It’s been pointed out that I have committed the sin of using undefined

jargon.

For the record, PID stands for Proportional Integral Derivative.

PID is a ubiquitous type of feedback controller, mostly thanks to being

conceptually quite simple. The input is an error signal (or a

measurement and

setpoint signal) of some process under control. The PID controller

applies 3

types of feedback:

P - proportional, in which the control output is proportional to the

error

signal.

I - integral, in which the control output is proportion to the

time-integral of

the error signal.

D - derivative, in which the control output is proportional to the

time-derivative of the error signal.

These three terms are added together to produce the control output. By

the right

selection (“tuning”) of the 3 gain values, stable feedback control of a

wide

variety of processes is possible.