简介:Mostofthemaintenanceoptimizationmodelsincondition-basedmaintenance(CBM)considerthecost-optimalcriterion,butfewpapershavedealtwithavailabilitymaximizationformaintenanceapplications.AnoveloptimalBayesiancontrolapproachispresentedformaintenancedecisionmaking.Thesystemdeteriorationevolvesasathree-statecontinuoustimehiddensemi-Markovprocess.Consideringtheoptimalmaintenancepolicy,themultivariateBayesiancontrolschemebasedonthehiddensemi-Markovmodel(HSMM)isdeveloped,theobjectiveistomaximizethelong-runexpectedaverageavailabilityperunittime.Theproposedapproachcanoptimizethesamplingintervalandcontrollimitjointly.AcasestudyusingMarkovchainMonteCarlo(MCMC)simulationisprovidedandacomparisonwiththeBayesiancontrolschemebasedonhiddenMarkovmodel(HMM),theage-basedreplacementpolicy,Hotelling’sT2,multivariateexponentiallyweihtedmovingaverage(MEWMA)andmultivariatecumulativesum(MCUSUM)controlchartsisgiven,whichillustratestheeffectivenessoftheproposedmethod.
简介:Aco-designschemeofevent-triggeredsamplingmechanismandactivefaulttolerantcontrol(FTC)isdeveloped.Firstly,afaultdiagnosisobserverisdesignedtoestimateboththefaultandthestatesimultaneouslybyusingtheevent-triggeredsampledoutput.SomeH∞constraintsbetweentheestimationerrorsandtheevent-triggeredsamplingmechanismareestablishedtoensuretheestimationaccuracy.Then,basedontheconstraintsandtheobtainedfaultinformation,anevent-triggereddetectorandastaticfaulttolerantcontrollerareco-designedtoguaranteethestabilityofthefaultysystemandtoreducethesensorcommunicationcost.Furthermore,theproblemoftheeventdetectoranddynamicFTCco-designisalsoinvestigated.Simulationresultsofanunstablebatchreactorarefinallyprovidedtoillustratetheeffectivenessoftheproposedmethod.