Safety relevant application of satellite based localisation in transportation with the focus on railways.
2015 International Association of Institutes of Navigation World Congress, Prague, Czech Republic, Oktober 2015. IAIN, IEEE.
With the general applicability of satellite based localization systems (GNSS) and satellite based augmentation systems (SBAS) proven the way is paved for safety relevant applications in railways. Secondary lines currently equipped with no or only a not up-to-date train control system can benefit from satellite based train localization like the currently introduced European train control system (ETCS). Thus the efficiency of operation can be increased including the reduction of costs for infrastructure equipment. This paper considers the requirements of trains running on different track categories resulting in an application fitted system design with a development strategy leading to an according safety case and safety assessment. The migration from existing systems to satellite based localization on the one hand and from one level of ETCS without satellite based localization (e.g. level 2) to a level with satellite based localization (e.g. level 3 or higher) is considered as well. The components of satellite based localization which shall be used for the safe train localization are of high quality but are not certified according railway standardization. After taking into account the normative background of the targeted application domain – railways – and the originating domain of the equipment – satellite based localization – a solution is suggested to include the localization equipment as industrial components. The safe localization will be reached by the redundant combination of sensors and the use of a safe controller. This design takes into account the requirements towards the functions, the product and the mounting place of the localization unit on the train.