The Design And Research Of Car Seat Skeleton Variant Design System Based On Case-based Reasoning

The car seat skeleton is the most important part of the car seat.At present,there is a lot of repetitive work in the research and development process of car seat skeleton in car seat manufacturing enterprises,with it a long design cycle and low design efficiency,it is difficult to meet the complex and changeable market demand of car seat.In order to improve the design quality,design efficiency and reduce the research and development cost of the car seat skeleton,this paper conducts a thorough and systematic research on the variant design technology of the car seat skeleton,and puts forward a verifiable design mode and automatic design method for the set seat skeleton.The parametric driven variant design and database driven variant design of the car seat skeleton were realized by CATIA CAA secondary development technology,which made the design of parts in the car seat skeleton more simple and efficient,and the automatic assembly of car seat skeleton parts is also realized.Then,based on the idea of knowledge reuse,the CaseBased Reasoning（CBR）technology was used to study the variant design method of car seat skeleton,and the software platform for automatic design of car seat skeleton based on case-based reasoning is developed.Based on axiomatic design theory,an example of automobile seat skeleton was analyzed,its characteristic information was extracted,and object oriented technology was used to express the instance information of each level.The organization structure and storage mode of the case library were studied,and the case information of the seat skeleton was stored by Access database.The case library of the framework product in the case reasoning system was constructed,which laid a foundation for the development of the automatic design platform of the car seat skeleton based on case reasoning.In order to improve the retrieval efficiency,a multi-level retrieval algorithm combining the template method and K-nearest Neighbors（KNN）algorithm is proposed.Aiming at the problem that the retrieval accuracy of KNN algorithm is easily affected by K value,At the same time,in order to improve the accuracy of KNN retrieval algorithm,this paper uses the idea of information entropy to improve and optimize the traditional KNN algorithm,improve the accuracy,recall and accuracy of KNN algorithm,making the result of case retrieval more accurate.Using CATIA CAA secondary development technology to build the car seat frame parts parametric design template,this template driven to quickly generate a series of the seat frame component instance,meeting customer requirements and in the case database,based on case reasoning frame of automatic design system provides the instance data support.CATIA is chosen as the software system development platform,with the aid of CATIA CAA V5 variant design software development tools to complete the entry,the design of the main interface,combining with an instance of the library building technology and the case retrieval technology to write the corresponding function module driver,developed based on case reasoning frame of automation design software platform,An example of car seat frame variant design based on case-based reasoning is given to demonstrate the practical application effect of the system.