a power point presentation on block diagram representation of control system

1. BLOCK DIAGRAM
REPRESENTATION
MADE BY - NIRALI MONANI
BRANCH - ELECTRONICS & COMMUNICATION

2. INTRODUCTION
• A Block Diagram is a shorthand pictorial
representation of the cause-and-effect
relationship of a system.
• The interior of the rectangle representing the
block usually contains a description of or the
name of the element, gain, or the symbol for the
mathematical operation to be performed on the
input to yield the output.
• The arrows represent the direction of information
or signal flow.
dt
d
x y

3. COMPONENTS OF BLOCK DIAGRAM

4. ADVANTAGES OF BLOCK DIAGRAM
• THE FUNCTIONAL OPERATION OF THE SYSTEM
CAN BE OBSERVED FROM BLOCK DIAGRAM
• BLOCK DIAGRAM GIVES THE INFORMATION
ABOUT PERFORMANCE OF SYSTEM
• BLOCK DIAGRAM IS USED FOR ANALYSIS &
DESIGN OF CONTROL SYSTEM
• IT IS VERY SIMPLE TO CONSTRUST THE BLOCK
DIAGRAM FOR BIG & COMPLICATED SYSTEM

5. DISADVANTAGES OF BLOCK DIAGRAM
• BLOCK DIAGRAM FOR GIVEN SYSTEM ARE NON
UNIQUE
• SOURCE OF ENERGY IN THE SYSTEM IS NOT
SHOWN IN THE DIAGRAM
• IN THE PROCEDURE OF REDUCTION OF BLOCK
DIAGRAM ALGEBRA SOME IMPORTANT
FUNCTIONSMAY BE OMITTED . THERE IS NO
CHECK FOR IT
• IT DOESN’T GIVE ANY INFORMATION ABOUT
PHYSICAL CONSTRUCTION OF THE SYSTEM

6. Canonical Form of A Feedback Control System

7. Characteristic Equation
• The control ratio is the closed loop transfer function of the system.
• The denominator of closed loop transfer function determines the
characteristic equation of the system.
• Which is usually determined as:
)()(
)(
)(
)(
sHsG
sG
sR
sC


1
01  )()( sHsG

8. RULES OF BLOCK DIAGRAM
REDUCTION

9. Reduction techniques procedure
:1. Combining blocks in cascade or in parallel
1G 2G 21GG
1G
2G
21 GG 
14

10. 2. Moving a summing point behind a block:
G G
G
:3. Moving a summing point ahead of a block
G G
G
1
15

11. 4. Moving a pickoff point behind a block:
G G
G
1
5. Moving a pickoff point ahead of a block:
G G
G
16

12. 6. Eliminating a feedback loop:
G
H
G
1H
G
G
1
GH
G
1
17

14. THANK YOU !!!