Towards Model Checking Executable UML Specifications in mCRL2

We describe a translation of a subset of executable UML (xUML) into the process algebraic specification language mCRL2. This subset includes class diagrams with class generalisations, and state machines with signal and change events. The choice of these xUML constructs is dictated by their use in the modelling of railway interlocking systems. The long-term goal is to verify safety properties of interlockings modelled in xUML using the mCRL2 and LTSmin toolsets. Initial verification of an interlocking toy example demonstrates that the safety properties of model instances depend crucially on the run-to-completion assumptions

Services interfaces for interoperability of signaling computer interlocking on borders

Technological developments in the field of railway signaling have allowed more and more flexibility in the management of rail traffic, especially with computer interlocking. However, differences in signaling principles from one country to another as well as differences in the structure of interlocking software and communication protocols depending on suppliers lead to interoperability difficulties at the borders between computer interlocking. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the European rail traffic management system (ERTMS) project. Unfortunately, the interoperability between interlocking themselves is still not achieved. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the ERTMS project. Unfortunately, the interoperability between interlocking themselves is still not achieved. This article draws up a proposed model for interfacing at the interlocking boundaries based on service-oriented architecture (SOA). In addition, to ensure the coupling of SOA services to the internal functions of the signaling computer interlocking, a distributed architecture of programmable logic controller according to the IEC 61499 standard is suggested

Homogenous and interoperable signaling computer interlocking through IEC 61499 standard

The technological evolution of signaling systems has created a dependency from infrastructure managers to suppliers and industrials dominating the market. Indeed, for each deployed computer interlocking, the modification of field equipment is required to allow an adaptation with the new interlocking in terms of communication protocols and logical interface. In addition, to ensure safe traffic of trains, the communication of railway signaling data is necessary between interlockings. However, delayed deployments from one station to another make the establishment of communication channels costly and difficult, or even impossible, since each supplier keeps confidential its communication protocols and usually opts for interfacing based on wired logic. This paper presents our approach to a homogeneous architecture of interlocking meeting modularity requirements, interoperability, and logical interfacing between interlockings. This approach relies on a classification of internal functions of the computer interlocking, a distribution of the execution of those functions and making useful information available for interfaces between adjacent interlockings through the IEC 61499 standard coupled with service-oriented architecture (SOA)

Alister 2.0 - Programmable Logic Controllers in Railway Interlocking Systems for Regional Lines of the DB Netze AG

Railway interlockings are dominated by highly proprietary systems. We present the development project Alister 2.0 -- an interlocking system based on industry-proven standard components: Safety PLCs in distributed nodes communicate over safe network protocols. This enables a highly productive and highly maintainable fail-safe interlocking system for centralised traffic control

OnTrack: Reflecting on domain specific formal methods for railway designs

OnTrack is a tool that supports workflows for railway verification that has been implemented using model driven engineering frameworks. Starting with graphical scheme plans and finishing with automatically generated formal models set-up for verification, OnTrack allows railway engineers to interact with verification procedures through encapsulating formal methods. OnTrack is grounded on a domain specification language (DSL) capturing scheme plans and supports generation of various formal models using model transformations. In this paper, we detail the role model driven engineering takes within OnTrack and reflect on the use of model driven engineering concepts for developing domain specific formal methods toolsets

High-Speed Rail Projects in the United States: Identifying the Elements of Success-Part 2, MTI 06-03

In August 2005, the Mineta Transportation Institute issued the report, High-Speed Rail Projects in the United States: Identifying the Elements for Success. The report noted that since the 1960s, highspeed ground transportation (HSGT) has “held the promise of fast, convenient, and environmentally sound travel for distances between 40 and 600 miles.” After briefly discussing the different experiences with HSGT between the United States and its Asian and European counterparts, the report proceeded to review three U.S. cases—Florida, California, and the Pacific Northwest—as a means for identifying lessons learned for successfully implementing high-speed rail (HSR) in the United States. This report is, in essence, volume 2 of the previous study. Also using a comparative case study approach, this effort adds to the earlier work with three additional cases—the Chicago Hub, the Keystone Corridor, and the Northeast Corridor (NEC). As with the earlier report, the goal of this study is to identify lessons learned for successfully implementing HSR in the United States. Given the early stages of most of these projects, “success” is defined by whether a given HSR project is still actively pursuing development or funding. However, in the case of the Northeast Corridor, a fuller discussion of success is provided since HSR has been implemented on that corridor for some time now