Pietro Salvatori

A multiple satellite fault detection approach for railway environment

The aim of this work is related to railway sector and particularly with the introduction of the GNSS (Global Navigation Satellite System) into that environment. More in details, our aim is to evaluate system performance in terms of integrity of the navigation data. In the train control system, the integrity is one of the most challenge feature to achieve. Under that assumption, an algorithm that is able to exclude multiple SIS (Signal in Space) faults has been designed. In the design of the approach a multi-constellation framework has been taken into account. Simulation results highlighted promising outcomes both in terms of detection probability and in terms of false alarm rate.

A GNSS based solution for supporting virtual block operations in train control systems

This paper deals with the adoption of GNSS (Global Navigation Satellite System) applications for the evolution of ERTMS (European Railway Traffic Management System) system. We have studied a solution to monitor the train integrity and to accurately locate the position where the last coach of the train is stopped when a failure causes the split of the train into two sections. Train integrity is mandatory for the introduction of the “moving block” functionality foreseen by ETCS (European Train Control System) Level 3 that will bring major long-term benefits in terms of maintenance and operational capacity. The novelty of our approach lies in the exploitation of the multi-constellation capability to fast detect the train split with the shortest distance between the departed train sections compatible with the highest safety conditions set by the ETCS standard. The results are presented in a parametric form by varying the number of constellations and the probability of false detection and missed detection.