fuzzy in PLC

Discussion in 'General Electronics Chat' started by h.d, Dec 2, 2007.

  1. h.d

    Thread Starter Active Member

    Oct 22, 2007
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    hi all,
    i want to ask about PLC and kinds of PLC's which have fuzzy logic capabilities , and if you can feed me with some applications.
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    I worked at Allen-Bradley for several years, and as far as I know, none of the PLC guys would EVER consider using fuzzy logic on an industrial process where lives are at stake. On top of that they would never consider trying to explain fuzzy logic to the plant electricians who understand and revere ladder logic. Industrial control moves at a glacial pace compared to other segemnts of industry.

    Come to think of it I'm not sure I know of any practical applications of fuzzy logic. I think it was one of those flash-in-the-pan kind of things. I could be wrong however, so let us know what you find out.
     
  3. h.d

    Thread Starter Active Member

    Oct 22, 2007
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    ok first , thanks for your replay,
    about fuzzy functions ,some of siemens PLC's have that function but up to know i font know which it .
    i will still search,thats is a PLC lab. project from doctor so sure thier are PLC's
    with fuzzy logic control.
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
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    Looks like Allen-Bradley is even making them now. For use in mills, no less.

    From what I can tell, the "fuzzy" part of "fuzzy logic" is all in the sales literature. The part about "can only be described with words" is actually done with calculus. ("Derivative" is a word, aint' it?)
     
  5. Papabravo

    Expert

    Feb 24, 2006
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    The joke was that "we don't have that product yet", but "we're shipping the sales literature in volume".
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    I kinda like the thought of fuzzy logic in PLC's. The greater part of the worker is out of the beam path, so energize the laser. There is only 1 of 10 fingers in the path of the cutter, start planing. And so on...
     
  7. Papabravo

    Expert

    Feb 24, 2006
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    Nothing like a laser to warm the cockles 'o yer heart.
     
  8. h.d

    Thread Starter Active Member

    Oct 22, 2007
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    am dont understand well what you are say??
     
  9. RiJoRI

    Well-Known Member

    Aug 15, 2007
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    Those, h.d., are humorous examples of why fuzzy logic might not be a good idea in an industrial environment.

    I know National Semiconductor had fuzzy logic software for their COP-8 chip. It ran on a PC, and would fuzzify and de-fuzzify and produce output for their chip. Unfortunately, they no longer make the chip, and I guess they do not have the Fuzzy-ware.

    Maybe it was Bob Pease of NS that killed it off: http://www.national.com/rap/Story/fuzzylogic2.html

    --Rich
     
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