“…The knowledge base comprises a database that provides necessary definitions to ensure a proper functioning of the controller and a rule base that contains a set of fuzzy control rules [21]. A fuzzy control rule provides a convenient way to represent control goals and policies of field experts and has the following form:
where x
i and u
fl are linguistic variables representing i th input of the controller and fuzzy logic control input, respectively, A
i
j and B
j are linguistic values of the linguistic variables x
i and u
fl , respectively, and M is the number of fuzzy control rules.…”