1. Sem I 2013/2014 BDU 20302 Electromechanical & Control Systems

2. Congratulations…Welcome to UTHM PARIT RAJA….A Place To Be..
DR. ZAMRI BIN OMAR Department of Aeronautical Engineering Faculty of Mechanical & Manufacturing Eng. Phone : Room: A4/C08-06 Mobile : 7618/

3. BDU20103 Electromechanical & Control Systems
Chapter 1 – Introduction Chapter 2 – Model of Industrial Control Devices Chapter 3 – Time Response Analysis Chapter 4 – Control System Design Chapter 5 – Flight Control Systems RPP ; a. Syllabus b. Assessment c. References
Total lecture weeks : 14 1st Part : 8 Weeks 2st Part : 6 Weeks

4. Important Reminder!!
Class participation 2. Punctuality & the look 3. Communication 4. E-Learning: The Author 5. Rules

5. Chap 1 : Control System
physical systems such as domestic appliances, transport, communication, manufacturing.

6. Chap 1 : Control System
What is Control System ?  deals with daily-life physical systems.  dynamic systems, contain several variables need to be controlled  control approach: modelling, open & closed loop, analysis, stability.  a device to control the power source  to cause the output is a dependent of the input  it has objectives : to get what you want !
Systems ?  an assemblage of inter-related components.  governed by physical laws.  diverse meaning.
Aircraft Control ?  purely mechanical.  hydro-mechanical.  fly by wire.  fly by light ?
physical systems such as domestic appliances, transport, communication, manufacturing.

7. Chap 1 : Flight Control System
physical systems such as domestic appliances, transport, communication, manufacturing.

8. Chap 1 : Flight Control System
evolution
physical systems such as domestic appliances, transport, communication, manufacturing.

9. C1 : Block Diagram Representation
Systems Representation  represented as block diagram
a block has input, output.  arrow represents signal (arrow in is i/p, arrow out is o/p)  Single input/output(SISO), multiple input/output (MIMO)  disturbance may occur.  input; controlled signal  output; dependent signal  disturbance; uncontrolled i/p signal

10. Example; Power Plant System
C1 : Block Diagram
Example; Power Plant System
disturbance
disturbance
disturbance
 input; fuel rate, f (m3/s)  output; electrical power, W (KW)  System components; represent by blocks  output of a block = input to another block  disturbance; system inefficiency, weather

11. C1 : Open Loop Control
Open Loop Control  o/p has no effect on the control action.  contains one signal path  Inboard aileron deflection is controlled by switch position  each position/setting causes a different electrical current (power)  performance; depends on the controller accuracy  user can’t control efficiency of the controller  if any disturbance occurred; a/s system cannot correct itself
Flight control system

12. C1 : Open Loop Control
Open Loop Control  o/p has no effect on the control action.  contains one signal path  Inboard aileron deflection is controlled by switch position  each position/setting causes a different electrical current (power)  performance; depends on the controller accuracy  user can’t control efficiency of the controller  if any disturbance occurred; a/s system cannot correct itself
Flight control system

13. C1 : Open Loop Control

14. C 1 : Open Loop Block Diagram
 The flight control system can be represented by the following block diagrams
components; controller, system  a one way signals  Might not get the desired aileron deflection;  controller inefficiency  excessive external load

15. C1 : Closed Loop Control
Closed Loop Control  the performance of aileron control system can be improved by introducing;  an operator dedicated to control the knob settings  aileron deflection sensor  desired angle = medium (4o), set knob to 2  strong wind, T ≠ 2o (too low); ; change the knob setting to 3  after a while, T = 6o (too big); change knob setting to 2 please!!  the T can be regulated/set at 4o, but may be oscillated  needs a large effort from the operator  this system is known as a closed loop (feedback system);

16. C1 : Closed Loop Block Diagram
Closed Loop Control  extra components; actuator & sensor  if the operator is replaced by a mechanical/electrical device;  an automatic feedback system

17. C1 : Block Diagram Elements
 a block / blocks
 summing point
 take-off point

18. C1 : Exercise; Block Diagram
Exercise 1  A Cessna170’s pilot controls the plane to maintain in a straight & level flight. Sketch a block diagram to illustrate the feedback system.

19. C1 : Exercise; Block Diagram
Exercise 2  an operator is to maintain the liquid level in the reservoir. The operator compares the actual level with the desired level and opens and closes the valve, adjusting the fluid flow out to maintain the desired level. Sketch the block diagram for this system.

20. Block Diagram Examples

21. Block Diagram Examples

22. Block Diagram Examples

23. C1 : Transfer Function Concept
Transfer Function (TF)  a ratio of output to input. Symbol/letter in the block represents TF, G(s)  ratio of Laplace transformation of o/p to Laplace transformation of i/p  for an open loop system
 for a feedback system,

24. C1 : Closed Loop Transfer Function
 the forward path TF,
 the feedback path TF,
 the open loop TF,
 the closed loop TF,

25. C1 : Block Diagram Reduction – To derive TF
Transfer Function in Series  consider a system with 2 blocks in series,
 It can be reduced/simplifed to,
 TF in series is,

26. C1 : Blocks in Series – TF Derivation
 1 and 1 can be written as,
 eliminate 2,
 For blocks in series, multply all individuals TF to obtain total TF

27. C1 : Blocks in Series – Example
 The TF for this power plant system is,

28. C1 : Blocks in Parallel – TF Derivation
Transfer Function in Parallel  parallel; arrows are in the same direction, not necessarily same signs  consider a system with 2 blocks in parallel,
 It can be reduced/simplified to,

29. C1 : Blocks in Parallel – TF Derivation
 Tf for each block can be written as,
 at the summing point;
 thus the overall TF (4/1) is,
 For blocks in parellel, add up all individuals TF to obtain total TF

30. C1 : Blocks in Parallel – Example+
 the TF is, -
Prove it !!
 the TF is,

31. C1 : Feedback System (Closed Loop); TF Derivation
Transfer Function for Feedback  feedback, positive feedback  consider a feedback systems,
 It can be reduced/simplified to,
 carefully examine !!

32. C1 : FB Loop - TF Derivation
 The overall TF (4/1) we can write the following,
 Eliminate 2 and 3

33. C1 : FB Loop - TF Derivation
 The overall TF for a FB loop,
 or,

34. C1 : Block Diagram (BD) Reduction Rules
 A summary of BD reduction rules is here.
 Tutorial 1 is here.

35. C1 : Block Diagram Reduction – Example 1
 obtain the TF for the following system,

36. C1 : Block Diagram Reduction – Example 2
 obtain the TF for the following system,

37. Assignment 1
 Write a 5-6 pages articles about flight control.  Figures/diagrams should take 2 pages maximum.  Dateline: 20 September 2012