Positioning Approach for Train-Infrastructure Interaction Assets Health Status Monitoring

Railway infrastructure and vehicle maintenance costs are estimated at above 20,000M£ per year at European level. In this context, SIA (System for vehicle-infrastructure Interaction Assets health status monitoring) has the objective of developing new services to provide prognostic information about the health status of the railway's most demanding assets in terms of maintenance costs, at the points of the interaction between the vehicle and the infrastructure (wheelset, pantograph, rail and catenary). In SIA, events captured by a network of sensors are time-stamped and accurately positioned. The core positioning technique in SIA will be based on Global Navigation Satellite Systems (GNSS). Positioning using GNSS in the railway environment is very challenging due to events such as satellite masking, signal reflection problems (multipath) and the presence of interference. Hence, adaptation of a precise positioning algorithm tailored for the railway environment is essential in SIA. In such an algorithm, the availability and accuracy of the positioning can be improved by taking a multi-constellation approach (i.e. GPS plus GALILEO), using complementary sensors such as IMU and utilizing track map geometry characteristics. Such a positioning algorithm adopted for SIA and some preliminary results presented in this paper.