Chemical Process Control

Current revision (unreviewed)

[edit] What is Process Control?

Actuator: The mechanical device that cause the activation or movement of a final control element.

Final Control Element: A physical device whose activation or movement causes a change in a dynamic process. In process control, the most common final control elements are control valves.

IMC-PID Tuning: A method for PID tuning that selects tuning parameters to approximate an IMC-derived controller.

Ladder Logic: A semi-graphical programming language used to represent control algorithms. The language is expressed using symbols for logic devices. The arrangement of the device symbols and their connections has the appearance of a ladder.

Laplace Transform: An integral transformation from time domain to Laplace domain. Given a function of time $f (t)$ , the Laplace transform is given by the following

$F(s) = \int_0^\infty \! f(t)\; e^{-s t} dt$

The use of

F (s)

to represent the Laplace transform of

f (t)

is a common convention; however, in dynamics and control it is common to use

f (t)

and

f (s)

to represent a time-domain function and its Laplace transform, respectively.

PLC: Programmable Logic Controller, a microprocessor-based electronic device for implementing control algorithms.