On Saturday 30 August 2014 22:08:57 andy pugh did opine And Gene did reply: > On 31 August 2014 00:30, Gene Heskett <[email protected]> wrote: > > Net result would be a scale factor of 1, but with the > > tolerance of the slot windows & photocel response filtered out > > because every step presented to the real world would then be the > > average of the last 4 > > I suspect that if you set up the PID to use only FF0 and I that the > result would be quite similar. > I don't think P is right for closed-loop spindle because zero error > does not mean that you need zero duty cycle...
It has been my experience that no Pgain = pretty soft speed vs load performance. Lots of Pgain and the speed is held quite well under load. But I'll play just to see if I can learn anything. Bringing up the Igain had the effect of slowing it quite drastically. Running at 500 revs, with Igain at the default .1, raise it to 10 and it slows to about 125 rpms. That tells me something else is out of balance as the last time I had it working with a different driver, Igains effect on speed obtained wasn't a huge problem. I had always brought up Pgain while running a variable speed program loop until I had a few % of overshoot at each speed change, then depressing the overshoot with small Dgain to square up the response. Igain then pulled it closer to the requested speed. But this is tuning differently for sure. Igain should have only a minimal effect of speed if everything else is correct, maybe 10% if the scaling is off somewhere. 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) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
