ControlofMechatronicSystems
Model-DrivenDesignandImplementationGuidelines
PatrickO.J.Kaltjob
EcoleNationaleSuperieurePolytechnique Yaounde,Cameroun
Thiseditionfirstpublished2021
©2021PatrickO.J.Kaltjob
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LibraryofCongressCataloging-in-PublicationData
Names:Kaltjob,PatrickO.J.,author.
Title:Controlofmechatronicsystems:model-drivendesignand implementationguidelines/PatrickO.J.Kaltjob.
Description:Hoboken,NJ:JohnWiley&Sons,2020.|Includes bibliographicalreferencesandindex.
Identifiers:LCCN2018051541(print)|LCCN2019022413(ebook)|ISBN 9781119505808(hardcover)
Subjects:LCSH:Mechatronics.|Manufacturingprocesses.
Classification:LCCTJ163.12.K342019(print)|LCCTJ163.12(ebook)| DDC621–dc23
LCrecordavailableathttps://lccn.loc.gov/2018051541
LCebookrecordavailableathttps://lccn.loc.gov/2019022413
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Contents
Preface xiii
Acknowledgment xix
AbouttheCompanionWebsite xxi
1IntroductiontotheControlofMechatronicSystems 1
1.1Introduction 1
1.2DescriptionofMechatronicSystems 1
1.3GenericControlledMechatronicSystemandInstrumentationComponents 6
1.3.1TheDataProcessingandComputingUnit 6
1.3.2DataAcquisitionandTransmissionUnits 7
1.3.3Electrically-drivenActuatingUnits 7
1.3.4MeasuringandDetectingUnits 7
1.3.5SignalConditioningUnits 7
1.4FunctionsandExamplesofControlledMechatronicSystemsandProcesses 8
1.5ControllerDesignIntegrationStepsandImplementationStrategies 9 ExercisesandProblems 16 Bibliography 26
2Physics-BasedSystemsandProcesses:DynamicsModeling 27
2.1Introduction 27
2.2GenericDynamicModelingMethodology 27
2.3TransportationSystemsandProcesses 28
2.3.1SeaGantryCraneHandlingProcess 28
2.3.1.1Model1 33
2.3.1.2Model2 33
2.3.2VerticalElevatorSystem 35
2.3.3HybridVehiclePowertrainwithParallelConfiguration 38
2.3.3.1MotorDrivingandRegeneratingModel 40
2.3.3.2VehicleGearBoxModel 41
2.3.3.3BrakeSystemModel 41
2.3.4DriverlessVehicleLongitudinalDynamics 42
2.3.5AutomatedSegwayTransportationSystems 45
2.4BiomedicalSystemsandProcesses 47
2.4.1InfantIncubator 47
2.4.2BloodGlucose-InsulinMetabolism 50
2.5FluidicandThermalSystemsandProcesses 53
2.5.1MixingTank 53
2.5.2PurifiedWaterDistributionProcess 57
2.5.3ConveyorCakeOven 60
2.5.4PoultryScaldingandDefeatheringThermalProcess 64
2.6ChemicalProcesses 68
2.6.1CrudeOilDistillationPetrochemicalProcess 68
2.6.2LagerBeerFermentationTank 73
2.7ProductionSystemsandProcesses 75
2.7.1SingleAxisDrillingSystem 75
2.7.2Cement-BasedPozzolanaPortalScraper 78
2.7.3VariablePitchWindTurbineGeneratorSystem 81 ExercisesandProblems 84
Bibliography 102
3Discrete-TimeModelingandConversionMethods 105
3.1Introduction 105
3.2DigitalSignalProcessingPreliminaries 105
3.2.1DigitalSignalCharacterization 105
3.2.2DifferenceEquation:Discrete-TimeSignalCharacterizationUsingApproximation Methods 109
3.2.2.1NumericalApproximationUsingForwardDifference 109
3.2.2.2NumericalEquivalenceUsingBackwardDifference 110
3.2.2.3NumericalEquivalenceUsingBilinearTransform 110
3.2.3 Z -TransformandInverse Z -Transform:TheoremsandProperties 117
3.2.4ProcedureforDiscrete-TimeApproximationoftheContinuous ProcessModel 119
3.2.4.1 Z -TransferFunctionsandBlockDiagramManipulation 119
3.2.5ConversionandReconstructionoftheContinuousSignal:Samplingand HoldDevice 124
3.2.5.1SamplerandHold-BasedProcessModel 124
3.2.5.2ConstructionMethodsofaContinuousSignalfromaDataSequence 127
3.3SignalConditioning 135
3.4SignalConversionTechnology 137
3.4.1Digital-to-AnalogConversion 137
3.4.2Analog-to-DigitalConversion 140
3.5DataLoggingandProcessing 145
3.5.1ComputerBusStructureandApplications 145
3.6ComputerInterfaceandDataSamplingIssues 149
3.6.1SignalConversionTimeDelayEffects 155
3.6.1.1NyquistSamplingTheoremandShannon’sInterpolationFormula 156
3.6.2EstimationoftheMinimumSamplingRatetoBeSelected 157
3.6.2.1RemarksonSamplePeriods 160 ExercisesandProblems 161 Bibliography 168
4Discrete-TimeAnalysisMethods 169
4.1Introduction 169
4.2AnalysisToolsofDiscrete-TimeSystemsandProcesses 169
4.2.1DiscretePoleandZeroLocation 169
4.2.2DiscreteFrequencyAnalysisTools:FourierSeriesandTransform (DFT,DTFT,andFFT) 176
4.2.2.1DiscreteSystemFrequencyResponse 178
4.2.2.2SketchingProcedurefortheFrequencyResponseofaDiscreteSystem 179
4.2.2.3PropertiesofaFrequencyResponse 179
4.3Discrete-TimeControllerSpecifications 181
4.3.1TimeDomainSpecifications 182
4.3.2FrequencyResponseSpecifications 184
4.4Discrete-TimeSteady-StateErrorAnalysis 186
4.5StabilityTestforDiscrete-TimeSystems 187
4.5.1Bound-InputBound-Output(BIBO)StabilityDefinition 188
4.5.2Zero-InputStabilityDefinition 188
4.5.3BilinearTransformationandtheRouth–HurwitzCriterion 188
4.5.4Jury–MardenStabilityTest 190
4.5.5Frequency-BasedStabilityAnalysis 191
4.6PerformanceIndicesandSystemDynamicalAnalysis 191 ExercisesandProblems 192 Bibliography 194
5ContinuousDigitalControllerDesign 197
5.1Introduction 197
5.2DesignofControlAlgorithmsforContinuousSystemsandProcesses 197
5.2.1DirectDesignControllerAlgorithms 199
5.2.2DiscretePIDControllerAlgorithms 201
5.2.2.1ProportionalControlAlgorithm 201
5.2.2.2DerivativeControlAlgorithm 202
5.2.2.3IntegralControlAlgorithm 202
5.2.2.4PIControlAlgorithm 202
5.2.2.5PDControlAlgorithm 202
5.2.2.6ClassicalPIDControllerAlgorithm 202
5.2.2.7PropertiesofandSomeRemarksonPIDControllerAlgorithms 204
