When the subway speaks – passenger information systems with UHF RFID
For passengers, it's a matter of course: shortly before the stop, the appropriate announcement is made, the doors open on the right side, and the displays update automatically.
What sounds like routine is based on precise and robust positioning technology in the background. In order for automated announcements and door releases to be triggered at exactly the right time, the vehicle must know its position with track precision – even in tunnels or in bad weather.
GPS seems like the obvious choice, but it has its limitations in urban and underground rail transport. GPS does not work in tunnels, its accuracy suffers in urban canyons, and precise location determination is virtually impossible when there are several parallel tracks. In addition, reference points along the route must be measured with great effort.
UHF RFID as a reliable positioning technology
FEIG ELECTRONIC GmbH relies on passive UHF RFID technology (RAIN RFID) for the precise positioning of rail vehicles. The solution works regardless of weather conditions, is suitable for tunnels, and is track-accurate.
At the heart of the solution are the LRU4000X and MRU400iX UHF RFID readers, which have been specially developed for railway applications and are mounted directly on or under the vehicle. Both devices comply with the relevant test standards according to EN50155 and are designed for robust use in rail vehicles.
An RFID antenna for transponder detection is installed under the vehicle. The MRU400iX has an integrated antenna and, when properly mounted, can also detect transponders without an additional external antenna.
Robust, battery-free, and maintenance-free transponders are installed in the track bed as waypoints. These contain a unique identification number that is recorded by the reader when the vehicle passes over them.
UHF mid range reader ID MRU400iX
The ID MRU400iX combines robust UHF RFID reading with edge computing and security for industrial and railway applications.
From transponder to automated action
When the vehicle passes a transponder installed in the track bed, the RFID reader reads its ID and transmits it to the on-board system or the ITCS computer. Thanks to flexible communication interfaces – for example, via TRDP, Ethernet, or RS485 (robust M12 circular connectors) – FEIG readers can be seamlessly integrated.
The on-board system then decides which action to trigger, for example:
Playing the correct stop announcement
Controlling door release on the correct side
Updating displays
Supporting other operational processes
The principle always remains the same: a transponder in the track bed is detected, the information is processed, and the appropriate function is triggered.
Robust, low-maintenance, and flexibly expandable
The RFID-based solution impresses with its mechanical robustness, maintenance-free transponders, and comparatively simple installation. Additional waypoints can often be easily implemented during operation by adding further transponders – without complex re-measurement.
FEIG ELECTRONIC GmbH has been developing and supplying UHF RFID systems for railway applications for around 15 years. The readers, which are specially designed for the rail sector, have proven themselves in numerous applications worldwide and enable precise, reliable, and economical positioning for modern passenger information systems.
Are you planning an RFID-based positioning system for your subway or light rail application? Find out how UHF RFID can be reliably integrated into your existing ITCS or passenger information system.
Contact FEIG ELECTRONIC GmbH for individual advice on reader selection, system integration, and project implementation.