Mechatronics Solutions CH1&2

8/10/2019 Mechatronics Solutions CH1&2

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Two marks Questions

Mechatronics [MH1031]

Unit 1

1. What is Mechatronics? Give examples.

Mechatronics is the synergistic integration of mechanical engineering with electronics &

Intelligent control algorithms in the design & manufacture of products process.

Examples washing machine! "o#ot! automo#ile electronic fuel in$ection & antiloc% #ra%e

systems! digital camera etc.

. 'escri#e various elements of measurement system with help of a #loc% diagram.

(ensor It responds to the )uantity #eing measured #y giving as its output

a signal which is related to the )uantity.

(ignal conditioner It ta%es the signal from the sensor & manipulates it into

a condition which is suita#le for either display *or+ for

use to exercise control.

'isplay ,he output from the signal conditioner is displayed.

-. Identify the sensor! signal conditioner & display elements in the measurement systems of a+

mercury in glass thermometer #+ a ourdon pressure gauge.

a+ (ensor / mercury

signalconditioner/fine#orestem

display / mar%s on the stem.

#+ (ensor / curved tu#e

signal conditioner / gears

display / pointer moving across a

scale.

0. Identify the various elements that might #e present in a control system involving a

thermostatically controlled electric heater.

rocess 2 heater

3ontrolled varia#le 2 temperature

Measurement device 2 #imetallic strip

3omparison element 2 thermostat

3orrection element 2 relay.

4. What is meant #y se)uential control & illustrate with an example.

,he control system in which the actions are strictly ordered in a time or event driven

se)uence is %nown as se)uential control.

Example domestic washing machine. ,he operations to #e carried out in the correctse)uence are! pre wash cycle! main wash cycle & rinse cycle.


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5. (tate steps that might #e present in the se)uential control of a dish washer.

Water in! rinse! water out

Water in! heat water! rinse! water out

Water in! rinse! water out

6. 3ompare & contrast the traditional design of a watch with that of a Mechatronics designed

product.

,raditional design Mechatronics design

i. ul%y i. 3ompact

ii. 7imited functions ii. More functions

iii. "e)uires rewinding iii. 'oes not re)uire rewinding

iv. 3ostlier iv. 3heaper.

8. 3ompare and contrast the control system for the domestic central heating system involving a

#imetallic thermostat and that involving microprocessor.

imetallic element Mechatronics design

i. (low i. 9ast

ii. 7imited accuracy ii. More accurate

iii. (imple functions iii. Many functions

iv. 3heap iv. More 3heap.

:. 7ist the advantages of Mechatronics system.

1. Increased functionality and letter design

. More use of electronics & software instead of mechanical function

-. ;ssumes responsi#ility for process & operation with little interference of

operators.

0.


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0. Its replacement is difficult.


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1. What are the %ey elements of Mechatronics system.

1. Information system

. Mechanical system

-. Electrical system

0. 3omputer system

4. (ensor & actuators

5. "eal time interfacing.

=nit /

1. 'efine sensor & transducer

(ensor is an element in a measurement system that ac)uires a physical parameter and

changes it into a signal. ,ransducer is a device that converts the energy from one form to

another.

. 'efine range & span.

,he range of a transducer defines the limits #etween which the input can vary. ,hespan is the maximum value of the input menus the minimum value.

-. 'efine accuracy & precision

;ccuracy It is defined as the a#ility of an instrument to respond to a true value of a

measured varia#le under the reference conditions.

recision It is defined as the degree of exactness for which an instrument is designed

to perform.

0. 'efine sensitivity.

It is the relationship indicating how much output may #e o#tained per unit input.

4. 'efine


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"ange 6> to 1>>> @ a

9ull range output 0> mA

Bon linearity & hysteresis >.4C full range output. ,he range indicates that the

transducer can #e used to

measure pressures #etween 6>

& 1>>> @a It gives an output of 0> mA

when the pressure is 1>>> @a

Bon linearity & hysteresis willlead to erros of >.4C of1>>>! *ie+ 4 @a.

11. What is the non2linearity error! as a percentage of full range! produced when a 1@potentiometer has a load of 1>@& is at onethird of its maximum displacement.

( )

( )

( )( )

7

& -

7

7

& -

" D1@! " D1>@! xD>.--"

x 2x"

non2linearity errorD F1>>C"

x 12x 1"

>.1 >.-- 2>.--D D >.6C

>.1F>.-- 12>.-- 1

1. What is displacement & position sensor.

'isplacement sensors are concerned with the measurement of the amount #y whichsome o#$ect has #een moved. osition sensors are concerned with the determination of the

position of some o#$ect with reference to some reference point.