5.2.3PIDControllerGainsDesignUsingaFrequencyResponseTechnique 205
5.2.3.1DesignProcedureforPIDControllerDesign 205
5.2.4PIDControllerGainsDesignUsingaRootLocusTechnique 220
5.2.4.1DesignProcedures 221
5.2.5FeedforwardControlMethods 226
5.2.5.1CommandInputFeedforwardControlAlgorithm 226
5.2.5.2DisturbanceFeedforwardControlAlgorithm 234
5.3ModernControlTopologies 235
5.3.1StateFeedbackPIDControlAlgorithms 235
5.3.2MPCAlgorithms 246
5.3.3Open-LoopPositionControlUsingSteppingMotors 249
5.4InductionMotorControllerDesign 252
5.4.1ScalarControl(V/f Control) 252
5.4.1.1Open-LoopScalarControl 253
5.4.1.2Closed-LoopScalarControl(SlipControl) 253
5.4.2VectorControl 253
5.4.2.1DirectTorqueControl 254
5.4.2.2SpeedControlofACMotors 256
x Contents
5.4.2.3SpeedControlofDCMotors 257 ExercisesandProblems 259 Bibliography 281
6Boolean-BasedModelingandLogicControllerDesign 283
6.1Introduction 283
6.2GenericBoolean-BasedModelingMethodology 284
6.2.1SystemOperationDescriptionandFunctionalAnalysis 284
6.2.2CombinatorialandSequentialLogicSystems 288
6.2.2.1CombinationalModelingTools:TruthTable,SOP,ProductofSums(POS), K-Maps 289
6.2.2.2SequentialModelingTools:SequenceTable,SwitchingTheory,andState Diagram 290
6.3ProductionSystems 297
6.3.1PorticoScratcher 297
6.4BiomedicalSystems 299
6.4.1Robot-AssistedSurgery 299
6.4.2LaserSurgeryDevices 303
6.5TransportationSystems 307
6.5.1ElevatorMotionSystems 307
6.5.2Fruit-PickerArm 311
6.5.3DriverlessCar 313
6.6Fail-SafeDesignandInterlockIssues 317
6.6.1LogicControlValidation(Commissioning) 317 ExercisesandProblems 318 Bibliography 336
7HybridControllerDesign 337
7.1Introduction 337
7.2RequirementsforMonitoringandControlofHybridSystems 337
7.2.1RequirementsforHybridControlSystemDesign 338
7.2.2RequirementsforOperationsMonitoringSystemDesign 338
7.2.3ProcessInterlockDesignRequirements 339
7.3DesignMethodologyforMonitoringandControlSystems 340
7.4ExamplesofHybridControlandCaseStudies 347
7.4.1ElevatorMotionSystem 347
7.4.2Bottle-CleaningProcess 350
7.4.3Cement-DryingProcess 352 ExercisesandProblems 362 Bibliography 375
8MechatronicsInstrumentation:ActuatorsandSensors 377
8.1Introduction 377
8.2ActuatorsinMechatronics 378
8.3ElectromechanicalActuatingSystems 379
8.3.1Solenoids 379
8.3.2DigitalBinaryActuators 381
8.3.3DCMotors 382
8.3.4ACMotors 387
8.3.5SteppingMotors 389
8.3.6TransmissionMechanicalVariables 390
8.4Electro-FluidicActuatingSystems 393
8.4.1ElectricMotorizedPumps 393
8.4.2Electric-DrivenCylinders 395
8.4.3Electrovalves 396
8.5ElectrothermalActuatingSystems 398
8.6SensorsinMechatronics 400
8.6.1MeasurementInstruments 402
8.6.1.1RelativePosition(Distance) 402
8.6.1.2AngularPositionMeasurementUsinganEncoderandaResolver 409
8.6.1.3VelocityMeasurement 412
8.6.1.4AccelerationMeasurement 414
8.6.1.5ForceMeasurement 416
8.6.1.6TorqueMeasurement 417
8.6.1.7FlowMeasurement 417
8.6.1.8PressureMeasurement 419
8.6.1.9Liquid-LevelMeasurement 420
8.6.1.10RadioFrequency-BasedLevelMeasurement 422
8.6.1.11SmartandNanoSensors 422
8.6.2DetectionInstruments 423
8.6.2.1ElectromechanicalLimitSwitches 424
8.6.2.2PhotoelectricSensors 424
8.6.2.3RFID-BasedTrackingandDetection 424
8.6.2.4BinaryDevices:PressureSwitchesandVacuumSwitches 426 ExercisesandProblems 426 Bibliography 434
AStochasticModeling 437
A.1DiscreteProcessModelState-SpaceForm 437
A.2Auto-RegressiveModelwithaneXogenousInput:ARXModelStructure 438
A.3TheAuto-RegressiveModel–ARModelStructure 438
A.4TheMovingAverageModel–MAModelStructure 438
A.5TheAuto-RegressiveMovingAverageModel–ARMAModelStructure 439
A.6TheAuto-RegressiveMovingAveragewitheXogenous InputModel–ARMAXModelStructure 439
A.7SelectionofModelOrderandDelay 439
A.8ParameterEstimationMethods 440
A.9LSEstimationMethods 442
A.10RLSEstimationMethods 443
A.11ModelValidation 443
A.12PredictionErrorAnalysisMethods 444
A.13EstimationofConfidenceIntervalsforParameters 444
A.14CheckingforI/OConsistencyforDifferentModels 445
BStepResponseModeling 447
C Z -TransformTables 451
DBooleanAlgebra,BusDrivers,andLogicGates 455
D.1SomeLogicGates,Flip-Flops,andDrivers 455
D.2OtherLogicDevices:DriversandBusDrivers 457
D.3Gated R S Latch 459
D.4D-Type(Delay-Flip-Flop) 459
D.5RegisterorBuffer 461
D.6Adder 461
ESolid-StateDevicesandPowerElectronics 463
E.1PowerDiodes 463
E.2Diode–TransistorLogic(DTL) 464
E.3PowerTransistors 465
E.4Resistor–TransistorLogic(RTL) 465
E.5Transistor–TransistorLogic(TTL) 466
E.6MetalOxideSemiconductorFET(MOSFET) 466
E.7Thyristors 467
Index 469
Preface
Thecontrolofmechatronicsystemsandelectrical-drivenprocessesaimstoprovidetools toensuretheiroperatingperformanceintermsofproductivity,optimization,reliability, safety,continuousoperations,andevenstability.Thisisusuallyachievedthroughhybrid controlparadigmsusingdigitaloranalogtools.Nowadays,digitaltoolsarewidelyusedto implementcontrolsystems,astheyoffernumerousadvantagesincludingtheirability:(i)to easecontrol-systemimplementation;(ii)todesigncomplexandbuilt-inintelligentinformation processingcombiningmultiplefunctionsforcontrol,faultdetectionanddiagnostic,monitoring,anddecisionplanning;(iii)tointegratelogicandcontinuouscontrolalgorithms,aswell assupervisionprograms,intohybridcontrolstrategies;(iv)toenhancethesynchronization ofinputandoutputprocessoperations;(v)tocoordinatecontrolactionsamonggeographicallydistributedsystemsandprocesses;and(vi)toachievereliableandoptimaloperating conditions.
