EC09 604 Control Systems- Question bank 2013-14

Prepared by Susan Varghese Page 1

MODULE II

Topic Question mark Month &Year

Regulation

Time domain analysis & test

signals

What is transportation lag? 2 May 12 2009

What are standard test signals? explain 5 5

Dec 10 Jun 07

2004 2004

Time response of a system

Discuss in detail about the time response of a i)First order system ii) Second order system

10 May 12 2009

Determine the step response of a second order system 5 May 12 2009

Derive the time response of second order system for unit impulse 15 Jun 07 2004

Derive the unit step response of a second order system/ explain the steps

10 15

May 13 Dec 10

2009 2004

Derive the response of the first order system to unit step input 5 Dec 08 2004

Derive the response of the first order system to unit ramp input 5 Jun 08 2004

Obtain the unit step response of a unity feedback control system

whose open loop transfer function is given by

15 Jun 08 2004

A speed control system is expressed by the transfer function

find the output if an input of 2 volt is applied

Forward path TF of a UFB system is given by

determine the time response of the system for a unit step input.

Time domain specifications

Define overshoot 2 May 12 2009

Define and explain damping ratio and its significance 5 Dec 10 2004

A system having a forward path transfer function

and

unity feedback. Determine the value of undamped natural frequency, damping ratio. If tachometer feedback is introduced, the feedback transfer function becomes (1+kS) what should be the value of ‘k’ to obtain damping ratio 0.6.Also calculate the percentage peak overshoot, first under shoot and settling time with 2% of final value

15 Dec 08 2004

Obtain the relationship between damping ratio and the amount of overshoot for a second order system

5 Jun 09 2004

Forward path TF of a UFB system is given by

Find the percentage of peak overshoot, settling time for a unit

step input.

Forward path TF of a UFB system is given by

Determine the percentage of peak over shoot, rise time and

settling time for 2% tolerance.

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EC09 604 Control Systems- Question bank 2013-14

Prepared by Susan Varghese Page 2

For a second order system whose open loop transfer function

G(s)

. Determine the percentage of peak overshoot, time

to reach the maximum overshoot when a step displacement of

18o is given to system. Find tr, Time constant and ts for an error

7%

UFB system with a minor rate feedback loop is given below

i) In the absence of rate feedback (ie α=0) determine

%Mp to a unit step input and ess from a unit ramp

input.

ii) Determine the constant α which will decrease the Mp

to a 15% for a unit step input. What is the ess to unit

ramp input with this value α.

The altitude control system for a missile is shown. Determine

K1 & K2 in order that the closed loop system may have

undamped natural frequency of oscillation ωn = 10 rad/sec and

damping ratio of ζ= 0.5. What will be ts & Mp for a unit step

input?

Forward path TF of a UFB system for a unit step is given by

find the time response of the closed loop

system. And also determine the percentage of peak over shoot

and rise time.

For a unity feedback system,

find

for K=

-10 and hence find the transient response for the unit step input.

Error constants/coe

fficients

Determine the error coefficients for the system having

2 May 13 2009

Determine the type and the static error coefficients of the system given in figure

5 Jun 11 2004

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EC09 604 Control Systems- Question bank 2013-14

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Find the static error constants for the given UFB system

Obtain the dynamic error coefficients for a UFB system whose

open loop transfer function

. Find steady state error

of the system when it subjected to an input .

Find the steady state error when it is

subjected to an input

.

Obtain the dynamic error coefficients for a UFB system whose

open loop transfer function

subjected to an input

find the value of 10% steady state error

for unit ramp input

Concepts of stability-

location of roots in the s-

plane

Explain the concept of stability with an example 5 Jun 11 2004

Stability from characteristic

equation-Routh

Hurwitz criterion

A system is described by the following characteristic equation. Find the Routh’s stability criterion S4+2S3+3S2+2S+15=0

6 May 12 2009

Apply Routh’s criterion to test the stability of the system described by S5-2S4+2S3+4S2-11S-10=0 .Explain the procedure.

