On Oct 9, 2010, at 9:51 AM, Peter C. Wallace wrote: > On Sat, 9 Oct 2010, Stuart Stevenson wrote: > >> Date: Sat, 9 Oct 2010 10:08:34 -0500 >> From: Stuart Stevenson <[email protected]> >> Reply-To: "Enhanced Machine Controller (EMC)" >> <[email protected]> >> To: EMC2-Users-List <[email protected]> >> Subject: [Emc-users] tuning question >> >> Gentlemen, >> assessment please >> >> Fanuc AC servo amp w/+-10 V velocity input - encoder feedback from motor >> Fanuc AC servo motor >> PPMC >> EMC2 2.5.0-pre >> Touchy GUI >> >> http://www.mpm1.com:8080/machines/enshu.ini >> >> the following are the variations from the .ini file and the resultant >> screenshots >> >> FF1 0 >> FF2 0 >> http://www.mpm1.com:8080/machines/Screentshot1.png >> >> FF1 0 >> FF2 0 >> Pgain 50 >> http://www.mpm1.com:8080/machines/Screentshot2.png >> >> FF1 .5 >> FF2 0 >> Pgain 50 >> http://www.mpm1.com:8080/machines/Screentshot3.png >> >> >> Pgain 50 >> http://www.mpm1.com:8080/machines/Screentshot4.png >> >> >> in screenshots 1 2 and 3 notice the squared trace on the beginning of the >> accel and decel >> I get this on all axes including the spindle and am unable to tune it away >> I have tried many different combinations of tuning values >> the best trace is the spindle with a max accel of 2 - this allowed a much >> higher Pgain and stiffened the spindle considerably >> the spindle has very little inertia as it drives only the gearbox and >> spindle >> I see the squared traces on the spindle >> the ending traces work smooth until I start getting the tuning a lot tighter >> then the traces tend to even out on all axes >> do you believe this is a result of the marriage between the fanuc hardware, >> ppmc and emc2? >> motion of the axes feels, looks and cuts smooth and accurate - the following >> error spikes are the focus >> suggestions, comments >> thanks >> Stuart >> >> -- >> dos centavos > > screenshots 1,2 and three look like simply not enough FF1 (error proportional > to velocity) > > screenshots 4 looks like FF1 is correct and you are seeing residual errors > (jerk = derivative of accel) These might be due to phase lag so could be > partially ameliorated by bumping up the sample rate. > > 2 pfennigs > BTW I did notice that TRAJ period is set to 10 X servo rate. Setting both at 2 KHz might spiffy things up a bit.
Dave > > ------------------------------------------------------------------------------ > Beautiful is writing same markup. Internet Explorer 9 supports > standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. > Spend less time writing and rewriting code and more time creating great > experiences on the web. Be a part of the beta today. > http://p.sf.net/sfu/beautyoftheweb > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
