> 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? > > > > > 200 = x/(dt = 1/1000 seconds) = x*1000*seconds <=> x = 200/1000 = 0.2 so > > velocity = 0.2/dt*(number of counts) > > > > > > I once visited a seminar with an old man from Analog Devices and had not > > find a single case then ohms law did not work. > > > > > > Regards Nicklas Karlsson > > > > ------------------------------------------------------------------------------ > > 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 > > > > Peter Wallace > Mesa Electronics > > (\__/) > (='.'=) This is Bunny. Copy and paste bunny into your > (")_(") signature to help him gain world domination. > > > ------------------------------------------------------------------------------ > 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 ------------------------------------------------------------------------------ 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
