Research On Case Retrieval Based On Grey Relation For Complex Product And System

The design knowledge of complex product is multi-hierarchical,multi-attribute and so on.Research on the intelligent design system of complex product,can contribute to shorten the cycle of product development,reduce the cost of product design,,enhance the competitiveness of product market.Case-based reasoning,which is an important method of artificial intelligence,is widely applied.Its core idea is that according to the design problem,apply case retrieval algorithm,search similar cases from case-base,modify similar cases that do not meet the requirements,the solution of the design problem can be got.The study of the design method of complex product based on case-based reasoning is the key content in this paper.On the basis of current researches from both domestic and overseas sources,the key techniques and realizing method are solved.The expression method of multi-hierarchical gene encoding is presented,the structure and function of complex product can be described by real number encoding.The knowledge representation method of object-oriented model is put forward,which can realize the mapping relationship among presentation layer,functional layer and data layer in the design system.According to complex product’s multi-hierarchy,case-base is built.Study on the methods of weight,the variation coefficient method is used to ascertain weight of case feature attribute.Combining grey-relational theory and Euclidean distance,the method for computing degree of similarity is presented.Genetic algorithm can be applied in the case modification.The similar case are used as the initial population.The best individual preservation strategy is applied in the genetic algorithm.Take CNC tool spindle as an example,study results show that the two algorithm is scientific and practical.The new case should be put into case-base,which is design scheme of complex product.With the platform of Visual C++6.0,the backstage data-base makes use of Microsoft SQL Server 2008.CNC design system that is case-based reasoning is developed.Illustrated by the example of CNC bed,the specific application of each module in the system is introduced.