Learn to Ride the Electrohydraulic PID Seesaw
Proportional integral derivative control can easily be understood through simple analogies.
Maybe it can interest people, innocents and less innocents.
When explaining operation of complex equipment, such as an electro-hydraulic closed-loop position control, different approaches are adopted depending upon who the explanation is aimed at. Such explanations tend to fall into one of two categories — a full mathematical analysis for people with a strong control theory background, and a very simplistic instruction-manual style for everyone else.
The explanation that follows aims to fall in between these two extremes for the benefit of those who do not have a classical control theory background but nevertheless want to understand something of the why of a control system rather than just the what. If you can grasp the basic function of each component or adjustment, you may not be able to design a system from scratch — but you should have a much better understanding of how it works, how to set it up, and what to look for when something goes wrong.