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- From: farzin@apollo3.ntt.jp (Farzin Mokhtarian)
- Subject: Complete contents of the booklet "Clearly Fuzzy"
- Message-ID: <sehari.727624894@vincent1.iastate.edu>
- Originator: sehari@vincent1.iastate.edu
- Sender: news@news.iastate.edu (USENET News System)
- Organization: Iowa State University of Science and Technology, Ames, Iowa.
- Date: Thu, 21 Jan 1993 14:01:34 GMT
- Lines: 959
-
-
- Complete contents of the booklet "Clearly Fuzzy" by:
-
- OMRON Corporation
- International Public Relations Section
- 3-4-10, Toranomon, Minato-ku
- Tokyo, 105 Japan
-
- Tel: 81-3-3436-7139
- Fax: 81-3-3436-7029
-
- Contact: Tadashi Katsuno
-
- ---------------------------------------------------------------------
-
- 1. Introduction
-
- Fuzzy Logic is attracting a great deal of attention in the industrial
- world and among the general public today. Quick to recognize this
- revolutionary control concept, OMRON seriously began to study Fuzzy
- theory and technology in 1984, back when the term "Fuzzy" was still
- relatively unknown.
-
- Just three years later, OMRON stunned the academic world and triggered
- today's boom when it exhibited its first super-high-speed Fuzzy
- controller. It was developed jointly with Assistant Professor Takeshi
- Yamakawa of Kumamoto University and shown at the Second International
- Conference of the International Fuzzy Systems Association (IFSA).
-
- OMRON has since dedicated itself to exploring the potential of this
- innovative technology. The company invited Professor Lotfi A. Zadeh,
- the founder of Fuzzy theory, to be a senior advisor, and welcomed
- researchers from China, a country known as one of the leaders in
- Fuzzy Logic study. As a result of technological exchanges with
- research institutes of various countries, OMRON's Fuzzy Logic-related
- activities are reaching a global scale. Since 1984, OMRON has applied
- for a total of 700 patents, making the company an international leader
- in Fuzzy Logic technology.
-
- OMRON's enthusiasm for Fuzzy Logic stems from the company's goal of
- creating harmony between people and machinery. As a key technology
- in OMRON's future, we will be working hard to strengthen and refine
- this exciting technology and give it truly useful applications at
- production sites, in offices, in public facilities, as well as in
- everyday life.
-
- We hope this booklet will be useful in increasing your knowledge,
- or at least in sparking your interest in this exciting technology.
-
- OMRON Corporation
-
- ------------------------------------------------------------------
-
- 2. Truly Friendly Machines
-
- 2.1. Arrival of the Fuzzy Boom
-
- The current Fuzzy boom was triggered by the presentation of trial
- Fuzzy applications at the Academic Conference of the International
- Fuzzy Systems Association (IFSA). The obvious feasibility of these
- forerunners of today's Fuzzy Logic deeply impressed conference
- attendees. Nowadays in Japan, Fuzzy Logic is successfully being
- applied to industrial systems such as elevators and subways and
- to an array of consumer electronic products. Convenient Fuzzy Logic
- home electrical appliances include washing machines that sense the
- dirtiness and type of fabric to automatically determine water flow
- and detergent requirements; and vacuum cleaners capable of detecting
- not only the presence but the degree of dust on a floor!
-
- 2.2. Shades of Gray
-
- The theory of Fuzzy Logic was introduced to the world by Professor
- Lotfi A. Zadeh of the University of California at Berkeley.
- Professor Zadeh observed that conventional computer logic is
- incapable of manipulating data representing subjective or vague
- human ideas, such as "an attractive person" or "pretty hot".
- Computer logic previously envisioned reality only in such simple
- terms, as on or off, yes or no, and black or white. Fuzzy Logic
- was designed to allow computers to determine valid distinctions
- among data with shades of gray, working similarly in essence to
- the processes which occur in human reasoning. Accordingly, Fuzzy
- technologies are designed to incorporate Fuzzy theories into
- modern control and data processing, to create more user-friendly
- systems and products.
-
- 2.3. A Warm Welcome in the Orient
-
- Since Fuzzy Logic's world debut 26 years ago, theoretical and
- practical studies have been carried out in countries around
- the globe; Fuzzy Logic research is currently underway in over
- 30 nations including the USA, Europe, Japan and China. It may
- be surprising to some to note that the world's largest number
- of Fuzzy Logic researchers are in China, with over 10,000
- scientists and technicians presently hard at work. Japan ranks
- second in Fuzzy Logic manpower, followed by Europe and the USA.
- Among all nations however, Japan is currently positioned at the
- leading edge of Fuzzy Logic application studies. So it may be
- that the popularity of Fuzzy Logic in the Orient reflects the
- fact that Oriental thinking more easily accepts the concept of
- "Fuzziness".
-
- 2.4. Fuzzy - Part of Every Day at OMRON
-
- OMRON is also hard at work in the Fuzzy Logic field. Projects
- currently on the go at OMRON include working to establish a
- Fuzzy technological base, developing new products incorporating
- Fuzzy theory, adapting Fuzzy Logic technology to existing
- products and conducting seminars for interested audiences
- from outside OMRON. Fuzzy Logic has in fact grown to such
- proportions that it has become an integral part of the new
- corporate culture at OMRON.
