universiti putra malaysiaumum dalam industri untuk mengkaji sifat-sifat bahan ferromagnetik. teknik...
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UNIVERSITI PUTRA MALAYSIA
DEVELOPMENT OF MOBILE MAGNETIC IMAGING SYSTEM BASED ON 1-D HALL SENSOR ARRAY
NG WEI SHIN
FK 2012 108
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DEVELOPMENT OF MOBILE MAGNETIC
IMAGING SYSTEM BASED ON 1-D HALL SENSOR
ARRAY
NG WEI SHIN
MASTER OF SCIENCE
UNIVERSITI PUTRA MALAYSIA
2012
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DEVELOPMENT OF MOBILE MAGNETIC IMAGING SYSTEM
BASED ON 1-D HALL SENSOR ARRAY
By
NG WEI SHIN
Thesis Submitted to the School of Graduate Studies,
Universiti Putra Malaysia, in Fulfillment of the Requirement for the Degree of
Master of Science
February 2012
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Abstract of thesis presented to the Senate of University Putra Malaysia in fulfillment of
the requirement for the degree of Master of Science
DEVELOPMENT OF MOBILE MAGNETIC IMAGING SYSTEM
BASED ON 1-D HALL SENSOR ARRAY
By
NG WEI SHIN
February 2012
Chairman: Associate Professor Norhisam Misron, PhD
Faculty: Engineering
Non-destructive evaluation (NDE) is one of the most common methodologies in the
industries proposed to examine the properties of ferromagnetic materials. The NDE
technique includes some kind of microscopy to examine the external surfaces of
specimens in detail which rely upon magnetic, ultrasonic and radiographic methods.
Therefore, NDE technique can be used to perform shapes evaluation of ferrous objects
without permanently altering its characteristic. The NDE technique used in this thesis for
shapes evaluation is based on the magnetization characteristic of ferrous objects.
This thesis describes the development of prototype Mobile Magnetic Imaging System
applying the NDE technique for the shapes evaluation of ferrous objects. The Mobile
Magnetic Imaging System is able to evaluate the shapes of ferrous objects underneath a
non-ferromagnetic surface with the application of magnetic imaging technique proposed
in this research. The magnetic imagings for the shapes of ferrous objects are
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accomplished by performing the 2-D contour plot with 2-D array matrix of induced
voltage signal, VH and magnetic field, B.
The operation of Mobile Magnetic Imaging System is based on the magnetic flux
leakage testing (MFLT) principle performed on the surface of ferrous objects. As the
system navigates across a ferrous object, the permanent magnets on the system
magnetize the ferrous object. The magnetized ferrous object forms the magnetic circuit
with permanent magnets, thus, develops the closed loop flow of magnetic flux, m. The
1-D Hall sensor array on the system is exposed to the magnetic field, B caused by the
flow of magnetic flux, m from permanent magnets to the ferrous object. The 1-D Hall
sensor array consists of linearly integrated solid state Hall effects sensors to detect the
magnetic field, B and translate to Hall induced voltage signals, VH. The Hall induced
voltage signals, VH from 1-D Hall sensor array are constructed into a 2-D array matrix
which is employed for magnetic imaging.
Lastly, the prototype of the Mobile Magnetic Imaging System is presented. In addition,
the performance parameters of Mobile Magnetic Imaging System are identified which
include the size of the specimen under evaluation, moving speed of system and thickness
of non-ferromagnetic surface above ferrous objects. Therefore, experimental results to
study the performance of Mobile Magnetic Imaging System are presented in this thesis.
Firstly, it presents the ability of the system in visualizing the shapes of ferrous object
specimens with magnetic images. In addition, the improvements towards magnetic
imaging technique of ferrous objects are proposed by considering the absolute value of
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induced voltage signals, |VH| and magnetic field, |B|. Secondly, the result presents the
ability of the system to visualize the shapes of actual ferrous objects employing
improved magnetic imaging technique. Lastly, the effect of perpendicular gap towards
accuracy of Mobile Magnetic Imaging System in shapes evaluation is studied. Based on
the experimental results, the optimized perpendicular gap for shapes evaluation is at
10mm.
In summary, the Mobile Magnetic Imaging System is proven to be able to visualize the
shapes of ferrous objects embedded underneath a non-ferromagnetic surface.
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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai
memenuhi keperluan untuk Ijazah Master Sains
PEMBANGUNAN SISTEM PENGIMEJAN MAGNETIK MUDAH ALIH
BERDASARKAN SUSUNAN PENGESAN HALL 1-D
Oleh
NG WEI SHIN
Februari 2012
Pengerusi: Profesor Madya Norhisam Misron, PhD
Fakulti: Kejuruteraan
Kajian Tanpa Kemusnahan (NDE) merupakan salah satu cara yang paling dikenali
umum dalam industri untuk mengkaji sifat-sifat bahan ferromagnetik. Teknik NDE
termasuk beberapa jenis mikroskopi untuk memeriksa permukaan luar spesimen secara
terperinci yang bergantung kepada magnetik, ultrasonik dan radiografi. Maka, teknik
NDE boleh digunakan untuk melaksanakan penilaian keatas bentuk-bentuk objek ferus
tanpa mengubah ciri-cirinya secara kekal. Teknik NDE yang digunakan dalam tesis ini
untuk penilaian bentuk-bentuk adalah berdasarkan ciri magnetik objek-objek ferus.
