On Tue, 7 Nov 2017 10:27:00 -0800 (PST) "Peter C. Wallace" <[email protected]> wrote:
> On Tue, 7 Nov 2017, Nicklas Karlsson wrote: > > > Date: Tue, 7 Nov 2017 19:24:40 +0100 > > From: Nicklas Karlsson <[email protected]> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <[email protected]> > > To: "Enhanced Machine Controller (EMC)" <[email protected]> > > Subject: Re: [Emc-users] PID refresher for Gene? (limited resolution) > > > >> On Tue, 7 Nov 2017, Nicklas Karlsson wrote: > >> > >>> Date: Tue, 7 Nov 2017 19:15:58 +0100 > >>> From: Nicklas Karlsson <[email protected]> > >>> Reply-To: "Enhanced Machine Controller (EMC)" > >>> <[email protected]> > >>> To: "Enhanced Machine Controller (EMC)" <[email protected]> > >>> Subject: Re: [Emc-users] PID refresher for Gene? (limited resolution) > >>> > >>> On Tue, 7 Nov 2017 09:55:28 -0800 (PST) > >>> "Peter C. Wallace" <[email protected]> wrote: > >>> > >>>> On Tue, 7 Nov 2017, Nicklas Karlsson wrote: > >>>> > >>>>> Date: Tue, 7 Nov 2017 18:48:24 +0100 > >>>>> From: Nicklas Karlsson <[email protected]> > >>>>> Reply-To: "Enhanced Machine Controller (EMC)" > >>>>> <[email protected]> > >>>>> To: "Enhanced Machine Controller (EMC)" > >>>>> <[email protected]> > >>>>> Subject: Re: [Emc-users] PID refresher for Gene? > >>>>> > >>>>> On Tue, 7 Nov 2017 12:28:31 -0500 > >>>>> Gene Heskett <[email protected]> wrote: > >>>>> > >>>>>> On Tuesday 07 November 2017 10:08:33 Peter C. Wallace wrote: > >>>>>> > >>>>>>> On Tue, 7 Nov 2017, Gene Heskett wrote: > >>>>>>>> I fail to see why a 2 or 3 percent error in duty cycle and or > >>>>>>>> quadrature results in so much noise. There simply is no way in hell > >>>>>>>> that spindle can be moving at 200 rpms on one servo-thread sample, > >>>>>>>> and 600 rpms on the next sample one millisecond later while its > >>>>>>>> filtered display on a pyvcp tach dial says 400 rpms. > >>>>> > >>>>> Mean value = (200rpms + 600rpms)/2 = 800rpms/2 = 400 rpms. > >>>>> > >>>>> 2 pulses each millisecond, add some noise and sometimes it is 1 pulse > >>>>> while other times 3 pulses each millisecond. Multiply by 200 => 200*(1 > >>>>> 2 3) = (200, 400, 600). > >>>>> > >>>>> How many pulses each time value is calculated? > >>>> > >>>> > >>>> Not relevent, velocity estimation on Hostmot2 firmware calculates > >>>> velocity > >>>> based on the number of counts divided by the time between the counts (the > >>>> sample time is not used in this calculation) > >>> > >>> Yes it is. > >> > >> > >> > >> Nope, you did not understand what I posted, the servo thread time is not > >> used > >> in the velocity estimation with hostmot2 firmware > > > > But you divide by time between samples? > > > > Nope, time between counts Then it should all be good, it make a huge difference, it is the same method I use. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
