简介：Nonlinearcontrollabilityandattitudestabilizationarestudiedfortheunderactuatednonholonomicdynamicsofarigidspacecraftwithonevariable-speedcontrolmomentgyro(VSCMG),whichsuppliesonlytwointernaltorques.Nonlinearcontrollabilitytheoryisusedtoshowthatthedynamicsarelocallycontrollablefromtheequilibriumpointandthuscanbeasymptoticallystabilizedtotheequilibriumpointviatime-invariantpiecewisecontinuousfeedbacklawsortime-periodiccontinuousfeedbacklaws.Specifically,whenthetotalangularmomentumofthespacecraft-VSCMGsystemiszero,anyorientationcanbeacontrollableequilibriumattitude.Inthiscase,theattitudestabilizationproblemisaddressedbydesigningakinematicstabilizinglaw,whichisimplementedthroughanonlinearproportionalandderivativecontroller,usingthegeneralizeddynamicinverse(GDI)method.Thesteady-stateinstabilityinherentintheGDIcontrolleriselegantlyavoidedbyappropriatelychoosingcontrolgains.Inordertoobtainthecommandgimbalrateandwheelaccelerationfromcontroltorques,asimplesteeringlogicisconstructedtoaccommodatetherequirementsofattitudestabilizationandsingularityavoidanceoftheVSCMG.Illustrativenumericalexamplesverifytheefcacyoftheproposedcontrolstrategy.

简介：Inthepaperwediscusssomepropertiesofthestateoperatorsoftheoptimalobstaclecontrolproblemforellipticvariationalinequality.Existence,uniquenessandregularityoftheoptimalcontrol,problemareestablished.Inaddition,theapproximationoftheoptimalobstacleproblemisalsostudied.

简介：Forthepurposeofsolvingoptimalcontrolproblemofawall-crawlingmobilerobotworkingonsphericalcontainers,weproposetheHamel'sformalismforPontryaginMaximumPrinciple,whichgivesageneralframeworkfortheoptimalcontrolofamechanicalsystemwithvelocityconstraints,especiallynonholonomicconstraints.Theeffectivenessoftheproposedframeworkisshownbythesimulationsfortheaboveproblem.

简介：Manymoderncontrolapplicationsareinterdisciplinaryinnature.Varietyofdisciplinesareorientedonapplicationofcontroltheoryandmodelingofmechanical/biomechanicalsystemstosolvepracticalproblemsintheirspecificfields.Bearingthisinmind,thereareincludedinthisspecialsubjectsomeinterestingcontributionscoveringdifferentareassuchasbifurcationsandchaosindynamicalsystems,stabilityofdynamicalsystems,originalnumericalmethodsofvibrationanalysis,non-smoothsystems,engineeringsystemsanddifferentialequations,controlindynamicalsystems,asymptoticmethodsinnonlineardynamics,vibrationsoflumpedandcontinuoussystems,dynamicsinlifesciencesandbioengineering.

简介：可变几何学捆绑操纵者(VGTM)有潜力在未来空间应用程序，一个动态模型对系统的动态分析和控制重要工作。在这份报纸，一条途径被介绍由独立变量为VGTM的动态方程建模，它由二双octahedral组成捆绑单位和3-revolute-prismatic-spherical(3-RPS)平行操纵者。在这条途径，二邻近的身体的运动学的递归的关系并且几何抑制被用来推出VGTM的运动学的方程，并且Jourdains速度变化原则被采用建立系统的动态方程。建议动态模型的有效性被数字模拟的比较与软件亚当斯验证。而且，为轨道追踪系统的一个活跃控制器被计算转矩方法设计。控制器的有效性数字地被证明。

简介：

简介：这份报纸用单个万向节的控制时刻旋转罗盘(CMG)和磁性的torquers(MTQ)集中于小活泼的卫星的态度控制问题。因为他们的转矩扩大能力，CMG为活泼的卫星被认为是有效转矩发电机。然而，他们由于他们的复杂内部机制对失败脆弱。在这份报纸，CMG的不同失败盒子被分析。灵活失败容忍的控制策略被自动地在操作CMG和MTQ之中再分配要求的控制转矩开发，与提供CMG失败介绍的致动器动力学变化的可变limiter。关于在不同失败盒子下面的不同方向的演习的表演也被讨论并且检验。数字模拟证明建议策略在一或二CMG失败的情况中维持某些活泼。而且，有仅仅离开的一CMG的幸存策略也被验证。指太阳的稳定和指地球的稳定能在这种情况中被完成，它完成一些基本使命要求。

