Semantic Web Technology Based Study On Mechanical Design Methods And Techniques

With the cross merging of artificial intelligence and internet technologies, the Semantic Web technologies, whose aim is realizing the automatic manipulation of information contained in normal Web pages, are developing fast and becoming ripe. At the same time, in many fields like biology, geography, library and information etc., the application studies of Semantic Web technologies are already under way. The application study of Semantic Web technologies in mechanical design field is already start up and becoming research focus. While, at present, research activities are mainly focused on information and knowledge integration, for example, design knowledge sharing, reusing and cross-plateform interoperation etc. Few studies devote themselves into the studies of Semantic Web technologies based mechanical design methods and automatic utilization of design information. Funded by national natural science foundation project named "Study on CAD knowledge and engineering semantic based design knowledge reuse oriented by middle and small enterprise", this thesis performs several key techniques studies on ontology and semantic web based mechanical design.On the basis of summarizing the existent ontology construction methods, by consulting other domain ontology construction methods and by combining personal experience in mechanical domain ontology construction, a domain ontology construction method, which is considered to be more comprehensive, is proposed. With the construction of requirement design ontology as a case, the pheasibility of this method is proved.With regard to the innovative design, by combining ontology and Semantic Web technologies, which aim to realize reuse and sharing of information and knowledge, with theory of inventive problem solving TRIZ, method of solving technical conflict based on ontology is proposed and the flow chart of solving technical conflict based on ontology is given. By making use of ontology compile software Protege and ontology description language OWL, on the base of technical conflict solution theory, which comes from TRIZ, the technical innovation ontology is constructed, which paves way for ontology based technical innovation in semantic web in the future.With regard to the adaptive design, a new case representation and case revision method based on domain CBR ontology is proposed. In this method, the reusability of case base is improved by making use of ontology to represent cases. The successful rate of case revision is raised by adding case feature intention class to domain CBR ontology. Firstly, with classical concept of ontology and CBR theory as foundation, the definition and components of domain CBR ontology are abstracted. Secondly, the superiorities of ontology over traditional way of case representation are given and the key class of domain CBR ontology- case feature intention class and its function are emphatically introduced. Thirdly, the detailed processes of construction of domain CBR ontology and case revision based on domain CBR ontology are given. In the end, domain CBR ontology of bucket wheel, named bucket wheel CBR ontology, is described in OWL.With regard to the detailed design, two aspectes study are performed. First of all, A framework of ontology based technical document tacit knowledge retrieval is proposed. In this framework, by using the SWRL rule to extent the ontology instance knowledge base, the tacit knowledge is obtained, and so as to serve as retrieval object. In this method the recall ratio of semantic retrieval is improved. Secondly, by borrowing idea from the Semantic Web vision and employing Semantic Web and MAS technologies, an architecture of Ontology- and MAS-Based Mechanical Design Intelligent Document(OMBMDID), which can enable intelligent agents to locate needed document segments oriented by meaning, grasp the knowledge contained in documents and put it into use automatically, is proposed. Firstly, the research context and positioning of this paper are discussed. Then, aiming at knowledge contained in mechanical design documents, semantic annotation granularity and semantic annotation categories are analyzed. On the basis of above analyses, the architecture of OMBMDID is proposed. The application analysis about semantic annotation, semantic retrieve and automatic utilization of document knowledge are also given.With methods proposed above as unit techniques, the semantic technology based mechanical design integrated system framework, which is designed to support innovative design, adaptive design and detailed design, is proposed. The components of this framework and its implementation techniques are also introduced. In the end, with bucket wheel excavator as case, the case study about above methods are given, the feasibility of semantic web technology based mechanical design is proved.In the end, the main study results and innovation points is summed up. The future research directions are also discussed.