简介：TheControlTheoryandTechnology(CTT)publisheshighqualitypapersonthetheory,designandapplicationsinthesystemsandcontrolfield.Topicsofinterestsofthejournalareinthebroadareaofsystemscontrolandautomation,includingbutnotlimitedto:SystemTheoryandControlTheory,NonlinearSystemsandControl,ComplexityandComplexSystemTheory,Modeling,IdentificationandEstimation,OptimalControlandOptimization,RobustandH-infinityControl,Learning

简介：Frictiondragprimarilydeterminesthetotaldragoftransportsystems.ApromisingapproachtoreducedragathighReynoldsnumbers(>104)areactivetransversalsurfacewavesincombinationwithpassivemethodslikearibletsurface.Fortheapplicationintransportationsystemswithlargesurfacessuchasairplanes,shipsortrains,alargescaledistributedreal-timeactuatorandsensornetworkisrequired.Thisnetworkisresponsibleforprovidingconnectionsbetweenaglobalflowcontrolanddistributedactuatorsandsensors.ForthedevelopmentofthisnetworkweestablishedatfirstasmallscalenetworkmodelbasedonSimulinkandTrueTime.TodeterminetimescalesfornetworkeventsondifferentpackagesizeswesetupaRaspberryPibasedtestbedasaphysicalrepresentationofourfirstmodel.Thesetimescalesarereducedtotimedifferencesbetweenthedeterministicnetworkeventstoverifythebehaviorofourmodel.Experimentalresultswereimprovedbysynchronizingthetestbedwithsufficientprecision.Withthisapproachweassurealinkbetweenthelargescalemodelandthelaterconstructedmicrocontrollerbasedreal-timeactuatorandsensornetworkfordistributedactiveturbulentflowcontrol.

简介：Adual-stageservosystemconsistsofaprimarycoarseactuatorforfacilitatinglargemotionandasecondarymicro-actuatorforsmallbutprecisemotiontoimprovetrackingperformance.Piezoelectricmicro-actuatormadefromleadzirconatetitanate(PZT)hasbeenapopularchoiceforthesecondarystage.However,theadvantagegainedbytheresolutionofthesecondaryPZTactuatorisreducedbyitsinherenthysteresisnonlinearity.Modelbasedhysteresiscompensationtechniquesarepreferredduetotheirsimplicityandfastresponse.Identificationandmodelingaretwosubstantialpartsinsuchmodel-basedtechniques.ThispaperpresentsarigorousanalysisandmodelingofthehysteresisofPZTmicro-actuator.ModifiedGeneralizedPrandtl-IshlinskiiandColeman-Hodgdonmodelsarestudied.Identificationofthemodelthroughnonlinearleastsquareandparticleswarmoptimizationareexaminedandcompared.Severalanalysesaredonethroughtuningofthemodelparametersandidentificationtechniques.Experimentalanalysisandsimulationresultsunderscoretheeffectivenessofthismodelingapproach.Finallyasadesignexample,adual-stagesimulationanalysisisdonetoshowtheeffectivenessofsystematicmodelingonhysteresiscompensation.

简介：Thispaperdealswiththevectorcontrol,includingboththedirectvectorcontrol(DVC)andtheindirectvectorcontrol(IdVC),ofinductionmotors.ItiswellknownthattheestimationofrotorfluxplaysafundamentalroleintheDVCandtheestimationofrotorresistanceisvitalintheslipcompensationoftheIdVC.Intheseestimations,theprecisionissignificantlyaffectedbythemotorresistances.Therefore,onlineestimationofmotorresistancesisindispensableinpractice.Forafastestimationofmotorresistances,itisnecessarytoslowdowntheconvergencerateofthecurrentestimate.Ontheotherhand,forafastestimationoftherotorflux,itisnecessarytospeedupitsconvergencerate.Itisverydifficulttorealizesuchatrade-offinconvergenceratesinafullorderobserver.Inthispaper,weproposetodecouplethecurrentobserverfromthefluxobserversoastorealizeindependentconvergencerates.Then,theresistanceestimationalgorithmisappliedtobothDVCandIdVC.Inparticular,intheapplicationtoIdVCthefluxobserverneedsnotbeused,whichleadstoasimplerstructure.Meanwhile,independentconvergenceratesofcurrentobserverandfluxobserveryieldanimprovedperformance.Asuperiorperformanceinthetorqueandfluxresponsesinbothcasesisverifiedbynumeroussimulations.

