Using qualitative bond graph reasoning to derive look-up tables for fuzzy logic controllers

摘要

Qualitative reasoning, bond graphs and fuzzy logic are developed respectively in three different fields: computer science, system dynamics and automatic control. They all have their own strengths and weaknesses. Fortunately, these methods are compensating and they can be used to offset each other's weaknesses. Qualitative reasoning on bond graphs leads to ambiguities in its reasoning process while these ambiguities can be resolved by self-organising fuzzy logic through employing the system identification approach to articulate models. On the other hand, fuzzy logic treats a system as a black box and does not use any structural information, while qualitative reasoning on bond graphs contains this information and can be used to systematically derive look-up tables in fuzzy logic. The paper presents a method of using structural information to generate look-up tables, which will then be used for fuzzy logic control. An example is analysed to explain the concepts.