CAD Model Retrieval For Easy Adaptation

Adaptive reuse of existing computer aided design(CAD)models is an effective method for product innovative design.How to quickly and accurately retrieve the CAD model that meets the current design requirements is the first step for new product design using adaptive reuse.However,there are lots of works related to CAD model retrieval,few works considered whether the retrieved CAD model is easy to adapt.The CAD model retrieved by the existing methods still needs lots of manual interaction to adapt or even reconstruct,which seriously affects the efficiency of the above product design method in practical application.To solve the above problems,this paper proposes a CAD model retrieval method for easy adaptation.The main research contents are as follows:(1)A dual-level descriptor representing the key content of CAD model is proposed,which describes CAD model from geometry and topology.Firstly,D2 shape distribution and Point Feature Histogram(PFH)are introduced to quantitatively describe the global shape and local features of CAD model.Secondly,in order to determine the key content related to the global shape and local features of CAD model through geometric details,the improved particle swarm optimization is used to find key faces of CAD model,and geometric descriptor is extracted according to key faces.Finally,in order to explicitly represent the key design parameter of CAD model,key face attribute adjacency graph is proposed based on the key faces and consistent design parameters.The key face attribute adjacency graph as topological descriptor represents the key topological information and associated dimensional constraints of CAD model.(2)Based on the dual-level descriptor,a dual-level evaluation method of CAD model for easy adaptation is designed.Firstly,based on the geometric descriptor,the geometric similarity evaluation method is designed,which can retrieve the candidates with similar key geometry(global shape and local features)for the query model through geometric details.Then,based on the topological descriptor,the topological similarity evaluation method associated with the design parameters is designed,and the CAD models with the same design parameters as query model is further retrieved from the above candidates,that is,the candidates for easy adaptation is determined.Based on the proposed method,a CAD model retrieval prototype system for easy adaptation is designed and implemented,and some comparative experiments are carried out.The experimental results show that the CAD model retrieval method for easy adaptation proposed in this paper has high retrieval accuracy and efficiency,and the retrieved CAD model is easy to adapt.