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.