Ec6405 CS QB 2
Ec6405 CS QB 2
Ec6405 CS QB 2
PART B
1. Write the Differential equations governing the mechanical translational
system shown in fig. and find the transfer function.
5. Derive the transfer function for the armature and field controlled DC
Motor. (AUC, May-June 2014).
6. Find the transfer function C(S)/R(S) for the system shown in fig.
7. Using Block diagram reduction technique finds the transfer function for the
system shown in fig.
e overall gain C(S) / R(S) for the signal flow graph shown in fig.
the overall gain C(S) / R(S) for the signal flow graph shown in fig.
a signal flow graph and find the closed loop transfer function for the block diagram shown in fig.
UNIT 2
TIME RESPONSE ANALYSIS
PART A
is time response?
are transient and steady state response of a control system? (AUC, Nov-Dec 2012)
reference to time response of a control system, define peak time.(AUC, Nov-Dec 2012)
are poles and zeros?
is first order and second order systems?
is the order of a system?
guish between type and order of a system.
he system is classified depending on the value of damping?
are all the time domain specifications?
e delay time and rise time. (AUC,May - June 2014)
e peak overshoot and settling time.
a neat sketch explain all the time domain specifications.
will be the nature of response of a second order system with different types of damping?
is damped frequency of oscillation?
is steady state error?
he advantages of generalized error coefficients. (AUC, May - June 2012).
derivative controller is not used in control system?(AUC, May - June 2012)
he steady state error to a various standard inputs for type - 2 systems. (AUC, May - June 2013)
are static error constants?
osed-loop transfer function of second order system is C(S)/R(S) = 400/ S 2 +6S +400. Determine the damping ratio and natural
ncy of oscillation. (AUC, May - June 2013)
are type 0 and type 1 systems? (AUC, May - June 2014)
he expressions and draw the response of first order system for unit Step input.
r a second order system Y(s)/R(s) = n2/ s2+2ns+n2. Find the response y(t) to a input of unit step function. (AUC, N
2)
he expressions for Rise time, Peak time, Peak overshoot, delay time.
onal control system with velocity feedback is shown in fig. What is the response of the system for unit step input?
feedback control
x(0.5s+1)(0.2s+1). Determine the steady state error for unit step , unit ramp, unit acceleration inputs. A
e the damping ratio and n of the dominant roots. (AUC, Nov-Dec 2013)
y feedback system is characterized by an open loop transfer function is G(s)= K / s(s+10). Determine the gain K ,so that
ll have a damping ratio of 0.5. For this value of K, determine settling time, Peak overshoot and time to Peak overshoot
p input. (AUC, May - June 2012)
limit steady state error to 0.1 when input to system is 1+6t. (AUC, Nov-Dec 2012)
11. The open loop transfer function of a unity feedback control system is given by
G(s)=K/s(sT+1) where K and T are positive constants. By what factor should the
amplifier gain be reduced so that the peak overshoot of unit step response of the system
is reduced from 75% to 25%. (AUC, May - June 2012)
12. A certain unity negative feedback control system has the following forward path
transfer function G(s)=k(s+2)/s(s+5)(4s+1). The input applied is r(t)=1+3t. Find the
minimum value of k so that the steady state error is less than 1. (AUC, May - June
2012)
UNIT 3
FREQUENCY RESPONSE ANALYSIS
PART A
1. What is frequency response?
2. List out the different frequency domain specifications?
3. Define resonant Peak (r)?
4. Define Resonant frequency (f)?
5. What is bandwidth?
6. Define Cut-off rate?
7. Define Gain Margin?
8. Define Phase cross over?
9. What is phase margin? (AUC, Nov-Dec 2013)
10. What is Bode plot?
11. What are the main advantages of Bode plot?
12. Define Corner frequency.(AUC, Nov-Dec 2012),(AUC, May - June 2014)
13. The damping ratio and the undamped natural frequency of a second order system are
0.5 and 5 respectively. Calculate the resonant frequency. (AUC, May - June 2014)
14. What is polar plot?
15. Define gain cross over frequency?
16. Define Phase cross over frequency?
17. How do you calculate the gain margin from the polar plot?
18. How do you find the stability of the system by using polar plot?
19. State Nyquist stability Criterion for a closed loop system when the
20.
21.
22.
23.
24.
25.
26.
27.
plot by showing slope contributions from each pole and zero. .(AUC, May - June 2012)
2. For an unity feedback system with closed loop transfer function G(s)/1+G(s) derive the
equations for the locus of constant M Circles and Constant N Circles. .(AUC, May June 2012)
3. Write the procedure to obtain Nichols chart from Constant M Circles. .(AUC, May June 2012)
4. Plot the Bode diagram for the following transfer function and obtain the gain and
phase Cross over frequencies. ( AUC May June 2013)
G(S) = 100/ S (1+0.2S) (1+0.1S)
5. Sketch the Bode plot and hence find Gain cross over frequency, Phase cross over frequency,
Gain margin and Phase margin.
Design a suitable lag - lead compensator to give, velocity error constant = 10 sec ,
phase margin = 50, gain margin 10 dB.
14. For a certain system,
G(s) = 0.025/s (1+0.5s) (1+0.05s).
-1
Design a suitable lag compensator to give, velocity error constant = 20 sec ,
phase margin = 40
15. A unity feedback system has an OLTF
G(s) = K / s(s+2)(s+60).
Design a Lead-Lag compensator is to meet the following specifications.
(i) P.M is atleast 40, (ii) Steady state error for ramp input 0.04 rad.
16. Given G(s) = Ke-0.2s/ s(s+2)(s+8), find K for the following two cases. i) Gain margin equal to 6db
ii) Phase margin equal to 45. (AUC, Nov-Dec 2012).
17. Draw the pole zero diagram of a lead compensator. Propose lead compensation
using electrical network. Derive the transfer function. Draw the bode plots. (AUC,
Nov-Dec 2012)
18. Explain in detail the design procedure of lead compensator using Bode plot.
( AUC May June 2013)
UNIT 4
STABILITY ANALYSIS
PART A
1. Define stability.
2. What is the necessary condition and sufficient condition for stability in routh
9.
10.
11.
12.
13.
PART B
1. Construct Routh array and determine the stability of the system whose
UNIT 5
STATE VARIABLE ANALYSIS AND DIGITAL CONTROL
SYSTEMS
PART A
1. Explain the concept of state.
2. Define state variables and state vectors. ( AUC May June 2013)
3. What is state trajectory?
4. Define state and state variables. .(AUC, Nov - Dec 2012)a
5. What is meant by sampled data control system? .(AUC, May - June 2012)
6. Explain the advantages of state variable method over conventional method.
7. Derive the transfer function from state model.
8. What are the different methods of state variable representations?
9. What is the necessity of compensation in feedback control system?(Aus,
May-June 2014)
10.
Write the transfer function of lag-lead compensator. ?(Aus, May-June
2014)
11.
Elaborate upon the basis of selecting suitable state variables for a system.
12.
What is characteristics equation of a system matrix A?
13. What is homogeneous and nonhomogeneous state equation?
14. Define state transition matrix using classical method.
15. What are the properties of state transition matrix? .(AUC, May - June 2014)
16. Draw the circuit diagram of sample and hold circuit? .(AUC, May - June
2014)
17. What is zero input response and zero state response?
18. What is Jordans canonical form?
19. Obtain the complete solution of nonhomogeneous state equation
13. Explain the electric network realization of lead compensator and also
14. Describe the procedure for the design of lag compensator using Bode