The INTEGRAIL Project

Project Acronym

INTEGRAIL

Full Title

GNSS-1 Rail User Navigation Equipment

Abstract

INTEGRAIL shall open the way for profitable use of the EGNOS signal in safety-critical railway traffic management and control. The system aims at achieving significant improvements for the rail traffic operator w.r.t. cost, redundancy and reliability of the present train speed measurement systems, which are based on odometers, by adding satellite navigation information and the integrity information offered by EGNOS.

The primary objective of INTEGRAIL is to provide reliable position and integrity information under varying operational conditions. This is achieved by tailored requirements analysis, appropriate sensor selection, performance simulation and actual testing of the system "in-the-field". In the present project, train operations on secondary or rural lines are targeted for application testing purposes.

In addition to assessment and public promotion of the test results, general recommendations will be derived which will be valuable for the future standardization of EGNOS supported train control systems within the European Rail Traffic Management Standard ERTMS.

Objectives

The basic idea of INTEGRAIL is to open the way for profitable use of the EGNOS signal in railway traffic management and control. For passenger transport, this task is a safety-critical application.

Railway traffic control essentially is organized "speed dependent", as defined by the European Railway Traffic Management System standard (ERTMS). In this context, the train's speed is traditionally measured by on-board odometers counting the rotational periods of the wheels and axles. This primary sensor system which provides relative position data shall in the future be backed by the so-called Eurobalises, which are mounted in regular intervals on the tracks and provide absolute positioning data. The effort to install and maintain the Eurobalises, however, is enormous, particularly if seen in a Europe wide context.

INTEGRAIL aims at achieving significant improvements for the rail traffic operator w.r.t. the cost, redundancy and reliability of the on-board speed measurement system by adding satellite navigation information and -- even more important -- the integrity information offered by EGNOS.

INTEGRAIL consists of a set of commercial off-the-shelf (COTS) modules, integrated into transportable 19" boxes ('mobile units'). They have been installed on-board of two test locomotives which run on dedicated test tracks in Austria and Belgium. The movement and commanding of these mobile units is controlled by a central server facility which receives and emits GSM status messages.

In particular, the INTEGRAIL mobile unit comprises a GPS/EGNOS satellite navigation receiver, an odometer, supplemental sensors to allow coupled positioning (low-cost accelerometer, azimuth sensor), a digital track database, a communication unit, and a processing unit. Each INTEGRAIL mobile system provides reliable, integrity checked position, velocity, and time (PVT) data which are usable to support the test locomotives' Automated Train Control and Protection (ATP) system, if appropriate.

Work Description

INTEGRAIL consists of two major project phases:

• Phase I (covering the period between Kick-Off and Design Review) where the system requirements and definition are worked out, and
• Phase II (Design Review to Final Presentation) which actually covers the project realiziation and testing, i.e. design and development of the mobile units, testing, installation on the test trains, test runs (6 months in total), data evaluation, and promotion and recommendations for future activities.

In order to define the common objective of the project clearly enough, a system requirements document has been produced, which details the goals of INTEGRAIL and the technical way to their achievement. This core document is accompanied by sub-system specifications, an assessment of the major ERTMS requirements, a tailored test programme plan, and an assessment of applicable rail navigation techniques, sensors, and their fusion. The latter document includes performance simulation of different sensor combinations and test cases.

Procurement of the prototype mobile units has been completed end of 2002 with follow-on testing on dedicated railway tracks in Austria and Belgium. Test evaluation, promotion and project close-out have been performed in 2003.

Milestones