简介：Animalflightandswimminghavelongbeenofgreatinteresttopeople.Besidescuriosityabouthowtheirsophisticatedaero-andhydrodynamicfeatsareperformed,researchesareveryinterestedinthemechanicsofanimalflightandswimmingforthefollowingtworeasons.Oneisthatbiologistsneedtounderstandtheeffectsofaero-andhydrodynamicforceproductionandenergyexpenditureonthephysiology,behavior,evolutionandotheraspectsoftheanimals.The

简介：AnartificialdisturbanceisintroducedintotheboundarylayeroveraflatplatetoinvestigatetheeffectonthetransitionprocessintheMach6.5windtunnelatPekingUniversity.Alinearstabilitytheory(LST)isutilizedtopredicttheevolutionoftheeigenmodes,andthefrequencyoftheartificialdisturbanceischosenaccordingtotheLSTresults.Theartificialdisturbanceisgeneratedbyglowingdischargeonthesurfaceoftheplateclosetotheleadingedge.TheRayleigh-scatteringvisualizationandparticleimagevelocimetry(PIV)measurementsareperformed.Bycomparingtheexperimentalresultswithartificialdisturbanceswiththoseunderthenaturalcondition(withoutartificialdisturbances),thepresentpapershowsthatthesecond-modeinstabilitywavesaresignificantlystimulatedbytheartificialdisturbances,andtheboundarylayertransitioniseffectivelytriggered.

简介：作为盘子由作者更早开发了的压电的横梁类型的颤动控制的小浪途径的延期，这份报纸建议为压制把压成薄片的矩形的盘子的颤动的混合activepassive控制策略经由薄粘弹性的结合层与分布式的压电的传感器和致动器结合了。由于在直角的小浪理论放大函数变换的低通行证的过滤性质，这个waveletbased控制方法有能力自动地在反馈控制循环滤出像噪音的信号，因此减少剩余联合的风险完成哪个通常是溢出的来源不稳定性。而且，薄粘弹性的结合层的存在能进一步通过浪费数字错误在控制过程期间部分导致的任何另外的可能的噪音的体力改进系统的坚韧性和可靠性。一个模拟过程基于一种先进wavelet-Galerkin技术被建议认识到混合活跃被动的控制进程。数字结果表明建议途径的效率。

简介：稳定性和机械系统的围住的海角是重要研究话题之一。在这糊一个干燥磨擦振荡器的最终的围住的海角，属于非光滑的机械系统，被建议一个控制器设计方法调查。第一，为有推迟的州的反馈的名字的系统的稳定性的一个足够的条件被构造LyapunovKrasovskii功能导出。推迟的反馈获得矩阵被使用线性矩阵不平等方法计算。第二根据推迟的州的反馈，一个连续函数被Lyapunov重新设计设计保证磨擦振荡器系统的解决方案最终在全面控制下面被围住。而且，最终的界限能被选择适当参数在实践调整。因此导致磨擦的颤动或不稳定性能有效地被控制。数字结果证明建议方法是有效的。

简介：Itisconcernedwiththeproblemofdisturbanceattenuationwithstabilityforuncertainnonlinearsystemsbyadaptiveoutputfeedback.Byapartial-stateobserverandBacksteppingtechnique,anadaptiveoutputfeedbackcontrollerwasconstructed,whichcansolvethestandardgaindisturbanceattenuationproblemwithinternalstability.

简介：Strongasymmetricalvorticesappearontheleewardofslenderbodyathighanglesofattack,whichhasveryunfavorableeffectonthestabilityandcontroloftheaircraft.Amethodisdevelopedtocontrolthesideforceofslenderbodyathighanglesofattack,andisverifiedinwindtunnel.Athin-filmtriangularself-excitedoscillationflagisfixedatthetipoftheslenderbodymodelwhosesemi-apexangleis10°.Sideforceisapproximatelylinearlyproportionaltoroll-settingangleofself-excitedoscillationflagathighanglesofattack,andtheslopoffittingstraightlineobtainedbytheleastsquaremethodis-0.158.Thelinearrelationshipbetweensideforceandroll-settingangleprovidesconveniencefordevelopingsideforcecontrollawofslenderbodyathighanglesofattack.Experimentaldatashowsthatthesideforcecoefficientsvarylinearlywithroll-settingangleswhenaspecificplasticself-excitedoscillationflagisusedasthecontrolflag.Therangeofsideforcecoefficientandroll-settingangleare,respectively,-3.2to3.0and-20°to20°.Thedeviceissimple,effective,andisofgreatpotentialinengineeringapplication.

