简介:Anewandefficienttechniquefordeterminingoptimallocationsofsensorsandactuatorsofintelligentstructuresispresented.Theoptimizationofsensorandactuatorlocationsisbasedonthe1stordersingularvalueperturbationsofobservabilityandcontrollability.Usingthismethodtheoptimalplacementsofsensorsandactuatorsoftheintelligentstructurercanbeselected.Twonumericalexamplesaregiventodemonstratetheapplicationsofthemethod.Theimpulseresponsesofstructuresduetodifferentlocationsofactuatorswiththesamecontrollawareanalyzedindetail.
简介:Weproposeatwin-arraycapacitance(TAC)sensorforthemeasurementofconcentration,velocity,andflowrateofgas-solidtwo-phaseflow.Usingthesensitivitynon-uniformityofaneighboringelectrode,theregionalconcentrationofthecross-sectionwasreconstructeddirectly.Additionally,thefiniteelementmethodwasusedtoanalyzethecapacitanceofthesensorscomposedofadifferentnumberofelectrodes.TACsensorswith4,6,and8electrodeswerefoundtobethebestforregionalconcentrationmeasurements.Basedonthis,the8-electrodetwin-planeelectricalcapacitancetomography(ECT)sensor,the4-electrodeTACsensor,andthe6-electrodeTACsensorwereusedtomeasuretheconcentration,velocity,andflowrateofgranulesingranularflow.TheflowratesmeasuredbyECTandTACwerecomparedwiththeflowrateobtainedbyagravitysensortoverifythemeasurementaccuracy.Experimentsonverticalandinclinedpipelineswithgranularflowwerecarriedout.Wefoundthattheflowrateaccuracyofthe4-electrodeTACisdistinctlybetterthanthatofthe6-electrodeTACintheverticalpipelinewhiletheflowrateaccuracyofthe4-electrodeTACandthe6-electrodeTACweresimilarfortheinclinedpipeline.
简介:Basedonthetheoryforsmallfieldssuperposedonrelativelylargerfieldsinanelectroelasticbody,&theoreticalanalysisisperformedonacircularplatethickness-shearcrystalresonatorsealedinacircularcylindricalshellforpressuremeasurement.Asimpleexpressionisobtainedforpressureinducedfrequencyshiftsintheresonator,whichisexaminedfordesignoptimization.Numericalresultsshowthatthefrequencyshiftsdependlinearlyonthepressure,andthatapressuresensorwithasofteroutershellorasmallerthicknessratioofthecrystalplatetotheoutershellhashighersensitivity.