Park Signalling Limited 17th May 2012

Park SignallingLimited

COTS Based Signalling Systems

Park Signalling Limited

17th May 2012

17/05/2012 1© Copyright 2012, Park Signalling Limited

Road Rail Technology Convergence

17/05/2012 © Copyright 2012, Park Signalling Limited 2

Contents

• Introduction

• What is a signal

• Types of signalling

• Signalling costs

• What is COTS

• COTS issues

• COTS Applications

• The business case for COTS

• VLS (COTS in the cab)

• The future

• Conclusions17/05/2012 © Copyright 2012, Park Signalling Limited 3

What is a signalling system?

• Permits the safe passage of trains

• Signalling resolves train movement conflicts

– interlocking of signals and points

– points deadlocking

– prevents multiple trains entering a block section


When it goes wrong (1) ....


When it goes wrong (2)


What is a railway signal?


A railway signal, as its name

suggests, is above all a

means of communication. Its

purpose is to convey to train

drivers the safety related

instructions of signallers.

• Information

• Geolocation

• Fail safe

Types of signalling

• Mechanical

• Electromechanical

• Electronic


Mechanical Signalling


//upload.wikimedia.org/wikipedia/commons/9/95/Wsh_signals.jpg

Electromechanical Signalling


Computer Based Interlocking


Cab Signalling


What is COTS?

Commercial Off The Shelf

• Generally available

• Made by more than one manufacturer

• LOW COST


COTS - The Cat’s Cradle (1)

• Cost - A£ARP , A$AP

• Obsolescence – ICT neo-antiquities

• Trust – What if it fails?

• Safety - Can it be part of a safe system?


COTS - The Cat’s Cradle (2)

• It is difficult to apply conventional safety techniques to COTS ICT

– Access to source code & design info. problematic

– Certification time may exceed product life

– Any patch or upgrade may require re-certification

– The cost of the above may negate all initial savings


Cost of White Goods


0

100

200

300

400

500

600

700

800

1 2 3 4 5 6 7

Series1

19751935 20051955


Using VLS

Untangling it all - Back to basics

• Information

– Resilience, Redundancy, Edit distance

• Encryption

– Integrity, Fail-safety, Information hiding

• Location

– Accuracy, Precision, Predictability


Information & Edit Distance


Enormous

High

Low

Info

rmat

ion

Co

mp

lexi

ty

17/05/2012

Encryption & Integrity

22© Copyright 2012, Park Signalling Limited

If sender encrypts OK.. ..then receiver is failsafe

Encryption & Information


Encrypt Decrypt

E(Keys) D(Keys)

Control Centre Train

Wireless IP Network

Where Keys include: Train ID, Transmission Time, Signal Location, etc.

Train Location

• Trains only run on railway track!

– Trains occupy sequences of track locations

– Physical balises exist at precise track locations

– Virtual balises may be derived from GPS/INS, etc.

• Must be constrained to physical track locations

• May trade-off precision (e.g. tile area) for reliability


Galileo

trace

GPS

trace

Putting it all together - VLS


Control Centre

Train

S1

Sighting Distance

RFID

Pre-Tag

RFID

Post-Tag

Section Marker

Board S1

Wireless

Mobile

Comms.

Encrypted

Signal

ImagesEncrypted

Waypoint

Reports

Notes 1. Patent applied for: WO/2010/139920. 2. For more information see: www.park-signalling.co.uk/vls.htm

VirtualLinesideSignalling 1, 2

17/05/2012

VLS in the field


Prototype VLS Control Panel Bogie mounted RFID reader

Foxfield Rly. - VLS stopboard

2.4GHz RFID tag in 4-foot

17/05/2012

VLS in the cab


Ruggedised laptop PC with GSM/3G ( also connected to an external RFID tag reader )

A typical ‘Proceed’ aspect

Prototype VLS cab demo at Foxfield Railway (Stoke, UK)

Conventional signalling vs VLS

Conventional

• Reliance on cable

• Vulnerable to failure and theft

• Expensive linesideequipment

• Costly maintenance

• Degraded visibility in poor weather

VLS

• No lineside cable

• No scrap value

• Inexpensive COTS equipment onboard

• Less to go wrong

• Negligible maintenance

• Images presented to driver in-cab


Key benefits

• Reduce reliance on copper for power and transmission in insulated cables (Network Rail challenge)

• Rapid deployment for emergency signalling (eg, after copper theft)

• Cost reduction over conventional linesidesignalling and current in-cab signalling solutions


Is VLS safe?

• A signal image’s meaning cannot be undetectably changed by in-cab failures. Image encryption adds another layer to this.

• Encryption against the train identity prevents meaningful image display on the wrong train.

• Encryption against a timecode prevents meaningful display of highly delayed images.

• Encryption against an RFID tag or balise ID ensures geolocation.


The sequence in which a railway train passes through

geographic locations is determined by the track and is thus

entirely predictable for a particular signalled route

The future of COTS

The development of COTS equipment will continue to speed up.

Approval timescales are of the same order of the life of the product.


Conclusion

• Use of COTS is possible

• Requires intelligent use of its strengths

• Commercial pressures will force costs down

• Requires a cultural change


And finally....


17/05/2012

Houldsworth Mill Business Centre

Houldsworth Street

Reddish

STOCKPORT

SK5 6DA

Tel: +44(0)161 975 6161

Fax: +44(0)161 975 6160

email: [email protected]

web site: www.park-signalling.co.uk

© Copyright 2012, Park Signalling Limited 34

Park SignallingLimited

Park Signalling Limited 17th May 2012

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