简介：ApplyingLagrange–Germain'stheoryofelasticthinplatesandHamiltonianformulation,thedynamicsofcantileverplatesandtheproblemofitsvibrationcontrolarestudied,andageneralsolutionisfinallygiven.BasedonHamiltonianandLagrangiandensityfunction,wecanobtaintheflexuralwaveequationoftheplateandtherelationshipbetweenthetransverseandthelongitudinaleigenvalues.Basedoneigenfunctionexpansion,dispersionequationsofpropagationmodeofcantileverplatesarededuced.Bysatisfyingtheboundaryconditionsofcantileverplates,thenaturalfrequenciesofthecantileverplatestructurecanbegiven.Then,analyticsolutionoftheprobleminplatestructureisobtained.Anhybridwave/modecontrolapproach,whichisbasedonbothindependentmodalspacecontrolandwavecontrolmethods,isdescribedandadoptedtoanalyzetheactivevibrationcontrolofcantileverplates.Thelow-order(controlledbymodalcontrol)andthehigh-order(controlledbywavecontrol)frequencyresponseofplatesarebothimproved.Thecontrolspilloverisavoidedandtherobustnessofthesystemisalsoimproved.Finally,simulationresultsareanalyzedanddiscussed.

简介：Thesystemdynamicsofturningprocessescanbedescribedbyadelaydiferentialequation.Howtoimprovethestabilityandsuppressthevibrationofcuttingisofaninterestingtopic.Inthispaper,amultipletime-delaycontrollerisdevelopedbasedondiscreteoptimalcontrolmethodfortheturningvibrationscontrol.Numericalsimulationsarecarriedouttoverifytheefciencyofthecontroller.Resultsindicatethedesignedcontrollercansuppressthecuttingvibrationefcientlyandimprovethestabilityofthecuttingprocesses.Theinfluenceofdesignedtime-delayandsamplingtimeonthecontrolperformanceisalsodiscussed.

简介：Thetransformationmethodtocontrolwaveshasreceivedwidespreadattentioninelectromagnetismandacoustics.However,thismachineryisnotdirectlyapplicabletothecontrolofelasticwaves,becauseithasbeenshownthattheNavier’sequationdoesnotusuallyretainitsformundercoordinatetransformation.Inthisletter,weprovetheforminvarianceoftheNavier’sequationundertheconformalmappingbasedontheHelmholtzdecompositionmethod.Theneededmaterialparametersareprovidedtomanipulateelasticwaves.Thevalidityofthisapproachisconfirmedbyanactivestealthdevicewhichcandisguisethesignalsourcebychangingitsposition.Experimentalverificationsandpotentialapplicationsmaybeexpectedinnondestructivetesting,structuralseismicdesignandotherfields.

简介：

简介：InthispaperweanalyzetheoptimalcontrolproblemforaclassofaffinenonlinearsystemsundertheassumptionthattheassociatedLiealgebraisnilpotent.TheLiebracketsgeneratedbythevectorfieldswhichdefinethenonlinearsystemrepresentaremarkablemathematicalinstrumentforthecontrolofaffinesystems.Wedeterminetheoptimalcontrolwhichcorrespondstothenilpotentoperatorofthefirstorder.Inparticular,weobtainthecontrolthatminimizestheenergyofthegivennonlinearsystem.Applicationsofthiscontroltobilinearsystemswithfirstordernilpotentoperatorareconsidered.

