Algodoo

Proportional - simply pushes in the right direction with a force proportional to error.

Integral - accumulates error into a variable that will become arbitrarily strong, if proportional can't overcome an external force.

Derivative - acts against measured velocity to reduce oscillation.

This is a simulation of a PID controller, a mathematical asset with many applications in the real world. I understood the PD parts of it for years, even before I learned the name PID itself. However, I just couldn't understand the I part, Integral, until today, where I had a sudden epiphany, and it just clicked. Integral is the historic summary of all error values, summed up together! As the measured location sits offset to the target location, it accumulates an adjustment that takes into account external forces! Now to learn how to balance the 3 numbers for the most stable configuration...

CONTROLS:
QE to move target position
AD to rotate base (external force)

Thaks bai x oNe MiLlIoN!1!!1111!!!eleventyone!1