Hitachi Rail Signaling and Transportation Systems (STS) has selected AdaCore’s GNAT Pro Ada development environment targeting ARM processors for the modernization of its calculator of available safety (CSD) rail safety platform to ensure the safe circulation of trains on railway lines and metro networks.
Technical challenges of modernization
In March 2017, Hitachi Rail STS rolled out the interlocking management system of the Gare de Lyon in Paris as part of a renovation project commissioned by the French national rail company SNCF. The system, supported by a single safety platform, commands 170 switches, 115 light signals and 800 routes at any time and simultaneously, and thus requires a secure, reliable platform.
In 2018, facing the problem of obsolete equipment and the need for ever greater computing power, Hitachi Rail STS decided to further modernize its safety platform with the ambitious goal of developing a single platform that is also compatible with the constraints of rolling stock and ground signaling.
The first targets were the renovation of the metro lines in the city of Brussels with a Communication Based Train Control (CBTC) system, and the renovation of the interlocking systems of the first 280-mile high-speed rail line in France between Paris and Lyon.
HITACHI Rail STS identified two key areas of focus in order to achieve its goal:
- Conduct logic synthesis on the 68K CPU in order to house the voter function of the CSD in the processing system part of this component, thus making it possible to reuse the coded mono-processor production chain of the existing voter software.
- Port the existing application software, developed in Ada 95, to an ARM Cortex-A53 processor in the programmable logic part.
Choosing AdaCore’s solutions
The constraints imposed by porting the application software to an ARM processor led Hitachi Rail STS to contact AdaCore for possible solutions, including the choice of an Ada runtime and compiler targeted to ARM.
Hitachi Rail STS chose AdaCore's Linux-hosted GNAT Pro Ada development environment, combined with a Ravenscar SFP runtime, based on several factors:
- The possibility of certifying the runtime according to the railway standard EN 50128;
- Access to a POSIX/Linux development environment that, when combined with Ada compilation tools, offers easy implementation of binary generation processes;
- The possibility of reusing Linux tools; and
- Access to various AdaCore tools, including GNATcheck for coding standard application and verification including complexity metrics, and GNATemulator, making it possible to emulate an ARMv8 processor on a host system.
The new safety platform for the Wayside and On-Board projects
Development of this platform began in 2017 with the design of a new circuit board. The porting of the CSD software components came next, along with risk analysis and validation.
The current goal of Hitachi Rail STS is to obtain EN 50128 certification for this new platform by the end of 2020. Going forward, it will be the universal safety platform for use on all Hitachi Rail STS’s “Wayside” and “On-Board” projects.
