简介:Lowweightandcompactnessarethemainrequirementsoncomponentsforexoskeletons.Fordrivesthismeansalsohighefficiencytokeepenergystorageandpowertransducingdevicessmall.Thedigitalhydrauliccylinderdriveisanexcellentcandidatetobecomeasuperiortechnologyforexoskeletonactuation.Itrequiresseveralvalvestocontrolpressureinitsmanychambers.Solenoidvalvessufferfromthehighweightandspaceofthesolenoids.Inthispaper,thehydraulicbinarycounterinaconfigurationwithonlypassiveelementsisstudiedmathematically,sinceitcancontroladigitalcylinderwithmuchsmallerspaceandweightthanmagneticallyactuatedvalves.Fromqualitativeconsiderationsofthesystemequationssupplementedbyanumericalstudy,itisshownthatsuchacounterworksproperly.Butitposesrequirementsonthecontrolpressurerangewhicharedifficulttofulfilfordigitalcylinderdriveswithmorethanfivechambers.
简介:Remainingusefullife(RUL)estimationisatopicthathasgainedmoreandmoreattentioninthefieldoffluidpowersystems,thankstothetremendouspotentialsshownforimprovingsafetyandreducedproductionlosses.However,manychallengesrelatedtoRULestimationarenotsolvedyet,mainlyconnectedtothedefinitionofthehealthstatusofeachcomponent.Aprognosticmethodbasedonadata-drivenmethodologyforhydraulicsystemsishereproposedtoestimatethepercentageoflifealreadyspentbythemonitoredcomponents.Thepotentialsofthemethodologyareshownconsideringthecaseofatruck-mountedhydrauliccrane,forwhichasimulationmodelwasavailable.