Research On NC Machining Process Planning Instances Reuse Of Complex Surface Based On Knowledge Graph

Complex surfaces are widely used in aerospace,automotive,household appliances and other industries.With the increasing demand for products containing complex surfaces and the continuous maturation of NC technology,more and more instances of successful NC machining of complex surfaces have been accumulated.These NC machining instances contain detailed processing strategies and specific processing parameters,embodying the rich processing experience of NC experts,and have a valuable reference role in the process planning of NC machining for new complex surface workpieces.At the same time,there is a phenomenon of low utilization of the existing instances data of complex surface NC machining,and the reuse of data almost entirely relies on manual labor.To address the problems of low process planning efficiency and the difficulty of effective reuse of existing successful machining instances data in complex surface NC machining,this paper proposes a method to build the Knowledge Graph of complex surface NC machining process planning and realize the reuse of process planning instances based on the Knowledge Graph,as follows:(1)The Knowledge Graph of complex surface NC machining process planning is constructed by introducing Knowledge Graph technology.Based on the actual simulation process and relevant instances data in NX 12.0,the concepts related to complex surface NC machining are summarized,and the ontology model of complex surface NC machining process planning is defined based on ontology technology,i.e.,the pattern layer of the Knowledge Graph is constructed.The existing instances data are mapped into the Knowledge Graph based on the ontology model using D2 RQ tool,and Neo4 j is selected as the storage database of the Knowledge Graph.(2)The complex surface NC machining process planning instances data recommendation method is proposed.First,a data model describing the relationship between workpiece,feature,material,machining program,and machining parameters is designed.Then the Similarity-PPR instance data recommendation algorithm is proposed,and the corresponding subgraphs are generated by combining the similarity algorithm and the PPR algorithm.Finally,the high-ranked workpiece is recommended according to the material,selected machining program,and machining process of the new workpiece.(3)The method of reasoning analysis of instances data based on the Knowledge Graph is proposed.Firstly,the Knowledge Graph reasoning technology based on generative rules is introduced,and the instance data reasoning analysis method is proposed based on the Jena tool and SWRL language.The principle of complex surface NC machining instances data reasoning and the construction of reasoning rules are elaborated by taking the parameters affecting machining precision and tool path input in NX as instances.(4)Build a reuse system for complex surface NC machining process planning based on the Knowledge Graph.Based on the theoretical basis of the above research,the complex surface CNC machining process planning reuse system is developed by Pycharm,My SQL,D2 RQ,Neo4j,and Jena,etc.The system integrates instance workpieces recommendation,data visualization,and data reasoning,which can provide decision support for engineers to machine new complex surface workpieces.