Graffica Ltd - HERMES Simulator

Our Network Rail verified high-fidelity simulator (HERMES) was a natural follow-on from the simulation expertise we gained in air traffic management. It provides us a great base to digitally explore rail challenges with our clients.

High-Fidelity

Our microscopic simulation focuses on accuracy. We model the physics of the railway in a high level of detail so that trains move around the network as they do in the real world. The physics engine performs simulations on a second by second basis, evaluating elements such as train acceleration characteristics, the gradient and track adhesion. Producing a simulation that is faithful to the real world involves more than modelling the physics of the train and environment.

Human Factors and Variation

Human drivers have varying levels of experience and different personalities. Passenger levels change and the passengers themselves behave in different ways. The trains and infrastructure elements experience varying failure rates. Weather extremes impact operational performance. These represent some of the most complex and interesting parts of the railway to analyse. HERMES accounts for these variable elements with wide-ranging configuration possibilities, pluggable components and comprehensive disruption pattern definitions.

Component Architecture

HERMES is built using a component architecture which allows different versions of a component to be used interchangeably. You can switch in a driver behaviour tuned to a specific route via OTMR data or one that reflects operation under ETCS. The components can be third-party systems too, so you could switch in a real traffic management system to assess what benefits it can have – or compare the operation of multiple such systems against each other.

Rapid Innovation

The HERMES simulator is designed with rapid innovation in mind. The component architecture and system design help us explore innovations to varying readiness levels without compromising the robustness of the overall system. Our collaborative and dynamic approach allows us to reach successful outcomes whilst navigating changing requirements and evolving understanding through projects. This is essential when exploring some innovations that are, by definition, not well understood at the outset.

Compatibility and Interoperability

We seek to create successful outcomes with solutions that achieve real benefits for the rail industry. Consequently, we are keen to work with, and help build standards for, long-term interoperability. As a pragmatic approach, we also seek compatibility and interoperability with existing systems so that benefits can be achieved in the immediate term. HERMES is compatible with many infrastructure and timetable datasets including RailSys, Network Rail open data feeds and SDEF. We have also worked with RailML and our scheme diagram reader helps convert diagrams into data models.

Network Rail Verified

Having designed a simulator to be faithful to the real world, it is reassuring to know that it has been assessed as such by a highly competent external organisation. Network Rail have performed a number of separate verification exercises under different scenarios and parameter sets. The verification results have indicated realistic performance and driver behaviour models along with accurate interlocking.

Features

Timetable Planning

Use a simple and fully integrated environment to support you through all your timetable planning needs. Start from an existing infrastructure and timetable using one of several supported import formats or even create a new timetable from specifications with UIC 406 compression options and more.

HERMES puts all the information you need at your fingertips. Providing both microscopic and macroscopic capabilities, you can balance accuracy with immediate results showing speed profiles and train graph details. Minimum headway and junction margin calculations are available, as is a blocking time graph overview of the network. Paired with our timetable analysis functionality, we provide a well-rounded solution to support all timetable activities.

Timetable Analysis

Planning and analysis go hand-in-hand with our integrated environment so it’s time to see if the timetable really works when exposed to real world factors that deviate from the perfect day. HERMES offers a flexible and comprehensive set of disruptions to affect any part of the journey. Disruption occurrences and duration can be based on different types of random distribution or entirely manually configured. Additionally, configuring options for factors such as track adhesion and driver behaviour help to change a perfect day simulation to any possible day. Monte-Carlo running easily allows many randomised simulations to be run at the click of a button.

Combining this analysis with innovative visual representations provides an understanding of how robust the timetable is, how delays are caused, propagate, and are ultimately recovered.

Design & Evaluate Signalling Systems

For designing signalling systems within the scope of currently deployed technology or exploring designs against evolving technologies, HERMES is an ideal partner. Our simple and intuitive design tool allows signalling design to be performed easily and to a level of detail that suits the user.

Full support for conventional signalling including AWS and TPWS as well as ETCS level 2, 3 (3.6.0 is our most recent implementation) and a moving block prototype. HERMES has some support for multi-national signalling systems. The impact of signalling systems is obviously modified by drivers, so our configurable driver behaviours allow the human element to be explored, including the impact of DAS and ATO systems.

Power and Energy Consumption

Trains do not run without power – or at least they shouldn’t. If your simulator doesn’t factor in the effects of power (or lack of it) then you’re missing part of the picture.

Our simulator works with third rail, overhead and diesel power and of course supports transitions between these power types. Our electrical power model includes sub stations, track paralleling huts, on board rectifiers, regenerative braking, and pantographs.

Are the power resources available to run the timetable? Do higher throughputs such as when recovering from disruptions result in degraded performance? Click here for the answers.

Traffic Management

You can’t run a rail network without traffic management. Traditionally this has been performed by signallers and controllers with the levels of computerised assistance continually increasing. HERMES allows varying types of intervention to reflect the real world and to allow different interventions to be assessed:

Manual dynamic rerouting following a disruption – Supports a training use case and shows this type of decision making in practise
HERMES ARS module – See the impact of Automatic Route Setting
HERMES TMS module
Interface with a third party operational TMS – It doesn’t get more real than the real thing

HERMES Simulator

Features

Timetable Planning

Timetable Analysis

Design & Evaluate Signalling Systems

Power and Energy Consumption

Traffic Management

Case studies

Digital Railway Outline Business Case

HERMES ETCS Modelling

HERMES and the ON-TIME Project

The Thameslink Programme

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