C++ Neural Networks and Fuzzy Logic: Preface

Advantages and Disadvantages of Fuzzy Logic Controllers

The following list adapted from McNeill and Thro shows the advantages and disadvantages to FLCs for

control systems as compared to more traditional control systems.

Advantages:

•  Relates input to output in linguistic terms, easily understood

•  Allows for rapid prototyping because the system designer doesn’t need to know everything about

the system before starting

•  Cheaper because they are easier to design

•  Increased robustness

•  Simplify knowledge acquisition and representation

•  A few rules encompass great complexity

•  Can achieve less overshoot and oscillation

•  Can achieve steady state in a shorter time interval

Disadvantages:

•  Hard to develop a model from a fuzzy system

•  Require more fine tuning and simulation before operational

•  Have a stigma associated with the word fuzzy (at least in the Western world); engineers and most

other people are used to crispness and shy away from fuzzy control and fuzzy decision making

Summary

Fuzzy logic applications are many and varied. You got an overview of the different applications areas that

exist for fuzzy logic, from the control of washing machines to fuzzy logic based cost benefit analysis. Further

you got details on two application domains: fuzzy databases and fuzzy control.

This chapter dealt with extending database models to accommodate fuzziness in data attribute values and in

queries as well. You saw fuzzy relations; in particular, similarity and resemblance relations, and similarity

classes were reviewed. You found how possibility distributions help define fuzzy databases. You also learned

what fuzzy events are and how to calculate fuzzy means, fuzzy variances, and fuzzy conditional expectations.

Concepts related to linear possibility regression model were presented.

The chapter presented the design of a simple fuzzy logic control (FLC) system to regulate the temperature of

water in a hot water heater. The components of the FLC were discussed along with design procedures. The

advantages of FLC design include rapid prototyping ability and the capability to solve very nonlinear control

problems without knowing details of the nonlinearities.

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C++ Neural Networks and Fuzzy Logic:Preface

Advantages and Disadvantages of Fuzzy Logic Controllers

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