简介：Thispaperpresentsanapplicationofgain-scheduling(GS)controltechniquestoafloatingoffshorewindturbineonabargeplatformforaboveratedwindspeedcases.Specialemphasisisplacedonthedynamicsvariationofthewindturbinesystemcausedbyplantnonlinearitywithrespecttowindspeed.Theturbinesystemwiththedynamicsvariationisrepresentedbyalinearparameter-varying(LPV)model,whichisderivedbyinterpolatinglinearizedmodelsatvariousoperatingwindspeeds.Toachievecontrolobjectivesofregulatingpowercaptureandminimizingplatformmotions,bothlinearquadraticregulator(LQR)GSandLPVGScontrollerdesigntechniquesareexplored.ThedesignedcontrollersareevaluatedinsimulationswiththeNREL5MWwindturbinemodel,andcomparedwiththebaselineproportional-integral(PI)GScontrollerandnon-GScontrollers.ThesimulationresultsdemonstratetheperformancesuperiorityofLQRGSandLPVGScontrollers,aswellastheperformancetrade-offbetweenpowerregulationandplatformmovementreduction.

简介：In4-strokeinternalcombustionengines,air-fuelratiocontrolisachallengingtaskduetotherapidchangesofenginethrottle,especiallyduringtransientoperation.Toimprovethetransientperformance,managingthecycle-to-cycletransientbehaviorofthemassoftheair,thefuelandtheburntgasisakeyissueduetotheimbalanceofcycliccombustionprocess.Thispaperaddressthemodel-basedestimationandcontrolproblemforcyclicair-fuelratioofspark-ignitionengines.Adiscrete-timemodelofair-fuelratioisproposed,whichrepresentsthecycle-to-cycletransientbehaviorofin-cylinderstatevariablesundertheassumptionsofcyclicmeasurabilityofthetotalin-cylinderchargemass,combustionefficiencyandtheresidualgasfraction.Withthemodel,aKalmanfilter-basedair-fuelratioestimationalgorithmisproposedthatenableustoperformafeedbackcontrolofair-fuelratiowithoutusinglambdasensor.Finally,experimentalvalidationresultisdemonstratedtoshowtheeffectivenessofproposedestimationandcontrolschemethatisconductedonafull-scaledgasolineenginetestbench.

简介：Theproblemofair-fuelratio(AFR)controloftheportinjectionsparkignition(SI)engineisstillofconsiderableimportancebecauseofstringentdemandsonemissioncontrol.Inthispaper,thestaticAFRcalculationmodelbasedonin-cylinderpressuredataandontheadaptiveAFRcontrolstrategyispresented.Themodelutilisestheintakemanifoldpressure,enginespeed,totalheatrelease,andtherapidburnangle,asinputvariablesfortheAFRcomputation.Thecombustionparameters,totalheatrelease,andrapidburnangle,arecalculatedfromin-cylinderpressuredata.ThisproposedAFRmodelcanbeappliedtothevirtuallambdasensorforthefeedbackcontrolsystem.Inpracticalapplications,simpleadaptivecontrol(SAC)isappliedinconjunctionwiththeAFRmodelforport-injectedfuelcontrol.TheexperimentalresultsshowthattheproposedmodelcanestimatetheAFR,andtheaccuracyoftheestimatedvalueisapplicabletothefeedbackcontrolsystem.Additionally,theadaptivecontrollerwiththeAFRmodelcanbeappliedtoregulatetheAFRoftheportinjectionSIengine.

简介：ThisworkisaimedtorigorouslymanagevoltagesaturationandmaximumcurrentconstraintsinShuntActiveFilters.Inthisrespect,assuming'unconstrained'controlalgorithmshavealreadybeendefinedtoachievestandardobjectivesforsuchdevices(i.e.currenttrackingforharmoniccompensationandDC-busvoltageboundness),aplug-inunit,orientedtoextendthesystemoperatingregionandatthesametimepreservinggoodperformanceunderlargetransientsandoverloadconditions,ispresented.Thissolutionallowstoimproveavailability,robustnessandcomposabilityofShuntActiveFilters,whichareexpectedtobekeyfeaturesinpresentandnextgenerationcomplexandpossibly'smart'powergrids.Theproposedunitiscomposedbytwoparts.First,asuitableanti-windupstrategyisdefinedinordertodealwithcontrolinputsaturation.Itsmainpurposeistopreservetheoriginal'unconstrainederrordynamics',infaceofinputsaturation,whileguaranteeinglowcomputationalburdenandreducedperformanceimpairment(thelattergoal,inharmoniccompensationcontext,leadstorathernon-standardproblemformulation).Tothisaim,theanti-windupactsonthecurrentreferencesthroughasuitably-designedadditionaldynamics.Then,inordertocopewithcurrentlimitations,anadditionalstrategyhasbeendesigned;againthecurrentreferencesissuitablyshapedtocomplywiththefeaturesandboundsofthesystem,augmentedwiththeabove-mentionedanti-windupsolution.TheproposedschemecanbesimplyjoinedtoanykindofunconstrainedcontrolleradoptedtosteerShuntActiveFilters.Inthiswork,anInternal-Model-basedcurrentcontrollerisadoptedasabenchmarkcase.Theproposedapproachisvalidatethroughextensivesimulationtests.

