ர 03000EE304052001 Pages: 2

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Sixth semester B.Tech examinations (S), September 2020

Course Code: EE304
Course Name: ADVANCED CONTROL THEORY
Max. Marks: 100 Duration: 3 Hours
PARTA
Answer all questions, each carries5 marks. Marks

1 What is a PI controller? What are its effects on the system performance? (5)

2 What is a lead compensator? Obtain its frequency response characteristics (5)

3 What is state space? What are the advantages of state space analysis? (5)

4 What is pulse transfer function? What is the stability criterion of asampled datacontrol (5)
system?

5 Mention any two characteristics of Nonlinear systems. What are limit cycles? (5)

6 Define Describing function. What is the difference between stability analysis of linear (5)
and nonlinear systems?

7 What is the difference between describing function and phase plane method of stability (5)
analysis?

8 Explain Liapunov direct method of stability for nonlinear systems. (5)

PART B
Answer any two full questions, each carries 10 marks.

9 The open loop transfer function of a unity feedback control system is given by (10)
G(S) = K/[S(1+0.5S)(1+0.2S)]. It is desired that (i) the steady state error to unit ramp
input is less than 0.125 (ii) Phase margin>300 (iii) Gain margin>10 db. Design a
suitable compensator.

10 Design a suitable compensator for a unity feedback system with open loop transfer (10)
function G(S)=K/[S(S+4)(S+7)] 10 satisfy the following specifications.
(1)Percentage overshoot=12.63% (2)Natural frequency of oscillation=8
rad/sec(3)Velocity error constant>2.5.

11 Explain the Ziegler-Nichols method of tuning a PID controller when (a) dynamic (10)

model is known (b) dynamic model is not known.