简介：活跃的腱，由一个排水量致动器和一个并置的力量传感器组成，被Preumont和他的同事首先介绍稀释大灵活空间结构，和他们采用的控制算法的颤动是不可分的力量反馈。这篇论文论述一新比例积分(PI)强迫反馈算法完成更大的抑制为没有结构的要求的结构的比率当模特儿。控制系统的稳定性被显示出，并且类似于JPL-MPI的结构的模拟为空格结构的颤动控制表明建议算法的有效性。

简介：Inthe'90sDEMsimulationresearchwassuccessfulinexploringitspotentialinthesimulationoffiuidizationphenomenaandinitsapplicationtothedesignoffluidized-bedprocesses.Nevertheless,notmuchprogresshasbeenmaderegardingtherealistictreatmentofcollisionprocessesthatarecriticalindeterminingmacroscopicmodeoffiuidization.Allthroughthesecondhalfofthe'90s,theauthorinvestigated/demonstratedtheissuebyintroducingdifferentsurfaceinteractionscausedbyformationofliquidand/orsolidbridges,vanderWaalsforceandtheexistenceofsurfaceroughness.Inthefirstpartofthepresentationthesearetobesummarizedandthetasksremainingarediscussed.Inthesecondpart,arepresentedtheresultsfromanewlydevelopedforce-deformationmetertodemonstratethesignificanceofthesurfaceroughnessanditselasto-plasticcharacteristics.

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简介：Thispaperpresentstheproblemofcontrolofanti-aircraftmissilelaunchermountedonamovingcarrier-vehicle.Directexcitationsonthevehiclefromtheroadcauseadversevibrationsofthelauncher.Inordertoincreasetheprecisionoftheguidingsystemintheconditionsofself-propelledmovementofthesetuponabumpyroad,theadaptivecontrolalgorithmwasproposed.Someresearchresultsofcomputersimulationarepresentedinagraphicalform.

简介：Atheoreticalmodelingapproachaswellasanunsteadyanalyticalmethodisusedtostudyaerodynamiccharacteristicsofwingflappingwithasymmetricstroke-cyclesinconnectionwithanobliquestrokeplaneduringinsectforwardflight.Itisrevealedthattheaerodynamicasymmetrybetweenthedownstrokeandtheupstrokeduetostroke-asymmetricalflappingisakeytounderstandtheflowphysicsofgenerationandmodulationoftheliftandthethrust.Predictedresultsforexamplesofgivenkinematicsvalidatemorespecificallysomeviewpointsthatthewingliftismoreeasilyproducedwhentheforwardspeedishigherandthethrustisharder,andtheliftandthethrustaregeneratedmainlyduringdownstrokeandupstroke,respectively.Theeffectsofthreecontrollingparameters,i.e.theanglesoftiltedstrokeplane,thedifferentdownstrokedurationratios,andthedifferentanglesofattackinbothdown-andup-stroke,arefurtherdiscussed.Itisfoundthatlargerobliqueanglesofstrokeplanesgeneratelargerthrustbutsmallerlift;largerdownstrokedurationratiosleadtolargerthrust,whilemakinglittlechangeinliftandinputaerodynamicpower;andagain,asmallincreaseoftheangleofattackindownstrokeorupstrokemaycauseremarkablechangesinaerodynamicperformanceintherelevantstroke.

简介：一个新方法被开发因为在在同一直线上的振动点上稳定运动用限制的通报的形式主义绕三个身体问题转。关于在同一直线上的振动点轨道的Linearization与周期的系数产出一个不稳定的线性变化参数的系统。给变化方程，一条创新控制法律为振动点轨道基于典型代表赋值被介绍维护。选择理查森鈥檚的数字模拟为一条名字的轨道被进行的一条光圈轨道的第三顺序近似，和结果表明这条控制法律的有效性。关键词通报限制了三个身体问题-变化方程-振动点轨道维护-典型代表赋值工程被中国(10702003)的国家自然科学基础支持。

简介：Magneto-rheologicalvisco-elastomer(MRVE)asanewsmartmaterialdevelopedinrecentyearshasseveralsignificantadvantagesovermagneto-rheologicalliquid.Theadjustabilityofstructuraldynamicstorandomenvironmentalexcitationsisrequiredinvibrationcontrol.MRVEcansupplyconsiderablyadjustabledampingandstiffnessforstructures,andtheadjustmentofdynamicpropertiesisachievedonlybyappliedmagneticfieldswithchangelessstructuredesign.IncreasingresearchesonMRVEdynamicproperties,modeling,andvibrationcontrolapplicationarepresented.RecentadvancesinMRVEdynamicpropertiesandstructuralvibrationcontrolapplicationincludingcompositestructuralvibrationmitigationunderuniformmagneticfields,vibrationresponsecharacteristicsimprovementthroughharmonicparameterdistribution,andoptimalboundedparametriccontroldesignbasedonthedynamicalprogrammingprinciplearereviewed.RelevantmainmethodsandresultsintroducedarebeneficialtounderstandingandresearchesonMRVEapplicationanddevelopment.

