The November issue of Rail Engineer (issue 179) covered the Network Rail
long-term deployment plan for ETCS (European Train Control System).
ETCS, however, is only part of the overall digital railway programme, with the other parts including: traffic management (TM) to manage the flow of trains across the network, automatic train operation (ATO) to control a train’s traction and braking systems, telecom networks to provide the backbone to transfer data between the digital systems, and a connected driver advisory system (C-DAS) to support drivers with the delivery of operational performance and energy efficiency. While full ETCS will take many years to provide, other components in the programme are available now and are delivering results today. This includes C-DAS, which is being provided by KeTech Systems.
As the full Network Rail TM system will not be deployed for many years, the approach taken by KeTech is to utilise signalling and other data sources in order to provide a C-DAS that is truly connected to the underlying infrastructure – this is a key differentiator in the industry. A driver advisory system (DAS) is an on-board processor-based system that provides a driver with information to achieve the timetable sustainably, by regulating the speed profile and avoiding unnecessary braking. Standalone DAS (S-DAS) has data downloaded to the train at the start of its journey, but connected DAS (C-DAS) is enhanced with a communications link to provide realtime updates of information to the train, including processed signalling and Darwin information along with other information such as temporary speed restrictions. Darwin is the rail industry’s official train-running information engine, providing real-time arrival and departure predictions, platform numbers, delay estimates, schedule changes and cancellations. C-DAS is what it ‘says on the tin’ – it only ‘advises’ a driver, so the system does not require a high safety integrity in terms of signalling design and asset management. Safety is ensured by the trains normal onboard control and braking system together with the line side signalling system.
This allows more cost effective C-DAS solutions to be quickly rolled out compared to other safety critical components in the digital railway programme. C-DAS calculates and displays to the driver an energy-efficient speed profile to enable the train to meet the timetable, taking into account timing points, line speeds, including speed restrictions, and the train’s characteristics and capabilities. The advisory information helps the driver to achieve the timetable and monitors the train’s progress towards the next timing point to identify any changes required to the speed profile. This is complemented by a suite of reporting facilities. If the train is behind time and if the line and train speed limits are capable of a higher speed, then this will be advised to a driver, or, if the train is running early, a more efficient speed profile can be advised, both to save energy and wear and tear of the train. C-DAS also helps to ensure a train arrives at any junction in time to avoid timetable conflicts with other trains, and it can avoid the need to brake at adverse signals, therefore reducing the risk of signals passed at danger.
The information is provided to the driver through a user-friendly driver machine interface (DMI). In the case of the C-DAS project currently being rolled out by KeTech, this is via the driver’s updated DMI.
Modular and adaptable
KeTech Systems is based in the UK and has a long history of providing both station and train-borne innovative, high quality and highly reliable real-time information systems. Its products are scalable and modular, ensuring that they can be tailored to the varying needs of clients. KeTech has experienced, industry expert designers and engineers available to provide innovative solutions to bespoke railway industry requirements for software, electronics and system design. Its C-DAS solution is a natural evolution of KeTech’s unique real-time Universal Information System (UIS), platform which forms the foundation of all their real-time information solutions. KeTech was first involved in providing railway station customer information systems (CIS). Originally, these were standalone systems, but, over time, KeTech enhanced their CIS product with real-time data inputs from operational signalling train describers in order to provide accurate train positioning information. When a train leaves a platform, it is important that the display is cleared before the next train enters the platform. KeTech has therefore years of experience with designing systems with the appropriate low-latency requirement. For many years, KeTech has also been involved in providing onboard train passenger information systems (a mixture of software and hardware as required) for various train operators. This required systems to be designed to accommodate challenging levels of electromagnetic compatibility (EMC), vibration and power supply variables from a wide range of rolling stock deployed on the network, with minimum space for equipment.
