Research On Product Design Method Based On Artificial Immune System

Product design method plays an essential role in product development. Since the phenomenon of life implies infinite strangeness and dexterity, it can provide eligntenments and inspirations in efficient settlement of various complicated problems including product design. In recent years, as the rise and progress of diversified bionic computing techniques, product design methods based on various bionic computing techniques have come forth and acquired noticeable success. As a kind of emerging bionic computing technique that draws inspiration from the vertebrate immune system, Artificial Immune System (AIS) offers a powerful information processing and problem solving paradigm, hence it is natural to view AIS as a new means that provides intelligent supports for poduct design. In this paper, the product design method based on AIS is examined with the purpose to explore novel ideas and methods for product design.Aiming at providing an overall direction for carrying out product design based on AIS, a framework of product design based on AIS is established against the three-dimensional product design space, which consists of the dimension of hierarchies of product design composed of the hierarchy of design problem solving and that of product evolutive mechanism, the dimension of design process and the dimension of product design methods. In addition, according to the analysis of the common and clustering features of using AIS to solve engineering practical problems, the concept of engineering immune computing (EIC) is abstracted and generalized, and at the hierarchy of design problem solving, a framework of product design based on EIC is established as a sub-framework of the framework of product design based on AIS to direct design problems solving in product design.Because product design based on AIS covers a broad scope, it is impossible to carry out investigation for its each aspect. Thus in this paper, some representative aspects from the framework of product design based on AIS are selected as breakthrough points to be studied in detail.Firstly, a method of product function planning based on EIC is investigated to overcome the limitation that existing Axiomatic Design theory cannot deal with coupled design. The aim of the method is to offer function planning solutions for coupled design problems that appear in the procedure in design with Axiomatic Design, which is actualized by function identification based on the partition operation or immune clustering learning, measurement of the coupling strengths of coupled functions using the pair wise comparison technique based on triangular fuzzy number, and coupled function planning including the decoupling and the tearing operations. In reality the tearing operation can be considered as an optimization problem and can be achieved by the enumeration method or immune tearing method. In addition, the function planning of a condenser is taken as an example to illuminate and validate the proposed method. This part of study of the paper explores the application of EIC in solving two typical design problems, namely clustering learning and optimization, and shows that EIC can provide convincing supports for the conceptual design in the upriver phase of product design and the product design method of Axiomatic Design.Secondly, a novel approach called immune optimization approach (IOA) is studied and presented to solve the assembly planning problem. IOA not only can optimize the assembly sequences of products, but also can optimize the process of assembly operations. Therefore IOA optimizes the assembly procedures of products in reality. By introduction of manifold immune operations, IOA achieves both global and local searches, i.e. balanced search is achieved. Besides IOA also can deal with constraints efficiently, and can use heuristic experiences and knowledge on assembly to give guidance to assembly planning. For the above reasons, IOA can obtain good assembly sequences with satisfying efficiency. To demonstrate the validity and advantages of assembly planning using IOA, detailed case study is presented. This part of study of the paper explores the application of EIC in solving optimization problem, a widely existing design problem in product design, and shows that EIC can provide convincing supports for the process design in the downriver phase of product design and the product design method of DFA.Thirdly, the principle of creative design based on AIS is investigated. From the point of view of information processing and computation, the main excellent characteristics held by AIS are expounded. Then it is pointed out that creative design can be achieved by the avenue of creative computation, and the idea of conducting creative design based on AIS is analyzed and presented. Furthermore a framework of creative design based on AIS is established with immune creative design methods, involving the immunity aided creative design method for problem solving and the immune design method for product evolution serve as the kernel. The key techniques of implementing creative design based on AIS are also discussed. This part of study of the paper on the one hand offers a novel avenue to creative design by borrowing the computational and the creative patterns from the operational mechanism of the vertebrate immune system. One the other hand it shows that AIS can provide convincing supports for the product design method of creative design both from the design problem solving hierarchy and the product evolutive mechanism one.Finally, based on the research fruit of product function planning, a prototype system of product function planning based on EIC is developed to validate the correctness and the validity of the proposed method.