Did some servo tuning tonight, mounted monitor
First of all, I mounted a 17" monitor on the pendant, and brought in a
wireless keyboard. That made the pendant look less like an orphan.
Then I went on to deal with the annoying issue of PID tuning. First of
all, I know little about tuning. Second, there is two loops, one is
velocity loop in the servo drives, and also, there is a positioning
loop in EMC. Third, the drives have a test/offset pot that is very
hard to adjust to be anywhere close to no creep.
Of the above reasons, the first is the worst, of course.
So first I tuned the AMC servo drives using their standard method that
Gunner mentioned: I increased gain until the motors started to
vibrate, and backed out two turns.
Lack of tuning evidenced itself in large following errors, such as
0.005" or so.
After I increased P and slight messed with I, following error is
always under 0.002" on all axes, and usually is under 0.001". I do not
consider myself done, but this is a start and I can move to other
things for now.
i
Then I went through every axis, and by manipulating P and I, reduced
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