On Thursday 05 March 2020 09:25:01 Peter C. Wallace wrote: > On Wed, 4 Mar 2020, Gene Heskett wrote: > > Date: Wed, 4 Mar 2020 22:12:47 -0500 > > From: Gene Heskett <[email protected]> > > Reply-To: EMC developers <[email protected]> > > To: [email protected] > > Subject: Re: [Emc-developers] 2.7.15 PID Fix > > > > On Wednesday 04 March 2020 12:52:09 andy pugh wrote: > >> On Wed, 4 Mar 2020 at 17:26, Peter C. Wallace <[email protected]> wrote: > >>> It was first added to 2.8 and them merged into 2.7 before the > >>> 2.7.15 release AFAIK > >> > >> I think that they were added in 2010: > >> https://github.com/LinuxCNC/linuxcnc/commit/44586b831e1ef5e82600319 > >>0ab 317cda76b6e8e3#diff-912d11dfa52738be509f63e4ff1922a4 (And that > >> commit also includes documentation of the pins) > > > > Sort of. But it does provide some hints as to how to utilize it to > > improve control, If you have encoder feedback on axis axis then you > > could feed the feedback.deriv pin with the velocity of that axis's > > encoder. But from reading that, I fail to deduct a source for > > cmd.deriv. I am envisioning a differential, for instance between > > current command and previous command or maybe a sum2 with one input > > set for a gain of -1 and an rc lag from the command input to the > > other input giving a differential output according to the charge > > across the cap. Since we don't have a cap in hal components, we'ed > > have to use a low pass. But I quickly run out of imagination as to > > the rc time constant to synthesize. > > > > just discussing the howto's would I think be educational for those > > of us who never got the transcendental stuff in school 70+ years > > ago. > > > > Help? > > > > Thanks > > Normally you would just connect the joint velocity pin to the PID > command derivative > Ok, but thats the signal I disconnected around 2 years back to get rid of an instant following error for a movement of 1/10 the MIN_ERROR. So hooking it back back up now does what to my FF# settings?
> > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > 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. > > > > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
