Research On Principle And Method Of Evolutionary Design Oriented To Customization Products

Customization has been identified as a competitive strategy by an increasing number ofcompanies. Evolutionary design was one of effective approach to improve product quality andshorten developing cycle.This paper introduced an evolutionary design theory for customiza-tion product by utilizing biological evolution theory. Several key techniques involved wereinvestigated. Also, a support platform of product evolutionary design for crane was developed.Detailed contents were described in the following paragraphes.First,the principle and method of evolutionary design for customization product waspresented including several basic definitions，such as product genes，product population,product evolution mechanisms, evolution operator, evolution track and fitness evaluation.Several key techniques,such as product genes modeling, the selection strategies of initialpopulation, product evolution mechanisms and fitness evaluation method, were studied.Second, a product information model based on gene expression was established. Severaldefinitions including customization genes, function genes, structural genes, rule genes andgrowth genes were defined. The methods of how to Express, how to encoder, how to save andhow to search the product genes were researched.The storage strategy of product genes basedon threaded binary and the expression method of customer requirements base on customiza-tion genes were discussed.Third, two selection strategies of initial population based on the similarity evaluation ofproduct genome，the similarity threshold and fuzzy clustering grouping method，using theweighted Euclidean distance and the cosine correlation coefficient to measure the similaritybetween historical cases and the new customized product. A mathematical weighting methodunder the constraint of the rule of thumb were also proposed.Fourth, two product evolution mechanisms named SPBEM and MPBEM were presented. Several conception，such as serial selection，parallel selection，discrete crossover，continuouscrossover，partly mutation and complete mutation，were definited. Bee selection operator，crossover operator based on product genes tree，mutation operator based constraint directedgraph were established to solve the problem of mechanical customized product evolutiontrack planning.Fifth, the fitness function construction method base on estimated element was studied.Fitness evaluation index system of customization product was established considering cus-tomers, designers and corporate. The estimated element fitness function of functional andstructurcdness were discussed，and the cost fitness function based on based on cost estimateswas proposed.Finally, a support platform of product evolutionary design for crane was developed anddemonstrated the feasibility and the effectiveness of the customization product evolution the-ory.