RE: [CAD_CAM_EDM_DRO] Re: Servo tuning software

I use Zeigler Nichols for servo tuning as well.
It certainly gets one in the ballpark. If mechanical
systems were perfectly linear it would be exact.

Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia

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-----Original Message-----
From: the_maniacal_engineer [mailto:chris.stratford@...]
Sent: Tuesday, July 20, 2004 5:05 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Servo tuning software



there is a technique called zeigler nichols tuning that is an
empirical way to set the gains in a PID controller (D = K(1+ 1/Ti*s +
Td*s) ). The technique is as follows
1: turn off the I and D terms and adjust the P term (K) until the
system just starts to oscillate.
2: note the gain (ultimate gain) and the period (ultimate period)
3: set the gain K to .6 times the ultimate gain
4: set Ti to one half the ultimate period
5: set Td to 1/8 the ultimate period

that will get you most of the way there, and you can tweak to suit.