Fuzzy logic and neural network applications in ac drives

Abstract

Introduction: The concept of Fuzzy Logic (FL) was conceived by Lotfi Zadeh, a professor at the University of California at Berkley in 1965. He presented it not as a control methodology, but as a way of processing data by allowing partial set membership rather than crisp set membership or non-membership. This approach to set theory was not applied to control systems until the 70's due to insufficient small-computer capability prior to that time. Professor Zadeh in his paper presented a theory that if people without precise, numerical information input, are capable of highly adaptive control, the machines can also be made to work in this manner. He proposed that if feedback controllers could be programmed to accept noisy, imprecise input, they would be much more effective and perhaps easier to implement. Explained in most simple terms, FL is a problem-solving control system methodology that lends itself to implementation in systems ranging from simple, small, embedded micro-controllers to large, networked, multi-channel PC or workstation-based data acquisition and control systems. It can be implemented in hardware, software, or a combination of both. FL provides a simple way to arrive at a definite conclusion based upon vague, ambiguous, imprecise, noisy, or missing input information. FL's approach to control problems is similar to how a person would make decisions from imperfect information, and much faster. © Springer-Verlag Berlin Heidelberg 2010.