I'm curious what the current level of block lookahead is on lcnc compared to commercial controls. Anyone know the amount of data buffering that it can handle?
Phil T. The Feral Engineer Check out my LinuxCNC tutorials, machine builds and other antics at www.youtube.com/c/theferalengineer Help support my channel efforts and coffee addiction: www.patreon.com/theferalengineer On Tue, Aug 17, 2021, 9:36 PM Sam Sokolik <samco...@gmail.com> wrote: > It would be the same setup... Just using servo amps.. Velocity out of > the pid - position back from the encoders. > > On Tue, Aug 17, 2021, 8:14 PM andrew beck <andrewbeck0...@gmail.com> > wrote: > > > Not sure Sam. > > > > I have a 7i77 on this mill though also. So analog control > > > > On Wed, Aug 18, 2021, 12:51 PM Sam Sokolik <samco...@gmail.com> wrote: > > > > > I am going to ask a stuid question.. If you have a velocity run step > gen > > > with pid. Couldn't you hook a limit3 between the pid and steghen. > > > Because the input is velocity instead of position - wouldn't the > > > acceleration limit in the limit3 be jerk instead of acceleration? I > am > > > sure it doesn't work that way.. I was just thinking you have moved the > > > derivatives up one.. > > > > > > (I can tell you it doesn't seem to work in practice - probably because > > the > > > pid will always try to correct the error. Like maybe you would need to > > > negate the limit3 amount on the feedback side..) > > > > > > On Tue, Aug 17, 2021 at 1:28 PM Scott Harwell via Emc-users < > > > emc-users@lists.sourceforge.net> wrote: > > > > > > > I haven't tried it yet, but this looks promising. > > > > LinuxCNC S-Curve Accelerations > > > > > > > > > > > > > > > > Scott H > > > > > > > > > > > > On Tuesday, August 17, 2021, 12:57:06 PM CDT, Ralph Stirling < > > > > ralph.stirl...@wallawalla.edu> wrote: > > > > > > > > I've also been hoping to see this appear in a Linuxcnc update, > > > > as it has been worked on by a number of people for years. > > > > Here are the most recent threads about jerk-limited trajectory > > planning: > > > > > > > > > > > > > > > > > > https://forum.linuxcnc.org/24-hal-components/40152-jerk-limited-trajectory-planner-hal-component > > > > > > > > > > > > > > > > > > https://forum.linuxcnc.org/38-general-linuxcnc-questions/34666-c2-smooth-velocity-profile?start=0 > > > > > > > > -- Ralph > > > > ________________________________________ > > > > From: David Berndt [ber...@uberwin.com] > > > > Sent: Tuesday, August 17, 2021 9:01 AM > > > > To: Enhanced Machine Controller (EMC); andrew beck > > > > Subject: Re: [Emc-users] jerk control > > > > > > > > CAUTION: This email originated from outside the Walla Walla > University > > > > email system. > > > > > > > > > > > > I don't have a great need for it with my machines, or the time/brains > > to > > > > implement it. It just seems like a feature we really should have. > > > > > > > > I'd be willing to participate monetarily in some sort of system to > > > > incentivize the inclusion of jerk control. Perhaps an open-source > > feature > > > > bounty? Does the community want to consider that sort of thing? > > > > > > > > -Dave > > > > > > > > On Mon, 16 Aug 2021 23:06:05 -0400, andrew beck < > > > andrewbeck0...@gmail.com> > > > > wrote: > > > > > > > > > hey guys > > > > > > > > > > I am sitting here watching my cnc mill atm its shaking quite a bit > > > > > acceleration is 600mm/sec2 which is not that high i think. > compared > > > to > > > > > every other cnc mill i have used with a commercial controller. > they > > > have > > > > > jerk control and work much better. so looking forward to when we > get > > > > > jerk > > > > > control here on linuxcnc! > > > > > > > > > > but in the mean time i need a poor mans jerk control and thinking > of > > a > > > > > limit on the pid output to chop down the initial acceleration for > the > > > > > first > > > > > moment in time just so little moves don't shake it to death > > > > > > > > > > andy mentioned that I could maybe use a limit component to limit > the > > > > > initial acceleration for the first tiny moment in time to cut down > on > > > the > > > > > vibrations. > > > > > > > > > > how do you guys think that could work? > > > > > > > > > > Regards > > > > > > > > > > Andrew > > > > > > > > > > _______________________________________________ > > > > > Emc-users mailing list > > > > > Emc-users@lists.sourceforge.net > > > > > > > > > > > > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Cralph.stirling%40wallawalla.edu%7C7457b9607a2d4747a1e508d961a1b508%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637648169423748846%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=ue%2BwIaVhfay08NBevlCAvyOoNp0qVz9ojUuigRuCOOs%3D&reserved=0 > > > > > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > > > > > > > > > > > https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-users&data=04%7C01%7Cralph.stirling%40wallawalla.edu%7C7457b9607a2d4747a1e508d961a1b508%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637648169423748846%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=ue%2BwIaVhfay08NBevlCAvyOoNp0qVz9ojUuigRuCOOs%3D&reserved=0 > > > > > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > _______________________________________________ > > > > Emc-users mailing list > > > > Emc-users@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > > > > _______________________________________________ > > > Emc-users mailing list > > > Emc-users@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
