The basic concept of Feedforward control is to measure important disturbance variables and take corrective action before they upset the process.

1. Marathwada Mitramandal’s
COLLEGE OF ENGINEERING
Karvenagar, Pune
Accredited with ‘A’ Grade by NAAC
Presentation
On
Subject: Control System Engineering
by
Mr. A. M. Suryawanshi
Department of Electrical Engineering

2. Unit 1: Basics of Control System
Session- 2/40
Tracking, regulator system, feed forward system, transfer
function
Session Plan

3. Outline:
A. Attendance
B. Review of the previous session
C. Learning Outcomes of the session
D. Content
E. Student’s evaluation
F. Preparation for next session
G. Wrap up

4. B. Review of previous session:
• Basic concepts of control system
A control system is a system, which provides the desired response by controlling the output.
• Classification of control systems
1. Continuous time and Discrete-time Control Systems
2. SISO and MIMO Control Systems
3. Open Loop and Closed Loop Control Systems
• Types of control system feedback
There are two types of feedback −
1. Positive feedback
2. Negative feedback

5. C. Learning Outcomes of the session:
• Understand tracking, regulator system, feed forward system
• Define transfer function

6. D. Content:
Content
Learning /
Methodology
Faculty
Approach
Typical
Student
Activity
Skill/
Competency
Developed
Tracking, Regulator
system
PPT/Discussion Explains Understands
Critical
thinking
Feed forward system PPT/Discussion Explains Understands
Critical
thinking
Transfer function
Chalk and
Board/PPT/Discuss
ion
Explains Understands
Critical
thinking

7. Tracking, Regulator system
Tracking and regulation refer to the ability of a control system to track/reject
a given family of reference/disturbance signals.
1. Effect of Feedback on Overall Gain
2. Effect of Feedback on Sensitivity
3. Effect of Feedback on Stability
4. Effect of Feedback on Noise

8. Feed forward system
The basic concept of feedforward control is to measure important disturbance
variables and take corrective action before they upset the process.

9. S.NO. Feedback Control System Feed Forward Control System
1.
In feedback system output depends on the
generated feedback signal.
In feed forward system the signal is passed to some
external load.
2.
Measure of disturbances in the system is not
needed by feedback system.
Measure of disturbances in the system is needed by
feed forward system.
3.
All the disturbances are detected in
feedback system.
All the disturbances are not detected in feed forward
system.
4.
The loop in a feedback control system is a
closed loop.
The loop in a feed forward control system is an open
loop.
5. It focuses on the output of the system. It focuses on the input of the system.
6.
The variables are adjusted on the basis of
errors.
The variables are adjusted on the basis of knowledge.

10. Transfer function
The transfer function of a control system is defined as the ratio of the Laplace
transform of the output variable to Laplace transform of the input variable
assuming all initial conditions to be zero.
𝐺 𝑆 =
𝐶(𝑆)
𝑅(𝑆)
A transfer function represents the relationship between the output signal of
a control system and the input signal, for all possible input values.

11. E. Student’s evaluation
Q1. Compare feedback and feedforward control system
Q2. Explain and derive TF for negative feedback closed loop
control system

12. Concept of pole and zero: -
Poles: These are those values of s when placed in denominator, the transfer function tends
to obtain infinite value. Here, the poles of the system are -2 and -3.
Zeroes: These are those values of s when placed in numerator makes the transfer function
0. Here, the system have only 1 zero, ie, -1.
Modeling of Electrical and Mechanical systems (Only series linear and rotary motion) using
differential equations and transfer function: -
Design of control system means finding the mathematical model when we know the input
and the output.
The following mathematical models are mostly used.
1. Differential equation model
2. Transfer function model
There are two types of mechanical systems based on the type of motion.
1. Translational mechanical systems
2. Rotational mechanical systems
F. Preparation for Next Session:-

13. G. Wrap Up
In this lecture we have learned
Tracking, Regulator system:
Tracking and regulation refer to the ability of a control system to track/reject a
given family of reference/disturbance signals.
Feed forward system:
The basic concept of feedforward control is to measure important disturbance
variables and take corrective action before they upset the process
Transfer function:
A transfer function represents the relationship between the output signal of a
control system and the input signal, for all possible input values.