If only the site explained wtf a PID controller was ...
PID is a control loop algorithm: something which takes a desired value and an actual value from a sensor, and outputs something to some kind of actuator to try and get the actual value to match the desired value.
A simple example of a control loop algorithm is the "bang-bang" algorithm used by your thermostat. When it's too cold the furnace turns on, and when it's too hot the furnace turns off.
PID was discovered by observing boat helmspeople. It was observed that there are three major factors in their decision of how to turn the boat's wheel (the P, I, and D respectively).
First, they set the wheel to approximately where they think it needs to be to achieve the desired angle. That's the P, or proportional part.
Then they note the cumulative error over time, i.e. the distance away from the desired angle summed up over each moment that they are still waiting. As the cumulative error rises, they turn the wheel a bit further to compensate. This is the I, or integral term, which accommodates conditions where the controls are particularly dull, causing the proportional control to undershoot.
Finally they observe the rate at which they are approaching the desired angle and compensate negatively if they are approaching it more quickly than they expected. This is the D (derivative) term, which accommodates conditions where the controls are particularly sensitive and the proportional control overshoots.
PID just adds these three terms together with weights chosen for the specific application. Choosing those weights is the tuning process.
https://github.com/RicardoMonteiroSimoes/ClosedLoopControlBl...
It contains several blocks,P,I,D,PID,PT1 and PT2, basically the ones that were teached to me
Though I wonder if that's me that got older and have better understanding of things that I now think I get it, or is it your explanation. Probably both.
It's a common feedback control scheme for signal processing and engineering control more generally.
(And of course it doesn't need to explain what a Laplace transform is, as this is aimed at control engineers)
The entirety of the "fold" on my screen is an absurdly giant and seemingly irrelevant image, overlaid with the text "Tune your PID", "It has never been easier", and two buttons.
As I scroll down, the next thing my eyes catch is some mathematical nonsense, which tells me exactly nothing other than that this is a complex thing that is surely entirely over my head.
To people that know what a "PID controller" is, it's probably informative. I came in assuming that there was some sort of controller for OS program PIDs and was unable to grasp the context at all.
Heavily used for industrial automation, hackers here may know it from espresso machine hacking. (and I'm sure manyyyyy other uses)
My temperature controlled kettle does a way-more-than-optimal amount of switching when it's near the setpoint. That's consistent with using a PID controller into a PWM input.
Maybe there is a market opportunity for a water boiler that uses control techniques better suited to on/off inputs :)
I'm soon to become a dad for the first time and so my partner and I have become much more conscious and aware of babies around us and watching them learn things. It's really fun to apply control theory to that...
A friend has a young child who is learning to feed themselves. I was chatting with the friend while we drank beer and he helped the child eat dinner. using hands to pick up food (watermelon chunks) and bring it to mouth - very conservative and lossy PID-esque model of action, but you could watch small tuning improvements in real time. Then a spoon was introduced for sweet potatoes and the kid's PID controller clearly could not adapt to the change in mass in the system and we watched huge overshoots and control failures. Then it slowly improved...but isn't yet 'good'
then we tried to explain this to our partners (both reside in the 'S' in STEM)...
It's a dynamic control loop.
It has been explained.
Eg: The water is about to boil so I am setting the burner to medium from max to keep it at just below a rolling boil.