自动化专业英语复习

1.strategy2.competition3.propagate4.processcontrol5.variation6.constant7.terminology8.negligible9.manualcontrol10.automaticcontrol11.fluctuation12.damp13.feedbackcontrol14.positivefeedback15.feedforwardcontrol16.actuator17.encode18.switch19.value20.relay21.overrideswitch22.controlconfiguration23.stabilityaugmentation24.motivation25.bandwidth26.gain27.sensitivity28.static-system29.magnitude30.phase31.stationary32.commutator33.impedance34.transientresponse35.frequencyresponse36.characteristicequation37.relativestability38.denominationpolynomial39.numeratorpolynomial40.magnitude41.angles42.criterion43.oscillatory44.amplitude45.saturation46.distinctpole47.triangular48.matrix49.frequency-domain50.low-ordersystem51.low-passfilter52.signalprocessor53.distortion54.step-function55.cutofffrequency56.elude57.intuition58.esthetic59.analog60.innovation61.disposal62.tentative63.methodology64.constraint65.canonical66.storagetank67.troubleshootingcontrolloop68.orifice69.controllertuning70.trailanderror71.time-consuming72.vibration73.turbulence74.residence75.ultimate76.looptuning77.slope78.tangent79.intersect80.sigmoidalS81.calibrationGeneratedbyFoxitPDFCreator©FoxitSoftware’slawofmagneticinduction115.junction116.weld117.grounded118.deterioration119.oxidize120.irrelevant121.servomotor122.steppermotor123.controlvalve124.toxic125.rotaryvalve126.flammable127.hydraulicactuator128.pneumaticactuator129.modulate130.fragile1.Inrecentyearstheperformancerequirementsforprocessplantshavebecomeincreasinglydifficulttosatisfy.2.Thegoalofcontrolengineeringistoimprove,orinsomecasesenable,theperformanceofasystembytheadditionofsensors,controlprocessors,andactuators.3.Controlconfigurationistheselectionandplacementoftheactuatorsandsensorsonthesystemtobecontrolled,andisanaspectofsystemdesignthatisveryimportanttothecontrolengineer.4.ThecontrollerorcontrollawdescribesthealgorithmorsignalprocessingusedbythecontrolprocessortogeneratetheactuatorsignalsfromthesensorandcommandGeneratedbyFoxitPDFCreator©FoxitSoftware(P),theproportionalplusderivative(PD),theproportionalplusintegral(PI),andtheproportionalplusintegralplusderivative(PID)controllers,whicharewidelyandeffectivelyusedinmanyindustries.PPDPIPID6.Themotivationofusingfeedback,illustratedbytheexamplesinSection(1),issomewhatoversimplified.Intheseexamples,theuseoffeedbackisshowntobeforthepurposeofreducingtheerrorbetweenthereferenceinputandthesystemoutput.However,thesignificanceoftheeffectsoffeedbackincontrolsystemsismorecomplexthanisdemonstratedbythesesimpleexamples.5.However,therearenumeroussituationswhereinaphysicalsystemthatwenormallyrecognizeasaninherentlynon-feedbacksystemturnouttohavefeedbackwhenitisobservedinacertainmanner.6.Definitionofstability.Anunconstrainedlinearsystemissaidtobestableiftheoutputresponseisboundedforallboundedinputs.Otherwiseitissaidtobeunstable.7.GeneralStabilityCriterion.ThefeedbackcontrolsysteminFig.1.3.1isstableifandonlyifallrootsofthecharacteristicequationarenegativeorhavenegativerealparts.Otherwise,thesystemisunstable.1.3.18.RouthStabilityCriterion.AnecessaryandsufficientconditionforallrootsofthecharacteristicequationinEq.(12)tohavenegativerealpartsisthatalloftheelementsinleftcolumnoftheRoutharrayarepositive.GeneratedbyFoxitPDFCreator©FoxitSoftware(avoid)definition,butyoucanusuallyrecognizesomethingthatiswelldesigned.Onecharacteristicofgooddesignisthatitisexactlyrightforthespecificapplication.Everythingnecessaryispresent,buteverythingunnecessaryisabsent.10.Muchofengineeringismodifyingexistingdesigns.Anewmodelofanexistingproductisdesignedtoincorporatenewtechnologicaladvances:aneworimprovedsensororactuator,adigitalprocessortoreplaceananalogcontroller.11.ObviousIy(apparently,clearly),thesensormustproduceanoutputofsometypethatwillcorrelatepredictably(,)withvaluesofthevariablebeingmeasured.12.Thefirstofthefundamentallawsofprocesscontrolreadsasfollows:Allprocesscontrolstartswithmeasurement,andthequalityofcontrolobtainedcanneverbebetterthanthequalityofthemeasurementonwhichitisbased.13.Levelisdefinedasmeasurementofthepositionoftheinterfacebetweentwomedia.Thesemediaaretypicallygasandliquid,buttheyalsocouldbesolids,oraninterfacebetweentwoliquids.14.Differentialpressure(dp)measurementiseasytoinstall,hasawiderange,andprovidesafasterresponsetimethanexternal(,outer)cage(,box,case,shell)di