-
- -----------------------------------------------------------------------
-
- 3. "Fuzzy" Made Clear
-
- 3.1. What is "Fuzzy"?
-
- Originally stemming from the fuzz which covers baby chicks, the term
- "fuzzy" in English means "indistinct, blurred, not sharply delineated
- or focused." This term is "flou" in French and pronounced "aimai" in
- Japanese. In the academic and technological worlds, "Fuzzy" is a
- technical term. Fuzziness in this sense represents ambiguity or
- vagueness based on human intuitions rather than being based on
- probability. Twenty six years ago, Professor Lotfi A. Zadeh
- introduced "Fuzzy sets" to adapt the concepts of fuzzy boundaries to
- science. Fuzzy theory was devised around the Fuzzy sets and a new
- field of engineering known as "Fuzzy Engineering" was born. Although
- "Fuzzy sets" may sound very mathematical, the basic concept can be
- explained simply.
-
- 3.2. How Fuzzy Theory Works
-
- o Fuzzy Sets
-
- Let's take an example of the concept "middle age". When we hear the
- term "middle age", a certain image comes to mind. But, it is a
- concept with fuzzy boundaries which can not be handled by
- conventional computers using the binary system. This is where
- Fuzzy theory comes in. Let's suppose that we have concluded that
- middle age is 45. However, people 35 or 55 years of age can not
- be said to be "definitely not middle-aged". There is a feeling,
- however, that the implication of "middle age" is somewhat
- different inside those boundaries. On the contrary, those younger
- than 30 or older than 60 can be considered "definitely not
- middle-aged". Such a concept can be represented by a characteristic
- function called the "membership function" having a grade between 0
- and 1. A Fuzzy set is represented by this membership function.
- However, note that the grade within the membership function can be
- continuously varied between 0 and 1. This makes possible the
- quantitative representation of an abstract intention.
-
- o Crisp Sets
-
- In contrast, the binary system employed in conventional computers
- works by first specifying a fixed range, so that "middle age"
- represents the age range from 35 to 55 years old. According to
- this specification, people who are 34 or 56 years old are not
- "middle-aged". Unfortunately, someone who is now considered
- young at 34 will suddenly enter middle age as soon as their
- next birthday arrives! This sort of unnaturalness is due to
- inflexible value assignments. Such concepts with distinct values
- of 0 or 1 are called "crisp sets" as opposed to the "Fuzzy sets".
-
- -------------------------------------------------------------------
-
- 4. Fuzzy Theory in Action
-
- 4.1. Fuzzy Algorithm
-
- One example of Fuzzy theory applications is the handling of
- approximate numbers. If approximately 2 is added to approximately 6,
- the result will be something around 8. People often make this sort
- of calculation. For instance, we frequently estimate the result when
- performing a calculation such as "118 + 204." We would say that adding
- a number slightly over 100 to another slightly over 200 equals a
- number slightly greatly than 300. This sort of calculation comes
- easily to human beings but can not be so well handled by conventional
- computers, which must have crisp data with which to work.
-
- 4.2. The Logic in Fuzzy Logic
-
- Another field that applies Fuzzy theory concerns artificial
- intelligence, termed "Fuzzy Logic". One of the differences between
- Fuzzy Logic and conventional binary logic is that the truth value
- in Fuzzy Logic can be any value between 0 and 1, while that in
- binary logic is either 0 or 1. Another difference is that the
- Fuzzy proposition includes "fuzziness" as expressed in ordinary
- spoken language, in contrast to the crisp proposition which must
- be defined distinctly, and is not subject to human intuition.
-
- 4.3. Common Sense Fuzzy
-
- "Fuzzy inference" is a reasoning method using Fuzzy theory, whereby
- human knowledge is expressed using linguistic rules ("If A is B,
- then C is D") with variables B and D. Fuzzy inference is also called
- "daily inference" or "common sense inference" since it is performed
- by ordinary people. However, conventional computers that employ
- binary logic can not handle this reasoning. The use of Fuzzy theory
- enables the development of an expert system that can handle
- sophisticated knowledge and rich human experience through direct
- programming in an almost natural language.
-
- Binary logic based inference is possible only when data coincides
- exactly with the premise input. On the other hand, Fuzzy inference
- is possible even when the meaning of the fact differs slightly
- from the given knowledge. Drawing a conclusion like "Add a little
- cold water", Fuzzy inference matches the conclusion based on human
- experience, intuition, or possibly even reality.
-
- The "knowledge" part of Fuzzy inference has the structure "if A is
- B, then C is D" (example: "If the water is very hot, add plenty of
- cold water"). Concepts such as "very hot" and "plenty of cold
- water" are subjective and thus represented by Fuzzy sets.
-
- As you may know, Fuzzy theory was devised for the purpose of
- enabling machines to handle subjective human ideas and operate
- based on advanced knowledge as well as applications of human
- beings' intricate experiences. In other words, Fuzzy theory
- allows for the development of truly user-friendly machines.
