KATHREIN RFID reader for train identification at Swiss Federal Railways

The perfect condition of all rail vehicles not only serves passenger safety, it also prevents potential damage to the infrastructure, such as rails, overhead lines or train components. In order to be able to establish continuous condition monitoring, Swiss Federal Railways (SBB) marked all of its own rail vehicles with RFID for automated and clear identification. This identification makes it possible to localize these vehicles. The technology was integrated in collaboration with Enkom, and RFID readers and software from KATHREIN Solutions were used.

 

Challenges for rail operators

Rail operators and train control systems face a variety of challenges that can affect their efficiency and safety. One of the biggest hurdles is capacity management and congestion on rail networks. As demand continues to grow, it is becoming increasingly difficult to manage train traffic smoothly. Without intelligent solutions, this can lead to delays and inefficient use of resources.

Another key issue is safety and accident prevention. Given the high traffic density on the tracks, the control systems must be able to prevent accidents and react to emergencies at all times. The implementation of IoT technologies offers promising approaches here: Real-time monitoring, predictive maintenance and automated control systems can significantly reduce these challenges and make the operation of rail systems more efficient, safer and future-proof. KATHREIN Solutions has provided a comprehensive RFID solution including the CrossTalk software for the Swiss Federal Railways to ensure this.

Illustration: Vehicle identification using "RFID in Rail" is seen as an enabler technology with which all processes that rely on a vehicle ID can be digitized. Only with "wheel-accurate" vehicle identification can data and information be reliably assigned to the correct vehicle components and the necessary processes automatically triggered using appropriate evaluation methods.

 

Recognize critical developments at an early stage

SBB Infrastructure is the operator of the train control units (ZKE). ZKE are stationary measuring devices along the track that enable a comprehensive inspection of passing trains for various safety-relevant characteristics.

The aim of the infrastructure manager is to detect defective vehicles at an early stage and prevent certain incidents by taking targeted measures. For example, the train driver is warned to reduce speed if a temperature of 130 degrees is measured on an axle, which indicates a fault.

The route is adjusted to reach the next planned intervention point, where the vehicle is removed from the train. To ensure that operations are not disrupted, the infrastructure and all vehicles running on it are permanently monitored. For safety and cost reasons, SBB wants to avoid unexpected problems with passenger or freight rail vehicles. Proactive maintenance is an important process for a smooth, reliable timetable.

Advantages of the RFID solution

• Data is recorded and transmitted to the responsible railroad undertakings (RUs) or vehicle keepers
• Digitization and real-time analysis of the data enable early damage detection and precise allocation for alerting
• Automated train monitoring and non-discriminatory control of rolling stock using train control equipment
• Generation of added value through reliable vehicle identification at full line speed, including automation of manual processes, vehicle-specific condition monitoring and forecasting of vehicle condition development for the optimization of vehicle maintenance
• The data has the potential to forecast the development of vehicle condition. This would enable a predicted condition development and an increase in availability through vehicle identification
• Increased safety, condition optimization by eliminating causes and optimizing life cycle costs
• Clear assignment of wheel contact force measurements to individual wheels through vehicle identification with RFID, facilitates the tracking of wheel condition development

Vehicle condition monitoring: Monitoring of infrastructure and vehicles

The basis for the desired quality assurance measures was initially vehicle identification via RFID transponders, which made it possible to assign the data to a vehicle on an axle-by-axle basis. This is the only way to reliably track the vehicle status across several train control units and detect critical developments at an early stage.

The detection of vehicle axles was ensured via rail contacts installed on the track. By linking this data with the RFID identification data, it was possible to create an intuitive business event that provided information about the condition and individual vehicle data. The result: real-time transparency about the condition of the rail vehicles.

Illustration: Example excerpt from the SBB application developed by Kathrein Solutions to display the vehicle data collected on mobile devices.

 

First pilot tests

In 2013, SBB set up the first pilot site for the installation of train detection systems (ZKE). The aim of this pilot project was to prove that vehicles can be identified with axle or wheel accuracy and then combined with the measurement data from the ZKE systems under the given railroad operating conditions.

For the infrastructure tests, a train with four vehicles was first equipped with RFID tags. At the same time, another SBB division, the Passenger Division, also installed an initial system in a car wash. The aim there was to automate the washing process. Billing based on the selected wash program has already been automated. This pilot project therefore took place simultaneously in two divisions in 2013.

