Location sensing and digital map

High-precision localization for better use of the route network

To precisely control train traffic at all times in the future, and to achieve optimal use of the existing network, the intelligent traffic management system must know the exact position of all moving trains. This is where new digital technology comes in. With a combination of satellite positioning and sensors for environmental recognition onboard (eg, camera, radar, Lidar), as well as a high-definition (HD) digital map, it will be possible to locate trains accurately, in real time. 

In addition to the track-accurate  position, train speed, acceleration and train integrity  are determined accurately and made available to the intelligent traffic management system. The digital map is the central repository for static and dynamic infrastructure data. It is cloud based and scalable. Different applications load data relevant for specific applications from the cloud. A large part of the data is needed for automated driving and train location. For these purposes, the HD map depicts reality in a much higher level of detail than conventional navigation maps.

The advantages of location sensors

With the help of new location sensing  technology, trains are able to report their position – the precise front and back of the train – to the intelligent traffic management system. Combined with more modern interlocking technology, trains can run at closer, more flexible successions. This allows more traffic to travel on the same network, which significantly increases capacity – without having to build more tracks.

Implementation

First trial of sensor-based train traffic in Germany starts in Hamburg

Running since 2019, the Sensors4Rail cooperation project tests, for the first time, how sensor-based train location and environmental perception interacts with a digital map. The partners, Deutsche Bahn, Bosch Engineering, Siemens Mobility, HERE Technologies and Ibeo Automotive Systems equipped an S-Bahn vehicle with state-of-the-art sensor technology in October 2020. The sensors, as part of environmental perception, detect landmarks, and a high-performance onboard computer compares the landmarks with data stored in the digital map. The map contains objects along the route such as buildings, bridges and platform edges. This makes the map a ‘digital twin’ of the railway and its immediate surroundings. The installation of the new technologies has been completed since August 2021. The results were presented during special runs along the 23-kilometre route of the S21 line between Hamburg-Berliner Tor and Bergedorf at Hamburg’s Intelligent Transport Systems (ITS) World Congress 2021.

Certifiable Localisation Unit using GNSS (GNSS">CLUG) – concept for a secure localisation system
In the CLUG project – funded by the Galileo Satellite Agency (GSA) – satellite positioning based on the European satellite navigation system Galileo and GPS is combined with other sensors (‘sensor fusion’). In a joint European research project (with organisations including SNCF, SBB, Siemens, CAF and Airbus), a concept is being developed for an approvable, secure localisation system.

Several digital technologies combined

Combined with precise localization  in real time, even more will be possible with new control and safety technology. And axle counters and track circuits will no longer be needed. The expansion of location sensing  technology for Digital Rail for Germany is linked to the expansion of other technologies. For example, FRMCS/5G is indispensable for processing accumulating data volumes and thus for digitising the railway system.