trains – railway vehicle and track system integration the manchester metropolitan university...

TRAINS – Railway Vehicle and TRACK System Integrationthe

MANCHESTER METROPOLITAN

UNIVERSITY



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System Models to Assess the Impact of Change

The IEE Railway System Modelling – Not Just for Fun SeminarThursday 30th September 2004

Clive RobertsLecturer in Railway Systems

University of [email protected]

www.eee.bham.ac.uk/robertc



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Background• Rail Vehicle and Track System Integration Project

is funded through the EPSRC Systems Integration Initiative

• A 3-year collaborative industry/academia research project (ending January 2005)

• Research split between University of Birmingham and Manchester Metropolitan University

• Multi-disciplinary team: Civil Engineers, Vehicle Dynamicists, Software Engineers, Metallurgists, Electrical Engineers



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Project Motivation• Many problems span several engineering

disciplines and can only be effectively tackled by understanding the system as a whole

• Systems engineering together with conceptual systems modelling allows problems to be investigated more effectively

• In particular the rail industry needs a means of investigating the effects of changes on the whole system, not just within individual subsystems or components



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Systems Engineering Process



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Project Work Packages• Requirements Elicitation – to understand what is

required• System Modelling – to map the relationships and

interconnections between components• Compositional Modelling – to build new models

from model fragments and infer knowledge• TOOLS Database – to provide details of existing

task specific tools and the links between them• Decision Support System



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Requirements Elicitation

• Initial part of the Systems Engineering process• Decomposition of the problem in order to further

understanding• Identify stakeholder and system level

requirements• Requirements modelling• Understanding existing practices (cost modelling,

wear modelling....)



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Scenarios• Physical System Relationships

C1 C2

{Relationships}

What effect does C1have on C2?

{F}={Maintenance}{Maintenance}={grinding, lubrication}

{P}={hardness, size}

{F}={Maintenance}{Maintenance}={grinding, lubrication}

{P}={hardness, size}



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Scenarios

• Model Identification (identification)– To provide the user with models/tools that may

aid with a particular problem

TOOLSDatabase

Keywords(e.g. grinding)

Relevant tools anddetails



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Scenarios

• Model Identification (data flow)– To provide a series of models/tools which when

joined together may solve a particular problem

TOOLSDatabase

Input/OutputKeyworks

(e.g. grinding/renewal)

Chain set ofmodelling toolslinking input to

output



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Scenarios

• Document Database– To provide the user with information relating to

all aspects of a particular component / process

DocumentationDatabase

Keywords(e.g. grinding)

Relevantdocumentationand references



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Scenarios

• Expert Identification– Provide details of experts in a particular field

WWWExpertDatabase

Specificquestionsfrom user



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• Forms the foundations of the decision support system knowledge base

• Hierarchical relationship model to show simple interactions between physical components (elements)

• Model elicited from domain experts• Provides a means of communicating about the

domain under consideration

System Modelling



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System Modelling

Power

Environment

1. VEHICLE

2. INFRA-STRUCTURE

Mechanical Interface

Power/Signals

Passenger Use

Environment

Power/Signals

Power on Board

HumanFactors

Training

Human Factors

Human Factors



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System Modelling Environment

2.2SIGNALLING

2.1 TRACKSYSTEM (incsubstructures)

2.3 POWERSUPPLY

(XFORMER)

2.4STATIONS

2.5STRUCTURES

Track Circuit Signal

Power/Signals

MechanicalInterface to

Vehicle

Current Return

Power

Track Force

Data(Train Position)

Xformer power



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Compositional Model• The core of the decision support system engine• Builds on the simple foundation of the hierarchical

system relationship model• Captures the systemic knowledge in an organised

way• System knowledge is represented in logical sets• Software algorithms are linked to model

fragments in order to compose a scenario model for a given scenario



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Compositional Model

Element Relationship Name Element

Dependent Variables

Decision Variables

Physical PropertiesPhysical Properties

Logical Model Assertions

Rules/Assumptions

Dependent Variables

Decision Variables



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Compositional Modelling Terminology

• Decision Variables - elements that change the model depending on the decision that is made by the user

• Physical Properties- properties that relate to the physical arrangement of the model element

• Dependent Variables - elements that are only relevant when some interaction occurs in the relationship. They can form limiting parameters for behaviour i.e. if X>Y then Z.



