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Introduction to Control System | Open and Close Loop Control


The Control system is the origin of the modern Industrial Revolution. So, in this article, I will give Introduction to Control System | Open and Closed Loop Control

About Control System

Control systems are used everywhere from large industries to your home. A Control system is defined as per the short definition “manipulate input variable in such way that we get output as per requirement”

When the industrial revolution started in the 18th century production in the factory rapidly increased.

most of the operations done by humans were replaced by machines so the chances of human errors will decrease.

Then after implementing pneumatic control in plants adoption of automation was started. and later electrical-based automation started.

In the 21st century, it is necessary to have a properly automated plant. In industry, every parameter needs to be controlled either manually or automatically. 

Because of the evolution in industrial automation, most industrial parameters are controlled by using microcontrollers.

From small air supply to huge boiler’s pressure, temperature, Leval, or flow control. 

Classification of CS: –

Open-loop control:

In open-loop control, the controller consistently gives output without checking whether the output matches the set point or not so it’s fast but inaccurate. So, open-loop control is not used in critical industrial parameters.

Example of open-loop control: –

  • Fan

Closed-loop control:

In a close loop control output of the process is measured and compared with the setpoint and according to the set, the point controller gives a control signal to the final control element. So, we will consider the system to be a closed-loop in later portions.

CS Block diagram: –

  • Controller 
  • Comparator/error detector 
  • Process 
  • Final control element 
  • Sensor’s transducer 

Block Diagram of Control System
Block Diagram of Control System

Every block of the control system block diagram has its importance.

like sensor, part covers all the instrumentation in the industry. controller part covers all the automation-related things like PLC, DCS, HMI, SCADA, MES, ERP, and others.

The final control element covers all control elements like VFD and Control valve. All these connection lines are field buses for transferring data from one place to another place.

The Control system is the combination of all these blocks. This was just a briefing of the things covered in instrumentation and control.

We are trying to provide all information on each block and prepare you to become technical sound control engineers.

Example of Closed-loop control: –

  • Refrigerator
  • Air conditioner
  • Boiler Pressure Control

EndNote: –

The Control System is the Heart of any industrial automation. Without it, we can’t get efficient and reliable output.

You can find more about control system engineering on the Wiki Page

Now we are starting our journey toward industrial automation. In this journey, we learn and explore the Industrial World and start getting knowledge of industries step by step. I hope you will enjoy this journey.

If you want to know about our site then please visit our site introduction page: –

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