Abstract: Applies a kind of fuzzy set method, called fuzzy clustering analysis, to select HSS (High Speed Steel) grades for scheduled operation of machining center and presents a new fuzzy clustering algorithm integrating fuzzy set with expert system. An expert module is described here, which is a part of tool selection package embedded in CNC system developed by the authors. The specified physical and mechanical properties of tool materials are used as clustering features. The technological knowledge of the module is structured in production rules. The corresponding knowledge model and the algorithm are illustrated with exmples in detail. There are indications that the principle of the method can also, be applied to other fields, so it is of certain theory significance and considerable practical value.

Key words: CNC, Expert system, Fuzzy clustering, Material, Tool