On Thu, 6 Aug 2015, Gene Heskett wrote: > Date: Thu, 6 Aug 2015 11:22:54 -0400 > From: Gene Heskett <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: [email protected] > Subject: Re: [Emc-users] Encoder filtering > > On Thursday 06 August 2015 10:23:30 andy pugh wrote: > >> On 6 August 2015 at 15:12, Gene Heskett <[email protected]> wrote: >>> Control is very stiff, but still not rpm >>> accurate, asking for 2100 revs gets about 2650. >> >> There is a closed-loop spindle speed + orientation sample HAL file >> here: >> http://git.linuxcnc.org/gitweb?p=linuxcnc.git;a=blob;f=configs/sim/axi >> s/vismach/VMC_toolchange/spindle.hal;h=867a593045fc6a20a227b08173f632ec >> 583db328;hb=3a6ab378e8c5d6759914e08f61cd28e6bd526e3d > > To Peter C. Wallace: All this brings up a need for an edge detected > output pin from the encoders, one that is read by the read, and cleared > by that same read after being recorded into a .hal variable. > > Could that be added to a future version of the firmware? That would > simplify the hal code needed to do this job. > > Cheers, Gene Heskett
No firmware changes are needed to detect edges as a timestamp change is sufficient to determine whether 1 (or many) edges have occured Honestly though, I dont think its worth the effort, if you want good spindle velocity feedback at low speeds, the best way by far is a higher resolution encoder. Patching around velocity estimation noise and bandwidth issues with a low resolution encoder with large quadrature error by making changes in the driver does not seem to me to have general benefit. > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Genes Web page <http://geneslinuxbox.net:6309/gene> > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
