EVALUATION METHOD TO KINEMATIC SCHEME OF MECHANICAL SYSTEM BY MEANS OF

FUZZY DISTANCE MEASURE

ZHANG Dezhen  WEI Xiaopeng  CHANG Tian LI Rui

(Advanced Design Technology Center, Dalian University, Dalian 116622 )

Abstract: A new evaluation method to kinematic scheme of mechanical system is presented by means of a fuzzy distance measure. Taking the garment machinery in light industry as an example, the factor sets restricted in the conceptual design are established, and the hierarchy relationship among them is set up in terms of usability, dynamic performance as well as manufacturability. And then the evaluation criterion is proposed for all basic mechanical units. The ratings of various alternatives and their importance weights under different criteria are de-scribed in linguistic terms which are represented by the triangular fuzzy numbers. Secondly, the standard membership function is set up for the evaluate factors and their importance weights. Based on the factor hierarchy relationship, a three-grade fuzzy comprehensive evaluation model is set up for solving the problem, which characters multi-factors, multi-hierarchy features, multi-experts involving as well as various units composing. The concept of fuzzy distance measure is introduced to decide the final ranking of alternatives. Therefore, a comprehensive evaluation algorithm is proposed. Finally, an example is carried out to demonstrate the validation of the new method.

Key words: Conceptual design Comprehensive evaluation Distance measure Fuzzy numbers

CLC No: TH122

国家自然科学基金(50575026)和大连市科技基金(2004A1GX089)资助项目. Received 20060511, received in revised form 20061019