-
- -----------------------------------------------------------------------
-
- 5. An Invitation to Fuzzy Control
-
- 5.1. The Mechanism: Fuzzy Inference Control
-
- We can examine Fuzzy Control by using the example of controlling an
- automobile. In this example, input conditions are speed of the
- automobile and its distance to the automobile in front. Amount of
- control is expressed in terms of Braking strength.
-
- (1) Express experience and expertise in the form of rules.
-
- With Fuzzy inference control, these rules are called "production
- rules". They are represented in the form of "If X is A, then Y is B".
- To put it more simply, let's consider two rules as follows:
-
- Rule 1: If the distance between two cars is SHORT and the car
- speed is HIGH, then brake HARD for substantial speed
- reduction.
- Rule 2: If the distance between two cars is MODERATELY LONG and
- the car speed is HIGH, brake MODERATELY HARD (under the
- condition that the front car is moving at a constant
- speed).
-
- (2) Determine membership functions for the antecedent and consequent
- parts.
-
- The distance between the two cars and the car speed (antecedent parts)
- and the level of speed reduction, or braking strength (consequent
- part), are not numeric values but are represented by "Fuzzy Sets"
- expressed through linguistic rules. The distance between the two
- cars and the speed have a multiple number of Fuzzy values and are
- therefore called "Fuzzy variables". Hence, values (labels) of these
- Fuzzy variables and the shapes of membership functions can be
- determined. Membership functions (Fuzzy variables) can take three
- different shapes: Triangular, Bell-shaped and Trapezoidal.
-
- The shapes differ depending upon the characteristics of the machine
- to be controlled. Normally, there are three (large, medium, small),
- five (high, moderately high, normal, moderately low, low), or seven
- (large, medium and small both in positive and negative directions,
- centering around approximately 0) labels. Many Fuzzy controllers
- use seven labels, as in the OMRON FZ-3000 Fuzzy Controller, for
- example.
-
- (3) Replace linguistic production rules with codes for simpler
- expression.
-
- Although production rules can be expressed with everyday language,
- codes are used to simplify the input to the actual Fuzzy Controllers.
-
- (Distance between two cars: X1; speed: X2)
- (Braking strength: Y)
- (Labels - small, medium, large: S, M, L)
-
- Let's express the above rules using these codes.
-
- Rule 1: If X1 = S and X2 = M, then Y = L.
- Rule 2: If X1 = M and X2 = L, then Y = M.
-
- (4) Execute Fuzzy inference control.
-
- When the rules are programmed into the Fuzzy Controller and it is put
- into operation, the Controller will output the most valid control
- value based on the variable input conditions.
-
- 1) Establish grades (validity) of input in relation to the Fuzzy
- Sets determined by the rules.
-
- As for the Fuzzy Set (S: short distance) determined by rule 1, the
- grade (g11) of the input distance "30m" is 0.4. Similarly, the grade
- (g12) of the input speed "40km/H" is 0.2 according to the Fuzzy Set
- (M: moderately high speed). As for rule 2, grades (g21) and (g22)
- can be determined as 0.7 and 0.6 respectively.
-
- 2) Determine the grade of each antecedent part.
-
- The grade of antecedent parts can be determined by selecting the
- smaller value of the grades of inputs. This process is called
- "determining MIN (minimum)".
-
- Rule 1: As g11 = 0.4 and g12 = 0.2, the grade (MIN value) of
- antecedent part (g1) = 0.2.
- Rule 2: As g21 = 0.7 and g22 = 0.6, the grade (MIN value) of
- antecedent part (g2) = 0.6.
-
- 3) Adjust the membership function of the consequent part.
-
- The consequent part of rule 1 is Fuzzy Set (L) representing hard
- braking, while that of rule 2 is Fuzzy Set (M) representing medium
- (moderately hard) braking. The grades (amplitudes) of these Fuzzy
- membership functions are then adjusted to match the grades of their
- respective antecedent parts.
-
- 4) Total evaluation of conclusions based on these rules
- (determination of control amounts).
-
- When the conclusions are derived through inference based on each of
- these rules (adjusted Fuzzy Sets of the consequent parts), the final
- conclusion is then determined by summing the Fuzzy Sets of the
- conclusions for each rule. This process is called "determining MAX
- (maximum)".
-
- This process considers several variable factors, and is thus very
- similar to the human thinking process.
-
- With Fuzzy Control, steps (1) through (4) are performed continuously.
- In contrast, with information processing, these procedures are only
- executed each time the input data varies.
-
- 5.2. The Advantages of Fuzzy Inference Control
-
- o Parallel Control
-
- Conventional control based on modern scientific analysis determines
- the control amount in relation to a number of data inputs using a
- single set of equations to express the entire control process.
- Expressing human experience in the form of a mathematical formula
- is very difficult, perhaps impossible. In contrast, Fuzzy inference
- control has the following advantages over conventional control:
-
- 1) Expression of control is easy as it need only derive localized
- control rules for each location (or event) in the control range.
- 2) It therefore handles complex input/output by using many control
- rules, each of which is effective over a specific location.
- 3) Operations can be conducted in parallel (or simultaneously)
- within Fuzzy inference by executing various rules. This
- results in speedy operation, regardless of the total number
- of rules.