Even today, the washing and cleaning process is still carried out using RFID technology. The pilot system was already in operation in 2014. In the following years, the system was tested, refined and financially supported for a nationwide rollout from 2015 to 2018. During this time, all SBB locations were equipped with RFID technology, accompanied by extensive advocacy efforts to encourage vehicle owners to participate in the tests.

Although the technical implementation of the project was completed in 2018, continuous efforts are being made to integrate additional data sources and attract more vehicle owners to use the data for maintenance. This iterative process requires time for users to develop trust in the data and fully understand its potential applications.

Hardware & Software: installed RFID hardware

Passive RFID technology is being established throughout Europe as a vehicle identification solution in accordance with the GS1 "RFID in Rail" standard and ISO 18000-6C EPC Class1 Gen2. SBB has decided to use "RFID in Rail" across the board and to make some of the recorded data available to vehicle owners free of charge. Already 60 percent of the vehicles running on the SBB infrastructure are equipped with RFID tags for identification.

The installation of the KATHREIN readers required structural modifications, which were carried out jointly by ZKE and the supplier. All ZKE systems were equipped with RFID readers. That is around 120 systems at 70 locations. Typically, there is a ZKE site every 30-50 km. Each of the 70 or so locations comprises one to four tracks, each of which is assigned a reader.

Illustration: The RFID transponders in trains and the trackbed RFID readers must be extremely robust and withstand all weather conditions.

 

Robust RFID labels and readers

Passive RFID transponders are attached to the vehicles, which are read by RFID readers at transit speeds of up to 180 km/h. The RFID transponders on the trains and the RFID readers installed on the track require special robustness that can withstand all weather conditions. This is particularly important in winter in Switzerland, where the weather conditions can be extreme.

The Kathrein Reader ARU 3500 is specially designed for harsh environments and is therefore ideal for these conditions. The hardware costs were kept within limits for a single-track application thanks to the ARU 3500's internal antenna. For a two-track application, an additional Kathrein Reader ARU 3500 was connected as a slave.

The configured IDs (master and slave) on the main reader can then be used to assign each detection to the track. The rail vehicles are marked with an RFID tag in accordance with DIN standard EN17230. The readers used have a wide-angle antenna with a 65° wide angle and use the UHF-RF unit with a bandwidth of 865-868 MHz, with optimum connectivity via PoE+.

Data acquisition at 200 km/h, snow or heavy rain

The read requests from the RFID transponders on the vehicles included the vehicle number. The ZKE measurement data is enriched with target data such as timetable, formation and load information for intervention and analysis. In addition, the data had to be recorded reliably in a range from 5 km/h to 180 km/h.

Software and data visualization

Kathrein's CrossTalk software was used for this project. For user-friendly visualization, Kathrein Solutions developed an app tailored to SBB to display the recorded vehicle data (presence, vehicle number, axles) on various end devices. This visualization depicts each vehicle with each individual axle and provides an immediate overview and transparency for each rail vehicle recorded.

The RFID solution

Record and intelligently process data

Once the RFID readers have recorded the data, it is transferred to the app specially developed for SBB via the Kathrein CrossTalk software. Each reading point sends the data to three servers: a production server, a backup server and a test server. The RFID hardware is monitored centrally via an internal SBB system, which receives the reader status data via the Kathrein CrossTalk agent and the CrossTalk server.

Kathrein CrossTalk also enables the integration of RFID hardware into the leading SBB system. The Kathrein RFID reader is made intelligent by means of the CrossTalk agent so that it can provide the SBB system with its status data.

Real-time data for predictive maintenance

Kathrein Solutions has equipped SBB's 70 train control facilities with around 120 RFID readers to ensure comprehensive safety monitoring. These sophisticated measuring and sensor systems record around 11,000 trains per day and continuously and autonomously perform a variety of monitoring tasks.

Equipping vehicles with RFID tags is a prerequisite for predictive maintenance. The analysis of vehicle data such as temperature, axle load, brake and load data enables problems to be identified at an early stage. More than 40 million axles are measured every year. This includes around 10 million vehicle measurements.

Early detection improves vehicle condition and reduces damage to infrastructure and service interruptions. Sensors in the SBB network monitor key parameters such as axle temperature and brake functionality and detect anomalies. Real-time data analysis enables proactive intervention to prevent risks and ensure safety.