The CAD/CAPP Integration Technology And System Development For Box-type Part

Intensified market competition requires increasingly higher levels ofintegration and information and shorter time from design to manufacturingin enterprise product development processes to implement the integrationof design information and manufacturing information. The CAPP system,as a connecting link to design and manufacture, its productivity and qualityhave a significant impact on product development cycle and quality.For a rapid information conversion from design to manufacturing, thisarticle, oriented by specific needs in enterprise, selects the box-type partfor the study, by means of feature recognition technology to implement theintegration of CAD, CAPP, and develops a CAD/CAPP system.Feature recognition is an effective methods of manufacturinginformation conversion from design information, and it generally usesFAG to recognize the pre-defined features with access to information of allsurfaces and all edges. Feature recognition algorithm proposed in thispaper for the box-type parts, whose surfaces are more than its holes and areselected as the reference and measurement basis, mainly makes use of facemutual positional relationship to achieve feature matching authenticationbased on traces and the rule. The algorithm avoids a large number ofedges’ analysis process and can effectively identify the mostly usedfeatures such as holes, cavities, slots, and other features, and get thefollow-up process information, such as main reference information, theroughness, feature reference relationship, feature dependency.To take full advantage of the feature information obtained, theCAD/CAPP system integrates the genetic algorithm-based and constraineddecision-making function, whose optimization tool is the genetic algorithm, and it selects the processing cost optimization objectives. With penaltyfunction method, the introduction of the constraint relations to theobjective function ensures the reasonableness of the final process route andeconomy.Based on Pro/E as a platform for the development of CAD/CAPPsystem, this article uses the feature recognition algorithm to identifycommon features of the box-type parts, and combined with the support ofprocess database, the processes for one feature are gotten, then idealprocess with further cost can be calculated using genetic algorithm. TheCAD/CAPP system effectively verifies the accuracy and reasonableness ofthe proposed feature recognition algorithm, while helps develop processquickly, so it has a certain practical value.