🚁 A drone is trying to hover at a target height. A controller decides how hard to push the rotors, using the error — how far the drone is from the target. In class we build this with real hardware; here you can turn on the P, I and D parts one at a time and watch exactly what each one does.
Step 1
P — Proportional
Push harder the farther you are from the target. It reacts — but settles below the line and wobbles.
Step 2
P + I — add Integral
Adds up the leftover error over time to erase the steady droop — but too much makes it overshoot.
Step 3
P + I + D — add Derivative
Reacts to how fast the error changes and applies the brakes — smooths out the wobble.
Controller
P · Proportional
Output ∝ the current error.
I · Integral
Output ∝ the error added up over time.
D · Derivative
Output ∝ how fast the error is changing.
Try: Step 1 with only P — watch it hang below the line. Flip I on and it climbs
to target. Add D to calm the bounce. Press 💨 Gust to disturb
it and see the controller fight back.
Height vs. time
Target
Drone height
P
I
D
–
Error (m)
–
Overshoot
–
Settling (s)
–
Thrust