Automatic feature recognition from engineering drawings

Recognising features from 2D engineering drawings is one of the most important issues facing advanced integrated design and manufacturing. Although the problem of recognising features from a solid model has been extensively studied, most existing product models are expressed as engineering drawings. Moreover, the solid model can only provide complete 3D topological and geometrical data. Some essential machining information cannot be retrieved. In this study, an automatic transfer system is proposed with the capability of recognising linear swept features from engineering drawings. The swept profiles are first extracted from drawing views, then features can be identified from the swept profiles using a set of recognition rules. In addition to the feature types and their geometry, some annotations of drawings, e.g. dimensions and geometric tolerances, can also be recognised and attached to the recognised features by this approach.