Between 2008 and 2011, the system for opening and closing platform screen doors (DOF product) developed by CLEARSY, allows the gradual automation of the Paris metro line 1 without interrupting traffic. This is a world first. Today CLEARSY is finalizing a new version of the DOF system which is being deployed by the RATP. More available, optimized for maintenance, DOF will control the platform edge doors of line 4 for at least four years.
In 2006, the PARIS subway (RATP) placed an order with CLEARSY – for line 1 of the Paris metro – for a system to open and close the platform screen doors. The system, the project, named DOF-1, must allow line 1 to operate normally during the transitional period preceding its full automation, while automatic trains are gradually being introduced. These are controlled by the new system including the function of opening and closing the platform edge doors. And in December 2012, the line was operated in full automatic mode. Regularity of trains, increase in rotations, passenger safety: for CLEARSY as well as for RATP, this is a success. And a world first, adds Cyrille Delon. For the first time, a line has been automated without interrupting traffic. Cyrille Delon is in charge of the “systems projects” activity at CLEARSY and is leading the development of the system that will accompany the automation of line 4 of the Paris metro. Its name: DOF-4.
The generic DOF architecture developed by CLEARSY for the DOF-1 project and used again for the DOF-4 project includes two antennas and two on-board computers per train, one computer and one 2-meter antenna on the track per station. A five-function system serving a single purpose: the security of passenger exchanges. With the exception of the door closing function, all the controls are at least SIL3 certified. Even more: the authorization of the right side of the train doors opening is a SIL4 function. It is there to prevent an opening on the track side. The security of the system is based on the ability of the equipment to communicate critical information in real time. The computers provide information on the status (opening/closing) of the platform doors, and the position of the antennas provides information on the position of the platform in relation to the direction of travel of the train, explains Cyrille Delon. The driver is in charge to open the dialogue with the train’s door opening control. As long as the platform doors are open, the train is not allowed to start (SIL3 function).
The renewal analysis carried out by CLEARSY has demonstrated the compliance of the historical system (2008) with the normative reference applicable today. It also guaranteed that the security level of DOF-4 was at least equivalent to that of DOF-1. The new system is therefore in line with the technological continuity of the first system. Consequently, the principle of independence of functions has been retained: it guarantees at least partial availability of the system. But the DOF-4 is more available overall. The software correction provided and validated (security impact study) by CLEARSY significantly reduces the frequency of untimely security failures, insists Cyrille Delon. At the request of its customer, CLEARSY has also equipped the DOF-4 with a supervision system interfaced with the ground computer. Its skills (temperature control and ECU operating data, identification and feedback of functions in fallback, etc.) optimize maintenance operations.
The DOF-4 is installed on all 76 trains and 29 stations on line 4. To date, 27 of the 29 stations on line 4 are in service. The deployment (RATP) will be completed in autumn 2021 with the Barbara and Bagneux-Lucie Aubrac stations, which extend line 4 and will be put into service at the end of 2021. The system will control 1062 platform doors for at least four years, until the line is fully automated.