简介：Thedynamicsofclassicalroboticsystemsareusuallydescribedbyordinarydifferentialequationsviaselectingaminimumsetofindependentgeneralizedcoordinates.However,differentparameterizationsandtheuseofanonminimumsetof(dependent)generalizedcoordinatescanbeadvantageousinsuchcaseswhenthemodeleddevicecontainsclosedkinematicloopsand/orithasacomplexstructure.Ononehand,theuseofdependentcoordinates,likenaturalcoordinates,leadstoadifferentmathematicalrepresentationwheretheequationsofmotionaregivenintheformofdifferentialalgebraicequations.Ontheotherhand,thecontroldesignofunderactuatedrobotsusuallyreliesonpartialfeedbacklinearizationbasedtechniqueswhichareexclusivelydevelopedforsystemsmodeledbyindependentcoordinates.Inthispaper,weproposeadifferentcontrolalgorithmformulatedbyusingdependentcoordinates.Theappliedcomputedtorquecontrollerisrealizedviaintroducingactuatorconstraintsthatcomplementthekinematicconstraintswhichareusedtodescribethedynamicsoftheinvestigatedserviceroboticsysteminrelativelysimpleandcompactform.TheproposedcontrollerisappliedtothecomputedtorquecontroloftheplanarmodeloftheACROBOTERservicerobot.Thestabilityanalysisofthedigitallycontrolledunderactuatedservicerobotisprovidedasarealparametercasestudyforselectingtheoptimalcontrolgains.

简介：Theeffectsofturbulenceontheaerodynamicproperties,especiallysurface-pressurespectraandvortex-inducedvibrations,oftwo-dimensionalrectangularprismswithslendernessratiosof2and4areinvestigatedexperimentally.Particularattentionisgiventoturbulenceintegralscaleef-fectsfromtheview-pointofenergydistributioninfrequencydomain.

简介：Remainingusefullife(RUL)estimationisatopicthathasgainedmoreandmoreattentioninthefieldoffluidpowersystems,thankstothetremendouspotentialsshownforimprovingsafetyandreducedproductionlosses.However,manychallengesrelatedtoRULestimationarenotsolvedyet,mainlyconnectedtothedefinitionofthehealthstatusofeachcomponent.Aprognosticmethodbasedonadata-drivenmethodologyforhydraulicsystemsishereproposedtoestimatethepercentageoflifealreadyspentbythemonitoredcomponents.Thepotentialsofthemethodologyareshownconsideringthecaseofatruck-mountedhydrauliccrane,forwhichasimulationmodelwasavailable.

简介：Aninitial-boundaryvalueproblemforshallowequationsystemconsistingofwaterdynamicsequations,silttransportequation,theequationofbottomtopographychange,andofsomeboundaryandinitialconditionsisstudied,theexistenceofitsgeneralizedsolutionandsemidiscretemixedfiniteelement(MFE)solutionwasdiscussed,andtheerrorestimatesofthesemidiscreteMFEsolutionwasderived.Theerrorestimatesareoptimal.