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fgrgrc
08-12-2006, 02:42 PM
Anyone know of a good source of either PID parameters for various controlled fluids or a plain explanation of how to determine the P, I, D values

Peter_1
08-12-2006, 07:09 PM
On one of the technical leaflets of Eliwell (INvensys) or Dixell is explained how you can do this.

But even the, it stays always a little bit trial and error.

You just can't calculate this on forehand. You first have to look how fast the process is changing and how far the overshoots are in simple on/off (mostly with on/off settings or setting the PID in such a way that it acts as simple on/off)
Then you can calculate better how to set the PID.
That's anyway how we do it and how it's described in some handbooks.

Peter_1
08-12-2006, 07:21 PM
http://aabi.tripod.com/optimumpid/examples/optimum-pid-egnsr.htm
http://lorien.ncl.ac.uk/ming/pid/PID.pdf
http://www.lakeshore.com/pdf_files/Appendices/LSTC_appendixF_l.pdf
http://www.advice1.com/pid.htm
http://home.hccnet.nl/e.vd.logt/htm/regelen_pid_uk.htm

The explanation of Eliwell or Dixell was a more practical one. Haven't time now to serach for it.

Peter_1
28-05-2007, 09:25 AM
Thanks Peter!
No problem fgrgrcprklmn:mad:

US Iceman
28-05-2007, 03:08 PM
You are welcome Peter. It seems you found another thankful customer.:(

Brian_UK
28-05-2007, 05:01 PM
Makes you feel like making the first reply as "Yes I have and you?"

Peter_1
28-05-2007, 09:24 PM
Will do this the next time they make the first time a post like this.

mambro_01
07-09-2007, 05:30 PM
Hello All,

as far as I know the Eliwell controllers that has the PID management has also the self-tunning alghoritm, so it's not needed to calculate the right setting but just a fine tunning might be done manually