Fuzzy control algorithm for multi-objective problems by using orthogonal array and its application to an AMB system

Abstract

A new fuzzy logic control design algorithm suitable for multi-objective control problem is proposed based on the concept of orthogonal array, widely used for design of experiments in statistics and industrial engineering. The essence of the algorithm is to introduce an N-th order certainty factor for each rate defined from its F-value, in order to effectively exclude the less confident rules and rate the rules. The proposed algorithm with multi-objective decision table is found to be capable of detection of inconsistency and the rule classification, reduction and modification. It is also shown that the algorithm can be successfully applied to a simple numerical example and the fuzzy controller design of a rigid rotor-active magnetic bearing system with model uncertainties and harmonic disturbances.