On 08/26/2017 03:48 PM, Eric H. Johnson wrote:
Jon,
After doing piecewise refinement of encoder counts per engineering unit, I
finally managed a reasonable tuning. There still remains a slight bit of hum
that I do not get at higher resolutions, but the motor runs plenty cool so it
is definitely usable.
I would note that I started with Thornton's method using ff1 and ff2, which
basically worked on the other three axes. I could not get it to work on the
rotary axis, so went back to using I and D.
After doing this however (and possibly other config changes I have made along
the way), I am getting persistent following errors.
At the moment they always occur at head lifts / drops, when X and Y have
basically come to a stop. Head lifts are performed by an air cylinder and give
the system a bit of a jerk. Mostly I am now getting following errors in X and A.
Well, anything that adds a jerk to the system will affect
the encoder reading. So, you may have to just raise the value
of MIN_FERROR until it doesn't trip the following error any
more.
I cannot reproduce this with individual MDI moves, for example. I set the
following errors in the config absurdly high, but does not seem to have any
effect.
Note that FERROR is a multiplier on velocity that is added
to the MIN_FERROR. MIN_FERROR is the allowable error when
standing still. So, that is the one you want to adjust.
Jon
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users
