Automatic classification of 2 1/2 D components

Defining a number of plausible component setups for CNC manufacturing operations is a vital first step that must be taken before more detailed process planning can be done. Typically 2 1/2 D machined components are designed with a particular direction of manufacture implicit in their geometry, which, because humans are good at assessing shape, is never explicitly recorded. If totally automatic manufacturing systems are to be created, algorithms must be developed which define the 2 1/2 D aspects of a component with perspicuity. With this as an objective, the paper first defines several distinct classes of 2 1/2 D component (single, double and multi-sided) and then outlines an algorithmic approach for automatically distinguishing between them. For strictly single and double-sided components the tool approach directions are found, and the presence of overhung material detected. The method demonstrates how useful geometric reasoning can be performed without developing a complete understanding of an object's shape.