Thedigitalcontrolsystemarchitectureusuallyconsistsoftheintegrationofthefollowing functionalunits:adata-processingandcomputingunit,anelectrical-drivenactuatingunit,a measuringanddetectingunit,adataacquisition(DAQ)andtransmittingunit,andasignalconditioningunit.Thedata-processingandcomputingunitcanbeimplementedthroughdevices suchasamicrocontroller(μC),aprogrammablelogiccontroller(PLC)withacontrolfunction, adigitalsignalprocessing(DSP)unit,andafield-programmablegatearray(FPGA).
Thedesignofefficientcontrolsystemsrequiresthemathematicalmodelingofmechatronic systemsandprocessdynamics.Thiscanbeachievedinaccordancewiththeoperatingcharacteristics(discreteandcontinuous)andobjectives,aswellasthetechnologicalconstraints, oftherelatedinstrumentation(signalconversion,transmission,conditioning,measurement, actuation,etc.).However,inmostofthecurrentengineeringliteratureonthedesignofdigitalcontrolsystems,themathematicalfoundationofdiscrete-timeanddiscrete-eventsystemsis usuallypresentedseparatelyfromthetechnologicalconstraintsofcontrolinstrumentation.For example,theoperatingtime-delaymodelsandsignal-to-noiseratiosofdigitaldeviceinterfaces arenotusuallyconsidered.Hence,thetheoreticalcontrolalgorithmsproposedhavelimited practicalapplicability.
Challengesinthedevelopmentofapracticaldesignapproachforthecontrolofmechatronic systemsandelectrical-drivenprocessesare:(i)tosizeandselectcontrolinstrumentationin accordancewithcontrolledsystemdesignobjectives;(ii)todevelopaccordinglythemathematicaldiscretehybridmodelcapturingtheircontinuousanddiscreteeventbehavioristiccharacteristics;and(iii)tointegratethecontrolsystemswithrespecttotechnologicalconstraints andoperationalcharacterization(discreteandcontinuous)(e.g.timedelays,signal-to-noise ratios,etc.).
Thisbookintendstorevisitthedesignconceptforthecontrolofmechatronicsystems andelectrical-drivenprocesses,alongwiththeselectionofcontrolinstrumentation.By
reviewingthetheoryondiscrete-timeanddiscrete-eventsystems,aswellasvariouselements ofcontrolinstrumentation,itoffersanintegratedapproachfor:(i)themodelingandanalysis ofmechatronicsystemsdynamicsandelectrical-drivenprocessoperations;(ii)theselectionof actuating,sensing,andconversiondevices;and(iii)thedesignofvariouscontrollersforsingletomultiple-functionelectrical-drivenproducts(mechatronicsystems)andprocesses.Furthermore,itcoverssomedesignapplicationsfromseveralengineeringdisciplines(mechanical, manufacturing,chemical,electrical,computer,biomedical)throughreal-lifedigitalcontrol systemdesignproblems(e.g.driverlessvehicles,newbornincubators,elevatormotion)and industrialprocesscontrolcasestudies(e.g.powergrids,windgenerators,crudeoildistillation, brewerybottlefilling,beerfermentation).
Throughthisbook,thereadershouldgainmethodsfor:(i)modelformulation,analysis,andauditingofsingle-tomultiple-functionelectrical-drivenproductsandprocesses; (ii)model-drivendesignofthesoftwareandhardwarerequiredfordigitalcontrolinstrumentation;(iii)sizingandselectionofelectrical-drivenactuatingsystems(includingelectric motors),alongwiththeircommonlyusedelectro-transmissionelementsandbinaryactuators; (iv)selectionandcalibrationofdevicesforprocessvariablemeasurementandcomputer interfaces;and(v)modeling,operating,andintegratingawidevarietyofsensorsandactuators. Hence,thetextbookisorganizedintoeightchapters:
1) IntroductiontotheControlofMechatronicSystems.Chapter1givesabriefconceptualdefinitionandclassificationofmechatronicsystems,electrical-driventechnicalprocesses,and controlsystemsstructure.Here,afunctionaldecompositionofthegenericcontrolsystem architectureispresented,alongwithsomeexamplestoillustratecontrolinstrumentation forsensing,actuating,computing,signalconverting,andconditioning.Furthermore,typicalfunctionsofgenericcontrolledsystemsforelectromechanicalproductsandprocesses aredescribed,alongwiththeinterconnectionbetweenthecontrolinstrumentationelements.Genericrequirementsforcontrolsystemdesignareoutlinedbasedonchallengesto software-based(designofhybridarchitecture)andhardware-based(instrumentationsizing,compliance,andselection)controlsystemintegration.Thisissummarizedwithinalist ofthemajorstepsincontroldesignprojects.
2) Physics-BasedSystemsandProcesses:DynamicsModeling .Chapter2presentsnumerous examplesofdynamicsmodelingforvariouselectrical-drivensystemsandprocesses,includingtransportationsystems(e.g.asea-portgantrycrane,ahybridvehicle,aSegway,an elevator,adriverlesscar),productionsystemsandprocesses(e.g.anenergy-basedwind turbine,adrillingmachine,acement-basedpozzolanascratcher),chemicalprocesses(e.g. oildistillation,acakeconveyoroven,citywatertreatment,fermentation,poultryscalding anddefeathering),fluidicandthermalsystemsandprocesses(amixingtank,purifiedwater distribution,aconveyoroven,poultryscaldinganddefeatheringthermalprocesses),and biomedicalsystems(e.g.aninfantincubator,humanbloodglucoseinsulinmetabolism). Systemsandprocessbehaviorscanbecapturedthroughdifferentialequationsusingan experimentaldatamodelingapproachandclassicalphysicallawsofconservationandcontinuity.Theresultingmodelsarecapableofdisplayingmultipleandnonlinearvariablesas wellastime-variantparametercharacteristics,whichcanfurtherbesimplifiedaccordingto thesystemphysicalpropertiesoroperatingboundaries.Amethodologyforphysics-based modelingispresentedthroughthedeterministicorstochasticbehaviormodelsofcommonlyencounteredelectrical-drivensystemsandlarge-scaleprocesses.Areviewonlinear modelingmethodssuchasstochastics,dynamicsresponses,andstatespaceispresentedin theAppendices.
3) Discrete-TimeModelingandConversionMethods.Chapter3focusesonmethodsforderivingadiscreteapproximationofcontinuoussystemsandsignalsusingtoolssuchasthehold equivalent,pole-zeromapping,numericalintegration,and z-transformationtheorems.A technologicaldescriptionofcomputercontrolarchitectureandinterfaceisproposedwith respecttoDAQunitoperations,fromthebusstructuretodatagathering,logging,andprocessingwithrespecttosignalnoisereductionandapproximationconsideration.Critical issuesrelatedtosignalconversion,suchasaliasingeffects,alongwithamethodologyforthe selectionofasampleperiod,arealsocovered.Overall,thechaptertopicsincludetechnology andmethodsforcontinuoussignaldigitalconversionandreconstruction,suchasbilinear transformation,discrete-timecommandsequencegeneration,computercontrolinterface fordatalogging,conditioning,andprocessing,sampletimeselection,andcomputerconversiontechnologyusingvariousconversiontechniques(successiveapproximation,dual-slope ADC,delta-encodedADC,etc.),aswellasprocessingdelayeffects.
