SURPRISE 96
FUZZY LOGIC and ITS USES
ARTICLE 1
by Jeyakody Parthiban
Article #1
THE REVOLUTIONARY COMPUTER TECHNOLOGY THAT IS CHANGING
OUR WORLD
FUZZY LOGIC
Fuzzy logic has rapidly become one of the most successful of today's
technologies for developing sophisticated control systems. The reson for which is
very simple. Fuzzy logic addresses such applications perfectly as it
resembles human decision making with an ability to generate precise solutions
from certain or approximate information.
Fuzzy logic in Japan is becoming a text book example of how theory
translates into application. The idea was first introduced by Lofti A.Zadeh a
professor at the University of California at Berkely in 1965. Now day's
Japanese manufacturers use fuzzy logic in everything from cameras to industrial
process control. These technique are easier to design and also cheaper to produce.
Fuzzy Logic - a powerful new technology
As we all know, Japanese products have higher standards in comparision with other
countries. Because they use fuzzy logic technique in most of the products.
The Japanese have a famous automatically operated train in Sendai that moves
so smoothly you can hardly tell it's travelling.
A load of clothes into fuzzy washer and press start, and the machine begins to
churn , automatically choosing the best cycle.
Place chili, potatoes, or etc in a fuzzy microwave and push single
button, and it cooks for the right time at the proper temperature.
Fuzzy Logic was being made over cars: cushioning their ride, enhancing
safety, and cutting gas consumption by certain percentage.
There's a prototype of a prototype of a fuzzy helicopter that hovers automatically,
without adjustments by the pilot.
It schedules elevators and traffic lights, and prevents tunnel cave-ins at constructions
at constructions sites. If one were to visit Japan, one could see nation living slightly
further in the future.
Fuzzy Logic - It keeps a secret
Fuzzy logic does not make sense to most of us, because it uses a different way
of thinking. Conventional logic and conventional computers run on a logic that is
Boolean-that is, a thing is, or it is not.
For instance, you are tall or you are not, and you have to define as number,
say 6 feet. But , using common sense, if 6 feet is tall , you would not say
someone who is 5 feet 11.75 inches is short, would you?
Pluck a hair from normal man's head and he does not suddenly become bald.
Pull out another, and a third, and a fourth, and he still is not bald, keep
plucking and eventually the wincing man will have no hairs at all his head,
yet he is not bald.
If a number x is small , then x+1 is also small, if x+1 is small , then
x+1+1 is small too. Therefore , five trillion is a small number , and so
is infinity.
Fuzzy Logic -It is one of the Engineering tools
The most common
application is basically a fuzzy control system that maps one or more fuzzy states to others. The
following gives a general idea:
Consider a fuzzy control system that changes the motor speed of a car's air conditioner according to the
temperature . First of all, a set of fuzzy rules of the form "If...then..." need to be set up. They
might look like this, in this example:
If the temperature is 'cool,' then set the motor speed to 'slow.'
If the temperature is 'just right,' then set the motor speed to 'medium.'
If the temperature is 'warm,' then set the motor speed to 'fast.'
More complex problems (i.e. most other problems) would obviously require more and different rules,
drawing not only on temperature, but rather on a wide variety of variables such as humidity and air
pressure.
The rules might also include other logical operations. They be of the form "If A and B, then..." or "If A or
not-B, then...." And even this is just the tip of the iceberg.
Indeed, the possibilities for applications are virtually limitless. One of the most successful
implementations of fuzzy control systems is the subway in Sendai, Japan. Ever since a fuzzy control
system is used to control the train's acceleration, deceleration and braking, this system has proven
superior to both human and conventional automated controllers. Not only has the energy consumption
been reduced by 10%, but passengers hardly notice when the train is actually changing its velocity.
While the idea of fuzzy controlling technology has been enthusiastically received and embraced in
Japan, American and European companies were until recently still somewhat suspicious of anything
labeled 'fuzzy.'
The explanation offered by some people for this puzzling disparity argues that Eastern philosophy as
expressed in Bhuddism, for example, is more compatible with the notion of fuzziness than the European
tradition of Aristotle. Indeed, Bart Kosko, a pioneer in fuzzy logic, felt compelled to say: "My claim is
the Bhudda was really the world's first fuzzy theorist." Western duality teaches the clear distinction
between two opposites, whereas the Eastern concept of yin and yang expresses partial contradiction
and unity in multiplicity. Few western scholars (Hegel, for example) have developed similar concepts.
Also, Japanese language and literature is said to rely more on implication, evocation and suggestion
rather than confrontation, explicitness and precision. Of course, this is not an inherent property of a
language, but rather a question of preferred usage.
No matter what explanation one is inclined to believe, the fact is and remains that, when it comes to
fuzzy systems, Zadeh himself estimates that the West is half a decade behind Japan, and only now it is
finally showing interest in this field. Still, many experts feel that the crumbling of biases against fuzzy
logic and the emergence of more application-oriented textbooks and lectures on this topic may actually
put the West back on the forefront of fuzzy research. Otherwise it would not be the first opportunity
missed solely for being contrary to traditional methods and ideas.
REFERENCES
[1] Daniel Mcneil and Paul Freiberger " Fuzzy Logic"
[2] http://www.ortech-engr.com/fuzzy/reservoir.html
[3] http://www.quadralay.com/www/Fuzzy/FAQ/FAQ00.html
