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fuzzy logic

copacetic353copacetic353 Posts: 52
edited 2008-11-12 08:07 in General Discussion
hello,

i was wondering if anyone could explain fuzzy logic to me? to my understanding, fuzzy logic is practically a necessity when it comes to programming, say, an autonomous helicopter to control attitude and position.

i am fascinated by fuzzy logic and i cant seem to find very much info.

thank you!

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2008-11-11 18:05
    Have you read the Wikipedia article on fuzzy logic and the links from it? (en.wikipedia.org/wiki/Fuzzy_logic)
  • LeonLeon Posts: 7,620
    edited 2008-11-11 18:32
    I don't think that fuzzy logic is much use for controlling a helicopter. Kalman filters are often used for sensor fusion, though.

    Leon

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle
  • Paul BakerPaul Baker Posts: 6,351
    edited 2008-11-11 19:07
    This thread is being moved to the Sandbox since the topic is not Propeller related.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • copacetic353copacetic353 Posts: 52
    edited 2008-11-12 00:59
    isnt there some use for it in helicopter control?

    there has to be some way to control between full truth and full false, 0 and 1.

    whats a kalman filter?
  • Paul BakerPaul Baker Posts: 6,351
    edited 2008-11-12 02:48
    From wikipedia: "The Kalman filter is an efficient recursive filter that estimates the state of a dynamic system from a series of noisy measurements. "

    Basically a kalman filter is a way of providing a best estimate of the real world when the instrument you are using to measure the real world has noise in the reading. Since you can only know the approximate reading at any time, you use past data and a noise model to make the current measurement more accurate.

    Fuzzy logic is a way of expressing analog states, or states which can be off, on or somewhere between. The classic example is temperature, lets say 32 F is 100% cold and 0% hot, and 100 F is 100% hot and 0% cold, and 76 F is 50% hot 50% cold (ie neither hot nor cold). Then you could map what 85 F or 45 F would be.

    Hanno's ViewPort (free 45 day trial) has a section on fuzzy logic, you should check it out.

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.
  • LeonLeon Posts: 7,620
    edited 2008-11-12 08:07
    Kalman filters are used for combining the outputs from a gyro and accelerometer, for stabilising a helicopter.

    Leon

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Amateur radio callsign: G1HSM
    Suzuki SV1000S motorcycle
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