2. WHAT IS FEEDBACK SYSTEM?
A feedback system is a mechanism that seeks
to maintain a certain level of performance or
stability in a system.
Feedback plays an important role in order
to improve the performance of the control
systems. In this chapter, let us discuss the types
of feedback & effects of feedback.
3. Understanding Feedback
Systems
Definition of a Feedback System
At its core, a feedback system is a process that
feeds the output of a system back to the input,
thereby altering the input and influencing the
system's performance. Feedback systems can either
be positive or negative, depending on whether the
feedback reinforces or diminishes change.
4. POSITIVE FEEDBACK SYSTEM
Are those in which the feedback reinforces the change in
the system, leading to amplification and growth. This type of
feedback system is often associated with instability and rapid
change.
One example of a positive feedback system is the process of
childbirth. As the baby moves through the birth canal, the pressure
on the cervix increases, leading to the release of the hormone
oxytocin, which causes the uterus to contract. These contractions
push the baby further down the birth canal, which in turn
increases the pressure on the cervix, leading to more contractions.
5. Negative feedback systems
Are those in which the feedback signals counteract or
diminish the change in the system, leading to stability and balance.
This type of feedback system is often associated with homeostasis
and equilibrium.
One example of a negative feedback system is the process of
maintaining body temperature. When the body temperature rises
above the normal range, the hypothalamus in the brain sends
signals to the sweat glands to produce sweat, which cools the body
down. When the body temperature falls below the normal range,
the hypothalamus sends signals to the muscles to shiver, which
6. Components of a Feedback System
The basic components of a feedback system include
a sensor, a controller, and an actuator. The sensor
measures the output of the system and sends it to
the controller, which determines whether the
output is within the desired range. If the output is
outside the range, the controller sends instructions
to the actuator to adjust the input and restore
stability.
8. Components of a Feedback
System
For example, in a car's engine control system, there
may be sensors that measure the engine speed, the
air-fuel ratio, and the exhaust emissions, each
sending signals to their respective controllers to
adjust the fuel injection, ignition timing, and other
parameters.
9. Types of Feedback Systems
Feedback systems can be classified into
various types based on their complexity, timing, or
direction of feedback. Some common types include
linear, non-linear, time-delayed, and adaptive
feedback systems.
10. Linear feedback systems
Are those in which the input and
output are directly proportional,
meaning that a change in the input
causes a proportional change in the
output.
11. Non-linear feedback systems
Are those in which the input and
output are not directly proportional,
meaning that a change in the input may
cause a non-proportional change in the
output.
12. Time-delayed feedback systems
Are those in which the feedback
signal is delayed by a certain amount of
time, leading to oscillations or
instability.
13. Adaptive feedback systems
Are those in which the controller
adjusts its parameters based on the
changing conditions of the system,
leading to improved performance and
stability.
14. Advantages
There is reduction of non-linear effects that are most
often seen in open-loop systems.(open loop system
means a system that does not have any feedback)
Reduction in noise and disturbance.
Improved efficiency, accuracy and quality
Improved system stability and process certainty
Improved gain and bandwidth
15. disAdvantages
The feedback system makes the system complicated by increasing the
number of components like sensors and error detectors.
In feedback system the overall gain of the system is reduced and must be
compensated in the design.
If feedback system is not configured properly, then the system will
produce oscillating outputs which will make the system more unstable.
If some unmeasurable disturbances affect the system, then the feedback
control system takes time to produce desired output in such condition.
The feedback control system is a type of lagging control system, which
means that it will take some time to produce accurate outputs.
16. Applications of Feedback
Systems
Feedback systems are a type of control
system that uses information from a sensor to
adjust the behavior of a system. They are used in a
variety of fields, from engineering to biology,
economics, and social sciences. Let's take a closer
look at some of the applications of feedback
systems.
17. Feedback Systems in
Engineering
Feedback systems are essential in
engineering for controlling and regulating various
systems. They are commonly used in industrial
processes, robotics, and aerospace engineering.
For example, in robotics, feedback systems
are used to control the movement and position of
robotic arms and other components.
18. Feedback Systems in Biology
In biology, feedback systems are crucial for
maintaining homeostasis and regulating various
bodily functions. They are also involved in cell
signaling and gene expression.
For example, the regulation of blood glucose
levels involves a feedback system that uses insulin
and glucagon to maintain a stable level of glucose
in the blood.
19. Feedback systems play a vital role in economic
models and the stock market. They can be used to
predict market crashes and help stabilize economic
systems.
For example, in a stock market, feedback
systems can be used to analyze and predict the
behavior of stocks based on past performance and
market trends. This information can be used to make
informed investment decisions and to prevent
Feedback Systems in
Economics
20. Feedback Systems in Social
Sciences
Feedback systems are used in social
sciences for modeling and predicting various
phenomena.
For example, in political science, feedback
systems can be used to model and predict
voting behavior based on past voting patterns
and demographic data.
21. Identifying Goals and Objectives
Selecting the Right Type of Feedback
System
Implementing and Monitoring the
Feedback System
Designing Effective Feedback Systems
22. The first step in designing an effective
feedback system is identifying the goals and
objectives of the system. This includes
determining the desired output range, the
critical parameters, and the expected
performance.
Identifying Goals and
Objectives
23. Selecting the Right Type of Feedback System
It is based on the system's complexity,
dynamics, and stability. This may involve
choosing between positive or negative feedback,
linear or nonlinear systems, and time-delayed
or adaptive systems.
24. Implementing and Monitoring the Feedback
System
Involves setting up the necessary
components, testing the system, and analyzing
the results. Continuous monitoring and
adjustment are essential to ensure the system is
functioning effectively and meeting its goals.
25. Conclusion
Feedback systems are an essential part of
various fields and are crucial for maintaining stability
and regulating performance. Understanding the
different types of feedback systems and their
applications can help in designing effective feedback
systems that meet the desired goals and objectives.
The key to success in implementing feedback systems
is continuous monitoring and adjustment to ensure
