Closing the servo loop with HAL mesa 7i76

hey clive

probably way off the mark here I am a relatively new beginner here. But i had a problem with following error when i first powered my machine up and the problem was a bug in pnconf. in the hal file the max PID error for each axis was .0005 which on a metric machine is a tiny number. just changing it to .05 meant that I had no problems.

I started reading this because I want to follow along and connect the encoders back to the control also but just thought the max error bug may have slipped under the radar..

Regards

Andrew

Clive wrote:

PCW wrote:

I would set Pn110,111,112,114 to their minimums and see if that improves the tracking

Peter many thanks for looking into this.

Pn109 is set for zero which I think disables Pn110,111,112 not sure if it affects 114.

But I will of course try those settings.

My Naz drives MB has failed and I am trying to get the data off the raid HD's which is going to take me some time.

Ok After setting up another machine. I have now returned to the F-error problem.

To re-cap this is a 1.8kw servo with matching drive just on the bench it does not error at 3M/min but does at 4.5M/min.You can see from the GUI that it has over shot by 1mm when it error ed
.

.


What do I need to adjust and in what order to sort this.

You can see from the encoder velocity lagging the error that the drive has significant delay
from the command ( the commanded step rate determined mostly by FF1) and motion.
It looks like about a 20 ms delay (1/10 of a major division).

Unless this delay can be eliminated I suspect those drives will not be useful with external feedback.
(and may be a bit suspect as far as axis/axis coordination goes)

That said, is P as high as it can go without instability?
a larger amount of FF2 may also help
Plotting the commanded velocity would also help diagnosis

This is the manual for the drive:- www.dropbox.com/s/jp7t9hcszjcg6na/1.8Kw%...vo%20manual.pdf?dl=0

Would it be possible to put another encoder on the motor shaft or the screw and use that to close the loop !! Just a thought.

Thanks for the help.

Any progress for tuning this drive ?
Pn45-Pn50 i think are related