-
- o Logical Control
-
- Fuzzy inference control rules are expressed logically using simple
- linguistic rules ("If A is B, then C is D"). Because everyday
- language can be used, Fuzzy inference control proves ideal for
- expressing the sophisticated knowledge of experts and incorporating
- valuable intuition (or a "sixth sense").
-
- 1) Multiple conditions can be included as the antecedent part of
- the rules (e.g. If X1 = A, X2 = B and X3 = C, then Y = D).
- 2) Rules can be expressed with a single, common format regardless
- of normal or exceptional conditions.
-
- o Linguistic Control
-
- Fuzzy rules can be expressed using everyday language, giving the
- following advantages:
-
- 1) Fuzzy control is easy to understand by the machine operator or
- others.
- 2) The operator can easily interpret the effect or outcome of each
- rule.
-
- -----------------------------------------------------------------------
-
- 6. Growing Up: Fuzzy Technology Catches On
-
- 6.1. The Birth and Evolution of Fuzzy
-
- Fuzzy Logic was born only 26 years ago when Professor Lotfi A. Zadeh
- submitted a paper entitled "Fuzzy Sets" to the science magazine
- "Information and Control". In that paper, he labeled sets with unclear
- boundaries "Fuzzy sets," such as attractive people, tall people, and
- large numbers. According to Dr. Zadeh, the Fuzzy set plays an important
- role in pattern recognition, interpretation of meaning, and especially
- abstraction, the essence of the thinking process of the human being.
-
- 6.2. Is "Fuzziness" Really Better?
-
- Dr. Zadeh was one of the original founders of the modern control theory
- and remains an authority in this field. Modern control theory is exact,
- precise, and logical, harboring no hint of "fuziness".
-
- Today, however, the subjects of control have become increasingly larger
- in scale, in turn requiring more advanced and complex control systems,
- like those used to control robots and rockets. You need a tremendous
- amount of power if you want to use a computer to execute such
- complicated control using modern theory. Precise programming is
- needed for every instruction and every piece of data to put the
- computer into operation. It also takes an extremely long time to
- execute the programs. Dr. Zadeh devised Fuzzy theory to overcome
- these debilitating limitations of modern theory.
-
- There was also another, probably more important factor that encouraged
- him to come up with a new idea. Conventional computers work by
- identifying the factor which seems to have the strongest influence on
- the systems to be controlled, since it is impossible to simultaneously
- command all the factors that affect the system. In other words, the
- computer assumes that the system only consists of those selected items.
- Moreover, all assumed factors must be described digitally. So for some
- items which are unclear, the computer simply assigns an appropriate
- value. The computer is, of course, capable of accurate and fast
- computation. However, as the conditional parameters include many
- hypotheses, the computer may sometimes yield a ridiculous conclusion
- contrary to what common sense would lead us to expect. This is caused
- by its attempts to replace "fuzziness" with fixed numeric values.
- Thus, it became necessary to develop a theory capable of dealing
- with the vagueness prevalent in everyday decisions.
-
- 6.3. Strong Opposition
-
- Even though Dr. Zadeh's theory is now quite popular and quoted in a
- large number of academic papers, it had to endure skepticism and
- hostility from US researchers and academics in its early days.
- Some American mathematicians scoffed at the theory, saying that
- "fuzziness" could be represented using conventional mathematics.
- Once a noted authority in modern theory, Dr. Zadeh's ready
- acceptance of "fuzziness" was considered to be a frivolous
- escape from his own beliefs, and many criticized him for not
- fulfilling his duty as a scientist.
-
- 6.4. A Profile of Professor Zadeh
-
- You may want to know a little about the Professor. Here is a
- very brief profile:
-
- Lotfi A. Zadeh was born in Iran on February 4, 1921. In 1956,
- he was a visiting member of the Institute for Advanced Study in
- Princeton, New Jersey and held numerous distinguished visiting
- appointments around the US. In 1959 he joined the University of
- California's Electrical Engineering Department at Berkeley, and
- served as its chairman from 1963 to 1968.
-
- Before 1965, Dr. Zadeh's work focused on system theory and
- decision analysis. Since then his interests have shifted to
- the theory of Fuzzy sets, and its applications.
-
- Zadeh attended the University of Teheran, MIT, and Columbia
- University, and is a fellow of the IEEE and AAAS. He is also
- a member of the National Academy of Engineering. Now, Dr.
- Zadeh is a senior advisor to OMRON Corporation.
-
- 6.5. A Motivating Debate
-
- Here is a little story about how Fuzzy Logic was invented. One
- day, Dr. Zadeh got into a long argument with a friend about who
- was more beautiful, his wife or his friend's. Each thought his
- own wife was more beautiful than the other's wife. There is,
- of course, no objective way to measure beauty. The concept of
- "beautiful" greatly differs among people. Although they continued
- the argument for a long time, they could not arrive at a
- satisfactory conclusion. This argument triggered Dr. Zadeh's
- desire to express concepts with such fuzzy boundaries
- numerically, and he thereby devised Fuzzy sets. Thus goes the
- legend.
