轎車前圍模具數(shù)字化開發(fā)中逆向工程系統(tǒng)研究.pdf

1、上海大學碩士學位論文轎車前圍模具數(shù)字化開發(fā)中逆向工程系統(tǒng)研究姓名：萬軍申請學位級別：碩士專業(yè)：機械制造及其自動化指導教師：鞠魯粵20040201上海大學研究生論文用紙AbstractReverseEngineeringisakindofcomputeraideddesigntectmologythatcantransformphysicalobjectsintodigitalmodelspresentedincomputerItiswi

2、delyusedinindustrialproducts’designanddevelopingactivitiesThisPaDermakesathoroughandsystematicresearchofreverseengineeringtechnologyanddevelopsareverseengineeringsystemtoMfiltherequirementsof“SAN2000frontmoldsdigitizing”

3、projectThesystemconsistsoffiveparts，whicharethreedimensionalmeasuring，datapreprocessing，datasegmentation，surfacefittingandgraphexportrespectivelyThepaperisfocusedOffthereverseengineeringsystemandtheprinciples，methodsandi

4、mplementationsofeachpartofthereverseengineeringsystemaredepictedindetaijwithexamplesThemaincontentofthepaperiSjntroducedbrieflyasfollows：】Analyzingandcomparingvariousthreedimensionalmeasuringmethods，employingnon—contacto

5、pticalthreedimensionalmeasuringmethodtomeasure血ecoordinatesofthesurfacesoffrontmoldsandobtainaJargequantityofpointcloudsrepresentingthesurfaceinformation；2Makingpre—processingproceduresonthepointclouds，includingnoiseelin

6、fination，smoothinganddatareduction，puttingforwardanewmethodfordatareduction；3Segmentingthepointcloudsintosmallerpartusingacombinationofedgebasedmethodsandcurvaturebasedmethods；4Fittingsegmentedpointcloudsintosurfaceswith

7、amethodbasedonNURBSblendingalIthesurfacesintoonewholesurfaceusingextending，trimming，mergingandetc，，keepingthesurfacesincurvaturecontinuity；5EmployiugOpenGLmethodtoimplementtherepresentationofNURBSsurfacesincomputer；6Disc

8、ussingtheissue011graphexportandchoosingtheIGESformatastheexportstandard；7PuttingforwardtheflowchartofreconstructionprocessesforfrontmoldsThereverseengineeringsystemisappliedinShanghaiVolkswagenAutoCompany’Smoldsdigitizin

9、gprojectandhasachievedgoodresultsThroughthedevelopingoftheproject，ShanghaiVolkswagenCandoCAD／CAManalysisestoautofrontsmoldsmadfinishthemachiningofmoldsinNCcenterinaprecisewayThus，itCanchangethedesignofSAN2000autoByapplyi