Study on Case—Based Fixture Design.pdf

维普资讯 Intemational JournalofPlantEngineeringandManagement Vo1．7 No．4 December2002 Studyon Case-BasedFixtureDesign SHIQi。YANGHai—cheng，LIYuan， StateKeyLaboratoryofCAD／CAM ，Northwestern Polytechnical University。Xi 710072，P．R．China reasoning(CBR)isproposedinthsipaper．A methodofcaserepresentationOnthebassioffixture _ functoinsipresented，wherethe caserepresentatoinsiconstitutedofworkpieceknowledge，processing #aatreknoweldge，andfixturefeatureknoweldge．Running theprototypesystemshowsthattheknowl— edgerepresentatoinmethod．using eases，si口betterwayottransformand explainthe des~nknowl‘ edge． Keywords：case．basedreasoning，fixturedesign，knowledgerepresentation，caes retrieval 1 Introduction Fixturesareworkholdingdevicesandareusedinmostofthemanufacturingoperationssuchasma— chining，assembly，inspection，etc．Aspartofmanufacturingplanning，fixturedesing canbeama‘ iorcontributortohtemna ufacturing，lead—time，na dhtecostofaproduct．Owingtohtegreatvarieyt ofpartsandmanufacturingoperations，hteprocessesoffixturedesing becomemorecomplexandan— controlled．Moreover。htedesing ofafixturereliesheavilyonhtedesing ergexpertisena d experience aswe11aSthedatafrom manufacturing．processing，technical，nadparts¨ ．A computer—aidedfix‘ turedesing (CAFD)techniquehasbeendevelopedaspartofCAD／CAM intergation ．Nowadays， CAFDplaysna importantroleinflexiblemanufacturingsystems(FMS)andcomputerin‘tergated manufacturingsystems(CtMS)引．Thefirstthinghtatmustbeconsideredbyemployingacomputer infixturedesing istoesatblishasuiatbledesing planningmode1．Thepresenattionmehtod ofknowl- edgeusedindesignandhtedesing ergexperienceareesesntialtoestablishasuccessfulfixturedesing system ． Compared to classicalrule—based reasoning nad mod