Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

I thought we determined FF1 should be around 25.

At this point I thing setting I to 0 until you get a better handle on whats going on would be a good idea (I is usually the last thing to tune).

What happens if you increase D (try 30, 40, 50, 60) and show us the results?

Todd and tommylight, Many, many thanks!!

Attached are several screenshots, as the P goes up the f error goes down, up to a point where it slows.





many thanks!

That would be expected behavior. Increasing P will decrease following errror, but will also increasingly become more and more unstable, until at some point it goes completely out of control.

You need to increase D until you only have one small bump of over shoot, instead of the half a dozen (or more) wild oscillations you have now. If you find a point where increasing the D causes the system to become unstable, set D to about 2/3s the value for D that made it unstable and you will have to reduce your P until those oscillations are under control. (The I should be set to 0 while doing all this.)

Then use FF1 to get the cruising following error as close to 0 as you can.

Then use FF2 to try to smooth out the error during acceleration as best you can.

Todd, thank you!!

Attached are a few screenshots, I have tried several settings, this is the best so far!





Many thanks!!

Too much FF1. (causing you to have a negative following error while cruising.)

Does more FF2 reduce the following error on acceleration further?

(I think there is still too much over shoot, so more D and/or less P. it will be hard to tune the FF2 until you get the overshoot under control.)

It is also possible your your max acceleration could still be a hair too high, causing a big following error during acceleration because the motor just can't quite catch up to the commanded position.