fuzzy logic and plc

[rajsiyer 7]

Hi pete, Our common acquaintance rsdoran (who died 2-3 months ago) had referred to your capabilities and moods in one of his threads. I clearly recall having seen it someplace (the recollection of the place being fuzzy though ) I admire the spirit of the man. He went out of his way being useful to others by providing us the forums on plcs.net. He encouraged our automation community to come forth and give opinion. I was genuinely sad when he died, even though I could not put a face to his name!. Why I recall Rsdoran here is because of his attitude!. You see the purpose of these forums is to let everybody associated with our profession to share their experience and not do or say things that hurt the sentiments of a well meaning contributor, namely KP_EENG. What is gained by switching him off ?. Perhaps I may not prove ever that fuzzy is inherently more stable than PID.But then one cannot fail to notice that many new designs of loop controllers do feature FLC. The Japanese also have taken to them in a big way and it is not without reason. That I may not prove FLC is any better than PID is for other reasons; perhaps I am incomplete in my knowledge. Which is why I'm here... looking for a better way of doing things.Our ancestors did the right thing by not signing up for the flat earth society. Regards and best wishes though, Raj S. Iyer

[Peter Nachtwey 15]

Ron has nothing to do with this. See post 14.

[AutomaticLeigh 0]

KP_EENG I'm sure that everyone realises Mr. Nachtwey's comment was not intended to imply any dishonesty. My reason for posting is that I was looking for information on how to implement fuzzy control, not because I was trying to pick holes in someone else's work. I have a project at the moment where I think I may need a "Plan B", and instead of simple PID control, I may need multiple-input single-output for some loops. Fuzzy logic would seem to be an obvious candidate, but I have never used it. I often find a few lines of sample code to be invaluable with a new topic, so I was interested in the program which you very kindly posted. The value of forums such as this is the quality of the information. Having to present your solution in front of a knowledgeable community is (hopefully) what keeps the quality high. It appeared to me that your classifier was crisp, not fuzzy. I'm not suggesting that the technique won't work, only that it doesn't seem to me to be an example of fuzzy logic. In opening your work to public scrutiny, you inevitably face the risk of unfavourable criticism. Surely the response to that should be either to defend the work or accept that the comments may be valid.

[rajsiyer 7]

Oh great Brit, you have the grit, merit and above all the right spirit Thanks a millon, once again. The geeks here are indeed of a high standard. Best wishes, Raj S. Iyer