A practical approach for partitioning free-form surfaces

Abstract

This paper describes a simple but effective method for partitioning free-form surfaces. Here, based on the surface curvatures, a free-form surface can be successfully partitioned into convex, concave and saddle regions. The chain code technique in the image processing field is applied to determine the boundaries of each region. These regions can be separately machined by different kinds and sizes of cutting tool. Therefore, the machining time can be reduced significantly. A B-spline surface is given as an example to demonstrate the proposed method including partitioning and machining. A Matlab® program was developed to perform the surface partitioning task and to get the coordinates of all points on the boundaries. Pro/Engineer® Wildfire 2.0 was used to create the computer-aided design (CAD) model of the free-form surface and generate the tool path for each region for illustration purposes.

Keywords:

• free-form surface, surface partitioning, boundary, chain code.

Acknowledgement

The work upon which this paper is based is a part of MPO FI-IM5/065 research program grant at the Technical University of Liberec, Czech Republic.