Tesis ini menghuraikan pembangunan prototaip Sistem Pengimejan Magnetik Mudah
Alih dengan teknik NDE untuk mengkaji bentuk objek ferus. Sistem Pengimejan
Magnetik Mudah Alih ini mampu untuk mengesan bentuk objek ferus di bawah
permukaan melalui teknik pengimejan magnetik yang dicadangkan dalam penyelidikan.
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Pengimejan magnetik untuk bentuk objek ferus dicapai melalui perlaksanaan plot kontur
2-D dengan susunan matrik 2-D isyarat voltan dorongan, VH dan medan magnetik, B.
Operasi Sistem Pengimejan Magnetik Mudah Alih adalah berdasarkan prinsip Ujian
Kebocoran Fluk Magnetik (MLFT) yang dilaksanakan pada permukaan bentuk objek
ferus. Apabila sistem melalui objek ferus, magnet kekal pada sistem akan memagnetkan
objek ferus. Objek ferus yang dimagnetkan akan membentuk litar magnetik dengan
magnet kekal, maka, gelung tertutup dibentuk untuk pengaliran fluk magnet, m.
Susunan pengesan Hall 1-D pada sistem didedahkan kepada medan magnet, B yang
dihasilkan daripada pengaliran fluk magnet, m dari magnet kekal ke bahan
ferromagnetik. Susunan pengesan Hall 1-D yang terdiri daripada pengesan Hall keadaan
pepejal linear digunakan untuk mengesan medan magnet, B dan menterjemahkannya
kepada isyarat voltan dorongan Hall, VH. Isyarat voltan dorongan Hall, VH dari susunan
pengesan Hall 1-D membina susunan matrik 2-D yang digunakan untuk pengimejan
magnetik.
Akhirnya, prototaip Sistem Pengimejan Magnetik Mudah Alih telah ditunjukkan. Di
samping itu, parameter-parameter untuk mengkaji prestasi Sistem Pengimejan Magnetik
Mudah Alih yang telah dikenal pasti termasuk saiz spesimen untuk penilaian, kelajuan
sistem dan ketebalan permukaan bukan ferromagnetik di atas objek-objek ferus. Maka,
hasil-hasil eksperimen untuk mengkaji pretasi Sistem Pengimejan Magnetik Mudah Alih
telah dibentangkan dalam tesis ini. Dalam bahagian pertama, ia membentangkan
keupayaan sistem dalam memaparkan bentuk-bentuk objek ferus dengan imej magnetik.
Tambahan pula, peningkatan keatas pengimejan magnetik untuk bentuk-bentuk objek
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ferus telah dicadangkan dengan mengambil nilai mutlak isyarat voltan dorongan, |VH|
dan medan magnetik, |B|. Dalam bahagin kedua, hasil eksperimen membentangkan
keupayaan sistem untuk memaparkan bentuk-bentuk objek ferus melalui peningkatan
keatas teknik pengimejan magnetik. Dalam bahagian ketiga, kesan jurang serenjang ke
atas ketepatan Sistem Pengimejan Magnetik Mudah Alih dalam penilaian bentuk telah
dikaji. Berdasarkan keputusan eksperimen, jurang serenjang yang dioptimumkan untuk
penilaian bentuk adalah pada 10mm.
Dalam ringkasan, Sistem Pengimejan Magnetik Mudah Alih ini terbukti mampu untuk
memaparkan bentuk-bentuk objek ferus terbenam di bawah permukaan bukan
ferromagnetik.
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ACKNOWLEDGEMENT
First of all, I would also like to express my deepest appreciation and gratitude to my
supervisor, Assoc. Prof. Dr. Noshisam Misron, who has constantly contributed countless
hours and interest in providing ideas and suggestion to my research. His valuable ideas
enable me to complete my post-graduate studies within 2 years.
A part from that, my appreciation also extends to the members of supervisory committee
including Assoc. Prof. Dr. Mohd. Hamiruce Marhaban and Dr. Suhaidi Shafie. Their
valuable comments and suggestions throughout the duration of my research are very
useful. Besides, they are also very resourceful for seeking advice whenever I
encountered roadblocks during my research.
Besides, my great appreciation also goes to fellow post-graduate students Raja Nor
Firdaus and Shuhairi for their endless help and assistant in getting components and parts
throughout the duration of my post-graduate studies. Without their help, it would be
difficult for me to complete my post-graduate studies within these two years.
Last but not least, my greatest appreciation goes to my fiancé and both my beloved
parents for their encouragement and support throughout the duration of my post-
graduate studies. Without their encouragement, it wouldn’t be possible for me to
complete my post-graduate studies while still working in Intel Malaysia.
