#131 Introduction to CONTROL SYSTEMS | open loop and closed loop control system || EC Academy

Summary

This ECE Academy lecture introduces control systems, defining them as units that process input to produce output. It distinguishes between open-loop and closed-loop control systems, explaining their basic concepts, advantages, and examples. Open-loop systems are simple, cheap, and stable but less accurate, with examples like traffic lights and automatic washers. Closed-loop systems, exemplified by room heaters, are more accurate due to continuous monitoring but are complex, costly, and less stable. The lecture aims to provide a foundational understanding of control systems.

Takeaways

• 😀 A system is a unit that processes input to produce an output.
• 🔧 A control system is a combination of components working together to perform a specific operation where the output is controlled by the input.
• 🔄 There are two basic types of control systems: open loop and closed loop.
• 🔒 Open loop control systems process input without measuring or controlling the output, making them simple and less accurate.
• 🚦 Examples of open loop systems include traffic light signals, electric hand dryers, and automatic washing machines.
• 🔁 Closed loop control systems feed the output back to the input for comparison, creating a feedback loop that improves accuracy.
• 🌡️ A room heater maintaining room temperature is an example of a closed loop system, where the actual temperature is compared with the desired temperature.
• 📉 Closed loop systems are more accurate but also more complex, costly, and less stable compared to open loop systems.
• 💡 The simplicity of open loop systems makes them cheaper and more stable, but they lack the accuracy and control of closed loop systems.
• 🔎 The accuracy of a control system is a key factor in determining its type, with closed loop systems offering continuous monitoring and higher precision.
• 🛠️ The construction complexity and cost of a control system are influenced by whether it is open loop or closed loop.

Outlines

00:00

🔧 Introduction to Control Systems

This paragraph introduces the concept of control systems, defining a system as a unit that processes input to produce an output. It distinguishes control systems by their ability to regulate output based on input, highlighting their composition of interconnected components designed for specific operations. The paragraph also outlines two fundamental types of control systems: open loop and closed loop. Open loop systems are characterized by their simplicity, cost-effectiveness, and stability but lack accuracy as they do not measure or control the output. Examples include traffic lights, electric hand dryers, and automatic washing machines. In contrast, closed loop systems, exemplified by a room heater maintaining room temperature, are more complex, costly, and less stable due to continuous output monitoring and feedback, but they offer higher accuracy.

Keywords

💡Control System

A control system is a set of components that work together to achieve a specific goal by managing the behavior of other systems. In the context of the video, it is defined as a combination of components that process input to provide controlled output. This concept is central to the video's theme, as it sets the stage for distinguishing between open-loop and closed-loop control systems.

💡System

In the video, a system is described as a unit that takes in input, processes it, and provides output. This is a fundamental concept that underpins the discussion of control systems, as it establishes the basic operation of any system before delving into how control systems manage these operations.

💡Open Loop Control System

An open loop control system is one where the output is not measured or controlled based on feedback. The video uses this term to describe a simple system that processes input directly to produce output without any monitoring or adjustment based on the result. Examples given in the script include traffic light signals, electric hand dryers, and automatic washing machines.

💡Closed Loop Control System

This is a type of control system where the output is fed back into the system and compared with the input to generate an error signal, which is then used to adjust the system's behavior. The video highlights this as being more accurate than open-loop systems due to continuous monitoring and adjustment, using a room heater maintaining room temperature as an example.

💡Feedback

Feedback in control systems refers to the process where the output of the system is returned to the input to be compared with the desired outcome. The video explains that in closed-loop systems, feedback is crucial for accuracy and stability, contrasting it with open-loop systems that lack this mechanism.

💡Comparator

A comparator in the context of control systems is a device or function that compares the actual output with the desired input or set point. The video mentions the comparator's role in closed-loop systems to generate an error signal, which is essential for making adjustments to achieve the desired output.

💡Error Signal

The error signal is the difference between the desired input and the actual output detected by the comparator in a closed-loop system. The video describes how this signal is used by the controller to make necessary adjustments, emphasizing its importance in achieving accurate control.

💡Accuracy

Accuracy in control systems is the degree to which the system's output matches the desired outcome. The video contrasts the accuracy of open-loop and closed-loop systems, noting that closed-loop systems offer higher accuracy due to their continuous monitoring and correction of the output.

