Fuzzy logic control of linear systems with variable time delay

A closed loop control system incorporating fuzzy logic has been developed for a class of systems with unknown or variable time delay. A unique fuzzy logic controller structure has been proposed. To compensate for the time delay without specifically taking into account the past inputs or requiring a predictive model. The fuzzy logic controller consists of a rule base implementing a classical control strategy and a simple output membership adaptation mechanism to compensate for changes in the time delay. The fuzzy logic controller is applied to a tank temperature control problem and significant improvements in the system performance is observed