RE: P.I.D. Loop

["Pete Cook" <pete.cook-at-alltracorp.com>]

One other thing - He also suggested using an I Gain Limit to keep the I Gain
from driving the system into a low frequenct oscilation where the I Gain & P
Gain wind up chasing each other. Under those conditions the system can
appear to work for a while but can do some wierd things when it is supposed
to finally come to a stop...

Pete
>
>
> Pete,
>   This sure goes a long way to understanding P.I.D.
>                                   Thanks
>                                     Joe
>
>
> >From: "Pete Cook" <pete.cook-at-alltracorp.com>
> >Reply-To: emc-at-nist.gov
> >To: Multiple recipients of list <emc-at-nist.gov>
> >Subject: P.I.D. Loop
> >Date: Mon, 11 Feb 2002 14:11:22 -0500 (EST)
> >
> >
> >Got this info from Designing With Motion Handbook by Charles
> Raskin, PE Nov
> >1994
> >
> >P or Proportional Gai = (Kp) (error)
> >
> >It compensates for immediate changes in servo position error
> position.
> >
> >I or Integral Gain = (Ki) (Last Error Total +- New Error)
> >
> >Compensates for following error as the move progresses.
> >
> >D or Derivative Gain = (Kd) (Error - Previous error)
> >
> >Compensates for the error in the last update period. Compensates for
> >changes
> >in load or direction.
> >
> >Hope this helps water down the mud...
> >
> >Pete
> >
> >
>
>
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