Simulator Uses GNSS to Track Railway Positioning
With ever-increasing rail traffic, and in order to reduce costs without impact on quality of service and mostly safety, asset managers are consistently challenged to improve the performance of the railway network. With this in mind, the introduction of GNSS technologies in the signaling environment is a smart step in the evolution of rail networks.
Radio frequency signals for satellite positioning can be affected by several global and local anomalies, in combination with common issues of the railway environment, the positioning algorithm (PNT) as well as the railway equipment, have a crucial role in properly managing a variety of issues, also known as feared events. To produce the results with the highest safety level, PNT and equipment must be properly tested and verified. A recent activity with TDE and Hitachi Rail in Italy, has developed a testbed simulator to see how GNSS can be utilised on a railway.
The Sim4Rail Project developed, verified, validated, installed and commissioned a simulation testbed, suitable for the of GNSS Performance in a Railway Environment, at the ESA/ESTEC TEC Navigation Laboratory. In the frame of this activity, laboratory software tools have been developed as building blocks for a simulation testbed of positioning technologies in railway signalling applications.
As part of the activity, different versions of feared events had to be well characterised, modelled and simulated; to validate the simulated outputs. With this approach, conditions that are statistically unlikely to be observed in the field can be tested repeatedly in a highly controlled environment.
Five scenarios were tested. The first is a normal scenario where the train ran completely as expected with no obstacles and just one train per track. The second was more similar to an actual rail environment, with three different channels such as urban or rural rail use.
The third scenario involved the most feared events. On a railway-like simulation the activity included some of the worst situations a train can face, such as a jammed signalling system. The fourth and fifth used different equipment and data sets.
The testbed has been installed and commissioned for use in the ESA/ESTEC TEC Navigation Laboratory; while no further development is currently envisaged for the testbed itself, potential follow-ons include developing a multipath channel model for the railway environment.
4000121232 closed in 2022.
