Research Of Ontology-based Manufacturability Analysis Method Of Parts Design

When enterprise product design scheme is delivered to the manufacturing factory, difficult problems in the real conditions come out, such as lack of design parameters and corresponding process technology and machine tool equipment. Design and manufacturing units need to modify the product scheme again and again. The manufacturability analysis of mechanical parts is one of the effective ways to solve these problems. Manufacturability analysis definition of parts is widespread, congsidering the blank manufacturing, machining, heat treatment, assembly and maintenance.However, manufacturability analysis of parts is lack of effective knowledge expression and reasoning method.Considering these problems, this thesis puts forward ontology-based manufacturability analysis method the component design manufacturability analysis method, combining with the characteristics of ontology knowledge expression and reasoning. The manufacturability analysis method is studied in two aspects, namely the machinability and the assembling ability of parts.This thesis main research content is as follows:(1) Design ontology of parts is built, which consists of foundation layer, domain layer and instance layer. Foundation layer extracts core design and manufacturing from the STEP standard (ISO 10303 AP224), and determines the relationship between the core concepts. Foundation layer is expressed by OWL language. Domain layer is on the basis of foundation layer construction. On the one hand, domain layer contains expanded concepts and relations.On the other hand, rules library for manufacturability verification is build, which is expressed by SWRL language. In the instance layer, each size dimension of instance parts will be assigned the corresponding value.(2) The ontology reasoning machine for manufacturability analysis is put forward. Product design facts based on OWL Language (Web Ontology Language) and manufacturing constraints based on the and SWRL Language (Semantic Web Rule Language) can respectively be translated to JESS (Java Expert System Shell) facts and JESS rules. JESS reasoning machine can provide production advice.(3) The method of semantic ontology inference and query for assembling is proposed, which uses SWRL and SQWRL (Semantic Query-Enhanced Web Rule Language) to achieve the query and high-level reasoning function. The ontology inference framework for assembling is studied, which is divided into knowledge base layer, logic layer and application interface layer. The reasoning units in logic layer are emphasized in our research. We design seven reasoning units.(4) The manufacturability analysis system for parts design is developed, which aims to help designers find design problems in time, and correct problems before processing and manufacturing. The system verifies the effectiveness of the proposed method and theory.