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 ------------------------------------------------------------------------------ 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
