Fuzzy Diagnostic Expert System for Ultrasonic Testing (Application of Fuzzy Production Rule)

Abstract

This paper attempts to build up a diagnostic expert system for ultrasonic testing (UT) which inspects the weld defect encountered in welding structures. The proposed system can handle knowledge and data which include various kinds of uncertaities and ambiguities by use of fuzzy set theory. The knowledge is represented in terms of fuzzy production rules involving certainty factors, which help accommodate reasoning with uncertainty. The ambiguities of knowledge and data are represented by linear membership functions. The computational time required for inference is reduced because the proposed system uses the blackboard model dividing the knowledge source and working memory. In addition, the system has the ability to explain the reasoning that led to solutions of diagnosis. The results obtained by the proposed expert system are compared with those by UT experts, and the usefulness of the system is denoted by high consistency in the comparison.