As a result, KeTech has proven experience in the design and delivery of real-time railway systems linked to operational signalling equipment, together with on board systems involving train driver ergonomics and a safety integrity level. To date, KeTech has real-time information systems deployed with over 50 percent of UK Train Operators – a mixture on and off train systems. All these systems have to work reliably in the harsh EMC and challenging environmental envelopes. KeTech is therefore ideally placed to design a reliable user-friendly C-DAS system. Approached to provide a C-DAS system for Siemens’ Class 350 trains, KeTech designed and developed a system that is now being deployed in several subclasses of the Class 350 fleet and is currently operating in ‘shadow mode’ to gather/verify data – it is expected to ‘go live’ early in 2020. KeTech has designed the system to use an updated version of the current driver’s DMI, but a larger graphical, intuitive and standalone DMI has also been designed for possible use in other classes of train. The important point is it’s the same flexible C-DAS system that can be tailored to meet the requirements of any train operator or rolling stock fleet. All the KeTech systems are designed in-house within the UK, allowing complete control of all the specialist designs, both for hardware and software.
The communications link is provided by public LTE telecoms networks. This allows a much higher data bandwidth than that currently available via GSM-R. KeTech’s C-DAS intelligently manages communications connectivity and is able to fallback gracefully to S-DAS mode in the event of comms loss. KeTech believes its C-DAS will deliver the ‘gold standard driving reference’ that train drivers can rely on. It is the first, and only, situationally aware system capable of dynamically informing train drivers of critical changes on the route ahead of a train. The user-friendly DMI display presents important and useful information, such as route position, optimal speed, and coasting. Any significant events on the track will automatically be passed on to the driver in real-time. The intuitive system intelligently interprets the data and dynamically updates the advice on the drivers DMI.
With the capability to be completely connected to the whole rail network, KeTech’s C-DAS intelligently updates drivers and provides advice to facilitate a smoother journey, greater efficiency and significant energy savings. Unlike other C-DAS products, KeTech’s C-DAS does not just rely on Global Navigation Satellite System (GNSS) receivers, but has access to many other sources of positional and real-time information including signalling data and the train management system (TMS) – a train-borne distributed control information system, which uses data such as wheel rotation counting to ensure a reliable and accurate location information feed. KeTech’s C-DAS uses signalling (train describer) data to identify when a train has been changed from its planned route and reforecasts the revised route that the train will be taking, adjusting the route profile automatically. GNSS systems, such as the Global Positioning System (GPS), have many benefits for rail, but, for them to work reliably, there needs to be clear ‘line of sight’ from trains to satellites, and trains may be hidden by bridges, tunnels, cuttings and when traveling on sub-surface lines.
GNSS alone will not have adequate resolution to determine which line a train is on when several lines run parallel, and neither the infrastructure manager nor the train operator will have any control over the availability of the GNSS signal. Due to these limitations, KeTech uses GNSS as part of their fallback solution and not the prime source of positional information. As KeTech is also an electronics company used to designing SIL 2 (safety integrity level 2) systems, it has the capability to design any interfaces required to integrate with legacy train fleets, and its C-DAS bespoke design can be provided as a software or mixed technology solution. The flexible design is not limited just to the UK and it can be adapted for any infrastructure manager or train operator throughout the world. C-DAS, while delivering route and train status information to the driver with fuel efficiency and cost saving in mind, also facilitates passenger comfort and a smoother journey.
Passengers can get frustrated with experiencing a fast and potentially uncomfortable journey with hard braking, followed by waiting stationary outside a station for a platform to be available, even if the train still arrives at the platform on time. C-DAS provides a solution to this problem. So, KeTech’s C-DAS system is flexible and can be adapted to accommodate new and legacy train fleets. It is easy to operate and interpret, giving drivers peace of mind throughout their journey, while providing a better smoother journey for customers. Most importantly it’s here today and is part of the digital railway programme that can deliver results now, and not in several years’ time.
Published in Rail Engineer December Issue (180) 2019.