class #1: introduction to dynamical infrastructure systemsjerlynch/cee572/class01.pdf ·...

Class#1:IntroductiontoDynamicalInfrastructureSystems

JeromeP.Lynch,Ph.D.DepartmentofCivilandEnvironmentalEngineering

DepartmentofElectricalEngineeringandComputerScienceUniversityofMichigan

CEE572– DynamicalInfrastructureSystemsUniversityofMichigan

©2017

SystemsinCivilEngineering

9/4/17 Slide2©JeromeP.Lynch,2017

CharacterofInfrastructureSystems• Largephysicalsystemsofextremeeconomicimportance:

– Massivesystemsspanningoverlargegeographicalareas– Criticaltopublicsafetyandqualityoflife

• Oftendynamicwithatimebasistotheirbehavior:– Extremeloadsinducingmechanicalresponse– Injectionofcontaminationinsystem(e.g.,potabledrinkingwater)

• Havecomplexinteractions:– Infrastructure-to-infrastructureinteraction– Human-infrastructureinteraction– Builtenvironment-natureinteractions– Cyber-physicalinteractions

9/4/17 Slide2©JeromeP.Lynch,2017

ChangeinPerspectivesHistoricalApproachtoCivilEngineeringEducation:

Component-basedDesign

Today’sApproachtoCivilEngineeringEducation:System-basedDesign

9/4/17 Slide2©JeromeP.Lynch,2017

EmergenceofSystemicFailureThereisanurgentneedtostudythe

interconnectednessofcivilianinfrastructuretopreventsystemicfailureofkeysocietalsystems.

9/4/17 Slide2©JeromeP.Lynch,2017

Mega-scaleDisastersFailureofleveesduringHurricaneKatrina(2005)

TsunamiinducedfailureofchilledwatercoolingsysteminFukushimareactors(2011)

9/4/17 Slide2©JeromeP.Lynch,2017

TechnologyTrendsDriving“Systems”

Microelectromechanical Systems(MEMS)(Source:AnalogDevices)

Internet(Source:Wikipedia)

Moore’sLawforProcessorsandMemory(Source:Intel)

Edholm’s LawforWirelessCommunications(Source:Chema etal.2010)

9/4/17 Slide2©JeromeP.Lynch,2017

Cyber-PhysicalSystems• Cyber-physicalsystems(CPS):

– Coordinatedcombinationofsensing,computingandactuation– Integrationofembeddedcomputing,wirelesscommunicationand

low-costsensingallowstheworldtobedenselysensedandcontrolled– AvailabilityofwirelessInternetgivesfield-basedsensors/actuators

increasingaccesstocomputingresources

Cyber-physicalSystem(CPS)Framework

PhysicalSystem(Infrastructure)

ComputingSystems(Cyberinfrastructure +Computing)

Sensors/MonitoringSystems

Actuators/ControlSystems

EarlyEarthquakeWarningSystems(Source:NIPPONIA)

IntelligentTransportationSystems(Source:UniversityofMichigan)

9/4/17 Slide2©JeromeP.Lynch,2017

SystemsEducationinCEE• EmergenceofsystemsinUM’scivilengineeringcurriculum:

– CEE571:LinearSystemTheory:• Cross-listedCollegewide• Foundationalcourseteachingwellestablishedlinearsystemtheory.Canbeviewedasan“applied”linearalgebracoursegiventheheavyconcentrationonvectorandmatrixmathematicaltools.

– CEE572:DynamicalInfrastructureSystems:• Introductorycourseprovidingacoresetoftoolsandtechniquesrequiredforstudentsstudyingthedynamicsofinfrastructuresystems

• Notspecifictoanyonedomain– rather,examplesdrawnfrommanyapplicationareas(structures,hydraulics,transportation,etc.)

• Surveycourseofmanysystemmodelingconcepts• IntendedtomakeupforpotentialdeficienciesinUGpreparations• Afterthecoursecompletion,studentsarebetterpositionedtotakeadvancedsystemcoursesacrosstheCollegeofEngineering

9/4/17 Slide2©JeromeP.Lynch,2017

WhatisaSystem?Asystemisanythingthatischaracterizedbyinputsandoutputs:

SYSTEMu y(inputquantity)

(outputquantity)

Mostoften,relationshipsbetweeninputs&outputsisdynamic:

tt

u(t) y(t)

Mostsystemshavememory:Presentoutputsdependonpreviousinputs:u(t) y(t)

ttT T

9/4/17 Slide2©JeromeP.Lynch,2017

DimensionalityofSystemsSomesimplesystemsarecharacterizedbyasingleinput-singleoutput(SISO):

systemu y(inputquantity)

(outputquantity)

systemu1 y1

y2y3u2

Mostsystemsarecharacterizedbymultipleinputs-multipleoutputs(MIMO):

9/4/17 Slide2©JeromeP.Lynch,2017

Example:Building(Structure)

buildingsystemu

(groundaccel.)

y1 =1ststorydisp

y2 =2ndstorydisp

y3 =3rdstorydisp

9/4/17 Slide2©JeromeP.Lynch,2017

Example:Bridges(Structure)

!

