EXTRACTING ALTERNATIVE MACHINING FEATURES - AN ALGORITHMIC APPROACH

Automated recognition of features from CAD models has been attempted f or a wide range of application domains. In this article we address the problem of representing and recognizing a complete class of features in alternative interpretation for a given design. We present a methodo logy for recognizing a class of machinable features and addressing the computational problems posed by the existence of feature-based altern atives. Our approach addresses a class of volumetric features that des cribe material removal volumes made by operations on three-axis vertic al machining centers, including drilling, pocket-milling, slot-milling , face-milling, chamfering, filleting, and blended surfaces. This appr oach recognizes intersecting features and is complete over all feature s in our class; i.e., for any given part, the algorithm produces a set containing all features in our class that correspond to possible oper ations for machining that part. This property is of particular signifi cance in applications where consideration of different manufacturing a lternatives is crucial. This approach employs a class of machinable fe atures expressible as MRSEVs (a STEP-based library of machining featur es). An example of this methodology has been implemented using the ACI S solid modeler and the National Institute's of Health C + + class lib rary.