Editing Control engineering (section)

== History ==
{{see also|Control systems#History}}
[[File:Colonne distillazione.jpg|thumb| Control of [[fractionating column]]s is one of the more challenging applications.]]

Automatic control systems were first developed over two thousand years ago. The first feedback control device on record is thought to be the ancient [[Ktesibios]]'s [[water clock]] in [[Alexandria]], Egypt, around the third century BCE. It kept time by regulating the water level in a vessel and, therefore, the water flow from that vessel.
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This certainly was a successful device as water clocks of similar design were still being made in Baghdad when the Mongols [[Siege of Baghdad (1258)|captured]] the city in 1258 CE. A variety of automatic devices have been used over the centuries to accomplish useful tasks or simply just to entertain. The latter includes the automata, popular in Europe in the 17th and 18th centuries, featuring dancing figures that would repeat the same task over and over again; these automata are examples of open-loop control. Milestones among feedback, or "closed-loop" automatic control devices, include the temperature regulator of a furnace attributed to [[Cornelis Drebbel|Drebbel]], circa 1620, and the centrifugal flyball governor used for regulating the speed of steam engines by James Watt{{r|Keviczky_2019|p=22}} in 1788.

In his 1868 paper "On Governors", [[James Clerk Maxwell]] was able to explain instabilities exhibited by the flyball governor using differential equations to describe the control system. This demonstrated the importance and usefulness of mathematical models and methods in understanding complex phenomena, and it signaled the beginning of mathematical control and systems theory. Elements of control theory had appeared earlier but not as dramatically and convincingly as in Maxwell's analysis.

Control theory made significant strides over the next century. New mathematical techniques, as well as advances in electronic and computer technologies, made it possible to control significantly more complex dynamical systems than the original flyball governor could stabilize. New mathematical techniques included developments in optimal control in the 1950s and 1960s followed by progress in stochastic, robust, adaptive, nonlinear control methods in the 1970s and 1980s. Applications of control methodology have helped to make possible space travel and communication satellites, safer and more efficient aircraft, cleaner automobile engines, and cleaner and more efficient chemical processes.

Before it emerged as a unique discipline, control engineering was practiced as a part of [[mechanical engineering]] and [[control theory]] was studied as a part of [[electrical engineering]] since [[electrical circuits]] can often be easily described using control theory techniques. In the first control relationships, a current output was represented by a voltage control input. However, not having adequate technology to implement electrical control systems, designers were left with the option of less efficient and slow responding mechanical systems. A very effective mechanical controller that is still widely used in some hydro plants is the [[Centrifugal governor|governor]]. Later on, previous to modern [[power electronics]], process control systems for industrial applications were devised by mechanical engineers using [[pneumatics|pneumatic]] and [[Hydraulic system|hydraulic]] control devices, many of which are still in use today.

===Mathematical modelling===
[[David Quinn Mayne]], (1930–2024) was among the early developers of a rigorous mathematical method for analysing [[Model predictive control]] algorithms (MPC). It is currently used in tens of thousands of applications and is a core part of the advanced control technology by hundreds of process control producers. MPC's major strength is its capacity to deal with nonlinearities and hard constraints in a simple and intuitive fashion. His work underpins a class of algorithms that are probably correct, heuristically explainable, and yield control system designs which meet practically important objectives.<ref name=P&A>{{cite web|author1=Parisini, Thomas|author2=Astolfi, Alessandro|title=Professor David Q Mayne FREng FRS 1930 - 2024|url=https://www.imperial.ac.uk/news/253973/professor-david-mayne-freng-frs-1930/|date= 10 June 2024|publisher=[[Imperial College London]] news|access-date=14 June 2024}}</ref>