Date of Award

12-1993

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Meir Pachter, PhD

Abstract

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.

AFIT Designator

AFIT-GE-ENG-93D-25

DTIC Accession Number

ADA274660

Comments

The author's Vita page is omitted.

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