Recent Advances in Fuzzy Qualitative Reasoning

Fuzzy qualitative reasoning (FQR) is a form of approximate reasoning that can be defined loosely as the fusion of Fuzzy Reasoning (FR) with Qualitative Reasoning (QR). Both these research areas have as one of their goals the construction of computational reasoning tools that can predict and explain the behaviour of, often dynamic, systems whose analytic relations are incompletely specified. Whereas pure FR utilizes black box models, QR utilizes explicit structural models. And whereas pure QR operates with symbolic ‘quantities’, FR explicitly reasons with fuzzy intervals of varying precision that are supported directly by the real number line. Fuzzy reasoning has evolved significantly and attracted a great deal of attention and exploitation from the industrial and research communities in the forty or so years since its inception. It is good at facilitating communication with sensing and control level subsystems and it utilises powerful reasoning strategies through conditional statements so as to easily handle mathematical and engineering systems in