Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Control Engineering Exam Questions for EE Unit 64EE3013, Exams of Electrical Engineering

Exam questions for the unit 64ee3013: control engineering of the beng (hons) electrical and electronic engineering program at manchester metropolitan university. The questions cover topics such as root locus analysis, closed-loop transient performance, process control models, and pole placement controllers.

Typology: Exams

2010/2011

Uploaded on 10/06/2011

virtualplayer
virtualplayer ๐Ÿ‡ฌ๐Ÿ‡ง

4.2

(12)

302 documents

1 / 9

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
S373 09/09/02
THE MANCHESTER METROPOLITAN UNIVERSITY
FACULTY OF SCIENCE AND ENGINEERING
DEPARTMENT OF ENGINEERING AND TECHNOLOGY
SESSION 2000/2001
Examination for the
BEng (HONS) ELECTRICAL AND ELECTRONIC ENGINEERING (FULL-
TIME/PART TIME)
YEAR FOUR/FIVE
UNIT 64EE3013 : CONTROL ENGINEERING
Monday 21 May 2001
2.00 pm to 5.00 pm
Instructions to Candidates
Answer FIVE questions with not more than three from either section.
Figure Q1(a) and Jury Contours are provided on separate sheets.
Breakdown of marks for each question are shown in square parentheses.
pf3
pf4
pf5
pf8
pf9

Partial preview of the text

Download Control Engineering Exam Questions for EE Unit 64EE3013 and more Exams Electrical Engineering in PDF only on Docsity!

S373 09/09/

TH E MANCH ESTER M ETR O PO LITAN UNIVER SITY

FACULTY O F SCIENCE AND ENGINEER ING

D EPA R TMENT O F ENGINEER ING AND TECH NO LO GY

SESSIO N 2000/

Exam ination for th e BEng (H O NS) ELECTR ICA LAND ELECTR O NIC ENGINEER ING (FULL- TIME/PA R T TIME) YEA R FO UR /FIVE

UNIT 64EE3013 : CO NTR O LENGINEER ING

Monday 21 May 2001

2.00 pm to 5.00 pm

Instructions to Candidates

A nsw er FIVE questions w ith not m ore th an th ree from eith er section.

Figure Q 1(a) and Jury Contours are provided on separate sh eets.

Break dow n of m ark s for each question are sh ow n in square parenth eses.

  1. (a) Th e root locus diagram in figure Q 1(a) is for th e system sh ow n in figure Q 1(b ). Th e point m ark ed on th e locus corresponds to th e closed loop pole w h en th e controller gain K = 0..

(i) A ssess th e dam ping ratio of th e com plex poles. [3] (ii) Find th e 5% settling tim e associated w ith th e poles. [2] (iii) Locate th e position of closed loop zeros and discuss th eir effect on system response. [3] (iv) Can th e poles be regarded as dom inant? [2] (v) Find th e gain to cause th e system to b e com e unstab le on closed loop. [4]

Sh ow any construction w ork on figure Q 1(a) and h and th is in w ith your answ er book.

(b ) W ith K = 0.8, find th e system steady state error to a unit step reference input.

[6]

ss s

K s

s +

Figure Q 1(b )

Section A

  1. (a) A ch em icalb atch reactor is m odelled as 2 1

โˆ’ s

e Gs

s and its open-

loop frequency response is sh ow n in figure Q 3.

(i) Explain w h y such m odels are used in process controland sk etch th e process response to a unit step input. [3] (ii) Verify by calculation th at th e ph ase cross-over frequency is approxim ately 1.84 rs-1. [2] (iii) Verify by m easurem ents on th e Nyquist diagram th at th e gain m argin is approxim ately 2.5. [2] (iv) D e scrib e a m eth od by w h ich th ese m easurem ents m ay be approxim ated in closed loop and explain h ow th is can form th e b asis for self-tuning. [5] (v) D iscuss in qualitative term s th e effect of an increase in process dead tim e on th e gain m argin. [2]

