Date of Award


Document Type


Degree Name

Master of Science in Electrical Engineering


Department of Electrical and Computer Engineering

First Advisor

Meir Pachter, PhD


This thesis investigates the feasibility of a proposed hybrid linear/Fuzzy controller for nonlinear plants. The proposed controller concept is based on the use of multiple linearizations of a nonlinear plant, which describe the dynamics of perturbations about equilibrium points throughout the desired envelope of operation. A bank of linear compensators is developed, each corresponding to a linearized plant about a different equilibrium. The multiple control signals generated by the bank of compensators are then weighted and summed using Fuzzy Logic to produce a composite control perturbation signal, which is used to drive the nonlinear plant. Experiments were conducted to test and refine this control approach. Analysis shows that a linear/Fuzzy compensator based only on a bank of linear compensators is not feasible, largely due to the small regions for which the linearized models were valid and energy considerations within the plant/controller system. The analysis itself, however, suggests an alternate form for a hybrid Linear/Fuzzy approach, based on a bank of Fuzzy compensators smoothed by a linear controller. This concept is developed into the Model-Based Fuzzy Logic Controller (MBFLC). The concept of Fuzzy Logic Model Following Control is also addressed as a second hybrid approach.

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The author's Vita page is omitted.