Compact on-board PCB for vital control in autonomous train operations


Giovanni Mezzina, Mario Barbareschi, Giuseppe Narracci, Cataldo Luciano Saragaglia, Diana Serra and Daniela De Venuto

Presentation title

Compact on-board PCB for vital control in autonomous train operations

Authors

Giovanni Mezzina, Mario Barbareschi, Giuseppe Narracci, Cataldo Luciano Saragaglia, Diana Serra and Daniela De Venuto

Institution(s)

Polytechnic of Bari and Rete Ferroviaria Italiana SpA

Presentation type

Technical presentation

Abstract

In recent years, the European Union (EU) has pushed the railway sector towards the development of flexible, smart and real-time operating traffic management and decision support systems. For this purpose, the European railway sector starts pushing towards the introduction of highly automatized systems in their lines [1]. In this regard, it is necessary to design and implement in-cabin Autonomous Train Operation (ATO) systems, capable of performing various functions of control and autonomous train driving [2].

In this framework, we designed and realized a 10-layer dedicated printed circuit board (PCB) of a Vital Control Board (VCB) that interfaces and monitors most of the cabin subsystems, computes their responses and acts to preserve the overall system safety.

In particular, the VCB embeds a heterogeneous computing system on module (SoM), the AES-ZU3EG by AVNET® based on the Zynq Ultrascale+ of Xilinx, as central computation kernel. It also embeds a set of widely used communication protocols (SPI, CAN, RS-485, RS-422 and Ethernet) to interface all those subsystems, included in the cabin equipment, favoring the easy VCB inclusion in most of the already existing cabin equipment. The VCB also provides a piggyback slot directly connected to the programmable logic (PL) of the Zynq Ultrascale+. The layout of this piggyback slot has been carried out to allow the independent housing of two different communication boards: a NETX-based piggyback for Profibus communication, and a continuous signals repetition (RSC) oriented piggyback. This multi-piggyback design also shares the DB-15 connector interface for external operations.

Noteworthy, all the above-reported functionalities (high-performance computation via Zynq Ultrascale+, different communication interfaces, digital I/O) have been condensed in a single Eurocard board template (100 mm x 220 mm) with a height of only 4 horizontal pitches, while ensuring the full respect of the electrical safety guidelines (i.e., EN-50124 [3]) for railway electronic equipment.

To improve the fault detection, the VCB has been also provided with three main diagnostic connectors: (1) the power management diagnostic via dedicated PMBus, (2) a Lauterbach tracing connector for debugging and diagnostic over the Zynq Ultrascale+ device, (3) a 6 pin-header for the Zynq Ultrascale+ temperature and current monitoring.

References

[1] M. Ďuračík, E. Kršák, M. Meško and J. Ružbarský, Software architecture of Automatic Train Operation, 2019 IEEE 15th International Scientific Conference on Informatics, 2019, pp. 000051-000054.

[2] J. Hwang and H. Jo, RAMS management and assessment of railway signaling system through RAM and safety activities, 2008 International Conference on Control, Automation and Systems, 2008, pp. 892-895.

[3] CEI EN 50124- RAILWAY APPLICATIONS - INSULATION COORDINATION.