On Thu, 1 Nov 2012, andy pugh wrote: > Date: Thu, 1 Nov 2012 17:00:33 +0000 > From: andy pugh <bodge...@gmail.com> > Reply-To: EMC developers <emc-developers@lists.sourceforge.net> > To: EMC developers <emc-developers@lists.sourceforge.net> > Subject: Re: [Emc-developers] ferror calculation incorrect in motion > > On 1 November 2012 16:52, Peter C. Wallace <p...@mesanet.com> wrote: > >> >> Where this bug really causes problems is when you have a decent sized >> integral >> term so the integral part of the PID loop can track motion and null any PID >> error when slewing, therefore causing a large indicated ferror (that is >> basically impossible to tune out) > > > How large is this f-error?
it is one trajectory step per sample (assuming perfect pid tuning) so at 600 IPM and 1 KHz servo thread it would be 10 mills (10 I/S * .001 seconds) > To an extent it is a non-issue as long as it isn't big enough to trip the > f-error fault. > (Tune to minimum PID error, make sure that the f-error limit is big enough) > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto > ------------------------------------------------------------------------------ > Everyone hates slow websites. So do we. > Make your web apps faster with AppDynamics > Download AppDynamics Lite for free today: > http://p.sf.net/sfu/appdyn_sfd2d_oct > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
