I get a tracking error. the scale of my encoder is correct on my B axis display

Good morning, gentlemen,
I'm coming back to you because even with your advice I can't adjust my encoder. I still have my “joint 3 tracking error” problem. I've made a short video showing how the position of my encoder reacts, as soon as I touch it, I get a tracking error. on the other hand, the scale of my encoder is correct on my B axis display.

My config file are attach .

Could you help me?
Thank you

Set your following error limits wide (1 inch or 25 mm)
and post a halscope plot of the following error when
you do a motion.

my unit is degrees for a rotating axis. I don't know how to use a halscope.

Tuning/diagnosis will be quite difficult  without using halscope

Hello, please excuse me for the delay in replying but I have been sick.

Yes, I managed to adjust my PID but not exactly, I still have small ocillations at certain positions of my rotating B-axis.

I saw that there is an Autotune. But impossible to find any practical documentation on this program which apparently makes a PID setting automatically???

I'm looking at how to program an Autotune in python. Sending commands and retrieving data, tracking errors is quite simple with "Import Linuxcnc".

the regylge of a PID is very tedious in length. If an automatic program exists, I'm a taker.

If anyone has any information I'm interested.

Thank you

Unfortunately Autotune programs do no adjust the feedforward or deadzone terms so fairly useless
in real world situations.

I suspect for the best performance of a position control (stepgen or Ethercat or whatever) with an added
linear feedback device, you would need two PID loops, the local high bandwidth position loop plus a lower bandwidth
PID loop using the linear encoder feedback. This could be done in hal with two PID components with their outputs
summed.

Yes thank you but then I have no idea how to do it .

Regards

At the minimum you should:

Expand the ferror limits as explained above.

Learn to use halscope.

It will not really be possible to tune without using halscope
regardless of the hal setup.



 

but I know how to use the halscope. I know how to read the curves, but I don't know which parameter to adjust when, for example, I have oscillations in the error.