The document outlines lecture notes on mechatronics, covering control systems, key elements, representations as block diagrams, and various applications in industries. It emphasizes understanding concepts such as transfer functions, PID control, PLC systems, and the differences between open and closed-loop control systems. The document also includes objectives, outcomes, and references for further reading in the field of mechatronics.

1. Lecture Notes / PPT
UNIT II
Mechatronics – 302050

2. Syllabus
Block Diagram Representation
 Open and Closed loop control system,
 Identification of key elements of mechatronics systems and
represent into block diagram (Electro-Mechanical Systems),
 Concept of transfer function,
 Block diagram reduction principles,
 Applications of mechatronics systems:- Household, Automotive,
Shop floor, Industrial.

3. Objectives
1. Understand key elements of Mechatronics system,
representation into block diagram
2. Understand concept of transfer function, reduction and analysis
3. Understand principles of sensors, its characteristics, interfacing
with DAQ microcontroller
4. Understand the concept of PLC system and its ladder
programming, and significance of PLC systems in industrial
application
5. Understand the system modeling and analysis in time domain
and frequency domain.
6. Understand control actions such as Proportional, derivative and
integral and study its significance in industrial applications.

4. Outcomes
1. Identification of key elements of mechatronics system and its
representation in terms of block diagram
2. Understanding the concept of signal processing and use of
interfacing systems such as ADC, DAC, digital I/O
3. Interfacing of Sensors, Actuators using appropriate DAQ
micro-controller
4. Time and Frequency domain analysis of system model (for
control application)
5. PID control implementation on real time systems
6. Development of PLC ladder programming and implementation
of real life system

5. Assumed Knowledge
Dynamics:
 Engineering Mechanics
Mathematics
 Engineering Mathematics (I, II & III)

6. Reference Books
 Alciatore & Histand, Introduction to Mechatronics and
Measurement system, 4th Edition, McGraw Hill publication,
2011
 Golnaraghi & Kuo, Automatic Control Systems, John Wiley
publications, 2010

7. Control
A Control system performs following functions
• For particular input the system output can be controlled to a desired
particular value.
• If some conditions are satisfied it can give a particular sequence of
events as output corresponding to given input
Actual Response
Desired Response

8. Controllability
(Out of Syllabus)
 Before a controller is implemented it is necessary to test the
“Controllability” of the system
 Controllability is the ability of the system, to be controlled /
provide desired performance, provided an external disturbance
is available.

9. Open Loop Control
• Output is dependent on input but controlling action is totally
independent of the changes in output, is an Open Loop Control
System.
• No feedback is used, so the controller must independently determine
what signal to send to the actuator.
Input
Control
Law
Plant Output
u
Plant = Mathematical model of Input Amplifier + Actuator + Physical System
Input = Reference / Desired Input or Set Point Input
Output = Measured Output
Control Law = Mathematical model of the Controller

10. Examples of Open Loop Control

11. Advantages and Dis-advantages of Open Loop
Control
Advantages:
 Simple in construction
 Low cost
 Convenient to implement when output is difficult to measure
Disadvantages:
 The controller never actually knows if the actuator did what it
was supposed to do, i.e. it is inaccurate
 Unable to sense the environmental changes or disturbances

12. Closed Loop Control
e = Error = Input – Output
u = Control Input
Input
Control
Law
Plant Output
∑
+
_
e u
• Controlling action is dependent on the changes in output

13. Examples of Closed Loop Control

14. Examples of Automatic Closed Loop Control

15. Advantages:
 Accurate, since the controller modifies and manipulates the
actuating signal such that the error in the system will be zero.
 Self-correcting
 Senses the environmental changes, and disturbances in the
system.
Disadvantages:
 Complicated to design
 Costly
 Instable, since due to feedback , system tries to correct the error.
Advantages and Dis-advantages of Closed Loop Control

16. Key Elements in Mechatronic System

17. Key Elements in Mechatronic System: Example of Electro-
Mechanical System

18. Response of System
0 5 10 15 20 25 30 35 40 45 50
time (sec)
0 5 10 15 20 25 30 35 40 45 50
time (sec)
0 5 10 15 20 25 30 35 40 45 50
time (sec)
time (sec)
0 5 10 15 20 25 30 35 40 45 50
time (sec)
0 5 10 15 20 25 30 35 40 45 50

19. Transfer Function Models
 Why TF?
 Because it is easier / better to assess some things
using classical techniques, such as gain and phase
margin.
 How to determine TF?
 Derive the Governing Differential Equation
 Assume I.C=Zero and
 Take Laplace transform of output
 Take Laplace transform of input
 Transfer function = L (output) / L (input)

20. 1/s 1/s
1/m
M
F
y
k d
mass/spring/dam
system
F
Translational Mechanical Example 1

21.        
 
  k
ds
ms
s
f
s
y
s
f
s
ky
s
dsy
s
y
ms
f
ky
y
d
y
m













2
2
1
Input
Output
T.F
sides
both
of
Laplace
taking
and
0
I.C
Assuming
(EOM)
motion
of
Equation 


Translational Mechanical Example 1

22. Block Diagram
• Block diagram is a
diagram of a system in
which the principal parts or
functions are represented
by blocks connected by
lines that show the
relationships of the blocks
1/s 1/s
d
k
1/m
M
F
y
k d
mass/spring/damper
system
F y
displacement
velocity

23. Block Diagram
 Comparator
 Input/Reference/Output/Disturb
ance / Feedback Signal
 Blocks to represent:
 Sensor, Actuator, Plant,
Controller, Amplifier etc (in
symbolic form / transfer
function form)
 Subsystem is represented as a
block with an input, an output,
and a transfer function
 When multiple subsystems are
interconnected, a few more
schematic elements must be
added to the block diagram
 These new elements are
summing junctions and pickoff
points.

24. Block Diagram: Domain & Comparator

25. Block Diagram: Series & Parallel

26. Block Diagram: Feedback
 
 
 
   
 
 
 
   
s
H
s
G
s
G
s
R
s
Y
s
H
s
G
s
G
s
R
s
Y






1
TF
loop
Closed
1
TF
loop
Closed

27. Reduction techniques
2
G
1
G 2
1G
G
2. Moving a summing point behind a block
G G
G
1
G
2
G
2
1 G
G 
1. Combining blocks in cascade or in parallel

28. 5. Moving a pickoff point ahead of a block
G G
G G
G
1
G
3. Moving a summing point ahead of a block
G G
G
1
4. Moving a pickoff point behind a block

29. 6. Eliminating a feedback loop
G
H
GH
G

1
7. Swap with two neighboring summing points
A B A
B
G
1

H
G
G

1

30. Moving Blocks to Create Familiar Forms

31. Moving Blocks to Create Familiar Forms

32. Example 1

33. Example 1

34. Example 2

35. Example 2

36. Example 3

37. Example 3

38. Example 4

39. Example 5

40. Example 5

41. Example 5

42. Example 5

43. Applications of Mechatronic System
• Household
• Refrigerator
• Washing m/c
• Microwave
• Automotive
• Fuel injection system
• Power steering
• Air conditioner
• Shop floor
• Tool monitoring system
• Automated guided vehicle
• Conveyor system
• Bottle filing plant.

44. Fuel Injection

45. Electric Power Steering