paper: Team 1114 Controls and Programming Overview 2012

[JamesTerm]

Originally Posted by MICHAELABICK

Why would you want to reduce the d constant of PID in certain circumstances for speed PID?

I presume this was the
"Different from standard PID control. Instead of the PID calculation setting
the output, the PID calculation is an adjustment to the output
o output = output + calcPID(currentSpeed)
"
?

But if I had to guess, I know that (at least for our power wheel)... the more momentum and kinetic energy built up on higher speeds the less P is needed... but I cannot see yet how that equates to D except that if D is too high it will reverse oscillate. We too had to use a large D though. This attachment is P=4 and D=7. Where magenta is the predicted velocity, Cyan is the encoder velocity, green is the voltage, and yellow is the PID in action.

I'm still trying to master PID... I'd love to get it down to a 2 radian per second tolerance like 1114 has done! We are around 20 radians tolerance.