4) Discrete-TimeAnalysisMethods.Chapter4presentsmethodsrelatedtodiscretesystem dynamicalanalysisinthefrequencyandtimedomains.Moreover,stabilitydefinitions andtestsfordiscretetimesystemsarediscussedandcontrolledsystemperformance assessmenttoolsareoutlined.Thechapteraimstopresentdiscretecontrollerdesignspecifications.TopicsincludefrequencyanalysistoolssuchasDTFT,FFT,andDFT,discrete zero-andpole-locationplots,stabilitytestsandcriteriafordiscretetimesystems (Jury–Marden,Routh–Hurwitz),steady-stateerrors,performanceindices(ITAE,ISE),and timeandfrequencypropertiesforcontrollerdesign(settlingtime,percentageovershoot, gainandphasemargins).
5) ContinuousDigitalControllerDesign.Chapter5presentsvariousapproachestothedesign ofPIDcontrolleralgorithms,suchascontinuoustimedesign,discretedesign,directdesign usingrootslocus,andfrequency-responsetechniques,aswellassomeadvancedtechniques suchasmodelpredictivecontrol.Hence,usingtime-orfrequency-domaincontrollerspecifications,numerousexamplesofthedesignandtuningofcontrolalgorithmsaredescribed, rangingfromPIDfamily,deadbeat,feedforward,andcascadetonon-interactingcontrol algorithms.Inadditiontostabilityanalysistests,performanceindicesanddynamics responseanalysisarederivedinfrequencyandtimedomains.Furthermore,theopen-loop controllerdesignforsteppermotorsandscalarandvectorcontroldesignsforinduction motorsaredescribed.Modelpredictivecontrolalgorithmssuitableforprocessoperations withphysical,safety,andperformanceconstraintsarealsopresented.Comparativeanalyses betweenclassicalPIDcontrollerswithvariousstatefeedbacktopologiesforDCmotor speedcontrolareperformed.Overall,chaptertopicsincludecascadecontrol,designand tuningmethodsfordiscrete-timeclassicalPIDfamilycontrollers,andscalarandvector control.Thedigitalstatefeedbackcontrollerconceptisrevisitedforcaseswhereitis notpossibletomeasureallstatevariables.Comparatively,analysesbetweenclassicalPID controllersandvariousstatefeedbacktopologiesforDCmotorspeedcontrolarepresented.
6) Boolean-BasedModelingandLogicControllerDesign.Chapter6presentsBoolean function-basedmodelsthathavebeenderivedbyusingsequentialorcombinatoriallogic-basedtechniquestocapturetherelationshipbetweenthestateoutputsof discrete-eventsystemoperationsandthestateinputsoftheirtransitionconditions.Hence, afterperformingprocessdescriptionandfunctionalanalysis,adesignmethodologyofa logiccontrollerforprocessoperations(discreteeventsystems)isproposed.Subsequent systemsbehavioristicformalmodelingisachievedbyusingtechniquessuchastruthtables andK-maps,sequencetableanalysisandswitchingtheory,statediagrams(Mealyand Moore),andevenstatefunctioncharts.Someillustrativeexamplescoveringkeylogic
controllerdesignstepsarepresented,fromprocessschematicsandinvolvedI/Oequipment listings,wiringdiagramswithsomedesignstrategiessuchasfail-safedesign,andinterlocks, tostatetransitiontables,I/OBooleanfunctions,andtimingdiagrams.Examplesoflogic controllerdesignsincludecasesofelevatorverticaltransportation,anautomaticfruit picker,adriverlesscar,andbiomedicalsystemssuchasrobotsurgeryandlaser-based surgery.Overall,thechaptertopicscover:(i)themethodologyforBooleanalgebrabasedon themodelingofdiscreteeventsystems;and(ii)logiccontrollerdesignmethodologyforthe derivationofI/OBooleanfunctionsbasedontruthtablesandKarnaughmaps,switching theoryorstatediagrams,wiringandelectricaldiagrams,andP&IandPFdiagrams.
7) HybridProcessControllerDesign.Chapter7presentsagenericdesignandimplementation methodologyforprocessmonitoringandcontrolstrategies(logicandcontinuous),with algorithmstoensuretheoperationalsafetyofhybridsystems(i.e.systemsintegrating discrete-eventanddiscrete-timecharacteristics).First,thefunctionalandoperational processrequirementsareoutlined,inordertodefinehybridcontrolandsupervision systemswithrespecttologicandcontinuouscontrolsoftware,dataintegrationandprocess datagathering,andmulti-functionalprocessdataanalysisandreporting.Subsequently,a methodologyisproposedforthedesignofmonitoringandcontrolsystems.Somecases areusedtoillustratethedesignofprocessmonitoringandhybridcontrolforelevator motion,dryingcementpozzolana,andabrewerybottle-washingprocess.Overall,chapter topicsincludehybridcontrolsystemdesign,pipingandinstrumentationdiagrams,system operations,FASTandSADTdecompositionmethods,processstartandstopoperating modegraphicalanalysis,andasequentialfunctionalchart(SFC),aswellasprocessinterlock design.
8) MechatronicsInstrumentation:ActuatorsandSensors.Chapter8providesanoverviewof electrical-drivenactuatorsandsensorsencounteredinmechatronics,includingtheirtechnicalspecificationsandperformancerequirements.Thisiscoveredforelectromechanical actuatingsystemssuchaselectricmotorsaswellassomeelectrofluidicsandelectrothermalactuatingsystems.Similarly,binaryactuatorssuchaselectroactivepolymers, piezo-actuators,shapealloys,solenoids,andevennanodevicesaretechnicallydescribed andmodeled.Additionally,aspectrumofdigitalandanalogsensinganddetectingmethods aredescribed,alongwiththetechnicalcharacterizationandphysicaloperatingprinciples oftheinstrumentationcommonlyencounteredinmechatronicsystems.Presentedsensors includemotionsensors(position,distance,velocity,flow,andacceleration),forcesensors, pressureortorquesensors(contact-freeandcontact),temperaturesensorsanddetectors,proximitysensors,lightsensorsandsmartsensors,capacitiveproximity,pressure switchesandvacuumswitches,RFID-basedtrackingdevices,andelectromechanical contactswitches.Inaddition,somesmartsensinginstrumentationbasedonelectrostatic, piezo-resistive,piezo-electric,andelectromagneticsensingprinciplesarepresented. Overall,chaptertopicsincludeactuatingsystemssuchasmotors(AC,DC,andstepper), belts,screw-wheels,pumps,heaters,andvalves,alongwithdetectionandmeasurement devicesofprocessvariables(force,speed,position,temperature,pressure,gasandliquid chemicalcontent),RFIDdetection,sensorcharacteristics(resolution,accuracy,range,etc.), andnanoandsmartsensors.
