The Train Control and Monitoring System (TCMS) is the brain and the communications backbone of the train, which has some essential roles on vehicle performance. It integrates and manages all on-board information; it makes train control decisions taking into account the global state of subsystems; it performs communication between equipment, between cars and between vehicles; and it integrates and interacts between different subsystems of the train.
Current practice in industry involves a standard physical TCMS network for train control functions and an additional network (often based on Ethernet) for other functions. This means a considerable amount of on-board cables and therefore weight and complexity. To make matters worse, current TCMS solutions only attain safety levels (SIL 2) which are not sufficient to allow the removal of train safety lines (i.e. more cabling) in place of pure data transmission through the communication buses due to their safe critical mission (SIL 4).
Today coupled trains have become an important bottleneck in terms of performance. Transmission through the auto-coupler is notably impaired by the contact nature and the performance of ETB is much lower. Wireless communications are already a reality, but there are no on-board applications in railways (except internet connection for passengers). As it stands, many uncertainties concerning technology, safety and security block any attempt to use them.
Even when communication is possible, often applications on each side of the coupling are incompatible due to different implementations, versions, or retrofitting states. Self-configuring adaptive solutions providing plug-and-play features through a functional open coupling may solve this issue.
Moreover, the safety braking related functions (safety brake, safety brake weighing) are still assigned to traditional pneumatic subsystems, components and piping. This implies that all safety related braking functions, due to intrinsic inaccuracy and to temperature and ageing related drifts, do not benefit from the typical accuracy of electronic controls. The fully electronic controlled brake system opens the possibility to optimize the blending between different brake subsystems easily as well as to handle fast changing adhesion conditions effectively. The result would be not only a better braking performance additionally an increasing of safety on train level could be reached by using adhesion independent brake.
CONNECTA aims at contributing to the Shift2Rail’s next generation of TCMS architectures and components with wireless capabilities as well as to the next generation of electronic braking systems. CONNECTA is conducting research into new technological concepts, standard specifications and architectures for train control and monitoring, with specific applications in train-to-ground communications and high safety electronic control of brakes.
The specific actions being undertaken within the scope of CONNECTA and contributing to the Shift2Rail’s Multi-Annual Action Plan on TD1.2 and TD1.5 are:
• To develop the general specifications of next generation TCMS and to generate the corresponding high level system architecture;
• To incorporate wireless technologies to train communication network solutions;
• To provide a train-wide communication network for full TCMS support including the replacement of train lines, connecting safety functions up to SIL4 and support of “fail-safe” and “fail-tolerant” principles, as well as communication mean for non-TCMS functions;
• To standardise functional interfaces of functions and sub systems as well as to define a generic functional architecture for the next TCMS generation;
• To facilitate the coupling of two or more consists supplied by different manufacturers and which could have different train functions;
• To develop a simulation framework in which all subsystems of the train can be simulated, allowing remote and distributed testing including hardware in-the-loop through heterogeneous communication networks;
• To achieve a performance improvement in safety relevant braking functions resulting in optimisation of the braking distances in safety braking;
• To optimise onboard systems by reducing the number of sophisticated pneumatic components and improving the overall LCC;
• To validate non-railway EN standards for use in safety-related railway applications.
