A control system is characterized by having elements that control other groups of devices that are planned to carry out certain tasks. They are currently used for accuracy and quick response in solving automation problems.
These systems have been used for centuries in different civilizations, whose objective was to address certain flow problems (see article “History of valves“). One of the earliest known automated control systems dates back to ancient Greece to regulate water platforms.
Denis Papin invented the “Papin pot”, today known as the “pressure cooker”, which aimed to cook food faster by cooking it through a safety valve. This invention was key to regulate and relieve pressure from different teams.
However, thanks to technological advances, automated control systems (see article “Advantages of intelligent pneumatic valve”) have better characteristics and greater efficiency when used.
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Types of control systems
- Automatic control system: They carry out processes automatically, which are fast, exact and independent. They function to measure data and compare it with the output. They are framed in closed loop systems, where the output to be controlled is fed from the input and they can make the comparison.
- Open loop control system: In these techniques the output has no consequence on the control system to arrange the operation.
- According to the expected response: As their name suggests, they are classified according to the response that is desired. However, there are two types: stable ones (provide a reduced indication in their output) and unstable ones (execute digested and unsummarized input).
- Hybrids or sets: Those where the hand of man and automation are present.
We must stand in mind that control systems have these very important characteristics: a variable to control, an actuator and reference point.
Characteristic of automatic control systems
- In the case of closed loop systems, feedback is the most important element.
- Choosing the inputs of a procedure so that the outputs are modified as expected.
- For automatic systems external power is essential.
- Exit sign.
- The variable can be controlled or undergo a transformation.
- They work under the following scheme: input, control system and output.
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Operations between blocks and representation
Generally, the operations between blocks are by means of mathematical terms (addition, subtraction, multiplication and division) and their action is through arrows. Other equations are also used when more detailed system actions are intended.
We must remember that “The representation is made through diagrams that seek the abbreviation of the system in a visual and understandable way. As for the engineering problems that may arise in automatic control systems, they are solved through analysis and design. The latter contemplates designs by analysis and by synthesis”.