简介:Computervisionhascomeintousedinthefieldsofweldingprocesscontrolandautomation.Inordertoimproveprecisionandrapidityofweldingimageprocessing,anovelmethodbasedonfractaltheoryhasbeenputforwardinthispaper.Comparedwithtraditionalmethods,theimageispreliminarilyprocessedinthemacroscopicregionsthenthoroughlyanalyzedinthemicroscopicregionsinthenewmethod.Withwhich,animageisdivideduptosomeregionsaccordingtothedifferentfractalcharactersofimageedge,andthefuzzyregionsincludingimageedgesaredetectedout,thenimageedgesareidentifiedwithSobeloperatorandcurvedbyLSM(LeaseSquareMethod).Sincethedatatobeprocessedhavebeendecreasedandthenoiseofimagehasbeenreduced,ithasbeentestifiedthroughexperimentsthatedgesofweldseamorweldpoolcouldberecognizedcorrectlyandquickly.
简介:Adual-beamelectronicspecklepatterninterferometry(ESPI)systemwasadoptedtogetspecklepatternsforthemeasurementofweldingdynamicdisplacementfields.Themathematicalmodelofthissystemwasdescribed,basedonwhichmethodsoftheESPIpatternimageprocessingwerediscussed.Graytransformationandhistogramequalizationwereusedtoenhancethecontrastofspecklepatterns.Adiscretecosineimageprocessingmethodwascarriedoutandanexponentlow-passfilterwaschosentoreducemultiplicativenoiseinspecklepatterns.Specklegrainnoisecanbeeliminatedeffectivelyaftertheseprocesses.
简介:Asadepositiontechnology,gasmetalarcwelding(GMAW)hasshownnewpromiseforrapidprototypingofmetallicparts.DuringtheprocessofmetalformingusingthearcofGMAW,lowheatinputandstabledroplettransitionarecriticaltohighqualityfiguration.TheeffectsofvariousprocessingparametersonfigurationqualitywerestudiedintheexperimentofGMAWrapidprototypingusingthewireofER50-6,includingweldingvoltage,wirefeedingrate,weldingspeedandsoon.TheoptimalparametersforER50-6areobtained.Simultaneously,itisverifiedthattherapidprototypingpartswithfavorablestructuresandqualitycanbeachievedundertheconditionsoflowheatinputandstabledroplettransition.
简介:AnexperimentalsetupofacquiringthecoaxialvisualimageofthemoltenpoolandkeyholeinhighpowerNd:YAGlaserweldingisintroducedinthispaper.Itisoneofthemostdifficultproblemsinacquiringcoaxialimagethatthecoaxialimagingsignalofmoltenpoolandkeyholemustbeseparatedfromthelaserbeamwithhighpower.Thisproblemwasresolvedbydesigningadichroiticspectroscope.Thecharacteristicsofimagingsignalwereanalyzedandthecoaxialimageofmoltenpoolandkeyholewasacquired.Asmoothingfilterandahomomorphicfilterweredesignedtoremovethelowfrequencynoiseandtoenhancetheimageaccordingtothecharacteristicsofimagingsignal.Atlast,edgesofmoltenpoolandkeyholeweredetectedandextractedbasedonimagesegmentationwiththreshold.