control system analysis

lab report

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Academic Year 2016/17

ENG540 Control Systems Analysis

Coursework

Deadline For Submission: At the end of the second lab session

Hand-in Instructions: Each student submits a report directly to the unit lecturer

Instructions for completing
assessment:

Students who miss the first lab session will be penalised and the mark

will be capped to a pass mark of 40%

Examiners: Dr Khalil Alkadhimi

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School of Engineering Registration Number

ENG540 CONTROL SYSTEM ANALYSIS 2016-17

Laboratory: First and second order systems, identification and analysis

1. Aim

The aim of this laboratory is to determine the transfer function of a first order system

(representing an actuator) and a second order system (representing a spring and flywheel)

obtained from experimental data. Analysis on the effect of feedback on the systems will be

carried out.

2. Assessment Guidelines

Write your student number in the box at the top of this page!

Attach this sheet with your report which will be collected at the end of the second laboratory

session. Any student who does not attend the first laboratory session will be awarded a mark

of 0%. Please make sure that the work you submit is clear, comprehensive and well

presented. Presentation that is either untidy, or lacks mathematical precision, will be

penalized. Finally, you should read the laboratory sheet in full so that you are aware of the

tasks ahead. In general you should be familiar with time response analysis. You will be

required to demonstrate an understanding of the theory of first and second order responses via

the results and data that you make. You will use a simulation package to produce time

response graphs that will be the basis for your assessment. Your graphs should be well

presented (neat, clear and contain all necessary information). It is very important to focus

your effort on recording results, interpreting and offering explanations, analysis and

conclusions where appropriate. As preparation work, you need to be familiar with how to

determine the transfer function of a first and second order systems for a given time

response and the calculation of the closed-loop transfer function.

3. First Order Transfer Function:

The Plot of a practical I/P and O/P data can be obtained from:

Servocad7 → file → import sample file → first order system

The general transfer function:

Where k is the gain and τ is the time constant.

A unit step input is applied to the system:

a. Determine the first order Transfer Function and discuss in details the method that you
used to obtain it.

b. Determine the CLTF if the system has unity negative feedback and calculate the new

values of k and τ
c. Determine the CLTF if the system has a negative feedback H(s) = 0.5 and calculate

the new values of k and τ
d. Discuss the performance of the open loop system compared with the closed loop

systems [ H(s)=1 and H(s)=0.5]

s) + (1

k
= G(s)



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4. Second Order Transfer Function:

The Plot of a practical I/P and O/P data can be obtained from:

Servocad7 → file → import sample file → Second order system

The general transfer function:

Where kss is the steady state gain, ωn is the un-damped natural frequency and ζ is the damping

factor.

A unit step input is applied to the system:

a. Determine the second order transfer function of the spring and the flywheel, showing
your work in details

b. Determine the CLTF if the system has unity negative feedback and calculate the new

values of kss, ξ and ωn.
c. Determine the CLTF if the system has a negative feedback H(s) = 0.5 and calculate

the new values of kss, ξ and ωn.
d. Discuss the performance of the open loop system compared with the closed loop

systems [ H(s)=1 and H(s)=0.5]





2

nn

2

2
nss

+ s2 + s

k
= G(s)

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Code of Practice for the Assessment of Students _ Grade Criteria (Level 2)

80+ (As below plus):

• Excellent work which contains relevant material and shows

analysis, originally or creativity of approach and a clear, well- articulated

understanding of the subject matter

• Wide research incorporating up to date, relevant original material.

Accurate citation and use of

references

• Excellent with few or no errors in organisation, structure, grammar,

spelling, punctuation, use of diagrams and tables

70-79 (As below plus):

• Very good work which is clearly written, well argued and covers the

subject matter in a thorough, thoughtful and competent manner. Contains

some originality of approach, insight or synthesis

• Good evidence of research and good use of source material. Good use

and presentation of references

• Very good presentation, presentation, organisation, grammar, spelling,

punctuation, diagrams and tables

60-69 (As below plus):

• A very good, well presented piece of work covering much of the subject

matter and which is clearly and lucidly written. Good attempt to consider

and evaluate the material presented

• Evidence of research in the topic area and satisfactory use of sources and

references

• Good organisation, structure, use and flow of language, grammar,

spelling, format,

diagrams, tables etc

50-59 (As below plus):

• Work that demonstrates understanding of the topic area with some

attempt to discuss material

• Evidence of research in the topic area extending beyond key texts

• Satisfactory presentation and/or use of references/bibliography according

to convention

• A satisfactory attempt to follow directions regarding organisation,

structure, use

and flow of language, grammar, spelling, format,

diagrams, tables etc

40-49

• Adequate work that attempts to address the topic and demonstrates some

understanding of the basic aspects of the subject matter

• Topic is researched using mainly books and internet. Attempts to use

and/or present references/bibliography according to convention

• A basic attempt to follow directions regarding organisation, structure, use

and flow of language, grammar, spelling, format,
diagrams, tables etc

Fail 30-39

FAIL Work in this range attempts to address the question/problem but is

substantially incomplete and deficient. Serious problems

with a number of aspects of language use are often found in work in this

range and the work may be severely under/over-length and/or fails to grasp

the nature of the topic matter. Content, analysis, expression, structure and

use of sources will be very weak or missing

Fail 0-29

FAIL No serious attempt to address the question or problem, and/or

manifests a serious misunderstanding of the requirements of the

assignment. Acutely deficient in all aspects