Introduction to Fuzzy Logic. James K. Peckol
Ideas are introduced and then revisited throughout the text, each time to a greater depth or in a new context.
Safety, security, and reliability are absolutely essential components in the development of any kind of system and system design process today. Such material is not an integral component in this text but should be stressed as companion technology.
As we stated in the opening of this Preface, finding a good balance between depth and breadth in today's approximate reasoning systems is a challenge. To that end, a couple of decisions were made at the outset. First, the text is not written around a specific microprocessor or software language. Rather, the material is intended to be relevant to (and has been used to develop) a wide variety of applications running on many different kinds of processors. Second, the artificial intelligence field and approaches to approximate reasoning are rapidly changing even as this sentence is being typed and read. In lieu of trying to pursue and include today's latest technologies, the focus is on the basics that apply to any of the technologies. The underlying philosophy of this book is that the student is well‐grounded in the fundamentals will be comfortable working with and developing state‐of‐the‐art systems using the newest ideas. Ohm's law hasn't changed for many years; the fields of computer science and electrical and computer engineering have and are.
The core material has been taught as a one‐quarter, senior‐level course in fuzzy logic development in several universities around the world. Based on student background, the text is sufficiently rich to provide material for a two‐to‐three‐quarter or two‐semester course in fuzzy logic and approximate reasoning systems development at the junior to senior level in a traditional four‐year college or university engineering program.
Beyond the core audience, the sections covering the assumed foundation topics can provide a basis on which the student with a limited hardware or software background can progress through the remainder of the material. The logic and software sections are not sufficiently deep to replace the corresponding one‐ or two‐quarter courses in the topics. For those with adequate background in such areas, the material can either be skipped or serve as a brief refresher.
Acknowledgments
Over the years, as I've collected the knowledge and experiences to bring this book together, there have been many, many people with whom I have studied, worked, and interacted. Our discussions, debates, and collaborations have led to the ideas and approach to design presented on the pages that follow.
While there are far too many to whom I owe a debt of thanks to try to list each here, I do want to give particular thanks to David L. Johnson, Corrine Johnson, Greg Zick, Tom Anderson, David Wright, Gary Anderson, Patrick Donahoo, Dave Bezold, Steve Swift, Paul Lantz, Mary Kay Winter, Steve Jones, Kasi Bhaskar, Brigette Huang, Jean‐Paul Calvez, Gary Whittington, Olivier Pasquier, Charles Staloff, Gary Ball, John Davis, Patrick F. Kelly, Margaret Bustard, William and Betty Peckol, and Donna Karschney for all they've done over the years. William Hippe, Alex Talpalatskiy, and my brother William Peckol, who have all spent many hours proofreading, commenting, and making valuable suggestions to improve the early, working versions of the text, deserve a special thank you. From John Wiley, I want to thank Sandra Grayson who supported the original idea of publishing this text and especially Louis Manoharan (Project Editor) and Kanchana Kathirvelu (Production Editor), both of whom helped to guide the manuscript through the editing and production phases, and the unknown copyeditors, compositors, and others whose efforts on and contributions to this project have been invaluable.
In any project, design reviews are an essential part of producing a quality product. I wish to express my appreciation and thanks to this project's many reviewers for their evaluations and constructive comments, which helped guide its development.
I want to extend special thanks to my family William, Suzanne, Joe, Paulette, Karl, and Lori, and to my daughters Erin and Robyn, and grandchildren Kyleen, Jordan, and Tara.
Finally, I extend a thank you to my many teachers, friends, colleagues, and students who I've had the pleasure of knowing and working with over the years.
About the Author
James K. Peckol, Ph.D., is a Principal Lecturer Emeritus in the Department of Electrical and Computer Engineering at the University of Washington, Seattle, USA, where he has been named Teacher of the Year three times and Outstanding Faculty twice. He is also the founder of Oxford Consulting, Ltd., a product design and development consulting firm. The author is a member of Tau Beta Pi, Who’s Who in the World, Who’s Who in Science and Engineering, and has been presented with the Marquis Who’s Who Lifetime Achievement Award.
His background spans over 50 years as an engineer and educator in the fields of software, digital, medical, and embedded systems design and development. Also, the author has published first and second editions of the book Embedded Systems: A Contemporary Design Tool.
As an engineer in the aerospace, commercial, and medical electronics industries, the author has worked on and contributed to the design and development of test systems for military aircraft navigation systems and radar systems, the Apollo color camera, various weather satellites, the Mars Viking Lander, flight control systems for a number of commercial aircraft, production of high‐quality electronic test instruments and measurement systems, and several defibrillation systems. Academic experience spans more than 25 years of developing and teaching software, digital design, fuzzy logic, approximate reasoning, networking, and embedded systems design courses for students from academe and industry with experience ranging from limited hardware or software backgrounds to those at the junior, senior, graduate, and industrial levels.
Introduction
THINGS TO LOOK FOR…
The topics that will be covered in the book.
Important first steps when beginning a new design.
Some of the strengths, applications, and advantages of fuzzy logic.
The differences between crisp and fuzzy logic.
Is fuzzy logic a newly developed technology?
Who is using fuzzy logic?
Should fuzzy logic be used for all designs?
Should a fuzzy system be implemented in hardware or software?
Where might tools called perceptrons and threshold logic be used?
What should we do after we have designed and built the hardware and firmware for our system?
I.1 Introducing Fuzzy Logic, Fuzzy Systems, and • • • • •
This section begins with some personal philosophy about fuzzy logic, fuzzy systems, and other devices. It begins with what fuzzy logic is and presents some introductory questions and answers about the field. It compares and contrasts fuzzy logic with the traditional classic or crisp logic and concludes with a high‐level view of the basic design and development process and potential applications for both approaches. In addition to fuzzy logic, this text provides a brief review of classical logic and presents and discusses the related areas of threshold logic and artificial neurons also termed perceptrons.
I.2 Philosophy
The chapters ahead bring us into the interesting world of threshold logic, fuzzy logic, and perceptrons. Welcome. The approach and views on solving engineering problems presented in this work reflect things that I have learned throughout my career. Yours