-
- 6.6. From Industry to Consumer
-
- The first applications of Fuzzy theory were primarily industrial,
- such as process control for cement kilns. Then, in 1987, the
- first Fuzzy Logic-controlled subway was opened in Sendai in
- northern Japan. There, Fuzzy Logic controllers make subway
- journeys more comfortable with smooth braking and acceleration.
- In fact, all the driver has to do is push the start button!
- Fuzzy Logic was also put to work in elevators to reduce
- waiting time. Since then, the applications of Fuzzy Logic
- technology have virtually exploded, affecting things we use
- every day.
-
- Major Areas of Fuzzy Research and Applications
-
- Field Major Applications
-
- Automation Steel/iron manufacturing, water purification,
- manufacturing lines and robots, train/elevator
- operation control, consumer products, etc.
-
- Instrumentation Sensors, measuring instruments, voice/character
- and analysis recognition, etc.
-
- Design/judgement Investment/development consultation, train
- scheduling, system development tools,
- trouble-shooting, etc.
-
- Computers Operators, arithmetic units, microcomputers,
- industrial calibrators, etc.
-
- Information Database, information retrieval, system
- processing modelling and mathematical programming, etc.
-
- 6.7. Historically Speaking ...
-
- The year 1990 witnessed the 25th anniversary of the invention of
- Fuzzy theory. It has undergone numerous transformations since its
- inception with a variety of Fuzzy Logic applications emerging in
- many industrial areas. Dividing these past years into different
- stages, the early 1970s are the "theoretical study" stage, the
- period from the late 1970s to early 1980s the stage of "developing
- applications for control", and that from late 1980s to the
- present the stage of "expanding practical applications".
-
- Here are the major events in the history of Fuzzy Logic:
-
- 1965: Professor L. A. Zadeh of the University of California at
- Berkeley introduces "Fuzzy sets" theory.
- 1968: Zadeh presents "Fuzzy algorithm".
- 1972: Japan Fuzzy Systems Research Foundation founded (later
- becoming the Japan Office of the International Fuzzy
- Systems Association (IFSA)).
- 1973: Zadeh introduces a methodology for describing systems
- using language that incorporates fuzziness.
- 1974: Dr. Mamdani of the University of London, UK succeeds
- with an experimental Fuzzy control for a steam engine.
- 1980: F. L. Smidth & Co. A/S, Denmark, implements Fuzzy
- theory in cement kiln control (the world's first
- practical implementation of Fuzzy theory).
- 1983: Fuji Electric Co., Ltd. implements Fuzzy theory in the
- control of chemical injection for water purification
- plants (Japan's first).
-
- 1984: International Fuzzy Systems Association (IFSA) founded.
- 1985: 1st IFSA International Conference.
- 1987: 2nd IFSA International Conference. (Exhibit of OMRON's
- Fuzzy controller, a joint development with Assistant
- Professor Yamakawa).
- Fuzzy Logic-controlled subway system starts operation
- in Sendai, Japan.
- 1988: International Workshop on applications of Fuzzy Logic-
- based systems (with eight Fuzzy models on display).
- 1989: The Laboratory for International Fuzzy Engineering
- Research (LIFE) established as a joint affair between
- the Japanese Government, academic institutes and
- private concerns.
-
- Japan Society for Fuzzy Theory and Systems founded.
-
- ------------------------------------------------------------------
-
- 7. A Fuzzy Future
-
- 7.1. Fuzzy Fever Hits Japan
-
- 1987 marked the start of Japan's so-called "Fuzzy boom", reaching
- a peak in 1990. A wide variety of new consumer products since then
- have included the word "Fuzzy" on their labels and have been
- advertised as offering the ultimate in convenience.
-
- For instance, Fuzzy Logic found its way into the electronic fuel
- injection controls and automatic cruise control systems of cars,
- making complex controls more efficient and easier to use. The
- "Fuzzy" washing machine has more than 400 preprogrammed cycles;
- yet despite this technological intricacy, operation is very
- simple. The user only needs to press the start button and the
- rest is taken care of by the machine. It automatically judges
- the material, the volume and the dirtiness of the laundry and
- chooses the optimum cycle and water flow. In air conditioners,
- Fuzzy Logic saves energy because it starts cooling more
- strongly only when a sensor detects people in the room.
-
- We could go on and on with examples of camcorders, television
- sets, and even fund management systems. The sweeping
- popularity of Fuzzy Logic in Japan might even surprise
- Dr. Zadeh, its founder.
-
- 7.2. No Limits: Promise for the Future
-
- Just from these few examples, it is clear that Fuzzy Logic
- encompasses an amazing array of applications. Fuzzy Logic can
- appear almost anyplace where computers and modern control
- theory are overly precise; as well as in tasks requiring
- delicate human intuition and experience-based knowledge.
- Now that your mind is open to Fuzzy thinking, here are some
- unique ideas applying Fuzzy Logic.
-
- 7.3. "Fuzzy" Child Care Expert System
-
- Here is an idea a 24-year-old housewife developed from her
- experience in raising children. It may seem obvious that
- babies don't drink the way it is described in child care
- books. They may drink a little or a lot depending on their
- physical condition, mood, and other factors. She conceived
- a Fuzzy Logic program that would recommend how much to feed
- the baby. The program determines the appropriate amount of
- milk according to a knowledge base that includes the child's
- personality, physical condition, and some environmental
- factors. Although adapting Fuzzy Logic to babies may seem
- silly, one can easily imagine using it to control the
- feeding of animals in captivity, for instance.
