简介:Thetightforeignexchangecontrolerahasgonewith,wind,andforeigncurrencyreserveofChinanowisupto300billionUSdollars;once"thecuffofoverseasinvestment",theforeignexchangecontrolsystemwillgowhere?
简介:SurvivabilityisoneoftheimportantissuesinATM-basednetworkssineevenasinglenetworkelementfailuremaycauseaseriousdataloss.Thispaperintroducesanewrestorationmechanismbasedonmulti-layerATMsurvivablenetworkmanagementarchitecture.ThismechanismintegratesthegeneralcontrolandrestorationcontrolbyestablishingtheWorkingVPslogicalnetwork,BackupVPslogicalnetworkandsparelogicalnetworkinordertooptimallyutilizethenetworkresourceswhilemaintainingtherestorationrequirements.
简介:Summary1.Thereare12powersystemsincluding5regionalpowersystemswithover1000MWofcapacityeach.In1989CentralandEastChinapowersystemswereinterconnectedbya±500kVHVDCLine.2.Thehierarchicalcontrolorganizationcanbedividedinto5levels,i.e.NCC,6RCCs,25PCCs,250DCCsandmorethan2000CCCs.3.AllcontrolcenterswillbeequippedwithSCADAandEMSinthenearfuture.4.Chinapowersystemhasalarge,dedicatedcommunicationnetworkofitsown.
简介:Acompoundneuralnetworkisutilizedtoidentifythedynamicnonlinearsystem.Thisnetworkiscomposedoftwoparts:oneisalinearneuralnetwork,andtheotherisarecurrentneuralnetwork.Basedontheinversetheoryacompoundinversecontrolmethodisproposed.Thecontrollerhasalsotwoparts:alinearcontrollerandanonlinearneuralnetworkcontroller.Thestabilityconditionoftheclosed-loopneuralnetwork-basedcompoundinversecontrolsystemisdemonstratedbasedontheLyapunovtheory.Simulationstudieshaveshownthatthisschemeissimpleandhasgoodcontrolaccuracyandrobustness.
简介:FortheARMAXsystemwithunknowncoefficientstheoptimaladaptivecontrolisdesignedsothatthefollowingrequirementsaremetsimultaneously:1)thetransferfunctionfromareferencesignaltothesystemoutputintheclosedloopequalsaprescribedrationalfunction;2)undertheconstraintmentionedin1)aquadraticlossfunctionisminimized;3)theparameterestimateisstronglyconsistent.
简介:Thecourse-keepingcontrolofunderactuatedhovercraftwithtwoaftpropellerswasconsidered.Thecontroloftheheadingerrorandcross-trackerrorwasaccomplishedbytheyawtorquemerelyinthiscase.Thehovercraftdynamicmodelisnonlinearandunderactuated.AtfirsttheControllabilityofcourse-keepingcontrolforhovercraftwasproved,thenacourse-keepingcontrollawwasderivedthatkeepshovercraftheadingconstantaswellasminimizesthelateralmovementofhovercraft.Theproposedlawguaranteesheadingerrorandswayerrorallconvergetozeroexponentially.Simulationtestswerecarriedouttoillustratetheeffectivenessoftheproposedcontrollaw.Forfurtherresearch,thedisturbanceinfluencewouldbeconsideredinthedynamicequations.
简介:Thispaperpresentsthestabilityofdifferenceapproximationsofanoptimalcontrolproblemforaquasilinearparabolicequationwithcontrolsinthecoefficients,boundaryconditionsandadditionalrestrictions.Theoptimalcontrolproblemhasbeenconveredtooneoftheoptimizationproblemusingapenaltyfunctiontechnique.Thedifferenceapproximationsproblemfortheconsideredproblemisobtained.Theestimationsofstabilityofthesolutionofdifferenceapproximationsproblemareproved.Thestabilityestimationofthesolutionofdifferenceapproximationsproblembythecontrolsisobtained.
简介:Aclassoflarge-sealesystems,wheretheoverallobjectivefunctionisanonlinearfunctionofperformanceindexofeachsubsystem,isinvestigatedinthispaper.Thistypeoflarge-scalecontrolproblemisnon-separableinthesenseofconventionalhierarchicalcontrol.Hierarchicalcontrolisextendedinthepapertolarge-scalenon-separablecontrolproblems,wheremultiobjectiveoptimizationisusedasseparationstrategy.Thelarge-scalenon-separablecontrolproblemisembedded,under;ertainconditions,intoafamilyoftheweightedLagrangianformulation.TheweightedLagrangianformulationisseparablewithrespecttosubsystemsandcanbeeffectivelysolvedusingtheinteractionbalanceapproachatthetwolowerlevelsintheproposedthree-levelsolutionstructure.Atthethirdlevel,theweightingvectorfortheweightedLagrangianformulationisadjustediterativelytosearchtheoptimalweightingvectorwithwhichtheoptimaloftheoriginallarge-scalenon-separablecontrolproblemisobtained.Theoreticalbaseofthealgorithmisestablished.Simulationshowsthatthealgorithmiseffective.
简介:Basedontheself-excitedvibrationtheoryofice,thevibrationcontroltechnologyofjacketplatformisstudiedinthispaper.Themagnetorheologicalsuspensions(MR)unitischosenasthedamper,thecontrolobjectivefunctionforvibrationexcitedbyiceisdeterminedbyinstantaneousoptimalcontrol(IOC)method,andgeneticalgorithm(GA)isusedtoselecttheoptimalcontrolforce.Forthejacketplatformof40minheightanda3-floordeck,thevibrationresponsesinducedbyicehavebeencalculatedbeforeandaftercontrolconsideringthedifferentthicknessandspeedofice.Itisshownthatthecontrolmethodpresentedinthispapercanreducethevibrationresponseby30%,anditisfeasibletoadoptMRabsorberandGAinthecontrolofvibrationinducedbyice.