choices. A real industrial case study is used to exemplify the features and the usage of the environment in testing one of the functionalities of the Radio Block Centre, the vital core of the European Rail Traffic Management System/European Train Control System (ERTMS/ETCS) Control System.

ERTMS/ETCS Virtual Coupling: Proof of Concept and Numerical Analysis

Railway infrastructure operators need to push their network capacity up to their limits in high-traffic corridors. Virtual coupling is considered among the most relevant innovations to be studied within the European Horizon 2020 Shift2Rail Joint Undertaking as it can drastically reduce headways and thus increase the line capacity by allowing to dynamically connect two or more trains in a single convoy. This paper provides a proof of concept of Virtual coupling by introducing a specific operating mode within the European rail traffic management system/European train control system (ERTMS/ETCS) standard specification, and by defining a coupling control algorithm accounting for time-varying delays affecting the communication links. To that aim, we define one ploy to enrich the ERTMS/ETCS with Virtual coupling without changing its working principles and we borrow a numerical analysis methodology used to study platooning in the automotive field. The numerical analysis is also provided to support the proof of concept with quantitative results in a case-study simulation scenario.

The Missing Link in the Realization of the African Integrated High-Speed Railway Network: Rules on Technical Standards and Operation

One of the major objectives of the African Union (AU) is to develop an integrated high-speed railway network connecting major African cities for improved continental trade and competition. This paper provides an overview of the main technical aspects of high-speed railway lines with special focus on cross-border operational and technical interoperability. It briefly describes the missing link in realizing a truly interoperable high-speed railway network for the African case. It introduces the technical aspects of railway lines that must be unified for cross-border operation. It also outlines the reasons that may explain the global success of the European Rail Traffic Management System (ERTMS), offering the author’s view on factors that continue to influence decision making in favor of ERTMS over other national and not interoperable solutions such as the Chinese Train Control System (CTCS). The paper concludes by suggesting the way forward for combined continental effort to realize the African Integrated High-Speed Railway Lines Network as part of the African Union’s Agenda 2063.

A Multi-Criteria Decision-Making Framework for the Evaluation of Train Control Information Systems, the Case of ERTMS

The huge potential offered by the implementation of a modern Train Control Information System (TCIS) could result in significant improvements in the railway sector in general. As a technology transfer, primarily in the European railway sector, the European Rail Traffic Management System (ERTMS) is expected to play an important role in providing better railway performances. However, the implementation of ERTMS entails certain dilemmas and disadvantages and the decision-making regarding it can be one of the crucial challenges for each railway. Having this in mind, the aim of this work is to propose a decision-making framework to support such a critical decision process through application of Strengths, Weaknesses, Opportunities, and Threats (SWOT) and Analytic Hierarchy Process (AHP) analyses. In the proposed approach, external and internal factors that simultaneously enhance and constrain ERTMS implementation were identified and presented through the SWOT analysis, while the AHP method was applied for the evaluation of the importance of identified factors. The thorough literature review represents a basis for creating a SWOT matrix and setting of judgments for the evaluation of the SWOT factors. The results of the AHP method highlight the importance of the factors within the SWOT matrix regarding ERTMS implementation. Results of the AHP method were checked by two additional weight assessments in order to provide the appropriate approach for factor evaluation. The proposed approach also shows a relatively simple and very suitable decision-making framework for consideration of other TCISs, too.

Safety Appraisal of GNSS-Based Localization Systems Used in Train Spacing Control

The use of global navigation satellite systems (GNSS) will provide significant advantages for ensuring the control of train movements on railway networks equipped with European Rail Traffic Management System/European Train Control System (ERTMS/ETCS). Indeed, this disruptive technology can play an important role for reducing the rail infrastructure’s equipment by enabling trains to determine their position in an autonomous way. Specific associated hazards have to be considered in the European signaling system. From this perspective, performances of GNSS-based localization systems were analyzed in different past studies. They highlighted what they can bring to the railway domain. For going further than performance-centric analyses to help inserting these systems safely in rail applications, this paper want also to focus on their operating uses. For that, the safety evaluation proposed in this paper is able to handle specific estimated confidence-related data that are associated to an estimated position. This paper first details the managed risks in ETCS due to the localization function with, in particular, those that may arise due to GNSS-based systems. It discusses the evolution of these risks when dealing with moving block operation of the ETCS-level 3. The safety evaluation approach is then explained. It relies in fact on extended integrity data handled in the case of the train spacing. Finally, it is applied in different operational cases to show evaluation results when real GNSS data are measured in a railway environment.

