RINA Railways Certification Laboratory performed tests for a validation with respect to UNISIG/ERA SUBSET 026, SUBSET 036 and SUBSET 085.
Our Balise Life Check has successfully passed the tests, and marked the first important step in its validation process.sts.
Figure 1. List of tests performed on the Balise Life Check System at RINA Certification Laboratory (extract from final test report).
Figure 2. Equipment under test at RINA’s laboratory.
Two families of tests were performed:
First, RINA Laboratory measured and characterized the quality and the intensity of the telepowering signal to ensure that the balises are properly energized.
The purpose was to prove that the Balise Life Check system will not cause neither damage nor perturbation to existing trackside and on-board signaling system, in compliance with UNISIG/SUBSET 036 requirements. Cross-talk issues with adjacent tracks and existing signaling cables were also addressed and tested.
Telepowering characteristics in balise ETCS Compatibility Mode has also been tested to ensure that the Balise Life Check system is capable of properly energizing legacy KER balises, STM balise system like TBL-1+ in Belgium, and ETCS Eurobalises. Telepowering compatibility mode uses toggling amplitude modulation and its parameters, like the toggling time difference in µs must be carefully verified in order to ensure proper ETCS balise uplink transmission.
All test results show that telepowering signal level, maximum flux, frequency precision and toggling amplitude modulation are perfectly compliant with UNISIG/ERA SUBSET 036 and 085 requirements.
Some results are pictures below:
Figure 3. Requirements for Telepowering signal (extracted from final test report).
Figure 4. Telepowering quality analysis results (extracted form final report).
Uplink Signal Analysis Assessment
The second set of tests purpose was to prove that the uplink signal quality measurements done by the Balise Life Check are as good as a real BTM (for some functions) and equivalent to those performed, in a lab environment, by an accredited laboratory. This is a key feature of the system since the Balise Life Check aims to offer “on-board balise testing laboratory” capability.
The tests consisted first, in testing the Balise Life Check in the same conditions as a BTM (Balise Transmission Module) for telegram detection, telegram demodulation, telegram decoding, balise group reporting and balise spatial positioning on track (according to SUBSET 036/085), and telegram packets and data extraction and analysis according to SRS (UNISIG/ERA SUBSET 026).
All these functions (except the last one) are performed by real BTM and also the Balise Life Check. The last one is performed at the ETCS kernel (EVC) level, but in the case of the Balise Life Check, it is performed directly after telegram decoding.
Figure 5. Example of Inter-balise distance measurement errors performed by the Balise Life Check, for deviated nominal and non-nominal uplink electrical parameters, in Free Air Conditions (extracted form final report).
Those tests were performed with good telegram, using different sequences in balise groups with up to 8 balises, and different mixes of telegram types (short telegram, long telegram), at speeds up to 300 km/h (as required by test specifications, even if the Balise Life Check is capable up to 500 km/h). But also the detection and identification of bad telegrams (faulty telegrams) was also assessed by the laboratory on our system.
A series of tests using shifted nominal and non-nominal FSK and RF parameters of the uplink signal were performed, in order to measure the capability of the Balise Life Check to analyze and measure electrical parameters of uplink signal, even in extreme non-nominal conditions. The results show exceptional capability of the Balise Life Check tool to perform deep FSK and electrical analysis of balise uplink signals.
Finally, the measurements, by the Balise Life Check system, of RF uplink electrical parameters like FSK Center Frequency, FSK modulation Frequency Deviation, transmission Mean Data Rate, FSK amplitude Jitter are equivalent, in terms of precision, to those performed by a static accredited laboratory with, errors below 1% (for frequencies quantities), and as low as 0.5 dB of amplitude jitter.
Figure 6. Electrical characteristics of RF FSK uplink signal for ETCS balises measured by RINA certification Laboratory Instruments (extracted form final report).
Figure 7. Same electrical characteristics of RF FSK uplink signal for ETCS balises measured by ERTMS Solutions Balise Life Check diagnostics tool (extracted form final report).
All test were passed satisfactory and the comparison of the Balise Life Check tool for balise analysis (telegram extraction, telegram analysis, SUBSET 026 telegram content analysis and balise RF uplink signal analysis) prove that the Balise Life Check system is a reproducible and reliable tool for on-board balise analysis in the scope of preventive and active maintenance of trackside balises infrastructure, for legacy KER balises, TBL-1+ balises and ETCS Eurobalises (Level 1, Level 2, Level 3).
Figure 8. Tests report conclusion table for Balise Life Check (extracted form final report).
If you are interested in the complete report, please click here.