简介：Thispaperaddressesamaster-slavesynchronizationstrategyforcomplexdynamicsystemsbasedonfeedbackcontrol.Thisstrategyisappliedto3-DOFplanarmanipulatorsinordertoobtainsynchronizationinsuchcomplicatedaschaoticmotionsofend-effectors.AchaoticcurveisselectedfromDuffingequationasthetrajectoryofmasterend-effectorandapiecewiseapproximationmethodisproposedtoaccuratelyrepresentthischaotictrajectoryofend-effectors.Thedynamicalequationsofmaster-slavemanipulatorswithsynchronizationcontrollerarederived,andtheLyapunovstabilitytheoryisusedtodeterminethestabilityofthiscontrolledsynchronizationsystem.Innumericalexperiments,thesynchronousmotionsofend-effectorsaswellasthreejointanglesandtorquesofmaster-slavemanipulatorsarestudiedunderthecontroloftheproposedsynchronizationstrategy.Itisfoundthatthepositivegainmatrixaffectstheimplementationofsynchronizationcontrolstrategy.Thissynchronizationcontrolstrategyprovesthesynchronization'sfeasibilityandcontrollabilityforcomplicatedmotionsgeneratedbymaster-slavemanipulators.

简介：Theactivecontrolofvibrationforabeamsubjectedtomulti-disturbancesisinvestigatedbasedonwavepropagatingsuppression.Inthiscontrolsystem,therearethesamenumbersofthesensors,thesignalinputtingtothecon-trollerandthedisturbances,butthereisonlyonecontroller.Itisalocalcontrolsystem,thesystemparametersdependonlyonthecharacteristicsofthestructureboundedbythesensorsandthecontroller,andweneednottakeintoaccounttheboundaryconditionsandthepropertiesofstructuresoutsideofthisfield.Thesys-temisefficientwhenastructurevibratesinmiddleandhighfrequencyregions.Somecontroldesignrulesaredevelopedfromthecalculationresults.

简介：传统的被动吸收器在一个狭窄、肯定的频率乐队以内是充分有效的。解决这个问题，推迟时间的加速反馈被介绍把一个被动吸收器变换成活跃的。两固有并且故意的时间延期被包括。前者主要来自信号获得并且处理，计算，并且适用使活动力量，和它的值被修理。后者在控制器被介绍，并且它的价值是活跃地可调节的。第一，机械模型被建立，频率反应方程被获得。稳定性的区域在控制参数的飞机被描出。第二，控制帕拉的设计计划--米被执行帮助选择反馈获得和时间延期的值。第三，试验性的研究被进行。否定、积极的反馈控制的效果被调查。试验性的结果证明控制参数的合适的选择可以拓宽颤动吸收的有效频率乐队。而且，当被动吸收器完全失败时，推迟时间的吸收器极大地压制主要系统的反响的反应。试验性的结果在对理论预言和数字模拟的好同意。

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简介：ThispaperstudiesMulti-modescontrolmethodforlibrationpointsformationestablishmentandreconfiguration.Firstly,relationsbetweenoptimalimpulsecontrolandFloquetmodesareinvestigated.Methodofgeneratingmodesisproposed.Characteristicsofthemodecoefficientsstimulatedatdifferenttimearealsogiven.Studiesshowthatcoefficientsofcontrolledmodescanbeclassifiedintofourtypes,andformationestablishmentandreconfigurationcanbeachievedbymulti-impulsecontrolwiththepresentedmethodofgeneratingmodes.Then,sincelibrationpointsformationisgenerallyunstable,mutli-modeskeepingcontrolmethodwhichcanstabilizefiveFloquetmodessimultaneouslyisproposed.Finally,simulationonformationestablishmentandreconfigurationarecarriedoutbyusingmethodofgeneratingmodesandmutli-modeskeepingcontrolmethod.Resultsshowthattheproposedcontrolmethodiseffectiveandpractical.

简介：Optimalcontrolsystemofstatespaceisaconservativesystem,whoseapproximatemethodshouldbesymplecticconservation.Basedonthepreciseintegrationmethod,analgorithmofsymplecticconservativeperturbationispresented.Itgivesauniformwaytosolvethelinearquadraticcontrol(LQcontrol)problemsforlineartime-varyingsystemsaccuratelyandefficiently,whosekeypointsaresolutionsofdifferentialRiccatiequation(DRE)withvariablecoefficientsandthestatefeedbackequation.Themethodissymplecticconservativeandhasagoodnumericalstabilityandhighprecision.Numericalexamplesdemonstratetheeffectivenessoftheproposedmethod.

简介：Inthisstudy,afowsolverwasdevelopedbasedonthegoverningRANSequationsofcompressiblefowsandwasfurtherextendedtoincludetheefectsofelectromagneticforcesnamelyLorentzforces.Lorentzforcesmaybeaddedasasourceterminthegoverningfuidfowequations.NumericalstudieswerecarriedoutforNACA0015aerofoilathighanglesofincidencesfrom15to30andcomparedwithsomeavailablecasesofexperimentalandincompressiblenumericalsolutions.Thehydrodynamicsperformancewasimprovedusingamagneticmomentumcoefcientofupto0.048.Thesizeoffowseparationzonewasdecreasedorcompletelyeliminatedbyincreasingthiscoefcient.Theoveralldragwasnotchangedconsiderably,howevertheoverallliftwasincreasedupto80percentatstallangles.