-
- 7.4. Fuzzy is for Everyone
-
- Many ideas have been derived from everyday activities in the
- home, like the Fuzzy ventilation system. It uses Fuzzy Logic
- to switch a fan on and off as dictated by its knowledge base
- of the amount of smoke, odors, and room temperature and
- humidity. The Fuzzy bath, for example, has a controller that
- keeps the temperature of the water just right, not too hot
- and not too cold. If the water is lukewarm at first, it adds
- heat at a slower rate than if it's cold, avoiding wasteful
- overheating.
-
- With the right Fuzzy outlook, you could be the next to
- discover another innovative application of Fuzzy Logic.
-
- ------------------------------------------------------------
-
- 8. OMRON and Fuzzy Logic
-
- OMRON is renowned worldwide for its leading-edge Fuzzy Logic
- technology research and applications. What has this
- technologically advanced company achieved and how? What does
- the future hold for this exciting Fuzzy Logic? Through an
- interview conducted in February 1991 with General Manager
- Masayuki Oyagi of OMRON's Fuzzy Technology Business Promotion
- Center, we hope to answer these questions.
-
- Q. How did OMRON become involved with Fuzzy Logic technology?
-
- A. In the early 1980s, we were fortunate enough to meet
- Assistant Professor Takeshi Yamakawa of Kumamoto University
- who specialized in this peculiar new technology known as
- "Fuzzy Logic". Our difficulties in control applications with
- conventional solutions, combined with his enthusiasm for
- Fuzzy Logic's abilities, led us to start studying it, but
- with only a few researchers. The late Executive Advisor
- Kazuma Tateisi (then Chairman), however, was most impressed
- with Fuzzy Logic and correctly predicted its importance.
- His encouragement led to the formation of the Fuzzy Project
- team, now the Fuzzy Technology Business Promotion Center,
- which conducts basic studies and explores new business
- opportunities.
-
- Q. OMRON's R&D efforts have given rise to numerous original
- applications for Fuzzy Logic. Could you give some examples?
-
- A. The most obvious example would be the Fuzzy controller, the
- first of its kind in the world. Developed in conjunction
- with Professor Yamakawa, this breakthrough was a huge
- sensation at every academic conference and fair it was
- exhibited at. Several varieties of Fuzzy controllers are
- already on sale on the Japanese market. There are also
- Fuzzy temperature controllers and Fuzzy software
- development support tools to assist programmers.
-
- To give some interesting applications, we developed a robot
- which can grasp something "pretty" soft and fragile - tofu
- (bean curd); and a can sorting machine capable of
- identifying cans by color. Overall, OMRON has more than
- 100 successful applications, 20 of which are now available
- to the public.
-
- As 1991 progresses, you can expect more OMRON Fuzzy Logic-based
- products to be introduced. To date we have applied for more
- than 700 patents, a figure that gives some indication of
- OMRON's strength in Fuzzy Logic applications.
-
- Q. Fuzzy Logic technology is obviously important to OMRON. What
- degree of importance does it have within the company?
-
- A. In President Yoshio Tateisi's 1991 New Year address to OMRON
- employees, Fuzzy Logic was identified as one of our core
- technologies for the 1990s. By 1994, over 20% of our entire
- product line will include some form of Fuzzy Logic.
- Considering the diversity of OMRON's products, this is a
- challenging and significant goal.
-
- OMRON's R&D investments account for approximately 7% of its
- total sales and I think Fuzzy Logic research represents
- nearly 1%.
-
- Q. OMRON is not alone in the Fuzzy Logic business. How does it
- distinguish itself from its competitors?
-
- A. One of the main characteristics of OMRON's Fuzzy Logic-related
- business is the completeness of its product line. OMRON is
- presently the only company which provides an entire range of
- Fuzzy Logic products, including digital and analog units, at
- virtually every speed, inference scale and computation capacity.
- OMRON also offers Fuzzy Logic products in complete sets,
- including chips, software, and development tools, which can be
- used both in-house and by customers. Almost eight years of
- experience with Fuzzy Logic have gone into all of these products.
-
- There are an amazing number of beneficial Fuzzy Logic applications
- bearing OMRON's name, both original and joint customer
- development projects; the largest number in the world, I think.
- This success lets us continue to satisfy each customer's
- particular needs.
-
- Q. Aside from being a fascinating technology, what makes it so
- attractive?
-
- A. OMRON doesn't think Fuzzy Logic itself makes products better.
- What is more important is the quality of user benefits that
- Fuzzy Logic can offer. Any business operates towards goals,
- such as major performance improvements, cost reductions,
- miniturizing, or others. To attain these goals, businesses
- will usually refine their operations, generally without
- concern for the kind of technology used. But they do care
- about whether the technology can really work for them. Where
- existing computers function perfectly, such as for wage
- calculation, Fuzzy Logic has no value. However, with
- applications that are difficult or impossible using
- conventional technology, Fuzzy Logic may be the answer.
