I'm kinda with Alex on this one. If the swing is slow enough to think of as a pendulum then you probably don't have enough P and/or to much I.
This tuning issues is not a matter of a single parameter that causes a certain type of bad behavior. All of the EMC tuning parameters interact. But worst than that, they interact with the similarly named parameters in the drive that you are using. It is common to over set these things in an effort to get a motor to settle down. Sounds to me like you've heard that the drive can affect tuning because you mention the kinds of drive signals. I like velocity mode best because it requires the least effort on the part of the CNC software. If velocity mode is an issue, the drive can't handle this mode easily or does not have proper feedback from the motor/axis then current mode would be my choice. That said, the last time we tuned on a SD drive, there was a "sorta dumb" mode that SD recommended when the CNC software had the ability to control PID. All that we set in the drive was current limit. Everything else was handled by EMC2. I would stay far away from position mode. There are two huge advantages of running servo motors in a set of real servo loops. The first advantage is torque at speed. The second is constant velocity. The position mode for your drive defeats the second of these and essentially turns a servo motor into what acts a lot like a stepper system. HTH Rayh On Thu, 2007-02-22 at 14:36 +0200, Alex Joni wrote: > I would say exactly the opposite. Increase P until the oscilation is > faster/shorter. > > Regards, > Alex > ----- Original Message ----- > From: "Kasparov, Aram" <[EMAIL PROTECTED]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Sent: Thursday, February 22, 2007 1:46 PM > Subject: [Emc-users] SEM /HJ-130 AC Servomotor > > > Hello > > I am working on tune up of SEM AC servomotor. > > Everything looks good, except that when I JOG motor, it turns as a > "pendulum". > > I meant that it passes point where it should stop, than shaft turns back > direction and again passes "center" point. That repeats 3 to 4 times until > shaft of the motor rest on the target position. > > I believe that need reduce P and increase D. > > I found some book about tune up of servo motors and their I found "symptom" > of problem with the tune up of AC servomotors. > > I am interesting in find out which parameter causes trouble? > > > > Also, my amplifier SD-94 (servo dynamics), can work in current, velocity and > position regime. Which one will be better for EMC2? > > I tried velocity and position regime > > > > > > Thank you, > > AramK > > > > > -------------------------------------------------------------------------------- > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of IT > > Join SourceForge.net's Techsay panel and you'll get the chance to share > > your > > opinions on IT & business topics through brief surveys-and earn cash > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > > -------------------------------------------------------------------------------- > > > > _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > -------------------------------------------------------------------------------- > > > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.441 / Virus Database: 268.18.3/696 - Release Date: 2/21/2007 > 3:19 PM > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
