EC2255 Control Systems B.E Model Question Paper : aalimec.ac.in

Name of the College : Aalim Muhammed Salegh College of Engineering
University : Anna University
Department : Electronics and Communication Engineering
Subject Code/Name : EC2255-Control Systems
Degree : B.E
Year : II
Semester : IV
Document Type : Model Question Paper
Website : aalimec.ac.in

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AALIMEC Control Systems Model Question Paper

B.E./B.Tech. Degree Model Examination
Fourth Semester -Ec2251 —  Control Systems– II
Time: Three hours
Maximum:100 Marks

Related : Aalim Muhammed Salegh College of Engineering EC2254 Linear Integrated Circuits B.E Model Question Paper : www.pdfquestion.in/1618.html

Paper – I

Part- A  :
1. Give the comparison between open loop and closed loop systems
2. What are the advantages of closed loop systems?
3. Name the signals used to evaluate the performance of the given system
4. What may be the damping ratio when the percentage of overshoot of the system is 100%?
5. Define gain margin and phase margin
6. Draw the circuit of lead compensator and draw its pole-zero diagram
7. State Routh -Hurwitz stability criterion
8. Define asymptotic stability and relative stability
9. State the properties of state transition matrix
10. Define controllability and observability.

Part B (5 x 16 =80 marks)
11. (a) (i) Obtain the transfer function of the block diagram shown in fig 1 using Block diagram reduction rules(8)
(ii) Obtain the transfer function of the mechanical system shown in fig2 (8)
OR
(b) (i )Obtain the transfer function of the Signal flow graph shown in fig 3 using mason gain formula(8)
(ii) Obtain the transfer of the electrical system shown in fig4 (8)

12. (a) (i) Derive the impulse response of the critically damped system(8)
(ii) Determine the time response specifications and expression for output for unit step input to a system having system equations as follows xydtdydtyd916522=++ Assume zero initial conditions (8)
(b) (i) Determine the generalized error coefficients and steady state error whose open loop transfer function is )10)(1(1)(++=ssssG and the feedback is )2()(+=ssHwith input 26)(tttr++=.Also determine Kp, Kv and Ka for unit step input.(8)

(ii) The unity feedback system is characterized by an open loop transfer function ??(??)=????(??+10)Determine the gain K, so that the system will have a dampingratio of 0.5. For this value of K, determine settling time, peak overshoot andtime to peak overshoot for a unit step input.

Paper – II

1. Define transfer function
2. Write Mason’s gain formula.
3. What is transient and steady state response?
4. Why derivative controllers are not used in control system
5. Define Phase cross over frequency and gain crossover frequency
6. Draw the polar plot of the function
7. State Nyquist stability Criterion for a closed loop system when the open loop system is stable.
8. What is meant by BIBO stability
9. What is sampled data control system?
10. Define state and state variable.

Part B (5 x 16 =80 marks)
11. (a) (i) Write the differential equation governing the mechanical rotational system shown in fig.1. Draw the torque –voltage and torque – current electrical analogous circuits and verify mesh and node equations(8)
(ii) For the mechanical system shown in fig , determine the transfer function(8)
OR
(b) (i)Using Mason Gain formula to obtain C(s)/R(s) of the system shown below (8)
(ii) Using block diagram reduction technique , find the closed loop transfer function C/R of the system whose block diagram is shown in below (8)
12. (a) (i) The open loop transfer function of a unity feedback control system is given by where K and T are positive constants .By what factor should the amplifier gain be reducedso that the peak overshoot of unit step response of the system is reduced so that the peakovershoot of unit step response of the system is reduced from 75% to 25% (8)
(ii) A unity feedback system has the forward transfer function . The input is applied to the system. Determine the minimum value of K1 , if the steady state error is to be less than 0.1
OR
(b)With suitable block diagram and equations , explain the following types of controllers employed in control systems:
a) Proportional controller
b) Integral controller
c) PI controller
d) PD controller
e) PID controller

Paper – III

1. What is meant by ‘block diagram’ of a control system? What are the basic components of a block diagram?
2. Give the comparisons between the open loop and closed loop systems
3. What is meant by peak overshoot and settling time?
4. List the advantages of generalized error coefficients.
5. Write a MATLAB command for plotting Bode diagram
6. What is meant by corner frequency in frequency response analysis?
7. Using Routh criterion, determine the stability of the system represented by the characteristic equation .Comment on the location of the roots of characteristics equation.
8. The damping ratio and natural frequency of oscillation of a second order system is 0.5 and 8 rad per sec respectively. Determine the resonant peak and resonant frequency.
9. What are the advantages of state space analysis.
10. What is meant by quantization?

Part B (5 x 16 =80 marks) :
11. (a) (i) Consider the mechanical system shown below. Identify the variables and write the Differential equations (6)
(ii) Draw the torque- voltage electrical analogous circuit for the mechanical system shown in fig2 (4)
(iii) Obtain the transfer function of the following electrical network.(6)
(b) (i )Construct Signal Flow Graph for the block diagram shown below and obtain the overall transfer function(8)
(ii) For the block diagram shown in fig determine the overall transfer function using block reduction rules (8)
12. (a) (i) Derive an expression for steady state error of a closed loop control system(6)
(ii) The closed loop transfer function of a second order system is gven by . Determine the damping ratio , natural frequency of oscillation , rise time , settling time and peak overshoot(10)
OR
(b) (i) Discuss the effect of derivative control on the performance of second order system.(8)
(ii) The figure shows PD controller used for a system Determine the value of Td so that system will be critically damped. Calculate its settling time. (8)