Erik Carlson

The Future of Train Signaling

Producing the source code for a railway interlocking system based on the description of a station has traditionally been a multistage manual process. We show how this process can be automated and made less error-prone by introducing model-driven development (MDD). This paper addresses the experience of developing a Domain Specific Language (DSL) to describe railway stations, Train Control Language (TCL), and tools to support this language. In the railroad domain where there are extreme safety requirements, it is essential to show that consistency and completeness can be assured. We address how the model is used to generate several different representations for different purposes. We look at advantages and challenges with our approach, and we discuss improvements to existing technologies to support our case better.

A Technique for Agile and Automatic Interaction Testing for Product Lines

Product line developers must ensure that existing and new features work in all products. Adding to or changing a product line might break some of its features. In this paper, we present a technique for automatic and agile interaction testing for product lines. The technique enables developers to know if features work together with other features in a product line, and it blends well into a process of continuous integration. The technique is evaluated with two industrial applications, testing a product line of safety devices and the Eclipse IDEs. The first case shows how existing test suites are applied to the products of a 2-wise covering array to identify two interaction faults. The second case shows how over 400,000 test executions are performed on the products of a 2-wise covering array using over 40,000 existing automatic tests to identify potential interactions faults.

Formalizing Train Control Language: Automating Analysis of Train Stations

The Train Control Language (TCL) is a domain-specific language that allows automation of the production of interlocking source code. From a graphical editor a model of a train station is created. This model can then be transformed to other representations, e.g. an interlocking table and functional blocks, keeping the representations internally consistent. Formal methods are mathematical techniques for precisely expressing a system, contributing to the reliability and robustness of the system through analysis. Traditionally, applying formal methods involves a high cost. This paper presents a formalization of TCL, including its behavior expressed in the constraint solving language Alloy. We show how analysis of station models can be performed automatically. Analysis, such as simulation of a station, searching for dangerous train movements and deadlocks, is used to illustrate the approach.

Train Control Language – Teaching Computers Interlocking

This paper describes how computer specialists are rarely trained in the world of tracks and trains, while signaling experts are rarely computer specialists. This paper is about bridging the gap between trains and computers with a specially designed language that enables the signaling experts to create consistent train interlocking systems. The language is supported by tailored tools created with open source technology on the development platform Eclipse. From the formal definition of the language in the form of a metamodel, a graphical editor is generated. The systems created with that graphic editor are then transformed for several purposes that are internally consistent. The editor makes sure that the systems conform to the language, and the language makes sure that the systems conform to the way interlockings are designed. The transformations then produce interlocking tables and even actual code automatically from the graphically created model.

Reducing development costs in industrial safety projects with CESAR

The demand for high Safety levels in industrial applications is growing. New certification and documentation requirements increase the product cost significantly. New or improved methods for high level specification and design may help to do part of the development process more automatically. In the CESAR project ABB, NTNU and SINTEF investigates if the Boiler Plate and Domain Specific Language approach for specification can be used to facilitate automatic generation of safety code and help to automatically document the process as required for safety authorization