Thistextbookemphasizesthemodelingandanalysiswithinreal-lifeenvironmentsaswellas theintegrationofcontroldesignandinstrumentationcomponentsofmechatronicsystems throughtheselectionandtuningofactuating,sensing,transmitting,andcomputingorcontrollingunits.Further,itlooksatthematchingandinterconnectingofcontrolinstrumentationsuch assensors,transducers,andactuatorsparticularlytheinterfacebetweenconnecteddevicesand
signalconversion,modification,andconditioning.Assuch,thereadercanexpectbytheend ofthebooktohavefullymastered:(i)thedesignrequirementsanddesignmethodologyfor controlsystems;(ii)thesizingandselectionoftheinstrumentationinvolvedinprocesscontrol, aswellasmicroelectromechanicaldevicesandsmartsensors;(iii)theuseofmicroprocessors forprocesscontrol,aswellassignalconditioning;and(iv)thesizingandselectionofactuatingequipmentforelectrical-drivensystemsandindustrialprocesses.Numerousexamplesand casestudiesareusedtoillustrateformalmodeling,hybridcontrollerdesign,andtheselectionof instrumentationforelectrical-drivenmachineactuationandDAQrelatedtosystemsdynamics andprocessoperations.Throughthesecasestudies,thereadershouldgainapracticalunderstandingoftopicsrelatedtothecontrolsystemandinstrumentation,allowinghimorhertofill acontrolandinstrumentengineeringpositionwhereheorsheisexpected:(i)topossessagood knowledgeofinstrumentationoperatingconditionsandcontrolrequirements;(ii)tosizeand selectcontrolinstrumentation;(iii)todesign,develop,andimplementdigitalcontrollers;(iv)to designengineeringprocessesandelectrical-drivensystems;(v)tocollaboratewithdesignengineers,processengineers,andtechniciansinthecost-andtime-basedacquisitionofsystems andprocessescontrolequipment;and(vi)toperformtechnicalaudittoensureinstrument compliancewithhealth-and-safetyregulations.
Thisbookwasconceivedtodevelopthereader’sskillsinengineering-basedproblem solving,engineeringsystemdesign,andthecriticalanalysisandimplementationofcontrol systemsandinstrumentation.Itallowsself-studyviacomprehensiveandstraightforward step-by-stepmodularprocedures.Inaddition,examples(withtheiraccompanyingMATLAB® routines,aswellas)anddesign-andselection-relatedexercisesandproblemsareprovided, alongwiththeirsolutions.Furthermore,adedicatedcompanionwebsite(emailauthorat kaltjob@uwalumni.comtohaveaccesstosecuredwebsite)allowsthereadertodownload additionalmaterialforteaching,suchasslidepresentationsonthechaptermaterial,datafiles foradditionallaboratorysessions,examplefiles,andinnovative2Dand3Dvirtuallabsfor physicalreal-lifesystems(i.e.model-basedsimulationtoolsthatcanbeassociatedtoreal-life systemsforin-classlabsessions).
Suggestionsforteachingplansforappliedcontroltheoryofmechatronicsystemsand electrical-drivenprocesseswouldbeasfollows:(i)Chapter1throughChapter5(up toSection5.3.1),foranintroductorydigitalcontrol-levelcourselastingonesemester; (ii)Chapters2,3,and5(Sections5.3and5.4)foradvancedcontrolstudentswithacontrol theorybackground;(iii)Chapters1,3(Sections3.3and3.4),and8forelectric-drivenmachine andinstrumentationstudentswithcomputerhardwareandsoftwareprogrammingexperience; (iv)Chapters2,3(Sections3.3and3.4),5(Sections5.2.4,5.3,and5.4),and6–8forfieldcontrol andinstrumentationengineersinterestedinthedesignormigrationofprocesscontrolof hybridsystems.
Acknowledgment
ThisbookmakesextensiveuseofMATLAB® routines,distributedbyMathworks,Inc.Auser withacurrentMATLABlicensecandownloadtrialproductsfromtheirwebsite.Someone withoutaMATLABlicensecanfilloutarequestformonthesite,andasalesrepwillarrange thetrialforthem.ForadditionalMATLABproductinformation,pleasecontact:
TheMathWorks,Inc.
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IntroductiontotheControlofMechatronicSystems
1.1Introduction
Therapidexpansionofautomatedelectrically-drivensystems(e.g.electromechanical machines)isrelatedtothedevelopmentofdigitalcontrolstrategiesinordertoenhancetheir performanceandextendtheirfunctionalitywhilesignificantlyreducingtheiroperatingcost andcomplexity.However,thosedigitalcontrolstrategiesaredependentontheperformance ofthecontrolinstrumentationrelatedtomeasurement,signalconditioning,actuating,and digitalcontroltechnologies.Recenttechnologyadvancementsofferaplethoraofcontrol systemsinstrumentation,eachwithdesign-specificrequirementsandcomplianceconstraints. Hence,inadditiontosystemmodeling,thedesignofdigitalcontrolstrategieshastoconsider: (i)theselectionofcontrolinstrumentationinaccordancewithperformanceobjectives;and(ii) theintegrationofthecontrolsystemsinstrumentationandprocessequipmentwithrespectto operatingconstraints.
Consequently,itissuitabletolayoutagenericdesignprocedurefordigitalcontrolsystems,especiallyin:(i)controllingelectrically-drivensystems;(ii)sizingandselectingcontrol instrumentationrelatedtoinformationprocessingandcomputing,electrically-drivenactuation,processsensinganddataacquisition;(iii)integratingthosecontrolinstrumentationwith respecttocontrolledsystemperformanceobjectivesandoperatingconstraints;and(iv)integratingmultifunctionalcontrolapplications.
Inthischapter,thedefinitionandclassificationofelectrically-drivensystemsandtechnicalprocessesarepresentedfirst.Thenthefunctionalrelationshipbetweenelectromechanical machinecontrolandcontrolwithininterconnectedandsynchronizedelectromechanicalsystemsisoutlined.Variouscomponentsofcontrolsystemsinstrumentationaredescribedalong withtheirdesignrequirements.Furthermore,majorstepsofcontrolsystemmigrationprojects arepresentedwithsomeillustrativeexamplesofindustrialprocesscontrol.Finally,keyproject managementstepsandtheassociatedsubsequentdesigndocumentsarelisted.
1.2DescriptionofMechatronicSystems
Mechatronicsystemsareeitherelectrically-drivenproductsortechnicalprocesses. Electricallydrivenproducts aremachinestransformingcurrent,voltage,orotherelectricalpowerinto mechanical,fluidic,pneumatic,hydraulic,thermal,orchemicalpower.Hence,thosesystems canbeclassifiedaccordingtotheirfunctionalobjectiveseitheras:(i)specializedmachines performingspecificoperations;or(ii)multipurposeandadjustablemachines.Controlsystems areasetoftechnologiesenablingalgorithmiccomputingorsignalprocessingdevicestouse signalsemittedfromanalogordigitaldetecting,sensing,andcommunicatingdevicesinorder ControlOfMechatronicSystems:Model-DrivenDesignAndImplementationGuidelines, FirstEdition.PatrickO.J.Kaltjob. ©2021PatrickO.J.Kaltjob.Published2021byJohnWiley&SonsLtd.