💡Stability

Stability in the context of control systems refers to the ability of a system to maintain its output without significant fluctuations. The video points out that open-loop systems are more stable because they lack the feedback mechanisms that can introduce variability in closed-loop systems.

💡Cost

The video discusses the cost implications of control systems, noting that open-loop systems are generally cheaper due to their simplicity, while closed-loop systems are more complex and therefore more costly, due to the additional components required for feedback and control.

💡Complexity

Complexity in control systems is related to the number of components and the intricacy of their interactions. The video explains that closed-loop systems are more complex than open-loop systems, which contributes to their higher cost and potential instability but also enables greater accuracy and control.

Highlights

Introduction to control systems and defining what a system is.

A system processes input to provide output.

Definition of a control system as a combination of components that perform a specific operation with controlled output.

Explanation of the open loop control system and its basic representation.

Advantages of open loop control systems including simplicity, low cost, and stability.

Disadvantages of open loop control systems, such as lack of feedback leading to less accuracy.

Examples of open-loop control systems like traffic light signals, electric hand dryers, and automatic washing machines.

Introduction to closed-loop control systems and their operation with feedback.

How a closed-loop control system uses a comparator to generate an error signal based on the difference between input and output.

An example of a closed-loop control system: a room heater maintaining room temperature.

Advantages of closed-loop control systems, such as higher accuracy due to continuous monitoring.

Disadvantages of closed-loop control systems including complexity, higher cost, and less stability.

The importance of understanding the differences between open loop and closed loop control systems.

The impact of control systems on various practical applications in everyday life.

The significance of feedback in improving the performance of control systems.

The role of the controller in a closed-loop system to adjust the output based on error signals.

The lecturer's hope that the audience has understood the topic of control systems.

Transcripts

hello friends welcome to ECE Academy in

this lecture we'll understand

introduction to control systems before

understanding what is control system we

need to understand what is it system a

system is an unit that takes input

process the input and provides the

output so the system will process the

input and it will provide the output now

we will understand what is a control

system control system is the combination

of components that are connected

together to perform a specific operation

here the output of the system is

controlled by the input that's why the

name control system so if you define up

to here that is the combination of

components that are connected together

to perform a specific operation so up to

here it is the definition of system

along with that if you add the output of

the system is controlled by the input

that is the definition of control system

so this is very important so the output

is controlled by the input in the

control system now there are two basic

types of control systems first one is

open loop control system and second one

is closed loop control system first we

will understand the open loop control

system this figure shows a simple

representation of open loop control

system you can see there is a system

where it is taking the input and that

input is processed and it is providing

the output here the system just process

the input and it will give the output

here output is not controlled or it is

not measured that's why it is known as

open loop control system so coming to

its advantages so this control system is

very simple it comes

action since it is simple in

construction we can say it is cheap and

since it is taking the input processing

the input and providing the output so

this system is stable since there is no

closed loop here no feedback here so the

system is less accurate so we can say

this system is less accurate the

examples of open-loop control systems

are traffic light signal electric hand

dryer and automatic washing machine so

here in all these three examples you are

just providing the input so whatever

input is provided so based on that it is

giving the output now let us understand

closed-loop control system this figure

shows the closed-loop control system

here in a closed-loop control system the

output is fed back to the input and the

comparator will compare the output with

input and gives the signal which is

known as error signal here controller

depending upon the error signal from the

comparator provides the output this is

how the closed-loop control system works

for example if we consider a room heater

whose functionality is to maintain the

room temperature here the feedback

element will monitor the output which is

the actual temperature with the input

which is the desired temperature if any

change at the output temperature that

will be compared by the comparator and

an error signal is given to the

controller so that it can vary the

output so this is one of the example of

closed loop control system the advantage

of closed loop control system is it is

more accurate compared to the open loop

control system since the output is

continuously monitored here will get

high accuracy

type of system compared to open-loop

control system it is complex in

construction since it is complex we can

say it is costly compared to open-loop

control system and since we are adding

more components in the closed-loop

control system it is less stable

compared to the open-loop control system

this is the brief introduction regarding

the control system I hope you have

understood the topic

thank you