Retrieval Method Of Engineering CAD Model Based On Dynamic Box Number

The current industrial development is moving towards the goal of Industry 4.0,and the design efficiency of new products is becoming more and more important for the competitiveness of enterprises.The 3D CAD model retrieval technology plays a significant role in the design of new products.Users can reduce the design cost by retrieving similar models,and get inspired and obtain design inspiration through the retrieved similar models.The classic D2 algorithm is simple and reliable,with fast calculation and strong compatibility,and is suitable for retrieval in various fields.However,under normal circumstances,the.number of boxes in the D2 algorithm is a certain constant value,which cannot be well applied to the characteristics of each model,resulting in insufficient retrieval performance.In order to explore the potential of the D2 algorithm,this paper improves the D2 algorithm and proposes a CAD model retrieval method in the engineering field based on the dynamic box number.The main research contents are as follows:(1)Analyze and summarize the current theories and methods of various model retrieval,similarity measurement methods,and lay a solid foundation for subsequent research.(2)To verify the retrieval results,a new DMU model library is created by collecting engineering parts.Rebuild the ESB model library and rebuild the Solid of Revolution model library.Implement algorithm performance analysis.(3)The classic D2 algorithm is rebuilt,and the A2 algorithm is newly built.Based on the change of norm and box value,statistical analysis is performed on the retrieval results to obtain the norm and the influence law of the box number on the retrieval accuracy.Then formulate retrieval rules according to the characteristics of the model and establish new DD2 and DA2 retrieval algorithms.(4)Multiple retrieval experiments based on DMU model library and ESB model library.The results show that DD2 algorithm and DA2 algorithm are significantly better than D2 algorithm and A2 algorithm,and the retrieval accuracy is higher.It is conducive to model design reuse and design inspiration.Based on the above research results,this article uses the C++ language to develop a set of engineering domain model retrieval programs on the VS2010 platform,extensively test DD2 and DA2,and verify their effectiveness.The design of new products is of great significance.