2 1IntroductiontotheControlofMechatronicSystems
toperformautomaticoperationsofsystemsorprocessactuation.Suchsystemsareexpected toperformthemroutinelyandindependentlyofhumaninterventionwithaperformance superiortomanualoperation.
Thus,controlsystemsaimtoprovidethenecessaryinputsignalstoachievethedesiredpatternsofvariationsofspecificprocessvariables.Therefore,thefunctionsofcontrolsystemsare embeddedinelectromechanicalsystems(machineorproductcontrol).
Example1.1 Figure1.1showsatypical3Dprintingrobotforcustomizedcookingwithspeedandtemperature-controlledsystemwhichcouldbecombinedwithmonitoringindicatorsfor cookingtimeandcookingstage,aswellasacontrolpanelallowingtheselectionofthefinal mixingoftheproductandcookingprogram.Thissystemwouldrequire:
1) theangularpositioncontrolofapressurevalvedeliveringsemi-liquefiedfood(paste),the x-y axispositioncontrolofthecarriagedrivingtheextruderhead(nozzle)madeoftwomotors withascrewmechanism,thetableangularspeedandthe z-axispositioncontrol;
2) theheatertemperaturecontrol(nozzlelevel);
3) theremotepressureandforcecontrolforthevalveinchargeofinjectingpressuredfood pastefeedbasedonenvironmental(e.g.spacemission)andbiologicalconditions(e.g.lower gravityforces);and
4) thelogiccontrolforthediscreteselectionofingredients.
Suchcontroldesigncombinationenhancestheproductormachinefunctionalitywhilereducingoperatingandmaintenancecosts.Thisisdonebyintegratingdataprocessingandcomputing
1.2DescriptionofMechatronicSystems 3 operationswithinafielddeviceormachine(e.g.washingmachine,navigationsystemsetc.). Amongthecommonlyencounteredautomatedmachinesorproductsarethosewith:(i)embeddedcontrolfunctions;(ii)dedicatedcontrolfunctions;or(iii)acontrolfunctionlimitedtoa coupleofsensorsandactuatorsinvolved.
Atechnicalprocessisthesumofallinteractingmachineswithinthatprocesstransformingand/orstoringmaterial,energy,orinformation.Suchtechnicalprocessescanbeclassified accordingtotheiroperationalobjectivesasfollows:
1) Transportation-relatedprocesses,suchasmaterialhandlingprocesses,energyflowprocesses,andinformationtransmissionprocesses.
2) Transformation-relatedprocesses,suchaschemicalprocesses,manufacturingprocesses, powergeneration,andstorageprocesses.
Technicalprocessescanbecharacterizedaccordingtofunctionalobjectives,suchas:
1) Processescharacterizedbyacontinuousflowofmaterialorenergy(e.g.cementdrying process,electricpowerdistribution,paperproduction).Here,theprocessvariablesare physically-relatedvariableswithacontinuousrangeofvalues,suchastemperaturesina heatingsystem.Theprocessparametersarephysicalproperties(e.g.powertransmission networkimpedance,liquefiedgasdensity).Processcontrolconsistsofmaintainingthe processstateonadeterminedlevelortrajectory.Inthiscase,processdynamicsmodelscan beobtainedthroughdifferentialequations.
2) Processescharacterizedbydiscreteeventoperationsrepresentingdifferentprocessstates suchasdeviceactivationordeactivationduringthestartuporshutdownofaturbine.Here, processvariablesarebinarysignalsindicatingthediscretestatusofdevicesormachines involvedinprocessoperationsaswellaschangeinlogicdevices(e.g.activatingeventsresultingfromON/OFFswitchpositioning).Theprocessdiscreteeventmodelscanbeobtained throughBooleanfunctionsorlogicflowcharts.
3) Processescharacterizedbyidentifiableobjectsthataretransformed,transportedorstored, suchassilicon-basedwaferproduction,dataprocessingandstorageoperations.Here,processvariablesindicatethestatechangesofobjectsandcanhaveacontinuousrangeofvalues (i.e.temperatureofaslabinacloggingmill,sizeofapartinastore)orbinaryvariables.Those variablescanalsobenon-physicalcategories(i.e.type,design,application,depotnumber) assignedtotheobjects.
Example1.2 Figure1.2,depictingasalt-generatingsolar-basedthermalpowerplantsubstation,illustratesanexampleofnon-continuousprocesses(discreteevent-orobject-related).In thispowerplant,solarradiationiscollectedbythousandsofsun-trackingmirrors(heliostats), whichreflectittowardasinglereceiveratopacentrallylocatedtower.Solarradiationisthe electromagneticradiationemittedbythesun.Assuch,itisnecessaryto:
1) Controlthecollectorangleandposition(suntracker)tofacethesuntocollectthemaximum solarradiationaswellastomaintainpeakpowerdespitevaryingclimateconditions.Thisis donebyadjustingtheoperatingsettingbasedonmeasuredvoltageandcurrentoutputsof thearray.
2) Logicallycontroltheenergystoragebyswitchingbetweencharging/dischargingoperating modesbasedonclimaticconditions(sunavailability),batterychargestatus,loadlevels,and levelofenergycollectedthroughsolarirradiationbymirrorarrays.
3) Controlthetemperatureofthecollectorusedtomeltasalt.Thehotmoltensaltisstoredin astoragetanktogeneratesteamandlaterusedtodrivetheturbineandattachedgenerator.
4) Controltheflowofheatedfluidcirculatingbetweenthetankandthecollector.Thisfluid withmoltensaltatalowtemperatureispumpedtothecoldcollectortowerforthenext thermalcycle.Theoperatingtemperatureoverthisthermalcyclederivesthequantityof energytobeextracted.
Digitalcontrolsystems aimtocoordinatetheoperationsofseveralelectrically-driven machinesinordertomeetspecificoperationalobjectivessuchaswaterpurification,voltage controlinanelectricalpowergrid,ortemperatureregulationinafermentationtank.Thus,it isusuallynecessarytoensuretheintegrationofalargenumberofcontrolsysteminstruments (fromdataprocessingandcomputingunitstomeasuringunits).Figure1.3illustratesthe genericcomponentsinthedesignofcomputercontrolsystemswithsupervisoryfunctions.An exampleoftherelationshipbetweenatechnicalprocessandelectromechanicalsystemcontrol isillustratedinFigure1.4.
Figure1.2 Steam-basedpowergenerationtechnicalprocessschematic.
Process supervisory and safety requirements
Operator panel
Operating conditions
Configuration variables
Control variables
Operating variables
Controller logic and panel design
Computer control and supervisory system
Operating variables
Machine or process sequences
Machine or process safety
Disturbance variables
Manipulated variables
Measured variables
Process status
Electrical systems or processes
Detecting and measurement system
Figure1.3 Genericcontrolledmechatronicsystemsandinstrumentationblockdiagram.Source:Adaptedfrom KaltjobP.
