Feature Recognition of Freeform Surfaces for CAD/CAM Integration

The computer aided design and manufacturing CAD/CAM integration systems were focused on product representation techniques or product modeling. In product design process trends are currently tend to use freeform surface that modeling by using (Non-Uniform Rational B-Spline Surface (NURBS), B-spline, Bezier) technique to suit aesthetic, functional and manufacturability requirements. Set of problem are faced difficulties in recognizing freeform feature such polishing process after the finishing machining process by multi-axis CNC machine, sheet metal forming, and freeform surface machining. In this research, a new developed methodology has been introduced for automatic recognition of the depression and protrusion features. The 3D CAD solid model is designed by freeform surfaces of non-uniform B-spline technique and then extracts their parameter by IGES standard format file. The developed methodology has four major steps: Subdivision of Non-uniform B-spline surface, surface analysis, primitives shape detection, and recognition of geometric features.