1-. Bame some sensors which are used for displacement measurement.

1. potentiometer sensor . resistance strain gauge element

-. push / pull displacement sensor 0. 7A',

10. Bame some sensors which are used for position measurement.

1. photo electric sensors .


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16. What is hall effect?

When a #eam of charged particles passes through a magnetic field! the #eam is

deflected from it straight line path due to the forces acting on the particles. ,his is %nown as

. Bame some signal conditioning operations.

;mplification! lineariation! comparision! protection! filtering! temperature

compensation! ;nalog to 'igital conversion! 'igital to ;nalog conversion.

1. What is the resolution of an ;' converter with a word length of 1 #its & an analogue

signal input range of 1>>v?

1>>"esolution D D0.0mA

1

. What is the conversion time for a 1 #it ;'3 with a cloc% fre)uency of 1 M.4 sec

1>

-. (tate shannonHs sampling theorem.

When the signal is sampled at a rate fs f

m! the signal can #e reconstructed from its

samples without distortion.

=nit / -

1. 'raw the sym#ols for

a+ a pressure relief valve #+ a valve c+ a 0 valve

. ; pneumatic system is operated at a pressure of 1>>> % a. What diameter cylinder will #e

re)uired to move a load re)uiring a force of 1 @B?

2-

&

2-

&

9orceressure D

;rea

1 ;D D1F1>

1>>>

J'D1F1>

0

' D >.>14

' D 10mm.-. If a stepper motor has a step angle of 6.4! what digital input rate is re)uired to produce arotation of 1> revsec?


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o

o

-5>Bo.of pulses per step D D08 pulsessec.

6.4

'igital input D08F1> D 08> pulsesrev.

0. (tate the num#er of degrees of freedom each of the following mechanism hasKour %nee / degrees of freedom / 1

Kour an%le / degrees of freedom / -

Wind screen wiper mechanism / 'L9 / 1

4. ; hydraulic cylinder is to #e used to more a wor% piece through a distance of 5> mm in >

secs. ; force of 14@B is re)uired to move the wor% piece. 'etermine the re)uired wor%ing

pressure & hydraulic flow rate if a cylinder with a piston diameter of 64mm is availa#le.

( )&

&

-

-

J >.>64;rea D D m

0

>.>5Fflowrate D D m sec.

>

9 14F1>pressure D D D @a

;

5. (uggest suita#le actuator for ro#ot arm $oint & $ustify.

6. ;n actuator has a stem movement which at full travel is 0>mm. It is mounted with a linear

plug process control valve which has a minimum flow rate of >.0 a maximum flow rate of >.

m-s. What will #e the flow rate when the stem movement is a+ 1> mm #+ > mm?

9or a linear valve the percentage flow rate is the same as the percentage stem

displacement.

a+ a percentage stem displacement of 4C gives a percentage flow rate of 4C *ie+ >.>4

m-s.

#+ a percentage stem displacement of 4>C gives a percentage flow rate of 4>C *ie+ >.1

m-s.

8. ;n actuator has a stem movement which at full travel is 0> mm. It is mounted on a process

control valve with an e)ual percentage plug & which has a minimum flow rate of >. m -s & a

maximum flow rate of 0 m-s. what will #e the flow rate when the stem movement is a+ 1>mm

#+ >mm.-

-

min D >.m sec

max D 0m sec

( max D 0>mm


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( max

1>0>

-

&>

0>-

max+

min min

0 D >. >.0m sec.

>.

0+ D >. >.8:m sec.

>.

S

a

b

=

=

=

:. What is mechanism & @inematics.

Mechanism are motion converters in that they transform motion from one form to some

other re)uired form. @inematics is the study of motion without regard to forces.

1>. What is %inematics chain & four #ar chain.

; se)uence of $oints & lin%s is %nown as %inematics chain.,he connection of four lin%s

to give four $oints a#out which turning can occur is %nown as four #ar chain.

11. What is cam? What are its types.

; cam is a #ody which rotates or oscillates and in doing so imparts a reciprocating or

oscillatory motion to a second #ody called the follower.

,ypes eccentric! heart shaped & pear shaped.

1. ; compound gear train consists of the final driven wheel with 14 teeth which meshes with a

second wheel with :> teeth. Ln the same shaft as the second wheel is a wheel with 14 teeth.

,his meshes with a fourth wheel! the first driver! with 5> teeth. What is the overall gear ratio?

3; ; .

