PID control: explanation & tuning rule of thumb

Most robotic applications require Proportional-Integral-Derivative (PID) control at a low level to control several processes. Be it the speed of a rover according to the distance to its target, or the thrust of each propeller of a multirotor to hover in one place.

Regardless of how basic PID control is, it can be sometimes a bit tricky to understand and tune a PID controller.