(c) Explain w h at is m eant by feedforw ard control. W h at advantages m ay be gained by its use?W h y in practice m ust feedforw ard controlalw ays be used togeth er w ith fe e d b ack control? [6]

Figure Q

  1. (a) Th e state variab le m odelof a m otor is given by

y(t) [ ] x(t)

u(t) x(t)

x(t)

x (t)

x(t)

2

1

2

1

Th e state variab le, x 1 (t), represents m otor speed (radian per second) and th e input u(t), is m easured in volt. (i) W rite dow n th e differentialequation representing x 2 (t)

  • . W h at ph ysicalquantity does th is state variab le represent? [2] (ii) D raw an analogue sim ulation of th is m odel. [5] (iii) Find th e steady speed reach ed w h en th e input, is a step of m agnitude 10V. [2] (b ) Th e m otor is now placed under closed-loop controlas sh ow n in figure

Q 4, w ith K =[โˆ’ 2 โˆ’ 1 ].

(i) Find th e system ch aracteristic equation. [6] (ii) Find th e system dam ping ratio and undam ped naturalfrequency. [2] (iii) D raw a sk etch of th e response of th e state variab les x 1 (t)and x 2 (t)to a unit step reference input over th e first 5 seconds of th e response. Sh ow th e steady state values and give an indication of k ey tim e dom ain perform ance criteria. [3]

Figure Q

โˆ‘ (^) x^ โ€ข (t) = Ax(t) + Bu(t)

K = [โˆ’ 2 โˆ’ 1 ]

  1. A plant w ith a transfer function Gp(z) is to b e controlled using a pole placem ent controller as sh ow n in Figure Q 6.

(a) D iscuss th e im plications for controller design if th e plant contains unstab le poles or zeros outside th e unit circle. [6] (b ) Th e continuous-tim e transfer function of th e plant is given as

ss

Gp s. W h en a sam pling intervalof 0.5 seconds is used,

sh ow th at ( 1 )( 0. 607 )

( )^0.^1065 (^0.^8467 )

z z

G z z p. Design a pole-placem ent controller

to give a closed-loop system w ith a second-order response w ith a dam ping ratio of 0.7, 5% settling tim e of 4 s and zero steady-state error for step inputs. [14]

R (z) (^) D (z) Gp(z) Y(z

Figure Q

  1. (a) Explain w h y a process reaction curve type of test is insufficient for accurately identifying param etric m odels of practical system s. Suggest a persistently exciting signalth at can be used for such tests. Give reasons and sh ow h ow it can b e generated. [6 ] (c) Th e input-output data ob tained from an identification experim ent is sh ow n in Tab le Q 7.

(i) Estim ate th e param eters of a first-order m odelth at fits th e data using least squares tech nique. [8 ] (ii) Explain h ow th e estim ated m odelcan b e validated. [6 ]

k 0 1 2 3 4 5 u(k ) 1 1 0 -1 -1 1 y(k ) 0 0. 2 0. 36 0. 288 0. 03 -0. 176

  1. (a) A h eat exch anger process describ e d b y th e transfer function

(z .z. )

G(z). 11 028

= (^2) โˆ’ + is to b e controlled in unity fe e d b ack configuration such th at th e output

Y(z) follow s th e reference input R (z).

Sh ow th at a m inim um variance controller of th e form uk = 5. 5556 [ rk + 1 โˆ’ 1. 1 yk + 0. 28 yk โˆ’ 1 ]can b e

designed to m eet th e requirem ent. [8] (b ) If th e actualprocess gain is 10% h igh er th an th at indicated by th e m odel used in (a), estim ate th e steady-state offset th at m ay result w h en controlled in closed-loop using th e controller designed in (a). [5] (c) Sh ow h ow th e offset can b e rem oved. [3]

(d) Com m ent on th e nature of controlsignalgenerated by a m inim um variance controller and sh ow b riefly h ow excessive controlaction can b e reduced. [4]

Table Q