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I certified that a Thesis Examination Committee has met on 27 February 2012 to
conduct the final examination of Ng Wei Shin on his thesis entitled “Development of
Mobile Magnetic Imaging System Based on 1-D Hall Sensor Array” in accordance with
the Universities and University Colleges Act 1971 and the Constitution of the Universiti
Putra Malaysia [P.U.(A) 106] 15 March 1998. The committee recommends that the
student be awarded the Master of Science.
Members of the Thesis Examination Committee were as follow:
Maryam binti Mohd Isa, PhD
Senior Lecturer
Faculty of Engineering
Universiti Putra Malaysia
(Chairman)
Mohd Nizar bin Hamidon, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Internal Examiner)
Roslina binti Sidek, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Internal Examiner)
Nasrudin bin Abdul Rahim, PhD
Professor
Faculty of Engineering
University of Malaya
(External Examiner)
___________________________________
SEOW HENG FONG, PhD
Professor and Deputy Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
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This thesis was submitted to the Senate of Universiti Putra Malaysia and has been
accepted as fulfillment of the requirement for the degree of Master of Science. The
members of the Supervisory Committee were as follow:
Norhisam Misron, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Chairman)
Mohd Hamiruce Marhaban, PhD
Associate Professor
Faculty of Engineering
Universiti Putra Malaysia
(Member)
Suhaidi Shafie, PhD
Senior Lecturer
Faculty of Engineering
Universiti Putra Malaysia
(Member)
___________________________________
BUJANG BIN KIM HUAT, PhD
Professor and Dean
School of Graduate Studies
Universiti Putra Malaysia
Date:
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DECLARATION
I declare that the thesis is my original work except for quotations and citations which
have been duly acknowledged. I also declare that it has not been previously, and is not
concurrently, submitted for any other degree at Universiti Putra Malaysia or at any other
institutions.
_____________________________
NG WEI SHIN Date: 27 February 2012
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TABLE OF CONTENTS
Page
ABTRACT
ABSTRAK
ACKNOWLEDGEMENT
APPROVAL
DECLARATION
LIST OF FIGURES
LIST OF TABLES
LIST OF ABBREVIATION
ii
v
viii
ix
xi
xiv
xviii
xix
CHAPTER
I INTRODUCTION
1.1 Problem Statement
1.2 Objectives of Research
1.3 Scope of Research
1.4 Thesis Outline
1
3
4
5
6
II
LITERATURE REVIEW
2.1 Overview of Magnetic Circuit
2.1.1 Magnetic Field
2.1.2 Magnetic Flux
2.2 Overview of Hall Sensor
2.2.1 Hall Effect Phenomenon in Semiconductor
2.2.2 Basics of Hall Effect Sensor
2.3 Advantages of Hall Effect Sensor
2.4 Overview of Embedded Device Design
2.4.1 Microcontroller
2.4.2 Analog Multiplexer
2.4.3 Universal Serial Bus Communication
Protocol
2.5 Related Research on Non-destructive Evaluation
2.6 Related Research on Signals Array Processing
Hardware
2.7 Summary
8
8
10
12
15
16
17
20
22
23
25
27
30
36
38
III
METHODOLOGY
3.1 Principle of Operation for Mobile Magnetic Imaging
System
3.1.1 Detection of Magnetic Field Perturbation
3.1.2 Construction of 2-Dimensional Hall Sensor
Signals Array Matrix
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39
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3.1.3 Visualization of the Shapes of Ferrous
Objects with Magnetic Images
3.2 Overview of Research Methodology
3.3 Development of Hall Sensor Array System
3.3.1 Design of Signals Sensing Unit
3.3.2 Design of Signals Acquisition Unit
3.3.3 Design of Signals Processing Unit
3.4 Limitation of Mobile Magnetic Imaging System
3.5 Experimental Setup
3.6 Summary
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47
50
52
55
62
70
71
73
IV
RESULTS AND DISCUSSIONS
4.1 The Prototype of Mobile Magnetic Imaging System
4.2 Performance Parameters of Mobile Magnetic
Imaging System
4.3 Specimens for Experiments
4.4 Magnetic Imaging of Ferrous Specimens
4.4.1 Magnetic Imaging with Induced Voltage for
Ferrous Specimens
4.4.2 Magnetic Imaging with Induced Magnetic
Field for Ferrous Specimens
4.5 Improvement on Magnetic Imaging Technique of
Ferrous Specimens
4.5.1 Magnetic Imaging with Absolute Induced
Voltage for Ferrous Specimens
4.5.2 Magnetic Imaging with Absolute Induced
Magnetic Field for Ferrous Specimens
4.6 Magnetic Imaging of Actual Ferrous Objects
4.7 Analysis on Effect of Perpendicular Gap Towards
Accuracy of Magnetic Imaging
4.8 Summary
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97
102
V
CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
5.2 Recommendations
104
104
106
REFERENCES
APPENDICES
LIST OF PUBLICATIONS
BIODATA OF STUDENT
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109
119
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