37 lines
1.9 KiB
Plaintext
37 lines
1.9 KiB
Plaintext
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There seem to be plenty of answers to the question of WHAT fuzzy logic
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is, and HOW it works. There are several good primers that provide
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a good introduction to those questions.
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I want to know WHEN I should use it, and WHY. What will I gain from it?
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Some say shorter and more simplified development time. But that is a
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rather, um, vague answer.
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There are many devices which [regretably?] can only be turned on or off.
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Examples are an electric water heater, electric stove, and an air
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conditioner. I do not understand how fuzzy logic can do anything but
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complicate these matters.
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One explanation was that if you set your AC on say, 75F, you don't want
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the AC to oscillate on and off as the temp goes below and above that
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point. But that's not how thermistats work anyway. Either they have
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a trigger point and a setting for how long the AC stays on, or they
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have two trigger points, one for turning it on, the other for turning
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it off. Either way, you've basically defined "too cold" and "too hot".
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Okay, so now we use fuzzy logic, and we start by defining how cold and
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how hot each degree is. Then we fuzzify everything, apply rules, and
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then defuzzify it. In the end, we still have one basic binary decision:
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either we turn the AC on, or we turn it off. There can be no added
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"smoothness". It's just on or off. I don't get it.
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Okay, so what about situations where the output is not binary? When I
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ask this question, people start telling me about a robot that's balancing
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a yardstick (or meterstick) on it's hand. Well, that's a real neat
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thing, and if I ever have to write one of those, I'll think about it.
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But I really don't understand why a polynomial wouldn't work as well.
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I'm trying to keep an open mind about this whole fuzzy thing, but I just
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can't imagine a situation where I could benefit from it. I'm willing to
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assume that the problem is my ignorance... So, enlighten me!
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