A Framework for Vulnerability Detection in European Train Control Railway Communications

Railway systems have evolved considerably in the last years with the adoption of new communication technologies. Aiming to achieve a single European railway network, the European Rail Traffic Management System (ERTMS) emerged in Europe to substitute multiple and noninteroperable national railway communication systems. This system and its security strategies were designed in late 1990s. Recent works have identified vulnerabilities related to integrity, authenticity, availability, and confidentiality. In the context of defining effective countermeasures to mitigate potential vulnerabilities, these vulnerabilities have to be analysed. In this article we introduce a framework that attempts to challenge ERTMS security by evaluating the exploitability of these vulnerabilities.

End-to-End Delay Model for Train Messaging over Public Land Mobile Networks

Modern train control systems rely on a dedicated radio network for train to ground communications. A number of possible alternatives have been analysed to adopt the European Rail Traffic Management System/European Train Control System (ERTMS/ETCS) control system on local/regional lines to improve transport capacity. Among them, a communication system based on public networks (cellular&satellite) provides an interesting, effective and alternative solution to proprietary and expensive radio networks. To analyse performance of this solution, it is necessary to model the end-to-end delay and message loss to fully characterize the message transfer process from train to ground and vice versa. Starting from the results of a railway test campaign over a 300 km railway line for a cumulative 12,000 traveled km in 21 days, in this paper, we derive a statistical model for the end-to-end delay required for delivering messages. In particular, we propose a two states model allowing for reproducing the main behavioral characteristics of the end-to-end delay as observed experimentally. Model formulation has been derived after deep analysis of the recorded experimental data. When it is applied to model a realistic scenario, it allows for explicitly accounting for radio coverage characteristics, the received power level, the handover points along the line and for the serving radio technology. As an example, the proposed model is used to generate the end-to-end delay profile in a realistic scenario.

Verification of the European Rail Traffic Management System in Real-Time Maude

The European Rail Traffic Management System (ERTMS) is a state-of-the-art train control system designed as a standard for railways across Europe. It generalises traditional discrete interlocking systems to a world in which trains hold on-board equipment for signalling, and trains and interlockings communicate via radio block processors. The ERTMS aims at improving performance and capacity of rail traffic systems without compromising their safety. The ERTMS system is of hybrid nature, in contrast to classical railway signalling systems which deal with discrete data only. Consequently, the switch to ERTMS poses a number of research questions to the formal methods community, most prominently: How can safety be guaranteed? In this paper we present the first formal modelling of ERTMS comprising all subsystems participating in its control cycle. We capture what safety means in physical and in logical terms, and we demonstrate that it is feasible to prove safety of ERTMS systems utilising Real-Time Maude model-checking by considering a number of bi-directional track layouts. ERTMS is currently being installed in many countries. It will be the main train control standard for the foreseeable future. The concepts presented in this paper offer applicable methods supporting the design of dependable ERTMS systems. We demonstrate model-checking to be a viable option in the analysis of large and complex real-time systems. Furthermore, we establish Real-Time Maude as a modelling and verification tool applicable to the railway domain. The approach given in this paper is a rigorous one. In order to avoid modelling errors, we follow a systematic approach: First, as a requirement specification, we identify the event-response structures present in the ERTMS. Then, we model these structures in Real-Time Maude in a traceable way, i.e., specification text in Real-Time Maude can be directly mapped to requirements. We explore our models by checking if they have the desired behaviour, and apply systematic model-exploration through error injection – both these steps are carried out using the formal method Real-Time Maude. Finally, we analyse ERTMS by model-checking, thus applying a formal method to the railway domain, and we mathematically prove that our analysis of ERTMS by model-checking is complete, i.e., that it guarantees safety at all times. • First full model of ERTMS, i.e., comprising all subsystems required for the full control cycle. • Systematic modelling, validation, and verification process on ERTMS. • Completeness argument for the verification of a hybrid system through finitely many time samples. • Modelling technique for time-robustness and tick-stability in case of numerical rounding errors. • Successful application of Real-Time Maude to a new industrially relevant domain.

New systems in management of railway traffic in Poland

The new computer's solutions and microprocessor technology, microcomputers and the programmable controllers (PLC) for management of train traffic, which are implemented, contribute to the creation of modern rail traffic control systems. These systems provide high reliability, low power consumption, stability and safety of the trains' movement. One of the most important things for the boards of railway European countries is unification the systems of rail transport, in particular unification the signaling systems and control of the rail traffic. A good solution is as soon as possible implementation the European Rail Traffic Management System (ERTMS), which connect the system of safe operation of trains ETCS and the digital Global System for Mobile Communications – Railways GSM-R.

Analysis of Big Data Streams to obtain Braking Reliability Information for Train Protection systems

Due to the long braking distance of railway systems and the high velocities achieved, railway operation needs to rely on train control systems. At the foundation of these systems are models to predict the motion of the trains, including their anticipated braking curve. Depending on the infrastructure manager, these braking curves need to be achieved with a given safety, which is typically in the rare event region of probabilities.In current settings, it is typical to develop these so called braking curves either by physical modelling of the train followed by a Monte Carlo simulation or following a heuristic approach, mostly based on the high level of safety over the past centuries. However, higher developed train protection and control systems, such as the European Rail Traffic Management System (ERTMS) or the Russian KLUB-U System together with current efforts towards quantitative risk analysis, e.g. the European Common Safety Methods, require a more formal approach to communicate the braking curve of a train between rolling stock and infrastructure. An a priori determined set of braking curves is feasible for trains running in fixed or a limited number of formations, such as multiple unit trains, however in the freight railway system due to its vast amount of different vehicles and possible train setups, the determination of the braking curves is prohibitive. In this work, a procedure is proposed to obtain the variation in braking force from accelerometer data onboard the vehicles. In order to allow for the large amount of data to be expected, the procedure is formalised in MapReduce form. The variation of the braking force from the expected value determined in this way can then be forwarded to a Monte Carlo Analysis using importance sampling methodologies to allow for an online calculation of braking curves based on the safety requirements communicated by the infrastructure manager. It is expected that such a procedure yields shorter braking curves than the safety factors currently proposed, leading to higher commercial speeds and thus higher infrastructure usage.

Application of Valuation-Based Systems for the availability assessment of systems under uncertainty

The aim of the paper is twofold. First, it proposes an original application of the Valuation-Based System (VBS) for the availability assessment of systems under uncertainty in a time-varying fashion. Uncertainties related to failure data of components (data uncertainty) and the system structure (model uncertainty) are analysed in the proposed model. Second, it proposes the application of the VBS for the availability assessment of the European Rail Traffic Management System (ERTMS) Level 2 under uncertainty according to the railway dependability standards. The originality of this work lies in the application of the VBS for the availability assessment of systems under data and model uncertainties, and the proposition of a temporal VBS to evaluate the instantaneous system availability.

A CPN/B method transformation framework for railway safety rules formal validation

This paper presents a “CPN/B method” based process for railway systems safety analysis. Achieving interoperability through the European Rail Traffic Management System (ERTMS/ETCS) is facing difficulties in railway safety assessment due to the interaction of national and European operating specifications. These specifications have been modeled using several formalisms, which makes it is extremely hard to preserve all requirements when switching between different formalisms. However, this problem, crucial for efficient progress in railway safety research, has received very little attention in the literature. In this respect, the purpose of this contribution is to provide a methodology to demonstrate safety in railway systems by converting CPN models, widely used in modeling, into B abstract machines. It aims at enabling a stronger combination of formal design techniques and analysis tools able to cope with the real complexity of systems and automatically prove that safety properties are unambiguous, consistent and not contradictory, considering an industrial railway context.

Expert knowledge elicitation to generate human factors guidance for future European Rail Traffic Management System (ERTMS) train driving models

The European Rail Traffic Management System (ERTMS) will have an impact on the train driving task and the behaviour of the train drivers. This paper presents a part of the final study of the series of studies that have been conducted as part of a three-year research project, which investigated the effects of ERTMS on the behaviour of the train drivers. In recent times, a number of models of train driving have been developed in order to inform the design of the train driving technology and understand the implications of the design of the train driving task on the performance of the drivers and their behaviour. An expert knowledge elicitation study was conducted to evaluate the existing train driving models and to generate a guidance on human factors for the future ERTMS train driving models. The study consisted of a workshop, which was conducted using the rail human factor experts who have been directly involved with the projects examining ERTMS. The current train driving models were evaluated and ideas were generated as to how these should be shaped in the future to include systems such as ERTMS. The findings of the study contributed to bridging the gap between the theoretical understanding of the cognitive strategies of the train drivers and the practical implementation of novel technologies by the rail industry.