Process material, energy, information inputs
Device control
Network transmission
Actuator Sensor
Electrically-driven machine
Central control
Network transmission
Electrically-driven machine
Actuator Sensor
Device control
Technical process control
Process material, energy, information outputs
Voltage, current inputs
Voltage, current inputs
Electrically-driven machine Logic control Detector
Actuator
Device control Sensor
Machine control
Voltage, current outputs
Integrated actuator
Embedded control Smart sensor Electrically-driven machine
Embedded device control
Voltage, current outputs
Figure1.4 Relationshipbetweentechnicalprocessandmachinecontrolsystems.Source:BasedonKaltjobP.
1.3GenericControlledMechatronicSystemandInstrumentation Components
Throughfunctionalsystemdecomposition,thedigitalcontrolsystemarchitecturecanbe dividedintothefollowingfunctionalunits:dataprocessingandcomputing,electrically-driven actuating,measuringanddetecting,dataacquisition,transmission,andsignalconditioning. Allthesecomponentsarepresentedinthesubsequentsubsections.Figure1.5summarizesthe connectionsbetweenallthemajorcontrolsystemsandinstrumentationcomponents.
1.3.1TheDataProcessingandComputingUnit
Thedataprocessingandcomputingunitisused:(i)tocontrolandregulatemachineoperations; (ii)tomonitormachinesandprocessesoperations;and/or(iii)tocoordinateoperationswithin thesameprocess.Dataprocessingandcomputingcouldbeperformedeither:
1) offline:thatis,thereisnodirectorreal-timeconnectionbetweentheprocessexecutionand thedataprocessingandcomputingunit;
2) onlineforopen-loopoperations:thatis,theprotection(safety)ofprocessoperationsand interlocking;or
3) onlineforclosed-loopoperations.
Commonlyencountereddataprocessingandcomputingdevicesare:digitalsignalprocessingdevices,programmablelogiccontrollers,microcontrollers,fieldprogrammablegatearrays amongothers,andadistributedcontrolsystem(DCS)(consistingofahistorianserverconnectedtoanetworkoffieldcontrollerdevices).Thosedevicesexecuteprogramroutinesfor:
1.3GenericControlledMechatronicSystemandInstrumentationComponents
(i)theacquisitionofprocessvariables;(ii)processconditionmonitoringandexceptionhandling(i.e.executingprocesssafetyoperations);(iii)thecontrolofmachineoperations(e.g. activation/deactivationofmotor,trackingofmotorspeed);and(iv)thearchivingandsharing ofprocessdatawithothercontroldevicesthroughthecommunicationnetwork.
1.3.2DataAcquisitionandTransmissionUnits
Dataacquisitionandtransmissionunitsareused:(i)tointerfacewithvariouscontroldevices (e.g.operatorpanel,detectingandmeasuringfielddevices);(ii)totransportprocessdata betweennetworknodes;(iii)tointegrateprocessdatafromdifferentsourcesonasingle platform;and(iv)tointegratecontrolfunctions(e.g.machinecontrolandprocesscontrol). Theseunitsoperatethroughdatatransferplatformsandtheirdatadistributionservice protocols.TheycanbedesignedbasedontheOpenSystemsInterconnectionmodel,whichis summarizedas:
1) thephysicallayer,beingeitherwiredorwirelessconnection,suchastwisted-pairwiring, fiber-opticcableorradiolink,andthecommutationunitconnectingthenetworktothe devices(e.g.fieldbusesfordatatransferbetweenprimarycontrollersandfieldcontrol devices);
2) thenetwork,transmission,andtransportlayersperformingfunctionssuchasdatarouting overthenetwork,dataflowcontrol,packetsegmentationanddesegmentation,errorcontrol andclocksynchronization.Inaddition,theselayersprovidemechanismsforpackettracking andtheretransmissionoffailedpackets;and
3) thesessionandpresentationlayersmainlyusedfordataformatting.
1.3.3Electrically-drivenActuatingUnits
Electrically-drivenactuatingunitsconvertvoltageorcurrentsignalsfromthecomputingunit intoappropriateinputforms(mechanical,electrical,thermal,fluidicetc.)fortheexecution ofmachine’sandprocessoperations.Thenthoseconvertedsignalsproducevariationsinthe machine’sphysicalvariables(e.g.torque,heat,orflow),oramplifytheenergylevelofthesignal, causingchangesintheprocessoperationdynamics.Someexamplesofactuatingelementsare relays,magnets,andservomotors.
1.3.4MeasuringandDetectingUnits
Measuringanddetectingunitsconsistoflow-powerdevices,suchassensorsandswitch-based detectorsinterfacingwithelectrically-drivenmachinesinvolvedinprocessoperations.Assuch, theyconvertrelatedphysicaloutputsignalsfromtheactuatingunitintovoltageorbinarysignalsreadytobeusedwithinthedataprocessingandcomputingunit.Somekeyfunctionsof thesedevicesare:(i)dataacquisitionrelatedtothechangeofmachinevariables;and(ii)conversionofthemachine-gatheredsignalintoelectricaloropticalsignals.Dependingonthenature oftheprocesssignalgenerated,asignalconditionercanbeadded.
1.3.5SignalConditioningUnits
Signalconditioningelementsconvertthenatureofthesignalgeneratedbythesensingdevice intoanothersuitablesignalform(usuallyelectrical).Thesignalconditioningunitscanalsobe embeddedwithinthesensingdevices.AnexampleofsuchaunitisaResistanceTemperature
Detector(RTD).Here,achangeinthetemperatureofitsenvironmentisconvertedintoavoltagesignalreflectingitsresistancechangethroughaWheatstonebridgeandthebridgeisasignal conditioningmodule.
1.4FunctionsandExamplesofControlledMechatronicSystems andProcesses
Mechatronicsystemsandprocesseshavebuilt-inintelligencethrougheithertheiradvanced informationprocessingsystemssuchasmultifunctionalcontrolsystemsorintelligent electromechanicalsystems(includingthermal,fluid,andmechanicalprocesses)suchas power-efficientmulti-axisactuationwithmotionprecisionanddetectionfeaturesorminiaturizedsmartdeviceswithembeddedinformationprocessingcapabilities.Theresulting controlledmechatronicsystemsandprocessesaimtoachievevariousobjectives:synchronize, controlandsequenceprocessoperations,ordetectandmonitorprocessstatus.
Table1.1presentssometypicalprocesscontrolobjectivesandtheircorrespondingcontrol functionsalongwithsomeillustrativeexamples.