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TYREMechanicalInterface

RAIL

Mtyre,rail

Rtyre,rail

flange thicknessflange depthflange angletip radiusroot radiusmaterial properties - hardness (steelgrading)

- cleanliness (inclusions)- residual strain- residual stress

- micro-structure- resilient wheel

tread anglewheel diametersurface roughness

roundness - flatovality

material propertiesmetallurgywheel profileinertiaresidual stressresidual straintemperature (operational)

X,Y co-ordinatessurface contaminationguidance - attack angle,lateral position(relativegauge)force - tangential force,creepage, lateral,longitudinal, spin.operational defectscontact stresswheel wear - evenhollowness, discontinuoushollowness

surface roughnesspropertiesprofiletwistmaterial properties - hardness(steel grading)

- cleanliness(inclusions)

- residual strain- residual stress

- micro-structure- resilient wheel

gauge corner radiushead radiiinclinationlongitudinal profileradius (curvature)jointscantgradientgauge

surface_contaminationcleanliness (inclusions)temperature (operationaltemp)guidance (location)- attackangle, lateral position(relativegauge)force - normal,tangential,creepage, lateral,longitudinal, spinrail wear - side wear, headwearoperational defectsside lippingcontact stresscorrugationnoise

Wheel profile type {new, worn,hollow worn}Axle typeBraking positionTraction and brakingperformanceTraction typeTurning IntervalInspection frequencyBrake typeQuality of maintenance

Rail type {S&C, Curvature, Straight,Transitional}Tamping intervalGrinding intervalQuality of maintenanceRail profile type (manufacturer and year)Inspection frequencyStandards/intervention level (permissible variation)light rail, heavy railrail inclination



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Tools used in the Railway SystemTools used in the Railway System

InfrastructureInfrastructure VehicleVehicle

V - IInteraction

V - IInteraction WheelWheel

W – R Interaction

W – R Interaction

RailRail

SubstructureSubstructure ManagementManagement

EnvironmentEnvironment



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TOOLS Database



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VAMPIRE : Vehicle Dynamics Simulation Package

VAMPIREVAMPIRE

IntroductionIntroduction



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DescriptionDescription InputsInputs OutputsOutputs ContactContact CommentsComments



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Tools Inputs/OutputsInputs/Outputs

Materials data

Rail Plan Vehicle dataTraction Data

Tractive Effort & Speed

ADAMS

GENSYS

NUCARS

SIMPACK

VAMPIRE

Route data

Tools Database - Agreed Case Studies

Traction power/traction control on RCF – c2the


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Vehicle parameters, Track description

Track

Forces

ABAQUS

ANSYS

HyperMesh

I-DEAS

Pro/MECHANICA

Medina

nCode

RCF

Fatigue Analysis



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ADAMS

GENSYS

NUCARS

SIMPACK

VAMPIRE

Track

Forces

Rail PlanTraction Data Vehicle dataRoute data

RCF

the MANCHESTER

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Tools Inputs/OutputsInputs/Outputs

REFRAIL

Chalmers

WLRM

Tractive Effort & Speed

Vehicle parameters, Track description

Tools Database - Agreed Case Studies

Traction power/traction control on RCF – c3



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Decision Support System

• A decision support system to aid railway stakeholders to make decisions regarding system changes is being developed

• At the core of the DSS sits a hierarchical system relationship model which is used to compose models for a given scenario

• The user interface will be able to answer questions such as:– What affect does x have on y– What affect does changing x have ......



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DecisionSupportSystemEngine

Enquiry:f(text, option)

TOOLSDatabase

ExpertDatabase

RelationModel

DocumentDatabase

JIP Tool ChainSet Prog.

{mn}{I,O}

WWW

{mn,D}

Tool 1

{D}

{D}

Tool 2

{D}

WWW

JIP ToolRelationship

Prog.

{cn|cn,pn}{Rn}

{cn|cn,pn}

{Ln|Dn}

Decision Support System



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Conclusions and Further Work• The project aims to generate a reasoned

framework based on Systems Engineering Models and Principles to help railway engineers identify the affects of changes on the railway systems

• A prototype decision support system is being developed incorporating system modelling, composition modelling and the tools database

• Further work will be undertaken in a follow-on project to build economics into the models

trains – railway vehicle and track system integration the manchester metropolitan university...

Documents

iee railway system modelling

decision support system

vehicle dynamicists

particular problem slide

wear modelling

conceptual systems

engineering disciplines

civil engineers