简介：

简介：Weanalyzedthephenomenonofferrofluidmagnetoviscosityinhigh-permeabilitywall-regionnon-magneticporousmediaoftheMullerkind.Afterupscalingthepore-levelferrohydrodynamicmodel,weobtainedasimplifiedvolume-averagezero-orderaxisymmetricmodelfornon-Darcynon-turbulentflowofsteady-stateisothermalincompressibleNewtonianferrofluidsthroughaporousmediumexperiencingexternalconstantbulk-floworientedgradientmagneticfield,ferrofluidself-consistentdemagnetizingfieldandinducedmagneticfieldinthesolid.Themodelwasexploredincontextsplaguedbywallflowmaldistributionduetolowcolumn-to-particlediameterratios.Itwasshownthatforpropermagneticfieldarrangement,wallchannelingcanbereducedbyinflatingwallflowresistancethroughmagnetovisco-thickeningandKelvinbodyforcedensitywhichrerouteafractionofwallflowtowardsbedcore.

简介：这份报纸为一组僵硬身体学习协调运动产生的问题。协调运动原语，相对equilibria和演习的二个班，当为产生的积木协调了运动，被给。在运动原语计划框架基于，一个控制方法面对不安为一个协调运动计划的柔韧的执行被建议。控制方法把相对equilibria稳定与演习设计相结合，并且导致计划框架的一个靠近环的运动。控制方法的表演通过数字模拟被说明了。

简介：Thecombinationoflaserdiffractionwithupstreamsamplingrealizedabreak-throughforthein-andon-lineparticlessizeanalysisinindustrialapplications.Today,thecombinationofrepresentativesampling,drydispersion,particlesizeanalysisbylaserdiffractionandintegratedfeedbackofthesampleiswellacceptedinmanyindustrialapplications.Nomoreinteractionsoftheuserarerequired,andforstandardapplicationstheon-linemonitoringofparticlesizesbecamenearlyassimpleasthernonitodngofanyotherprocessparameter.Theincreaseofinspectionintervalfrom24-houroperationtomonthshasincreaseduserconfidenceinthistechnology,andindustrieswithmoredemandingmeasurementrequirementsareseekingtobenefitfromthisperformance.Thischallengecouldnotbesolvedwithsimplescale-upsorscale-do,he.Newsolutionshadtobefoundforthesamplingsystem,themeasuringsensor,theadaptationtotheenvironmentalconditionsandtheprocessingoffeslgrowingvolumeofdata.

简介：Recently,someresearchesindicatethatpositivefeedbackcanbenefitthecontrolifappropriatetimedelayisintentionallyintroducedintocontrolsystem.However,mostworkistheoreticalonebutfewareexperimental.Thispaperpresentstheoreticalandexperimentalstudiesofdelayedpositivefeedbackcontroltechniqueusingaflexiblebeamasresearchobject.Thepositivefeedbackweightingcoefficientisdesignedbyusingtheoptimalcontrolmethod.Theavailabletimedelayisdeterminedbyanalyzing...

简介：Inremotesensingorlasercommunicationspacemissions,spacecraftneedfastmaneuverandfaststabilizationinordertoaccomplishagileimagingandattitudetrackingtasks.However,fastattitudemaneuverscaneasilycauseelasticdeformationsandvibrationsinflexibleappendagesofthespacecraft.Thispaperfocusesonthisproblemanddealswiththecombinedcontroloffastattitudemaneuverandstabilizationforlargecomplexspacecraft.Themathematicalmodelofcomplexspacecraftwithflexibleappendagesandmomentumbiasactuatorsonboardispresented.Basedontheplantmodelandcombinedwiththefeedbackcontroller,modalparametersoftheclosed-loopsystemarecalculated,andamultiplemodeinputshaperutilizingthemodalinformationisdesignedtosuppressvibrations.Aimingatreducingvibrationsexcitedbyattitudemaneuver,aquinticpolynomialformrotationpathplanningisproposedwithconstraintsontheactuatorsandtheangularvelocitytakenintoaccount.Attitudemaneuversimulationresultsofthecontrolsystemswithinputshaperorpathplanninginloopareseparatelyanalyzed,andbasedontheanalysis,acombinedcontrolstrategyispresentedwithbothpathplanningandinputshaperinloop.Simulationresultsshowthatthecombinedcontrolstrategysatisfiesthecomplexspacecraft’srequirementoffastmaneuverandstabilizationwiththeactuators’torquelimitationsatisfiedatthesametime.

简介：

简介：