学科分类
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9 个结果
  • 简介:Thepressurereflectedfromabi-laminatedpiezoelectricplatehasbeendeterminedusingtheThomson-Haskellmatrixmethod.Theplateiscomposedofapiezoelectriclayerwithgroundedvacuumandanelasticlayerincontactwiththefluid.Anincidentplanewaveinthefluidmediumstrikestheplateatdif-ferentangles.Therequiredelectricpotentialacrossthepiezoelectriclayertocancelthereflectionfromthefluid/elasticboundaryhasbeendeterminedforthepiezoelectricmaterialPZT-5atvariousthicknessparame-lersandincidentfrequencies.

  • 标签: UNDERWATER ACOUSTIC CONTROL laninated piezoeleetrie plate
  • 简介:ByapplyingtheHeavisidefunction,theequationsgoverninglaminatedplatespossess-ingspatiallydistributedpiezoelectricpatcheshavebeenestablished.Basedontheseequations,staticshapecontroloflaminatedplatesisdiscussed.Byusingageneticandcollocationalgorithm,theopti-mallocationsandscalesofthesepiezoelectricpatcheshavebeenselected.Numericalexamplesarepre-sentedtoillustratetheefficiencyofthealgorithmandthepiezoelectricactuators.

  • 标签: LAMINATED PLATE PIEZOELECTRIC material SHAPE control
  • 简介:有多重时间延期的一个灵活伸臂盘子的活跃控制用分离最佳的控制方法被调查。有多重时间延期的一个控制器被介绍。在这个控制器,时间延期效果在整个控制设计和没有近似在动态系统的数学模型被合并,假设在控制器推导被做,因此系统稳定性容易被保证。而且,这个控制器为两小时间延期和大时间延期是可得到的。建议控制器的可行性和效率这份报纸最后通过数字模拟被验证。

  • 标签: 柔性悬臂 多倍时间滞后 离散优化控制 时间延迟效应
  • 简介:Anewstochasticoptimalcontrolstrategyforrandomlyexcitedquasi-integrableHamiltoniansystemsusingmagneto-theological(MR)dampersisproposed.ThedynamicbehaviorofanMRdamperischaracterizedbytheBouc-Wenhystereticmodel.ThecontrolforceproducedbytheMRdamperisseparatedintoapassivepartincorporatedintheuncontrolledsystemandasemi-activeparttobedetermined.ThesystemcombiningtheBouc-Wenhystereticforceisconvertedintoanequivalentnon-hystereticnonlinearstochasticcontrolsystem.ThenItostochasticdifferentialequationsarederivedfromtheequivalentsystembyusingthestochasticaveragingmethod.Adynamicalprogrammingequationforthecontrolleddiffusionprocessesisestablishedbasedonthestochasticdynamicalprogrammingprinciple.Thenon-clippingnonlinearoptimalcontrollawisobtainedforacertainperformanceindexbyminimizingthedynamicalprogrammingequation.Finally,anexampleisgiventoillustratetheapplicationandeffectivenessoftheproposedcontrolstrategy.

  • 标签: 非线性随机优化控制 随机动态规划 随机平均 滞后MR阻尼器
  • 简介:Thispaperpresentsananalysisoftheactivecontrolofrandomvibrationforlaminatedcompositeplatesusingpiezoelectricfiberreinforcedcomposites(PFRC).WithHamilton’sprincipleandtheRayleigh-Ritzmethod,theequationofmotionfortheresultingelectromechanicalcouplingsystemisderived.Avelocityfeedbackcontrolruleisemployedtoobtainaneffectiveactivedampinginthesuppressionofrandomvibration.Thepowerspectraldensityandmeansquaredisplacementsoftherandomvibrationforlaminatedplatesunderdifferentcontrolgainsaresimulatedandthevalidityofthepresentcontrolstrategyisconfirmed.TheeffectofpiezoelectricfiberorientationinthePFRClayerontherandomvibrationsuppressionisalsoinvestigated.Theanalyticalmethodologycanbeexpandedtootherkindsofrandomvibration.

  • 标签: 纤维增强复合材料 随机振动控制 复合材料层合板 压电式 振动主动控制 瑞利-里兹法
  • 简介:Theeffectivenessofafluid-loadedsandwichedviscoelasticlayerinsuppressingacousticscat-teringandradiationhasbeenestimatedusingtheThomson-Haskellmatrixmethod.TheGU(GaunaurdandUberall)resonancetheoryhasbeenadoptedtohandlethreetypesofviscoelasticsubstrateswithair-filledin-clusions.Theeffectsofthevaryingthicknessofthesubstrates,thevolumefractionsoftheinclusionsandfre-quenciesofincidentwaveshavebeenstubbedtodeterminetheoptimalstrategiesofsignalreduction.Intheinvestigation,themonopoleresonancephenomenaoftheinclusionshavebeentakenintoaccount.

  • 标签: UNDERWATER ACOUSTIC CONTROL LAMINATED VISCOELASTIC plate
  • 简介:BasedontheFloquettheoryonordinarydifferentialequationswithperiodicallyvariablecoefficientsandthebifurcationapproachtononlinearequations,anumericalapproachtodeterminingthestabilityregionofcontrolparametersisestablishedforadynamiccontrolsystemcomposedofamovingbodylevitatedmagneticallyoverflexibleguideways.Thesystemisnonlinearlycoupledamongtheelasticdeformationofguideways,disturbancethelevitationpositionofthebodyandelectromagneticcontrolforces.Thenumericalsimulationisgivenforthesysteminthecaseinwhichthecontrolparametersaretakenwithinandoutofthestabilityregionrespectively.Resultsshowthatthisapproachisreliable.

  • 标签: ELASTIC guideways MAGNETICALLY levitated BODY DYNAMIC
  • 简介:为有致动器浸透的部分可见的非线性的伪Hamiltonian系统的最佳的颤动控制策略被建议。首先,一控制了部分可见的非线性的系统由于Charalambous和Elliott基于定理被变换成有限尺寸的一个完全可见的线性控制系统。然后部分平均它随机的微分方程和动态编程方程与完全可见的线性系统联系了的^o被分别地使用随机的平均方法和随机的动态编程原则导出。最佳的控制法律从解决最后的动态编程方程被获得。结果证明建议控制策略有高控制有效性和控制效率。

  • 标签: 随机动态规划 执行器饱和 哈密顿系统 振动控制 准非线性 动态规划方程
  • 简介:为在有致动器浸透的非白种人的宽带随机刺激下面的强烈非线性的系统的围住的最佳的控制策略被建议。首先,随机的平均方法用概括泛音功能在宽带随机刺激下面为控制强烈非线性的系统被介绍。然后,为浸透的控制问题的动态编程方程被提出从部分平均它吗?方程基于动态编程原则。由无界的最佳的控制组成的最佳的控制和围住的枪战影片控制被解决动态编程方程决定。最后,最佳地控制的系统的反应被解决方程与联系了的减少的Fokker-Planck-Kolmogorov(FPK)预言完成平均它吗?方程。一个例子被给说明建议控制策略。数字结果证明建议控制策略有高控制有效性和效率并且啁啾显著地被减少与枪战影片作比较控制策略。

  • 标签: 非线性系统 最佳控制理论 激励器 饱和度