Yes, that is an alternate way to incorporate the scale into the movement of the machine, but still leaves me with the problem when the drives are disabled.
Brian On Sat, Aug 7, 2010 at 5:47 PM, dave <[email protected]> wrote: > On Sat, 2010-08-07 at 12:07 -0500, Jon Elson wrote: >> Stephen Wille Padnos wrote: >> >> >> >> >> > Nothing has been removed, you would just use the stepgen in velocity >> > mode, with a PID driving it (making FF1=1 should give you the equivalent >> > of open-loop mode, plus or minus a step here and there). >> > >> > >> I have to retract my previous erroneous statement, after some more >> reading, Stephen is right (of course!) >> By running stepgen in velocity mode and using PID, you convert your >> stepper system into a true servo >> system. >> > >> > The real problem is that screw mapping is meant for systems that have >> > the screw between the feedback device and the table, but this machine >> > isn't like that since the scale is actually on the table. You can't >> > drive the PID very well with only scale feedback since it's too loosely >> > coupled to the motors, but that's irrelevant since you can't really use >> > steppers like servos anyway. >> > >> > >> An excellent point, the "screw error compensation" would not be >> correcting error on the LEADSCREW, it would be compensating for errors >> in the linear encoder, which may not be necessary at all. >> >> Jon >> > Just to confuse the situation and possibly display my own ignorance; > > It is possible to take position off the stepper for P and D and feed I > the linear scale to get final settling? > > Dave > >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by >> >> Make an app they can't live without >> Enter the BlackBerry Developer Challenge >> http://p.sf.net/sfu/RIM-dev2dev >> _______________________________________________ >> Emc-developers mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by > > Make an app they can't live without > Enter the BlackBerry Developer Challenge > http://p.sf.net/sfu/RIM-dev2dev > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers > ------------------------------------------------------------------------------ This SF.net email is sponsored by Make an app they can't live without Enter the BlackBerry Developer Challenge http://p.sf.net/sfu/RIM-dev2dev _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
