Help with PID loop

Hi all,

I have a bouncy PID loop as you will see in this video. Any suggestions on how to tune it?

I’m also considering swapping these brush motors out with torque motors which I suspect are better suited for the task. Any suggestions there are also welcome!

https://drive.google.com/open?id=1Mv05FWn-VM8TOTdeLgvq9bjthCjXd16y

@matthewepler - I don’t know whether this helps: this website: The Basics of Tuning PID Loops has some basic tips, specifically the “Initial Loop Tuning”-section and the following ones.

I usually start with a rather small P value and gradually increase it just to the point where is starts to oscillate. Than I reduce the value a little bit. I rarely bother with setting the I-value (ie leave it zero), and I basically never touch the D-value (ie, it’s also zero). There is this saying “D is for danger”. Certainly not the optimal approach, but I normally get something useable. Of course, it is no longer a real PID-controller… :slightly_smiling_face:

lower P increase I (even the loop time can be too high as the global response is low, of course lower the P I value can be enough if you have resolution enough)

@cpixip and @Matteo_Ricchetti your suggestions both helped! The contractor has reported a nice smooth action on the hub now. Many thanks for your assists!

happy to know that :slight_smile: