Mechatrnoics PPT Lecture notes on Actuators

Mechatronics PPT Lecture notes on Actuators

1. Lecture Notes / PPT
UNIT II
Mechatronics –302050

2. Syllabus
Block Diagram Representation
OpenandClosedloopcontrolsystem,
Identificationofkeyelementsofmechatronicssystemsand
representintoblockdiagram(Electro-MechanicalSystems),
Conceptoftransferfunction,
Blockdiagramreductionprinciples,
Applicationsofmechatronicssystems:-Household,Automotive,
Shopfloor,Industrial.

3. Objectives
1.UnderstandkeyelementsofMechatronicssystem,
representationintoblockdiagram
2.Understandconceptoftransferfunction,reductionandanalysis
3.Understandprinciplesofsensors,itscharacteristics,interfacing
withDAQmicrocontroller
4.UnderstandtheconceptofPLCsystemanditsladder
programming,andsignificanceofPLCsystemsinindustrial
application
5.Understandthesystemmodelingandanalysisintimedomain
andfrequencydomain.
6.UnderstandcontrolactionssuchasProportional,derivativeand
integralandstudyitssignificanceinindustrialapplications.

4. Outcomes
1.Identificationofkeyelementsofmechatronicssystemandits
representationintermsofblockdiagram
2.Understandingtheconceptofsignalprocessinganduseof
interfacingsystemssuchasADC,DAC,digitalI/O
3.InterfacingofSensors,ActuatorsusingappropriateDAQ
micro-controller
4.TimeandFrequencydomainanalysisofsystemmodel(for
controlapplication)
5.PIDcontrolimplementationonrealtimesystems
6.DevelopmentofPLCladderprogrammingandimplementation
ofreallifesystem

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

6. Reference Books
Alciatore&Histand,IntroductiontoMechatronicsand
Measurementsystem,4thEdition,McGrawHillpublication,
2011
Golnaraghi&Kuo,AutomaticControlSystems,JohnWiley
publications,2010

7. Control
AControlsystemperformsfollowingfunctions
•Forparticularinputthesystemoutputcanbecontrolledtoadesired
particularvalue.
•Ifsomeconditionsaresatisfieditcangiveaparticularsequenceof
eventsasoutputcorrespondingtogiveninput
Actual Response
Desired Response

8. Controllability
(Out of Syllabus)
Beforeacontrollerisimplementeditisnecessarytotestthe
“Controllability”ofthesystem
Controllabilityistheabilityofthesystem,tobecontrolled/
providedesiredperformance,providedanexternaldisturbance
isavailable.

9. Open Loop Control
•Outputisdependentoninputbutcontrollingactionistotally
independentofthechangesinoutput,isanOpenLoopControl
System.
•Nofeedbackisused,sothecontrollermustindependentlydetermine
whatsignaltosendtotheactuator.
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:
Simpleinconstruction
Lowcost
Convenienttoimplementwhenoutputisdifficulttomeasure
Disadvantages:
Thecontrollerneveractuallyknowsiftheactuatordidwhatit
wassupposedtodo,i.e.itisinaccurate
Unabletosensetheenvironmentalchangesordisturbances

12. Closed Loop Control
e = Error = Input –Output
u = Control Input
Input
Control
Law
Plant Output∑
+
_
e u
•Controllingactionisdependentonthechangesinoutput

13. Examples of Closed Loop Control

14. Examples of Automatic Closed Loop Control

15. Advantages:
Accurate,sincethecontrollermodifiesandmanipulatesthe
actuatingsignalsuchthattheerrorinthesystemwillbezero.
Self-correcting
Sensestheenvironmentalchanges,anddisturbancesinthe
system.
Disadvantages:
Complicatedtodesign
Costly
Instable,sinceduetofeedback,systemtriestocorrecttheerror.
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 System0 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?
Becauseitiseasier/bettertoassesssomethings
usingclassicaltechniques,suchasgainandphase
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/s1/s
d
k
1/m
M
F
y
k d
mass/spring/damper
system
F y
displacement
velocity Translational Mechanical Example 1

21.  

 kdsmssf
sy
sfskysdsysyms
f ky y d ym





2
2
1
Input
Output
T.F
sidesboth of Laplace takingand 0I.C Assuming
(EOM)motion ofEquation  Translational Mechanical Example 1

22. Block Diagram
•Blockdiagramisa
diagramofasystemin
whichtheprincipalpartsor
functionsarerepresented
byblocksconnectedby
linesthatshowthe
relationshipsoftheblocks1/s1/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/FeedbackSignal
Blockstorepresent:
Sensor,Actuator,Plant,
Controller,Amplifieretc(in
symbolicform/transfer
functionform)
Subsystemisrepresentedasa
blockwithaninput,anoutput,
andatransferfunction
Whenmultiplesubsystemsare
interconnected,afewmore
schematicelementsmustbe
addedtotheblockdiagram
Thesenewelementsare
summingjunctionsandpickoff
points.

24. Block Diagram: Domain & Comparator

25. Block Diagram: Series & Parallel

26. Block Diagram: Feedback






sHsG
sG
sR
sY
sHsG
sG
sR
sY




1
TF loop Closed
1
TF loop Closed

27. Reduction techniques2G 1G 21GG
2. Moving a summing point behind a blockG G G 1G 2G 21GG
1. Combining blocks in cascade or in parallel

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

29. 6. Eliminating a feedback loopG H GH
G
1
7. Swap with two neighboring summing pointsA 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
•Washingm/c
•Microwave
•Automotive
•Fuelinjectionsystem
•Powersteering
•Airconditioner
•Shopfloor
•Toolmonitoringsystem
•Automatedguidedvehicle
•Conveyorsystem
•Bottlefilingplant.

44. Fuel Injection

45. Electric Power Steering