Research On Construction And Application Of Knowledge Graph For High Speed Train Maintenance Design

With the increase in the number of high-speed trains in China,there are many questions exposed in the course of operation that insufficient consideration in maintainability design.High-speed train manufacturing enterprises and railway bureaus have accumulated a large number of operation and maintenance data and corresponding fault and maintenance knowledge which are important for high-speed train design stage,however,due to the lack of effective knowledge management and application methods in the field of high-speed trains at present,these data and knowledge cannot be directly fed back to the design stage to support the maintainability design of products,causes poor availability of products and more difficult to optimize the product lifecycle.Based on these questions,this thesis starts from the actual demands of high-speed train manufacturers,research on how to extract maintainability design knowledge from high-speed train operation and maintenance data using knowledge graph construction technology and how to support maintainability design activities by designers using extracted maintainability design knowledge,the main research contents of this thesis are as follows:(1)The connotation of maintainability design is analyzed,and the maintainability design activities contained in the design stage are combed based on the design process of high-speed trains.the characteristics and classification of maintainability design knowledge in the field of high-speed trains are defined,and the correlation between various types of maintainability design knowledge is clarified,and the technical route for the construction of maintainability design knowledge graph of high-speed trains is determined.(2)Referring to IDEF5 method and seven-step method,the construction method of maintainability design knowledge ontology for high-speed trains is proposed.By constructing the conceptual analysis and expression model of multi-domain maintainability design for highspeed trains,the content of maintainability design knowledge contained in various fields is expressed.Based on the construction method of maintainability design knowledge ontology for high-speed trains proposed in this thesis,the maintainability design knowledge ontology of design domain,fault domain and maintenance domain for high-speed trains is constructed respectively,and the three domain ontologies are fused through the conceptual interpretation mechanism to obtain the maintainability design knowledge ontology of high-speed trains with multi-domain ontology fusion.The ontology construction software protégé is used for structured storage and management of the constructed maintainability design knowledge ontology.(3)Based on the BERT-Bi LSTM-CRF model,the entity words related to the maintainability design of high-speed trains are identified from the operation and maintenance data,and the relational matching template of maintainability design of high-speed trains is designed with the help of experts in the field.Through relational matching,the triad of maintainability design knowledge of high-speed trains is extracted.Finally,the redundancy and error rate of the extracted maintainability design knowledge are reduced through knowledge fusion,and the data layer of maintainability design knowledge graph of high-speed trains is constructed.(4)The ontology knowledge of the model layer and the instance knowledge of the data layer of the maintainability design knowledge graph of high-speed trains are introduced into the Neo4 j graph database to complete the construction of the knowledge graph.Based on the graph database,a knowledge graph system for the maintainability design of high-speed trains is developed.In this thesis,the knowledge graph of high-speed train maintainability design is constructed,and the implicit maintainability design knowledge is obtained from the unstructured high-speed train operation and maintenance data.The ability of knowledge discovery and extraction in the field of high-speed trains is improved,and the feasibility of the knowledge graph construction method of high-speed train maintainability design proposed in this thesis is verified.Finally,the intelligent retrieval application of high-speed train maintainability design knowledge graph system is developed,it is proved that the knowledge graph can support designers for high-speed train maintainability design.