The use of PROLOG in the automatic recognition of manufacturing features from 2-D drawings

The automatic recognition of form features is widely regarded as an essential requirement for the integration of computer aided design (CAD) and computer aided manufacturing (CAM) in mechanical engineering. Most previous attempts at achieving this goal have been based on the use of solid model representations of the parts to be manufactured. However, solid modelling systems are currently used by only a minority of manufacturing organisations, whereas the vast majority of design data currently exists in the form of 2-D drawings. This paper describes a system, written in PROLOG and running on a PC, which takes as its input a 2-D drawing generated by a PC-based draughting system. The program not only automatically recognises the form features of the part represented by the drawing, but it also generates instructions to drive a numerically controlled machine tool in the manufacture of the part. Thus for the first time CAD/CAM integration appears to be possible for the large number of small and medium-sized companies using PC-based draughting systems.