简介：Thispaperproposesadecentralizedoutputfeedbackcontrolschemeappliedtotwo-areainterconnectedpowersystem.ThecontrollersynthesisproblemisformulatedasthescaledH∞controlproblemandanewLMI-basedalgorithmisproposedtocomputethedecentralizedcontroller.TheproposedcontrollerprovidesrobustnesswithregardtoparametricuncertaintiesandalsoattenuatesboundedexogenousdisturbancesinthesenseofL2-gain.Simulationresultsclearlyshowtheeffectivenessofdevelopeddecentralizedoutputfeedbackcontrolscheme.

简介：Thispaperdiscussesadistributeddecisionprocedurefordeterminingtheelectricitypriceforareal-timeelectricitymarketinanenergymanagementsystem.ThepricedecisionalgorithmproposedinthispaperderivestheoptimalelectricitypricewhileconsideringtheconstraintsofalinearizedACpowergridmodel.Thealgorithmisbasedonthepowerdemand-supplybalanceandvoltagephasedifferencesinapowergrid.Inordertodeterminetheoptimalpricethatmaximizesthesocialwelfaredistributivelyandtoimprovetheconvergencespeedofthealgorithm,theproposedalgorithmupdatesthepricethroughthealternatingdecisionmakingofmarketparticipants.Inthispaper,weshowtheconvergenceofthepricederivedfromourproposedalgorithm.Furthermore,numericalsimulationresultsshowthattheproposeddynamicpricingmethodologyiseffectiveandthatthereisanimprovementintheconvergencespeed,ascomparedwiththeconventionalmethod.

简介：探讨了漂浮基空间机械臂系统在轨捕获参数未知目标卫星后组合体航天器的镇定控制问题.首先在耦合空间机械臂系统捕获目标卫星操作过程动量、冲量的传递的基础上,建立了适用于漂浮基空间机械臂系统在轨捕获漂浮卫星控制系统设计的组合体航天器数学模型.利用该模型,设计了一种基于模糊高斯基神经网络的非奇异Terminal滑模控制算法.提出的控制算法不仅不要求系统动力学方程关于惯性参数呈线性函数关系,而且也不需要预知系统惯性参数;由于利用神经网络的自学习能力修正模糊控制的控制规则和隶属函数,这样在系统参数识别中,模糊神经网络可减少模糊规则数,更适应于空间机械臂系统在轨捕获的实际应用.最后通过仿真试验对比结果验证了所提出的控制算法的有效性.

简介：使用Chebyshev-Gauss(CG)伪谱法研究带动量轮和推力器的欠驱动航天器姿态最优控制问题.基于欧拉姿态角和动量矩定理导出两类航天器姿态运动模型,采用Clenshaw-Curtis积分近似得到性能指标函数中的积分项,应用重心拉格朗日插值逼近状态变量和控制变量,将连续最优控制问题离散为具有代数约束的非线性规划(NLP)问题,通过序列二次规划(SQP)算法求解.数值仿真结果表明,对两类欠驱动航天器的姿态机动最优控制均能达到设计控制要求,得到的姿态最优曲线与验证得到的曲线几乎完全重叠.

简介：针对地球静止轨道空间碎片清除需求,开展了服务星通过绳索拖拽空间碎片离轨多体动力学与控制仿真研究.分析了在轨拖拽期间系统拓扑构型,采用递推方法推导了考虑地球J2摄动的服务星和空间碎片柔性多体动力学方程组,建立了基于集中参数法的绳索动力学模型,通过约束方程将绳索与服务星和空间碎片相连接,建立了服务星姿态控制力矩方程,最后形成了服务星在轨拖拽空间碎片期间柔性多体系统多体动力学方程.通过悬链线模型与本文采用的集中参数模型的比较验证了本文采用的柔性绳索模型的正确性,然后通过数值仿真分析了与服务星质量接近的空间碎片被拖动期间动力学特性,为这类航天器总体设计及空间碎片清除策略制定提供了参考依据.