A Control Scheme for Automatic Level Crossings Under the ERTMS/ETCS Level 2/3 Operation

Level crossing (LC) safety is a crucial issue for railway operators and infrastructure managers. Accidents at LCs give rise to serious material and human damage, while seriously impacting the reputation of railway safety. In particular, some typical scenarios are behind the main part of train-car collisions, which occur at LCs. On the other hand, European Rail Traffic Management System (ERTMS) is the standard railway control-command and signaling system that is currently being implemented throughout Europe and elsewhere. The aim is to ensure railway interoperability while enhancing safety and competitiveness of the railway transportation. ERTMS specifications only provide a rough description when dealing with LC control. This paper elaborates on a functional control architecture for automatic LCs in the context of ERTMS operation Levels 2 and 3. Indeed, these operation levels ensure a continuous knowledge of train location thanks to the Global System for Mobile Communications—Railways link between the trains and the Radio Block Center. Hence, the established LC control scheme aims to ensure an optimal LC command based on the information regarding the train location and, thereby, prevent some potential risky scenarios and improve the global safety at LCs. To achieve this, a generic methodology is employed. First, a formal behavioral model is developed using the time Petri net (TPN) notation. Then, the problem is formalized on the basis of the established TPN, in such a way as to carry out a sound and trustworthy analysis. The various steps of the developed approach are detailed and illustrated in the course of this paper. To the best of our knowledge, this is the first work that seeks to elaborate a control strategy of automatic LC in the ERTMS operation context.

DEPLOYMENT OF ERTMS IN CZECH REPUBLIC

The article describes current situation and expected deployment of international standard for automatic rail vehicle protection in Czech Republic for period 2014 – 2020. Article introduces expected status in 2020 and subsequent implementation of commitments until 2026. It introduces expected result of gradual implementation for tracks and vehicles. It also displays brief deployment overview of European Rail Traffic Management System in European Union countries for each level of European Train Control System.

A Step Up in European Rail Traffic Management Systems: A Seamless Fail Recovery Scheme

The European Rail Traffic Management System (ERTMS) is becoming a worldwide de facto standard for high-speed railway signaling. A major shortcoming of this system is that it is attached to a single radio-bearer technology, the Global System for Mobile Communications-Railway (GSM-R). The migration of ERTMS toward Internet Protocol (IP) provides the opportunity to make ERTMS unaware of the underlying communication technology by establishing train-to-ground connectivity via multiple bearers. In this article, we evaluate Multipath Transmission Control Protocol (MPTCP) integration in the ERTMS protocol stack in a test bed as a way to use heterogeneous radio bearers seamlessly and simultaneously. We validate this strategy by comparing our obtained results to the European Integrated Radio Enhanced Network (EIRENE) requirements and demonstrate its functionality as a seamless fail recovery strategy.

Implementation of ERTMS: A Methodology Based on Formal Methods and Simulation with Respect to French National Rules

