Structure coding method for part engineering drawing

A kind of structure code based on part engineering drawing structure models is proposed. The geometric graph of part engineering drawing is labeled as functional surface. The functional surface which is attached topologically is determined according to the fact that whether they are in the common edge, or whether they have concurrent or point in the edge, and then the position relationship and distribution relationship between functional surface is also decided. Finally 2D structure model of part is generated. By referring to the linear symbolic notation for compounds in chemical database, a structure coding method is presented. The similar structure engineering drawing is retrieved by structure coding.