简介：基于拉格朗日描述的柔性多体系统动力学理论,采用绝对节点坐标有限元方法描述液体大变形运动,开展铁路液罐车内液体晃动模拟研究.本方法能够模拟液体自由表面的连续性变化,并适用于研究具有复杂外形容器的内部液体晃动问题.基于流体力学牛顿体基础理论,推导液体粘性方程和满足体积不可压缩的条件方程;采用基于绝对节点坐标方法描述的实体单元进行液体网格划分;采用罚函数方法描述液体与罐体之间的接触关系,组建液体-罐体耦合多体系统动力学方程.仿真计算液罐车内液体的横向和纵向晃动行为,发现液体自由表面形状呈非线性变化,不同断面处的高度和形状不同.

简介：电动太阳风帆(简称电动帆)是一种利用太阳风动能冲力飞行的新兴无质损飞行器.针对电动帆传统推力模型中忽略了姿态对推力幅值影响的问题,本文推导得出了一种解析形式的改进推力模型,并与最新的多项式拟合改进推力模型进行了对比.对比结果显示两种改进推力模型数值结果很接近,但本文的解析改进推力模型形式更简单.为了重新评估电动帆在深空探测中的性能,以地球至火星的飞行任务为算例,分别采用传统推力模型和解析改进推力模型进行了电动帆轨迹优化仿真.仿真结果显示,在相同特征加速度情况下,采用改进解析推力模型完成任务所需时间,大于采用传统推力模型所用时间.上述现象的原因在于传统推力模型中忽略了姿态改变对推力加速度大小的影响,并高估了电动帆所能产生的最大推进角.

简介：空间绳网的展开效果是空间绳网捕获任务成功的关键所在,而空间绳网展开效果的性能指标和设计参数都数目较多,且单次仿真试验耗时较长,为了避免进行耗时极长的全析因仿真试验,考虑采用正交试验设计方法以减少试验次数.本文针对影响空间绳网展开效果的设计参数开展了灵敏度分析,首先提出了空间绳网展开的性能指标和设计参数,然后基于正交试验设计安排仿真试验,获得了正交试验结果,最后综合运用极差法和方差法,对正交试验结果的各项性能指标依次进行了参数灵敏度分析.通过本文研究,精简了设计参数和待优化的性能指标的个数,为下一步的空间绳网展开参数优化设计打好了基础.

简介：本文主要研究了含间隙运动副桁架单胞的等效建模方法.主要考虑了桁架单胞的等效刚度问题以及阻尼问题.首先从间隙铰链开始研究,提出全面的铰链模型;其次提出用位移法将桁架单胞等效成板,即把桁架单胞看成是由梁元组成的钢架结构,运用平面钢架位移法得出桁架单胞的等效刚度矩阵,进而得出结构的整体固有频率和等效后的板的刚度矩阵.最后用有限元软件ANSYS对单胞结构在不同边界条件下进行了模态分析,将在自由边界条件下的固有频率和解析得出的频率做了对比,发现二者有很好的吻合度.结果表明由于间隙运动副的存在,使得桁架单胞结构的刚度降低,柔性增强.

简介：为研究含间隙齿轮碰振系统的全局及周期运动的稳定性及分岔条件,建立了齿轮副主动轮的单自由度非线性动力学模型.运用非光滑系统Melnikov理论研究齿轮系统异宿轨道全局分岔条件,然后,求得各分段系统的通解,再将每个切换面作为Poincaré截面,运用组合映射的方法分析系统的周期运动特性.最后通过数值模拟,得到不同参数条件下系统的运动状态和分岔特性,验证了Melnikov方法分析齿轮非光滑系统的有效性.

简介：建立了直齿行星齿轮的动力学模型.其中,齿与齿之间的啮合非线性由弹簧-阻尼器-间隙-啮合误差环节模拟.提出了一种以行星轮转角为变量的时变啮合刚度与时变啮合误差表达形式,解决了变转速下行星齿轮动力学模型的描述和求解问题.通过对动力学模型进行求解,分别研究了转速、齿侧间隙、啮合误差和负载等重要参数对行星齿轮动力学特性的影响.

简介：考虑执行机构性能、传感器空间指向等复杂约束,研究了空间飞行器姿态机动的路径规划问题.建立了姿态机动路径规划模型,并通过使用微分平坦理论将其映射到平坦输出空间,消除微分方程约束的同时降低设计空间维数;给出了平坦输出参数化描述的伪谱法,并运用共形映射、重心插值等技术改善了微分矩阵的病态特性,提高了路径规划的精度.仿真表明:该方法能够较快规划出满足约束的姿态机动路径,对工程应用具有一定参考价值.