On 10 December 2012 00:40, Gene Heskett <[email protected]> wrote: > I can't make Pgain cause more than about a 10% of that range cyclic wibble, > not near enough to hear it with the spindle at say 6 rps commanded. At > least at Pgains up to 150 or so, with FF0 = 100, FF1 = 20 and FF2 = 10.
What makes you think that you need FF1 and FF2? This s your spindle that we are talking about here, I think? > Should I be able to induce a rail to rail oscillation with Pgain? Not always. In the case of your spindle I think the physical time-constant and the servo period might be so far apart that it might never happen. > pid.N.feedback-deriv float in > I hadn't noticed this before, so encoder.0.velocity only feeds the > pid.N.feedback pin. > > It sounds as if I should feed both pins with encoder.0.velocity. Done, but > not tested yet. Not in your case, as encoder velocity is the controlled quantity, not the derivative thereof. encoder.velocity is only an appropriate feedback-deriv term in a position loop. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
