I have replaced the controller in a functioning mid 1980s Anilam system on a Bridgeport mill with a 2143. The servo motors have tachos for velocity feedback direct into the amplifiers which I am retaining. With such a setup do I need to adjust the KD gain or just leave it to the tachos and amplifiers.
When doing a test tuning I found little difference in performance with 00 (even 0.1) the position error cycles +/- by an amplitude dependent on the KI value.
With KD=500, KP=50 and KI=0, I get smooth rapid response with zero position error, however I am a little puzzled by the need for KI=0. I would have thought that a non zero number would be necessary to force the error that last little bit towards zero. Is this an unusual set of gains?
BTW. As far as I know I can only run the amps in velocity mode.
Galil_CoryB on 07/15/2014 - 14:40
tonyfoale-
The Galil controllers normal mode of operation is torque mode where the controller is expecting the amp to output the current to the motor unfiltered and without limits beyond the +-10V signal. Axis tuning will affect the position error as well as the rise time, settling time, and overall torque ripple. The KD and KP gains are completely dependent on the application hardware but it is not impossible for there to be 0 position error with KI for that axis set to 0.
For a more detailed method of tuning please take a look at our tuning appnote section.
http://www.galilmc.com/support/application-notes.php