1. ENT364/4 – Control System Sazali Yaacob
BEng(Malaya), MSc(Surrey), PhD(Sheffield)
Chartered Engineer, CEng (United Kingdom)
Member Institute of Engineers and Technologist, MIET (United Kingdom)

2. Course Assessment Lecture 3 hours per week
Lab/Tutorial/Design 2 hours per week
Final Examination 50 marks
Mid-SemesterTest 10 marks
Quiz/Design 25 marks
Lab works 15 marks

3. Weekly Schedule Week 1: Introduction Week 2: Modeling Week 3: Modeling
Week 4: Time Response
Week 5: Time Response
Week 6: Time Response/Root Locus
Week 7: Root Locus/Mid-Semester Revision

4. Weekly Schedule Week 8: Frequency Response Week 9: Frequency Response
Week 12: Design
Week 13: Design
Week 14: Revision

5. Introduction to control system
OBJECTIVES
Basic terminologies.
Open-loop and closed-loop
Block diagrams
Control structure
Advantages and Disadvantages of closed-loop

6. Human control

7. System control

8. GPS Control

9. Force Control

10. Vision Control

11. Sound Control Block Diagram for Active Noise Cancellation BEFORE ANC
Primary Source
(Loudspeaker)
Secondary source (Actuator)
Block Diagram for Active Noise Cancellation
24 cm
Error Microphone
Sensor Microphone
36 cm
Primary path
Error path
12 cm
BEFORE ANC
AFTER ANC

12. Satellite Control

13. Satellite Control

14. Satellite Control Magnetometer Magnetorquer Driver OBC ACS
Torque command for the MT
Processed attitude data
Attitude Ref

15. Process Control

16. Pilot Plant

17. Servo Control

18. Steering Control
Complete System Set-up for Mobile Robot using Mecannum wheel

19. Omni-directional Motion for the Mobile Robot

20. Basics terminologies subsystem subsystem subsystem
Sub-system and System
subsystem subsystem subsystem
System is a combination of physical and non-physical components that are configured to serve certain tasks to maintain the output
Subsystem is part of the system that is grouped for a certain function
blower
room
thermostat

21. Plant subsystem input output plant
Plant is the main subsystem where the control signal will act on and produce the output .
plant

22. Disturbance is unwanted signal that may sway the output
Controller is a subsystem that is used to ensure the output signal follows the input signal
disturbance +
input
plant
output
controller

23. Error is a signal made up of the difference of input and output
disturbance +
error + +
input
plant
controller -

24. Control Structure
For any control system the following flow structure is needed
Objective
model
analysis
design

25. Open-loop system Example of an open-loop system Turn table rheostat
motor
rheostat
amplifier
motor
Turn-table
Required speed
Actual speed

26. Closed-loop system example of closed-up system + - + - Turn-table
motor
tachometer
rheostat + -
Differential amplifier +
required
speed
Actual speed
amplifier
motor
Turn-table
tachometer -

27. Block Diagram input, R output, Y
Transfer function, H
input, R
output, Y
Transfer function is the ratio of the ouput over the input variables
The output signal can then be sderived as
Example of multi-variables C + + R E + - B
Block diagram reduction a b c a c H G =
H.G

28. Control signal R(s) + E(s) Y(s) - B(s) E(s error signal
B(s) feedback signal
R(s) reference signal
Y(s) output signal
Feed forward transfer function
Feedback transfer function
Open-loop transfer function
Closed-loop transfer function
B(s)
E(s)
Y(s)
E(s)
B(s)
H(s)
G(s)
H(s)G(s)

29. Characteristic equation
Open-loop
Assume,
gives .
Variable difference
Characteristic equation

30. Model Physical model Graphical model Mathematical model
Example: Current-voltage relationship
v – voltage in V
i – current in A
R – resistance in Ohm
Example: Force-deflection realtionship
di mana
f – force in N
k – spring constant
x – displacement in m
Mass-spring model sistem jisim-pegas
- applied force
x - displacement
- reaction force

31. Example: Mass-spring model sistem jisim-pegas
f – force in N
k – spring constant
x – displacement in m
Mass-spring model sistem jisim-pegas
From Newton’s law
where m is the mass and a is the acceleration.
Substituting
Lumped parameter model
Ohm’s law
Distributed parameter model
Heated plate
dan modelnya berbentuk

33. Torque-Speed Characteristics of a Squirrel-Cage Induction Motor

34. Identification procedure

35. Forward Plant Modeling

36. A two layer Artificial Neural Network

37. The Experimental Work

39. Analysis Transient state Steady state Stability
A state whereby the system response after a pertubation before the response approach to a steady condition
Steady state
A state whereby the system response becomes steady after a transient state
Stability
The condition of the steady state. If the response converges to a finite value then it is said to be in a stable condition and if the response diverges, it is known to be unstable.

40. Time response
Transient s state
Steady state

41. Example of Time Response

42. Design * Analogue controller A controller that used analogue subsystem
* Digital Controller
A controller that used computeras its subsystem
computer
drive
plant
sensor _ +
referene
input
Actual output

44. The Control Experiment.

45. The Induction Motor Unit Step Speed Response with the
Direct Inverse Control Scheme

46. The Error in the Speed of the Induction Motor with Direct Inverse Control Scheme

47. Speed Response to a Sine Wave Reference Signal under DIC Scheme.

48. Speed Response to a Ramp Wave Reference Signal under DIC Scheme.

49. Speed Response to a Square Wave Reference Signal under DIC Scheme.

50. Advantage of feedback loop
(1) Not susceptible to disturbance d + + y r + - H
Assume
, then changes in y is negligible
Not sensitive to parameters changed

51. (2) Insensitive to changes in parameters
Consider r + y - H
Define sensitvity as
where T is the transfer function of the system
 is the parameter of the system. . .
Closed-loop transfer function
Let us investigate the effect on the system when the plant is subjected to perturbance i.e., If
, thus

52. (3) Increased in bandwidth
Consider a first order
where K is the dc gain and T is the time constant
If a feedback is applied + - a
The closed-loop transfer function is
Hence the new time constant
is reduced

53. (4) Accurate control. Output for open loop Output for feedback systemIf
, thus .