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
Sell on Docsity
Sell on Docsity
Docsity AI
Docsity AI
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

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

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Open Loop Transfer Function - System Engineering and Control - Exam, Exams of Systems Engineering

Acharya Nagarjuna UniversitySystems Engineering

The key points are:Open Loop Transfer Function, Time Constant, Transmitter Time Constant, Disturbance Stream, Block Diagram, Load Gain Constant, Load Time Constant, Tachometer Gain, Sampling Time, Cascade Control

Typology: Exams

2012/2013

Uploaded on 04/10/2013

shazli_1991
shazli_1991 🇮🇳

4.4

(11)

101 documents

1 / 12

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Cork Institute of Technology
Bachelor of Engineering (Honours) in Mechanical Engineering -
Award
(NFQ – Level 8)
Autumn 2006
Systems Engineering and Control
(Time: 3 Hours)
Answer any FIVE Questions Examiners: Prof. M. Gilchrist
ALL questions carry equal marks. Mr. J.E. Hegarty
Dr. M. J. O’Mahony
1. (a) A process control system has the following open loop transfer function;
GsHs Ke
ss s
s
() () ()( )
=
++
−2
110
(i) Assuming initially K=5, plot the bode diagram and determine the gain margin
and phase margin for the system. Comment on its stability.
(10 marks)
(ii) What value of K will result in a phase margin of 60o and what would be the
corresponding gain margin?
(4 marks)
(b) Explain how dead-time compensation can be introduced to improve the
performance of control systems such as (a) above.
(6 marks)
2. A unit feedback position control system has the following open loop transfer
function:
GsHs s
ss
() () (. )
()
=
+
+
20 01 1
4
Determine the following closed loop frequency response parameters:
(i) Resonant Peak Mr
(ii) Resonant frequency ωr
(iii) System Bandwidth ωb (15 marks)
Comment on the values obtained and hence sketch the expected response to a unit
step input in the time domain? (5 marks)
pf3
pf4
pf5
pf8
pf9
pfa

Partial preview of the text

Download Open Loop Transfer Function - System Engineering and Control - Exam and more Exams Systems Engineering in PDF only on Docsity!

Cork Institute of Technology

Bachelor of Engineering (Honours) in Mechanical Engineering -

Award

(NFQ – Level 8)

Autumn 2006

Systems Engineering and Control

(Time: 3 Hours )

Answer any FIVE Questions Examiners: Prof. M. Gilchrist ALL questions carry equal marks. Mr. J.E. Hegarty Dr. M. J. O’Mahony

  1. (a) A process control system has the following open loop transfer function;

G s H s

Ke s s s

s ( ) ( ) ( )( )

− 2

1 10

(i) Assuming initially K=5, plot the bode diagram and determine the gain margin and phase margin for the system. Comment on its stability. (10 marks) (ii) What value of K will result in a phase margin of 60o^ and what would be the corresponding gain margin? (4 marks) (b) Explain how dead-time compensation can be introduced to improve the performance of control systems such as (a) above. (6 marks)

  1. A unit feedback position control system has the following open loop transfer function:

G s H s

s s s

Determine the following closed loop frequency response parameters:

(i) Resonant Peak Mr (ii) Resonant frequency ωr (iii) System Bandwidth ωb (15 marks)

Comment on the values obtained and hence sketch the expected response to a unit step input in the time domain? (5 marks)

  1. (a) An automatic level control system for a effluent treatment plant is shown in Fig. Q 3. Explain briefly the operation of the system and tune the controller to give PI control of the tank level (ignore for the present the effects of the disturbance flow Q (^) d ). The following parameters relate to the system block diagram: K (^) sp = Set point conversion factor = 4mA per m K (^) v = Control valve coefficient = 0.028 m^3 /s per mA τv = Control valve time constant = 20 s A = Tank area = 10 m^2 R = Outlet hydraulic resistance = 0.069 m^3 /s per m τT = Transmitter time constant = 5 s (12 marks) (b) A disturbance flow stream Q (^) d will on occasion enter the system. Suggest a suitable control strategy that will minimise the effect of the disturbance flow on the tank level H (^) act. The disturbance stream cannot be controlled but it can be measured. Show the implementation of your proposed control strategy on a modified block diagram of the system. (8 marks)
  2. Fig Q.4 shows the block diagram representation of the liquid level control system in a steam boiler drum. Under certain conditions this system will exhibit an “inverse response”. Explain what this means and determine the conditions under which it will occur. (15 Marks)

How can the control system be modified to compensate for this effect?

(5 Marks)

  1. Figure 5 shows a digital speed control system. Given that D(s)=KP transform this diagram into the Z-domain and plot the root locus for the system. Hence determine the limiting value of KP for stability and the value of K (^) P that will result in an underdamped response with a damping ratio of 0.5.

Data

K (^) m = Motor/Load gain constant = 10 rad/s per V

τm = Motor/Load time constant = 0.4 s

K (^) t = Tachometer gain = 2.4 V per rad/s

T = Sampling Time = 0.01 s

Q 2

H (^) act

Tank

Q (^) d LY 102

LIC 102

LT 102

H (^) set

Q 1

LCV 102

Q (^) d (s) H (^) set (s) K (^) sp G^ c(s)^ K^ v τv s+

As+R

Control Valve

Set Point Controller conversion

τT s+

Transmitter

H (^) act(s)

Tank Dynamics Q 1 (s)

Fig. Q

H (^) O (s) +- -

Swell

H (^) set (s) G (^) c(s)

K 1

s

K 2

τ 2 s+

Controller

Boiler Drum Dynamics

Shrink

Fig. Q

Fig. Q

-2 (^1 )( 10 1 )

s ss

+- Gs

R(s) C(s)

Fig Q

1 − e − s

Ts

V (^) C(s)

T = 0.01 s

ZOH

  • D(s)

Digital Filter

1

m m

K τ s +

K (^) t

Tacho

Motor/Load

Ω(s)

Sampler