-
- Q. Where does Fuzzy Logic exhibit an improvement over previous
- technology?
-
- A. The basic characteristic of Fuzzy Logic is that it can handle
- information with unclear boundaries, at any stage of input,
- processing, computation, memory or output. In other words, it
- can manage "fuzziness". The logic itself is purely mathematical,
- so the results are not "fuzzy" but rather very clear and precise.
-
- Consider the can sorting machine which I mentioned earlier. With
- Fuzzy Logic, a computer can be instructed to sort cans according
- to their colors such as "reddish" or "bluish", instead of by
- reading characters printed on labels. Certainly character
- recognition technology for reading labels is very advanced, but
- when the can is turned so that the label isn't visible, it can't
- work. This is exactly where Fuzzy Logic is best.
-
- Q. What else is happening with Fuzzy Logic at OMRON? How many people
- are involved with this technology?
-
- A. I'm not sure of the exact number but research on the technology
- itself in addition to developing applications involves many
- people. As an indication, at least 1,000 people have taken a
- Fuzzy Logic seminar.
-
- Some are members of the Laboratory for International Fuzzy
- Engineering Research (LIFE). One person from our Fuzzy Technology
- Business Promotion Center is now working at OMRON Advanced
- Systems, Inc. in Silicon Valley, studying American technology as
- well as introducing Japanese technology to the US staff. We are
- also planning joint studies with various overseas manufacturers
- and seminars are held regularly, probably weekly, for both OMRON
- employees and our customers. Although most of these activities
- are within Japan, we plan to expand them to other countries this
- year.
-
- The first product scheduled for marketing abroad in 1991 is the
- Fuzzy temperature controller, to be introduced at the upcoming
- Hanover Fair. This will be followed by the Fuzzy chip. OMRON will
- continue its marketing efforts overseas with Fuzzy Logic products,
- ultimately aiming for simultaneous worldwide release. This coming
- spring, a Fuzzy Logic product showroom will open at OMRON
- Electronics, Inc. in Schaumburg, Illinois.
-
- Q. That explains OMRON's aggressive marketing strategies. Some people,
- however, say that Fuzzy Logic in the US and Europe is not as
- popular as in Japan, partially due to the term "Fuzzy". What is
- your impression?
-
- A. I think there are positive and negative feelings about this term.
- In its early days, "Fuzzy" was not considered an academic term.
- Because of this, however, people got the impression that this
- technology was something quite singular which, I think, gave it
- more impact. On the down side, people thought that its results
- or ability would be "fuzzy", and questioned the product
- reliability.
-
- Regardless of that, the fact is that Fuzzy Logic is used in very
- demanding areas, including nuclear power plants. In the US, NASA
- is working to implement Fuzzy Logic control in space environments,
- an exceptionally difficult task. There are many energetic Fuzzy
- Logic researchers in the US, Europe, and other places, which is a
- favourable change from earlier criticism of this unique
- technology. In fact, American trade magazines are constantly
- asking us for interviews, and French and German groups have been
- visiting OMRON regularly since 1989. This makes me confident that
- Fuzzy Logic technology will grow rapidly in both US and Europe in
- the near future.
-
- If consumer electronics giants such as GE introduce products with
- Fuzzy Logic, you may see a boom even larger than the one
- experienced in Japan last year. New technology that can handle
- things conventional machines can not, will naturally surprise
- and excite people, in any market and in any country.
-
- Q. 1990 in Japan was considered the "year of Fuzzy Logic". What was
- OMRON's part in that and what are your comments on the boom?
-
- A. With Fuzzy Logic, OMRON's goal is to raise the functions and
- capabilities of machines to levels comparable to human beings.
- In a sense, it can be considered "Artificial Intelligence" (AI).
- The left hemisphere of a human brain is used for logical
- processes, like reading and talking, while the right hemisphere
- is for intuitive and emotional mechanisms as well as unconscious
- information processing. Conventional computers imitate the left
- side, while Fuzzy Logic plays the role of the right side.
-
- In chess, for instance, players make instant judgments, which
- would take many hours with a conventional computer. Such
- advanced thinking is the product of the cooperative efforts of
- both sides of the brain. We are imitating real life and are
- working on integrating conventional computers with Fuzzy Logic,
- expert systems, neural networks, and other technologies.
- OMRON's goal is to create machines that approximate human
- intelligence and capabilities, and yet still be compact and
- inexpensive.
-
- The 1990 Fuzzy Logic boom, I think, was the first wave which
- accurately reflected the direction of the technology and it
- motivated us to go further. The market's enthusiastic response
- was due to its sense that this long-awaited technology would
- create truly intelligent, user-friendly machines.
-
- -----------------------------------------------------------------
-
- 9. Main Events at OMRON Related to Fuzzy Logic Technology
-
- 1984 Research into Fuzzy Logic begun.
- 1986 Fuzzy Logic medical diagnosis system introduced.
- 1987 Assistant Professor Takeshi Yamakawa of Kumamoto University
- (now Professor of Kyushu Institute of Technology) introduces
- super high-speed Fuzzy controller, test-manufactured by
- OMRON, at the 2nd Conference of the International Fuzzy
- Systems Association.
