Spindle PID troubleshooting -- solved

I can move it there, seems more appropriate .
Thank you.

First you need to make sure that the pid.s component is actually used. Check the hal file. If you attach it here people can check for you.

If that is all good, I would say to set P=0 and adjust FF0 so the actual spindle speed agrees well with the commanded speed. Judging from your experiments FF0 should be perhaps 1.05.

Then start to increase P until the error is as small as you want. You can go on with I and D. The error is in the pid.s.error pin.

Yes, you probably need to increase P, you have

P = 0.4

Which means if you are 100 RPM low the PID output only adds
the equivalent of 40 RPM to the commanded speed...

That's not the problem. The problem, if you look at the screenshot, is that it's overshooting the compensation, but the hal variables in the screenshot show that it's still below. Screenshot shows the spindle already at 1293 RPM, but the setting is set for 1000 RPM. This is with P=0.4. It should have attempted to decrease the spindle speed, but, if you look at the halshow output, it shows that spindle-vel-fb-rps is 13.94723, and spindle-vel-cmd-rps is 16.6667, so, it's behaving correctly if you look at the rps variables. BUT, the spindle-fb-rpm is 1315.024, and that is CLEARLY above the G code spindle speed of 1000 RPM.

I need someone to tell me what hal variables to look for to further debug this problem.

Thanks.

Paul Tan.

Can you post your hal and in files?