Page 29 - 07

INTERCEPTOR DESIGN AND CONTROL FOR THE HIGH SPEED CRAFT 27

Figure 5.1 The first automated control system [18]

5.1 History of Control Systems
The development of machinery started with the more efficient factories due to the use of steam
engines and water wheels in the 18th century England, which is the beginning of the modern
manufacturing. Then in the early 1900s, accuracy of components such as bolts and nuts were
increased by starting to produce them separately in identical batches instead of producing them
individually according to a particular product. In 1909, Henry Ford’s idea of production lines
which breaks up the production process in sequences was a challenge.
Theoretical practices to control a process system using feedback were started in 1920s, the
development of automatic steering for ships and aircrafts was a particular aim in these studies.
Control systems were applied to military tasks (such as gun control or radar tracking) during the
Second World War (1940s). In the mid-1900s, feedback amplifiers and tool positioning by
numerical control was studied, thus developing open-loop control systems. Control systems
were improved and developed to be used in wider application areas and to be cheap with the
invention of the transistor (1948) and the inventions of microprocessors and computers (1970s).
[17]
5.2 Open and Closed Loop Control Systems
There are two types of control systems; open-loop and closed-loop systems. In open-loop
systems, the system output does not affect the input by any kind of feedback to adjust the
desired output. When the loop is closed by a feedback signal, it is a closed-loop control system,
this feedback signal is then used to adjust the inputs in order to acquire the optimum results with
the desired/required outputs. [17]
Samples of open-loop (Figure 5.2) and closed-loop (Figure 5.3) control systems can be seen
below.

Sayı 7, 2016 GiDB|DERGi