Feature recognition (FR) extracts features and their parameters from solid model.
A large percentage of 2.5D (prismatic) mechanical parts consist of features such as pockets, slots, and steps in addition to holes
The FR library is capable of recognizing these features from B-rep solid models. In Geometric’s FR terminology, such features are termed as volumetric features. A feature solid is created for every recognized volumetric feature. A feature solid is a solid which when added to or subtracted from the base body will result in creation of the particular feature in the base body. Application domains may find different uses for the feature solids. The module supports volumetric feature recognition from part models containing spline as well as analytic surfaces.
Output
After recognizing features, a list of features is given out as output along with the following associated information – feature id, feature type (hole/slot etc.), feature sub-type (blind or through), protrusion or depression, face classification, axis, depth, profile shape etc. For every feature that is recognized, a corresponding feature solid is created.
Automatic Feature Recognition (AFR)
AFR technology is a critical tool in CAD/CAM, specifically in the design and manufacturing of mechanical engineering parts.
Geometric’s AFR automatically recognizes form features such as holes (blind/through), bosses, pockets, slots (blind/through), ribs and corner notches (blind/through) from a given solid model.
- Automatically recognizes transition features such as fillets and chamfers
- The recognized features are versatile and largely domain independent
- A feature solid is created for every recognized form feature. A feature solid is a solid which when added to or subtracted from the base body will result in the creation of the particular feature in the base body. Application domains may find different uses for the feature solids
- Extracts user-defined planar shapes (such as square, tee, ell) and their parameters (such as length and radius) from cross-section profiles of feature solids
- Outputs information on the interactions between features
- Supports feature recognition of bodies containing spline as well as analytic surfaces
- Permits formulation of “compound” holes which are features consisting of more than one “atomic” hole (e.g. a counter-bored hole which is a compound feature formed by two atomic hole features)
- Implemented in C++ language
Interactive Feature Recognition (IFR)
IFR can be applied in cases where certain features are required in specific regions of a solid model.
Overview
It is possible that a feature may be required only one at a time, or in specific regions of a solid model. This is where IFR comes into play.
IFR takes clues from the user on the existence of features. These clues are then used to recognize the features. All modules of the feature recognition library support automatic (i.e. all over the model) and local (i.e. in specific regions, or one at a time) recognition of features.