' . 3 '

. '

; 3

ww w w

overall gear ratio D w w w w

B B

B B

14 14 1.

5> :> 0

= = =

=

= =

1-. Identify the motions involved in the following mechanism.

1. ,he %eys on a computer %ey#oard / translational motion

. ,he pen in an NK plotter / translational motion

-. ,he hour hand of a cloc% / rotational motion0. the pointer on a moving coil ammeter / rotational motion

4. ;n automatic screw driver / translational plus rotational motion.

10. ; d.c moter is re)uired to have a+ a high tor)ue at low speeds for the movement of large

loads #+ a tor)ue which is almost constant regardless of speed. (uggest suita#le forms of

motor.

a+ (eries wound d.c. motor #+ (hunt wound d.c. motor.

14. (uggest possi#le motors d.c *or+ a.c! which can #e considered for applications where a+

cheap! constant tor)ue operation is re)uired #+ high controlled speeds are re)uired c+ lowspeeds are re)uired d+ maintenance re)uirements have to #e minimied.

a+ '.3. shunt wound #+ induction motor


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5. What are the criteria that need to #e considered for selecting a 73?

1. input output capacity is re)uired

. type of input output is re)uired

-. sie of memory is re)uired

0. speed & power re)uired for 3= is needed.

6. Mention specific features of 73Hs

1. 73Hs are rugged & designed to withstand vi#rations temperature! humidity & noise.. ,he interfacing for inputs & outputs is inside the controller.

-. ,hey are easily programmed.

8. (tate the programming methods of 73.

1. 7adder programming . (tructured text programming

-. 9unction #loc% diagram 0. (e)uential function charts

4. Instruction list

:. What are the three ma$or types of 73 application?

1>. Bame the two ways in which input output is incorporated into the 73.

11. 'raw the ladder logic diagram to represent a+ two switches that are normally open & #oth

have to #e closed for a motor to operate #+ Either of two! normally open! switches have to #e

closed for a coil to #e energied & operate an actuator.

1. What is ladder programming?

,he ladder programming involves each program tas% #eing specified as though a rung

of a ladder. ,hus such a rung could specify that the state of switches ; & are #oth closed

then a solenoid! the output is energied.

1-. Write a#out internal relays?

,he internal relays #ehave li%e relays with their associated contacts! #ut in reality are

not actual relay #ut associated #y the software of the 73. Internal relays are used when there

are programs with multiple input conditions.

10. What is an up counter & down counter?


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;n up counter could count up to the preset value *ie+ events are added until the num#er

reaches the set values! when the set value is reached the counters contact changes state.

; down counter could count down from the preset value to ero *ie+ events are

su#tracted from the set value. When ero is reached the counters contact changes state.

14. What are operations that are carried out with a 73 on data words?

1. moving data. comparison of magnitudes of data

-. ;rithmetic operations such as additons & su#traction

0. 3onversions #etween 3'! #inary & octal.

=nit / 4

1. What are the various stages in designing Mechatronics system?

,he various stages in Mechatronics design are

a+ ,he need#+ ;nalysis of the pro#lem

c+ reparation of the specification

d+ Generation of the possi#le solutions.

e+ (election of the suita#le solutions

f+ production of a detailed design

g+ roduction of wor%ing drawings

. What are the advantages of the micro processor controlled system?

,he microprocessor controlled system can cope easily with given precision &

programmed control. ,he (ystem is much more flexi#le. ,his improvement in flexi#ility is a

common characteristic of Mechatronics systems when compared with traditional systems.

-. 7ist down the various Mechatronics elements in an automatic camera.

,he #asic elements of the control system used in an automatic camera is #ody! lenses &

flash. ,he other elements are

1. sensors / 7ight sensor! range sensor! lens sensor metering sensor.

. solenoid valve

-. flash setting unit

0. motor drives! oom & exposure unit.

0. What are the axes of a pic% & place ro#ot?,he ro#ot has three axes a#out which motion can occur

a+ "otation in a cloc%wise *or+ counter cloc%wise direction of the unit on its #ase.

#+ ;rm extension or contraction & arm up or down

c+ Gripper open *or+ close.

4.


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;3,=;,L" 9=B3,ILB

Motor I 9ilm transport

Motor II (hutter & mirror action! film rewind

Motor III 9ocusing drive

Motor IA 7ens aperture drive

Motor A 9lash oom drive

(hutter magnet Exposure time control

6. 7ist the difference #etween traditional design & Mechatronics design.

,";'I,ILB;7 'E(IGB ME3

Mechatronics Solutions CH1&2

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