Example1.3 Robot-assistedsurgeryisusingimage-guidedsystemstocommandandcontrol operationsinintravascularsurgery,asdepictedinFigure1.6.Suchasystemhasanembedded andintegratedcontrolsystemforitsmotionanddirection,aswellasoperationmonitoring, andmotionsynchronizationbetweenrobotarms.Expectedcontrolfunctionsinclude:
1) forcecontrolofarobotarmgripper;
2) synchronizedangularpositionandvelocitycontrolofeachmotor-drivenrobotjoint;
3) logiccontrolofreal-timeanomaliesdetection(locationoftheabnormalcellordysfunctionalorgan)andinspectionusing3Dimagingcameraprocessing(coloruniformity,selectionbasedonsizeandshape)andlaserrangingsensors;
4) pathgenerationandmotionplanning(position,speed,andaccelerations)forrobotnavigationwhileensuringcollisionavoidanceoftherobotmanipulator;and
5) logiccontrolofthediscreteselectionofsuitablecuttingtoolsfortherobotarms.
Table1.1 Functionsandimplementationstrategiesforcontrollingmechatronicsystemsandprocesses.
Controlsystem processingfunctions
Assessing,reporting,and monitoring
Safetycompliance, detection,and diagnostics
Controlandperformance enhancement
Implementation controlstrategies
Recordingprocessvariables throughsensorsanddetectors; real-time,model-based measurement,setting parameters,andinputsignals.
Interlockingincaseofdetected failuremodes,maintaining safetyoperationswhileensuring malfunctionhandling.
Controllingorregulatingsystem variables.
Examplesofcontrolledmechatronic systemsandprocesses
Remotepowerflowmeasurement, configurationandvoltagecontrol (SCADA)throughswitchgears, transformers,andcondensersina smartpowergrid.
Integratedsafetyandmonitoringof petrochemicalprocessvariablesand parameters(flowrate,temperatureetc.)
Positionandtemperature measurementaswellascontrolofa2D cuttingmachineryprocess.
Figure1.6 Image-guidedtele-assistedrobotintravascularsurgery.
Example1.4 Anunmannedelectricvehicledrivingsystemisexpectedtohaveanembedded andintegratedcontrolsystemforspeedanddirectioncontrol,trafficlightmonitoring,and motionsynchronizationwithotherusers.ConsiderthedriverlessvehicleinFigure1.7(a): ablockdiagramwithallrelevantinputandoutput(I/O)variablesinvolvedisdepictedin Figure1.7(b).
Example1.5 Here,anexampleofcontrolsystemforacrane-basedverticalmotionprocess isillustratedinFigure1.8,whileitsfeedbackblockdiagramandthelogiccontrolconnections areshowninFigure1.9(a)and(b).
Example1.6 Here,amilkybeverageprocessingfactoryisillustratedinFigure1.10.Inaprocessofsuchscale,asupervisory,control,anddataacquisitionsystem(SCADA)isusedtocollect plant-widedatathroughanindustrialnetworktoarchiveandtoensuretheexecutionofderived processsequences.Theequivalentblockdiagramdepictingtherelevantcomponentsofsuch SCADA-orientedprocesscontrolsystemispresentedinFigure1.11.
1.5ControllerDesignIntegrationStepsandImplementation Strategies
Mechatronicsystemsandprocessesaresystemsembeddingautomaticinformationprocessing functionssuchasforreporting,betterperformanceandcontrol,andsafeoperation.Such functionsareimplementedusingvariouscontrolstrategiesthroughadvancedcontroldesign algorithms,alongwithassociatedsmartactuatingorsensingdevices.Becauseacombination ofcontrolstrategiesiscommonlyusedandoperatedsimultaneously,itisnecessarytodevelop adesignmethodologytointegratecontrolstrategieswithinformation-drivenprocessing functionstoensurenear-optimalperformanceundervariousfunctionalitiesandsafeoperating conditions.Inaddition,thecontrolsystemmustcombinedigitallogicsequentialcontrolwith continuouscontroltoensureasynergeticeffectontheoperationofthemechatronicsystem.
Right hand joystick
Left hand joystick
Surgeon manipulating panel
Figure1.7 (a)Chassisofadriverlessvehicle.Source:BasedonKaltjobP.(b)Hybridcontrolblockdiagramofa driverlessvehicle.
Shaft position encoder
Command linear position, c(t),
Command angular position, θ(t) Cabin
Motor current, i(t)
Figure1.8 Crane-basedverticalmotioncontrolsystemschematic.Source:AdaptedfromKaltjobP.
Thisisusuallyencapsulatedinanautomationsoftwaresolutionassociatedwithsolidstate computingdevices(powerelectronics).
Furthermore,thecontrolarchitectureofthemechatronicsystemcoulduseeitherdecentralizedcontrolsystems,DCSs,hybridcontrolsystems,monitoringandcontrolsystems, fault-tolerantcontrolsystems,andembeddedcontrolsystems.Hence,someofthemare expectedtorequireremoteandsynchronizationtoolsthroughdatatransmissionandacquisitiontoolstoensurethecoordinationbetweenoperatingentitiesaswellbetweenmechatronic systemcomponents.Recallingthatanymechatronicsystemisbyitsdesignacombination ofelectrical,mechanical,andinformationprocessingtechnology,thecontrolsolutionof amechatronicsystemcouldcombine:(i)built-inintelligence;(ii)real-timeprogramming; and(iii)multifunctionaloperatingcharacteristics.Forexample,thiscouldresultinhigher serviceproductivity,quality,andreliability(e.g.reducedfailurerate),byembeddingintelligent, self-correctingsensoryfeedbacksystems.Thusanintegratedapproachissuitableforthe controlofanymulti-functionalmechatronicsystem.
Regardingmechatronicsystemsandprocesses,threemaintypesofintegratingcontroldesign strategycanbeconsidered:(i)spatialandstructuralintegration;(ii)functionalintegration;and (iii)performance-basedintegration.Here,thistextbookfocusesoncontroldesignintegration relatedtoinformationprocessing(i.e.advancedcontrolfunctionalongwithmonitoringand diagnosticfeatures).Assuch,inordertoachieveanefficientcontrolledmechatronicsystem,any controldesignprojectstepsmustencompassacoherentsynergyofselectionanddesigneffort
Reference inputs
Speed position
Position encoder
Tachometer
Continuous control
Hybrid control system
Lift traction system
Elevator cabin motor
Door system
Up/Down direction
Floor selection
Emergency stop Hold PB Control panels
Logic control
Monitoring unit
Floor panel outside elevator
Selection Up/Dn PBs Lights (floor Up/Dn indicators)
Data acquisition unit
Panel inside elevator
Selection floor PBs Emergency horn Lights (floor selections)
Elevator door motor
Limit switches
Detectors
(a)
Control unit
Driving control circuitry and programs Driving control circuitry and programs PWM controller
Data acquisition unit Safety programs (interlocks)
(b) Weight Obstruct Open/close Floor
Floor gate motor
Conversion unit
Sensing unit
Actuating unit
Vertical lift traction system
Bi-directional Motor and coupler
Conversion unit Floor gate system
Fan motor PLC PLC
Sensing unit
Conversion unit
Sensing unit
Bi-directional motor
Elevator door system
Bi-directional motor
Figure1.9 (a)Blockdiagramofthecranemotionfeedbackcontrolsystem.(b)Logiccontrolconnectionsofthe cranemotionfeedbackcontrolsystem.