- 1988 World's first super high-speed Fuzzy controller, FZ-1000,
- marketed.
- OMRON participates in the establishment of Laboratory for
- International Fuzzy Engineering Research.
- F (Fuzzy Logic technology research and marketing) project
- formed.
- OMRON participates in the Fuzzy Logic research project of
- the science and Technology Agency.
- Four working models of Fuzzy Logic systems displayed at
- the international workshop on Fuzzy Logic applications.
- 1989 Professor L. A. Zadeh welcomed to OMRON as senior advisor.
- Ten new products using Fuzzy Logic technology introduced,
- including chips, controllers, and software.
- Fuzzy Technology Business Promotion Center established.
- Bank note feeding mechanism using Fuzzy Logic developed
- for ATMs.
- Fuzzy hybrid control method developed.
- 1990 "LUNA-FuzzyRON" Fuzzy Logic software development support
- system developed.
- Fuzzy Logic human body sensor developed.
- Fuzzy controller related gain adjustment method devised.
- Failure diagnosis and prediction system for machine tools
- developed using Fuzzy Logic expert system.
- Fuzzy inference unit, C500-FZ001, marketed.
- Two new series of digital Fuzzy processors developed,
- FP-3000 series controllers and FP-5000 series multitask
- processors.
- Development tools for the FP-3000 marketed.
- Fuzzy inference molding machine support system developed.
- Fuzzy temperature controller, E5AF, marketed.
-
- ---------------------------------------------------------------
-
- 10. Fuzzy Logic Products
-
- OMRON has released numerous innovative products that use Fuzzy
- Logic. A few of those products scheduled for release overseas
- are listed below:
-
- o FP-3000 Digital Fuzzy Processor-Controller
-
- Cost-effective Fuzzy chip ideal for control and simple pattern
- recognition.
-
- * High-speed inference processing - 650 u-s/(5 antecedents and
- 2 consequents, 20 rules, 24 MHz (external clock speed)).
- * Bus interface similar to that of an SRAM allows connection to
- various CPUs.
- * Fuzzy Logic operation can be accomplished on a single chip
- (Single mode).
- * High 12-bit resolution.
- * Up to 128 rules applicable for each inference (Expanded mode).
-
- o FS-10AT Fuzzy Software Tool
-
- A personal computer software designed to create rules and
- membership functions for Fuzzy inference.
-
- * Compatible with IBM PC-AT.
- * Allows performance of trial control using A/D and D/A
- expansion boards.
- * Outputs created rules and membership functions as object
- code for the FP-3000 Fuzzy controller and FB-30AT Fuzzy
- inference board.
-
- o FB-30AT Fuzzy Inference Board
-
- FP-3000 chip-packaged board
-
- * Can be inserted into an IBM PC-AT expansion slot.
- * Uses the rules and membership functions created by the FS-10AT.
- * Provided with driver software, allows Fuzzy inference to run
- with the user's software.
- * Applications include evaluation and field tests of the FP-3000,
- and addition of Fuzzy Logic functions to personal computers.
-
- o E5AF Fuzzy Temperature Controller
-
- The industry's first temperature controller to employ Fuzzy Logic.
-
- * Highly precise (+/- 0.3% error) and fast response to external
- disturbance.
- * Hybrid control integrates PID control and Fuzzy Logic control to
- improve disturbance response significantly (50% higher than
- conventional PID control).
- * Easy operation - similar to that of conventional models.
- * Automatic Fuzzy Logic parameter setting. Fuzzy Logic parameters
- can be programmed to fit the application.
- * Ideal for use in physical/chemical equipment, industrial
- furnaces, and semiconductor manufacturing equipment.
-
- ------------------------------------------------------------------
-
- 11. Fuzzy Logic Technologies
-
- OMRON is also involved in regular development of practical Fuzzy
- Logic applications. Here are some examples:
-
- o Fuzzy Logic Failure Diagnosis and Prediction System for Machine
- Tools
-
- In a joint development with Komatsu Ltd., this system generates
- and displays various machine failure predictions in order of
- probability, enabling a much simpler detection of the real cause
- of the fault. It will reduce servicing time by 24%, and software
- development time to 1/5 of conventional systems.
-
- o Fuzzy Inference Molding Machine Support System
-
- This system uses Fuzzy inference to automatically remedy the
- conditions that cause plastic molding failures. Unlike
- conventional systems which call for expert attention, this new
- system only needs a simple defects input into the built-in
- controller. Fuzzy inference, with its expert knowledge base,
- takes care of the rest automatically, and at the same level
- of competence as a specialist.
-
- o Bank Note Feeding System Employing Fuzzy Logic for ATMs and CDs
-
- The texture and quality of bank notes stored in automatic teller
- machines (ATMs) and cash dispensers (CDs) are easily affected by
- ambient humidity, conveyance conditions, etc., which in turn makes
- stable bank note feeding difficult. With the aid of Fuzzy Logic,
- this new mechanism keeps the gap between the rollers at the
- optimum level, notably increasing the reliability of ATMs and CDs
- as well as reducing the need for maintenance.
-
- --
-