15 Dec 10 2004

Apply Routh criterion to test the stability of the system described by S5+0.5S4+3S3+1.5S2+0.5S+0.5=0

15 Jun 11 2004

Examine the stability of the given equation using Routh’s method S3+6S2+11S+6=0

5 May 13 2009

Check the stability of the system having the following characteristic equation using Routh Hurwitz criterion, S5+2S4+24S3+48S2+26S+50=0

7 Jun 07 2004

Using Routh’s criterion determine the stability of the following systems

i) Its loop transfer function has poles at S=0,S=-1, S= -3 and zero at S=-5, gain K of forward path is 10

ii) It is a type one system with an error constant of 10sec-1 and pole at S=-3 and s=-6

10 May 13 2009

Using Routh-Hurwitz criterions check the stability of the

system having characteristic equation and also comment about the location of the roots

of the system in s plane.

Using Routh-Hurwitz criterions check the stability of the

system having characteristic equation and also comment about the

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EC09 604 Control Systems- Question bank 2013-14

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location of the roots of the system in s plane.

Characteristic equation of a system is given below. Find the

value of K such that the system is just oscillatory.

Check the stability of the system having characteristic equation

and also comment about

the location of the roots of the system in s plane.

Stability from -Root locus

plot

Write a note on root locus 5 May 12 2009

Sketch the root locus for the system having

10 May 13 2009

For a unity feedback control system has an open loop transfer

function

sketch the root locus for 0<=K<∞.

15 Dec 08 2004

For a unity feedback control system has

sketch the complete root locus and find the value of K for which the root locus crosses the imaginary axis.

For a unity feedback control system has an open loop transfer

function

sketch the complete root locus and

determine the value of K for a damping ratio of 0.86.

For a unity feedback control system has an open loop transfer

function

sketch the complete root locus and

find the value of K for which the system just oscillates.

Sketch the root loci for the system having open loop TF system

For a unity feedback control system has an open loop transfer

function

sketch the complete root locus.

For a unity feedback control system has an open loop transfer

function

sketch the complete root locus.

For a UFB system has an open loop transfer function

sketch the complete root locus.

Frequency domain

Write a note on gain cross over frequency and resonant peak frequency

4 May 12 2009

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EC09 604 Control Systems- Question bank 2013-14

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analysis& frequency

domain specifications

Define gain margin and phase margin 5 Dec 08 2004

Determine analytically the gain margin and phase margin for the

function

15 Jun 09 2004

Bode plot

For a unity feedback control system has an open loop transfer

function

plot the bode diagram

and find the gain margin and phase margin.

For a unity feedback control system has an open loop transfer

function

determine the value of K so that

the system may be stable with GM equal to 6dB and phase margin equal to 45o

For a unity feedback control system has an open loop transfer

function

Using bode plot find the gain

margin and phase margin.

For a control system has an open loop transfer function

Using bode plot find the GM and PM.

Also find the value of K to obtain a phase margin of 60o

Draw the bode plot for the open loop transfer function

Find the gain margin and phase

margin

Draw the bode plot for the open loop transfer function

Find the gain margin and phase

margin

Draw the bode plot for the open loop transfer function

Find the gain margin and phase margin

Draw the bode plot for the open loop transfer function

Find the GM and PM

Draw the bode plot for the open loop transfer function

Find the GM and PM

Draw the bode plot for the open loop transfer function

where T1>Ta>Tb>T2

Polar plot or Nyquist plot

For the following forward path transfer function of an unity feedback control system draw the Nyquisit plot and hence test

the stability of the system

15 Dec 10 2004

Sketch the polar plot for

15 Jun 08 2004

Skect the polar plot for

8 Jun 07 2004

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EC09 604 Control Systems- Question bank 2013-14

Prepared by Susan Varghese Page 6

Draw the nyquist plot for the open loop TF

and

asses the stability range of K

Sketch the nyquist plot and determine the stability of closed

loop system

Draw the nyquist plot for the open loop TF

and

find gain margin, phase margin,ζ and ωn .

Draw the nyquist plot for the open loop TF

and

find the GM and PM

Draw the nyquist plot for the open loop TF

and

find the GM and PM

Draw the nyquist plot for the open loop TF

and find the GM and PM

Draw the nyquist plot for the open loop TF

and asses the stability range of K

Draw the nyquist plot for the open loop TF

and find the GM and PM

Draw the nyquist plot for the open loop TF

and

asses the stability range of K

Nyquist stability criterion

State Nyquisit stability criterion 2 May 13 2009

Explain the theory of Nyquisit criterion 5 5

Dec 10 Jun 08

2004 2004

compensators Explain Lag-lead compensator with circuit diagram 7 Jun 08 2004

Explain the concept of leadcompensator 5 Jun 07 2004

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