简介：

简介：Thispaperisconcernedwiththeglobalboundednessproblemforaclassofstochasticnonlinearsystemswithmatchedconditions.Theuncertaintiesinthesystemsareduetoparametervariationsandexternalstochasticdisturbance.Onlythematchedconditionsandthepossibleboundoftheuncertaintiesaredemanded.BasedonthestochasticLyapunovstabilitytheory,anexplicitcontrollerisconstructedinthegradientdirection,whichrendersresponsesoftheclosed-loopsystemsbegloballyboundedinprobability.Whenthesystemsdegradetolinearsystems,thecontrollerbecomeslinear.Illustrativeexamplesaregiventoshowtheeffectivenessoftheproposedmethod.

简介：Arobustcontrollerforbanktoturn(BTT)missileswithaerodynamicfinsandreactionjetcontrolsystem(RCS)isdevelopedbasedonnonlinearcontroldynamicmodelscomprisingcouplingsandaerodynamicuncertainties.Thefixedtimeconvergencetheoryisincorporatedwiththeslidingmodecontroltechniquetoensurethatthesystemtracksthedesiredcommandwithinuniformboundedtimeunderdifferentinitialconditions.Unlikepreviousterminalslidingmodeapproaches,theboundofsettlingtimeisindependentoftheinitialstate,whichmeansperformancemetricslikeconvergenceratecanbepredictedbeforehand.Toreducetheburdenofcontroldesignintermsofrobustness,extendedstateobserver(ESO)isintroducedforuncertaintyestimationwiththeoutputsubstitutedintothecontrollerasfeedforwardcompensation.Cascadecontrolstructureisemployedwiththeproposedcontrollawandthereinthecompoundcontrolsignalisobtained.Afterwards,controlinputsfortwokindsofactuatorsareallocatedonthebasisoftheirinherentcharacteristics.Finally,anumberofsimulationsarecarriedoutanddemonstratetheeffectivenessofthedesignedcontroller.

简介：Adual-ratepreviewcontrolstrategyforatypeofdiscrete-timesystemisproposedbasedonthetheoryofmultiratecontrol.First,byusingthediscreteliftingtechnique,thegeneraldual-ratediscrete-timesystemisconvertedintoasingle-rateaugmentedsystem.Onthisbasis,theaugmentederrorsystemisconstructedbyintroducingafirst-orderdifferenceoperatorandthepreviewablereferencesignal.Thenthetrackingproblemistransformedintoaregulatorproblemoftheaugmentederrorsystem.Theoptimalpreviewcontrollawoftheaugmentederrorsystemisobtainedbyusingstandardlinearquadraticoptimalpreviewcontroltheory,andthentheoptimalpreviewcontrolleroftheoriginalsystemisderived.Inaddition,thenecessaryandsufficientconditionsforthecontrolleraregiven.Finally,simulationresultsshowtheeffectivenessoftheproposedmethod.

简介：Thequantumbacterialforagingoptimization(QBFO)algorithmhasthecharacteristicsofstrongrobustnessandglobalsearchingability.IntheclassicalQBFOalgorithm,therotationangleupdatedbytherotationgateisdiscreteandconstant,whichcannotaffectthesituationofthesolutionspaceandlimitthediversityofbacterialpopulation.Inthispaper,animprovedQBFO(IQBFO)algorithmisproposed,whichcanadaptivelymakethequantumrotationanglecontinuouslyupdatedandenhancetheglobalsearchability.Intheinitializationprocess,themodifiedprobabilityoftheoptimalrotationangleisintroducedtoavoidtheexistenceofinvariantsolutions.Themodifiedoperatorofprobabilityamplitudeisadoptedtofurtherincreasethepopulationdiversity.Thetestsbasedonbenchmarkfunctionsverifytheeffectivenessoftheproposedalgorithm.Moreover,comparedwiththeintegerorderPIDcontroller,thefractional-orderproportionintegrationdifferentiation(PID)controllerincreasesthecomplexityofthesystemwithbetterflexibilityandrobustness.Thusthefractional-orderPIDcontrollerisappliedtotheservosystem.ThetuningresultsofPIDparametersofthefractional-orderservosystemshowthattheproposedalgorithmhasagoodperformanceintuningthePIDparametersofthefractional-orderservosystem.