Research on the knowledge recognition and modeling of machining feature geometric evolution

To discover the knowledge from the machining process planning, it is important to obtain the geometric change of machining feature firstly. This paper proposed a methodology to acquire and describe the change process of machining feature. First, the concept of global machining datum is presented to construct the attributed adjacency graph for faces on the process model. The datum attribute of the vertex correspondent to the face is the unique identifier of correspondent face in the process model sequence. The datum attribute of the vertex, corresponding to the model face, is used to discern the correspondent faces in adjacent process model sequence. Second, the new faces, extinct faces, and maintained faces in adjacent procedure are classified by detecting the parameter changes. Third, with the help of the change types and interrelation of the faces, an algorithm is presented for geometric changes recognition of machining feature. As a result, the change process of a machining feature is discerned as a sequence of machining status. At last, the evolution of machining feature recognition method is verified with an example of machining process planning.