This paper presents the latest results of a three years project which aims at contributing to the validation and implementation of a European system for railway signaling called ERTMS “European Rail Traffic Management System”. The management of railway trackside signaling in ERTMS is based on rules pertaining to each country and not on global rules. In order to perform a global safety assessment, a system analysis has to consider all these aspects. By the consequence, the main target of the project is to provide some methodological and software tools in order to perform consistency checking. The project named “Perfect” started in November 2012. The first step was to identify some critical scenarii leading to accidents or quasi accidents. The study leads us to focus on maintenance trains. In fact, even if there are not representing a big amount of the traffic, maintenance trains are involved in several critical situations. This intermediate result highlighted that there are no ERTMS running accidents because there were no ETCS2 implemented in France during the project. Consequently, the second step is to build a logical environment allowing replaying the identified scenarii under the ERTMS framework. This logical environment is obtained by a modeling task. Petri nets and B models may be used in order to provide some formal safety proofs. These two modeling tools are well accepted by some railway actors. Nevertheless ERTMS textual specification is not so formal. A semi-formal language like SysML seems to be well fitted to produce some intermediate models. A petri net model of the interlocking was proposed and a UML4secure Model was presented. The transformations of these two models into B machines have been published. Now we are able to prove some safety invariants on this global model of the system. In the last step of the project, based on the formal model some tests are generated, and then executed on the ERTMS simulation tool compliant with the official specifications. There are two kinds of motivations. The first one is to validate the assumption used by the safety proofs produced by the formal models. The second one is to play the critical scenarii in the 3D environment of the ERTMS compliant simulation tool. The scenarii are obtained from two different procedures. Firstly, the accident database analysis allows defining some critical elements. Secondly, when the formal analysis failed at providing all proofs, the corresponding scenario has to be tested. The influences of infrastructure design and working context have been revealed in this last step. During this three years project, an instrumented methodology based on formal methods and a 3D simulation framework has been developed. This global framework does not avoid all difficulties, but it may allow producing a safety proof in shortest and more deterministic time.

Fleet Migration Towards ETCS – Challenge and Experience Gathered

Alstom Transport is in the process of retrofitting the entire Danish rolling stocks fleet with the European Train Control System (ETCS) system. This paper describes how Human factors have been integrated in the design process of the final solution in order to provide a smooth transition to the European Rail Traffic Management System (ERTMS) technology. The scope of the Human factors activities taken into account are the design of the solution, the validation with drivers and Union, the training and the maintenance activities. We have developed a new methodology to address the fleet heterogeneity and the large number of rolling stocks to retrofit, the diversity of the Operators (historical public, and privates) and the diversity of the driver's needs (passenger, freight, and maintenance rolling stocks). We have adapted up-to date technology (3D printing, measurement tools) to implement rapid prototyping at the early stage of the design. We present the various meetings (information collection, brainstorming, discussion and solution definition) that lead to define the acceptable solutions. The different principles used to provide requirements to the mechanical designers are described. They deal with location of equipment and the way to minimize the number of components to be moved. We present how the cabs have been measured to get the required information in order to check the visibility according to international standard, to assess the room available to integrate the ETCS system, to check the reachability of controls and to check the risk of glare. We show the different sounds level measured and the criteria to ensure the right audibility threshold. The paper also discusses the way to manage the different proposals from the different actors (drivers, crew and maintenance people, mechanical designer, trainer, and installation people) of the project and the steps to reach a workable solution. This methodology leads to a better efficiency by achieving compromise with the different stakeholders.

Cyber security analysis of the European train control system

One of the key research issues in further strengthening the role of railways in the transportation system is to achieve the highest possible level of cyber security against significant threats to the signaling and telecom systems. The European Rail Traffic Management System (ERTMS) was designed in the 1990s with the security measures and strategies available at the time. However, ERTMS’ underlying communication technology, GSM-R, needs replacing, and replacement strategies are already underway. Due to their direct effects on safety, ERTMS security mechanisms also need updating to face current security threats. This article provides a security analysis of ERTMS’ safety layer, Euroradio, in terms of current security threats. After identifying its vulnerabilities, we present four main recommendations: a more robust cryptographic mechanism, a new key distribution scheme, a new key storage and system integrity module, and a set of countermeasures for avoiding radio jamming attacks.

Rapid, robust, distributed evaluation and control of train scheduling on a single line track

The technology for controlling the distance between two trains is shifting from traditional fixed red, yellow and green signals on the infrastructure track circuits towards more and more dynamic systems, which are based on moving blocks, where the distance is computed according to real-time positioning, and the control of the distance is computed on-line. This is the case, for example, in the European Rail Traffic Management System (ERTMS), which proposes three different levels, from 1 to 3. This paper addresses the time-honoured problem of scheduling trains on a single track, in the light of recent results in robust team decision theory. The control model can be used in two modes: as a decision support tool for train dispatchers to evaluate the distance between trains in the current schedule, and as a planning tool to evaluate the effects of timetable changes. The main contribution of the paper is the application of a recent result in robust team decision theory to control noncritical train distances in moving blocks, such as in ERTMS Level 3. The case study is related to real data from an ERTMS simulation and controller software tool.