INTEGRAIL Overview
Basic Objective
The basic objective of the INTEGRAIL development is to demonstrate the use of EGNOS for advanced railway traffic management and control.
Who can benefit from INTEGRAIL?
INTEGRAIL is the first step towards providing train position, velocity and heading by means of satellite navigation. At this stage it allows already for more profitable exploitation of low-density rail lines. Eventually, INTEGRAIL will provide the core of a virtual balise within the already emerging ERTMS standard.
Working Principle of INTEGRAIL
The working principle of INTEGRAIL combines satellite position data with traditional sensor readings. Cross-checks with train speed sensors (odometer) are performed on a regular basis. INTEGRAIL also caters for communication with the control center. The system is usable in safety critical applications, e.g. for supporting the locomotive's Automated Train Control and Protection system (ATP).
INTEGRAIL Platform
The INTEGRAIL platform consists of a set of state-of-the-art commercial components, integrated into a transportable 19" box ('mobile unit'). The mobile unit is installed on-board of a locomotive which for the demonstration tests runs on dedicated tracks in Austria (LogServ/CargoServ, Linz) and later in Belgium (SNCB). Each INTEGRAIL mobile system provides reliable, high-rate, integrity-checked train position, velocity, time (PVT) and heading data.
The mobile unit includes a GPS/EGNOS satnav receiver, standard interfaces to the train's power supply and odometer, supplemental sensors which allow dead-reckoning positioning when GPS/EGNOS is masked (low-cost accelerometer, azimuth sensor), a digital track database, a communication unit, a processing unit and a dedicated sensor fusion software.
Communication Scheme
Fig. 1 (click image to enhance) -- INTEGRAIL Communication Architecture
The INTEGRAIL communication scheme allows to remotely control the performance and the configuration of the mobile unit operating on the train by GSM commands. The mobile unit determines permanently and under all environmental conditions the train's current position (accuracy ca. +/- 10 m, 2 sigma), velocity (+/- 1 km/h, 2 sigma), quality indicator (confidence level close to 100%), direction of movement and health status of the unit and its components. All data can be accessed any time from the server or via Internet (TCP/IP) directly at the train operator's desktop and changed individually (password protection).
Live Demonstration
On June 16, 2003, an INTEGRAIL live demonstration has been accomplished which included real-time verification of the system's performance on private rail tracks in Linz, Austria (LogServ/CargoServ). Remote control of the mobile unit has been demonstrated to an interested public audience (experts from railway operators and industry), and the quality of the system according to the typical requirements of a rail operator has been assessed.
Funding
The INTEGRAIL development is funded by the European Space Agency (ESA).