bridge/sensorsystem

u1 y1

un yptrafficloads,wind,earthquakes

sensoroutputs

9/4/17 Slide2©JeromeP.Lynch,2017

Example:WaveEnergy(Power)

waveenergybuoyarray

u1 y1

un ypwaveheightsgeneratorcurrents

buoydispsgeneratorvoltagespoweroutput

9/4/17 Slide2©JeromeP.Lynch,2017

Example:ElectricalGrid(Power)

powergrid

u1 y1

un yp

powerconsumedbythe37substations

velocitiesofthe10generators

9/4/17 Slide2©JeromeP.Lynch,2017

Example:WaterDistribution(Hydro)

waterdist.network

u1 y1

un yp

pumpstationsflow

pressuresatnetworkjunctions

9/4/17 Slide2©JeromeP.Lynch,2017

CascadingSystems• Compositesystemofsimplersystems:

– “Systemofsystems”isacommonphraseforcompositesystems– Strongrelationshipsbetweensubsystemsthatdefinetheproperties

andbehaviorofthecompositesystem– Canweobserveandcontroleachsubsystem?Ifnot,howdoesthat

effectouranalysis,modelingandcontrolofthecompositesystem?

sub-system

1

u1

u2 sub-system

2

sub-system

3

u3

y1

y2compositesystem

9/4/17 Slide2©JeromeP.Lynch,2017

FeedbackSystems• Feedbackisacommonmethodofconnectingsubsystems:

– Canbeexploitedto“control”thecompositesystem– Evenifallsubsystemsarestable,compositesystemmaybeunstable– Feedbackrequiresallsubsystemstobeconsideredatonce:

• Wecannotanalyzeordesigneachsubsysteminisolationbecausetheyallinteractwitheachother

sub-system

1

u1

u2 sub-system

2

sub-system

3

u3

y1

y2compositesystem

9/4/17 Slide2©JeromeP.Lynch,2017

NewCarquinezBridge• NewCarquinezBridge(Vallejo,CA):

– LocatedintheSanFranciscoBayArea– seismicallyactivearea– Totalbridgelengthis1056m(mainspanof728m)– Maindeckconsistsofsteelorthotropicboxgirders– Hollowconcretetowerlegsandpre-stressedlinkbeam

!

9/4/17 Slide2©JeromeP.Lynch,2017

SystemMonitoring

dynamicbridgemodel

sensordynamicmodels

groundaccel

windloads

trafficloads

criticalstructuralresponses

y1

yp

sensorstrains

sensorvoltages

estimatesfor y1....yp

v1

vq

z1

zp

computeralgorithm

Known: Modelsforbridge,sensorsubsystems,sensorvoltagesv1 ...vq

Find: Valuesofz1 ...zp whichareascloseaspossibletoy1 ...yp

...Thisiscalledsystemmonitoring

9/4/17 Slide2©JeromeP.Lynch,2017

SystemIdentification

dynamicbridgemodel

sensordynamicmodels

groundaccel

windloads

trafficloads

criticalstructuralresponses

y1

yp

sensorstrains

sensorvoltages

estimatesfor y1....yp

v1

vq

z1

zp

computeralgorithm

Known: sensoroutputsv1 ...vqloaddata

Find: Approximatemodelforbridgesystem...Thisiscalled

systemidentification

9/4/17 Slide2©JeromeP.Lynch,2017

HealthMonitoring

dynamicbridgemodel

sensordynamicmodels

groundaccel

windloads

trafficloads

criticalstructuralresponses

y1

yp

sensorstrains

sensorvoltages

estimatesfor y1....yp

v1

vq

z1

zp

computeralgorithm

Known: Modelsforbridge,sensorsubsystems,sensorvoltagesv1 ...vq

Find: Likelihood&locationofstructuraldamage

...Thisiscalleddamagedetection orhealthassessment

9/4/17 Slide2©JeromeP.Lynch,2017

SystemControl

dynamicbridgemodel

sensordynamicmodels

groundaccel

windloads

trafficloads

sensorstrains

sensorvoltages

estimatesfor y1....yp

v1

vq

z1

zp

computeralgorithm(controller)

Known: Modelsforbridge,sensorsubsystems,actuationsubsystem

Find: Mosteffectivecontrolforcetoapplyforreductionofundesiredresponse

...Thisiscalledfeedbackcontrol

actuationload

criticalstructuralresponses

y1

ypactuatordynamicmodels

9/4/17 Slide2©JeromeP.Lynch,2017

CourseContentofCEE572• Systemssciencewhichemphasizesmathematicalanalysis:

– Modelingofdynamicsystemsascontinuousanddiscrete-timesystems:• Linearandnonlinearmodels• Differentialequationsandstate-spacemodels• Stabilityandtypicalresponses

– Transformationmethodsfromtimetofrequencydomains:• Laplacetransform(Fourier)andZ-transform(discreteFourier)

• Systemsengineeringwhichemphasizesdesignandcontrol:– Systemidentificationofoperationaldynamicsystems– Feedbackcontrolofdynamicsystems

• Applications:– Structuraldynamics– Transportationnetworks– Hydraulicnetworks

9/4/17 Slide2©JeromeP.Lynch,2017