Transcript Document

Fuzzy Logic & Intelligent Control
Systems
ASSLAMU ALIKUM
From

Muhammad Khurram Shaikh
BE (Elect) , NEDUET
MC(CS) , Bradley Univ, Peoria, IL , USA
[email protected]
Fuzzy Logic
Fuzzy logic emerged into the mainstream of
information technology in the late 1980’s and early
1990’s.
Fuzzy logic is an extension of classical Boolean
logic.
It implements logic on the continuous range of
truth-values [0,1].
An extension of expert systems technology in which
the rules can be expressed imprecisely.

Father of Fuzzy Logic







Lotfi Asker Zadeh
Born : February 12, 1921
Nationality : American
Field Mathematics
Institutions U.C Berkeley
Alma mater Columbia University
Known for Founder of Fuzzy Maths
Father of Fuzzy Logic
Brief History

Born in Baku , Azerbaijan as Lotfi Aliaskerzadeh
(or Askar Zadeh), to a Russian mother and an
Iranian father

Grew up in Iran, studied at Alborz High School
and Tehran University and moved to the USA in
1944.

Received an S.M. degree in electrical engineering
from MIT in 1946, and a PhD in electrical
engineering from Columbia University in1949,
where he taught for ten years, and was promoted
to full professor in 1957.

Taught at the UC Berkely since 1959.
Father of Fuzzy Logic
Contd.

Published his initial work on Fuzzy Set
in 1965 in which he detailed the
mathematics of fuzzy set theory.

In 1973; he proposed his theory of fuzzy
logic.
Introduction

Since fuzzy logic can handle approximate information in a
systematic way, it is ideal for controlling nonlinear systems
and for modeling complex systems where an inexact model
exists or systems where vagueness is common

Fuzzy logic is designed for situations where information is
inexact and traditional digital on/off decisions are not
possible. It divides data into vague categories such as "hot",
"medium" and "cold".
Fuzzy Logic is the name of the debut album by the Super
Furry Animals. The name comes from a mathematical term
which describes terms that are easy to understand by
humans but are not so easily understood by computers. For
example 30C may be hot if it were the outside temperature
but it would be cold if it were the temperature of a cup of tea.
So whether it is hot or cold depends on the context.

Intro Contd.

A conclusion reached by a computer
recognizing that all values are not absolutes
such as yes or no, black or white etc. Fuzzy
logic makes calculations considering values in
varying degrees between absolutes. For
example, a computer might recognize black and
white as absolutes, yet make an evaluation
based on a shade of grey, which is somewhere
between.
A typical fuzzy system consists of fuzzy rule
base, membership functions and an inference
mechanism.
Applications
Some of the major applications of fuzzy logic to expert system
development include its use to:








Control trains in Japan using fuzzy controllers (Miyamoto,
Yasunobu)
Cement kiln controller (Mamdani, Gaines)
Z-II is a fuzzy ES shell used in medical diagnosis and risk
analysis
Video camera technology for automatic focusing, automatic
exposure, image stabilization and white balancing
Automobiles in cruise control, brake and fuel injection system
Video and audio data compression
Stock exchange activities (Yamaichi, Hitachi)
Prevention of unwanted temperature fluctuations in airconditioning systems (Sharp, Mitsubishi)
More Applications
Examples where fuzzy logic is used











Automobile and other vehicle subsystem
Cameras
Digital Image Processing e.g. Edge Detection
Rice Cookers
Dishwashers
Elevators
Washing Machines & other Home Appliances
Video Game Artificial Intelligence
Pattern Recognition in Remote Sensing
Language Filters on message Boards and chat rooms
Microcontrollers and microprocessors
FL Definitions

Fuzzy set theory provides a formalism in which
the conventional binary logic based on choices
"yes" and "no" is replaced with a continuum of
possibilities that effectively embody the
alternative "maybe". Formally, the characteristic
function of set X defined by f(x) =1 for all x in X
and f(x)=0 for all x not in X is replaced by the
membership function.
FL Definitions Contd.

A form of logic in which variables can have degrees of
truth or falsehood

A system of logic dealing with the concept of partial truth
with values ranging between “completely true” and
“completely false.” It is often confused with probability,
which represents the degree of possibility of an
occurrence. Fuzzy logic sets need not sum to 1 as do
probabilities.

A form of artificial intelligence, stored on a computer
chip, that enables a camcorder or television to make
complex adjustments in focus or picture quality based on
ideal models.
ALLAH HAFIZ

SEE U SOON
Muhammad Khurram Shaikh
BE(Elect) NEDUET
MS(CS) Bradley Peoria, IL, USA
[email protected]