PID control loops - closed loop feedback

[KenWittlief]

thats pretty cool - I dont see any obvious mistakes in it.

have you been able to test it on your bot?

the one thing Im curious about, why did you close the loop on arm velocity instead of arm position?

for our arm control we integrate the joystick input and it creates a desired arm position - then we use a straight proportional desired-actual postion with a gain constant to create the motor drive

the arm sags a little bit if its holding a ball, but thats a function of the gain- the more gain you use, the less it will sag (before the error signal is enough to hold it)

closing the loop on position makes it easier to deal with the up and down limits - you just dont let the desired position exceed the limits.