On Mon, Oct 11, 2010 at 12:21 PM, Jon Elson <[email protected]> wrote:
> Stuart Stevenson wrote: > > On Sun, Oct 10, 2010 at 1:05 PM, Jon Elson <[email protected]> > wrote: > > > > > >> > >> Wow, that is really weird! > >> > >> > > the motor has an encoder so we built a splitter cable and routed the > encoder > > feedback to EMC2 and the drive. > > > No, the splitting of the signal is not weird, the fact that EMC is > getting unaltered encoder data, and > it has those weird lags at the accel inflection points. I was SURE it > was some kind of computer-caused > delay in the servo data. > Is it possible EMC2 responds faster than the Fanuc servo drive? > > I see the disturbance in two places when I have the accel as low as 2. > The > > accel is set to 50 in the example. > > > > > 50 inch/sec^2? On a big machine? That seems like it is too high, and > no surprise the > drive can't follow. There is electrical time constant in these motors, > as opposed to > mechanical time constant (real inertia). It takes time for the drive to > ramp up current in > the motor. If there is a tunable parameter in the drive for damping on > the torque (current) > loop, you may need to reduce that damping, or maybe even in the velocity > loop. The drive > just appears to be sluggish in response to any sudden changes in command. > > Jon > > Not knowing the exact signal the Fanuc 10/11M control sent to the servo drive I have used many different settings of the accel. The servo amp certainly has tuning parameters. Are some of them set by the control on startup. Are some of them read from nonvolatile storage in the servo amp? I don't know and I don't have any way of checking and I don't have any way of setting any parameters in the servo drive. My tuning logic tried to send the servo drive a fast accel signal to emulate the control. I started with 2 and adjusted up from there. > > > ------------------------------------------------------------------------------ > 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 > -- dos centavos ------------------------------------------------------------------------------ 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
