1. Why Fuzzy Logic?
Normally in logic we have a series of statement which are either true or false, yes or no, 0 or 1. In this context, the statement 'the temperature is 25 degrees Celsius' is an objective one and is either true or false. However, for many situations the answer is more like 'Errr'-'not sure'-'maybe'-'that depends' and so on For example', on a pleasant summer's day the statement 'the temperature is too light' is neither true nor false. The statement is qualitative one-it represents an opinion rather than an objective fact.For example, it need to be a bright sunny day on beach for me to feel warm. On the other hand, I could mention some visiting scientists at Control Systems Principles ho feel comfortable in a snow storm on top of a mountain. Do you see what I mean? There is no certainty to the situation-it depends upon the context.
Fuzzy logic deals with uncertainty in engineering by attaching degrees of certainty to the answer to a logical question. Why should this be useful? The answer is commercial and practical. Commercially,fuzzy logic has been used with great success to control machines and consumer products. In the right applications fuzzy logic systems are simple to design,and can be understood and implemented by non-specialists in control theory. In most cases someone with a intermediate technical background can design a fuzzy logic controller. The control system will not be optimal but it can be acceptable. Control engineers also use it in applications where the on-board computing is very limited and adequate control is enough. Fuzzy logic is not the answer to all technical problems, but for control problems where simplicity and speed of implementation is important then fuzzy logic is a strong candidate. A cross section of applications that have successfully used fuzzy control includes: