Design And Analysis Of Robot Manufacturing System For Automotive Industry.
Robots utilization in automotive industry has been greatly expanded because of its
importance in automotive factories. Factories are well suited for robotic automation
because many tasks in the manufacturing tend to be repetitive, dangerous and heavy.
Among the most widely used robotic assisted operation in the automotive industry is
welding process. This is due to the nature of welding operation itself where the job is
normally done under repetitive and continuous condition. Besides, utilization of
robot would also increase welding accuracy consistently. There are two main goals
of this project. The first goal is to analyze articulated robots that would execute spot
welding process on the car body. Second goal is to propose the design of a suitable
robotic manufacturing system (RMS) to execute spot welding operation for
automotive
industry.
Kinematics
analysis,
path
planning
analysis,
robot
programming and also simulation of the working robots will be carried out
throughout the studies in order to analyze the entire robot manufacturing system that
will be proposed. By conducting this study, the process of designing and analysis the
robot manufacturing system for automotive industry can be deeply understood. The
outcomes of this study could be used to establish a RMS in automotive industry.
i
Penggunaan robot dalam industri automotif telah banyak berkembang atas
kepentingannya dalam kilang(kilang automotif. Automasi robotik merupakan
penyelesaian yang baik untuk pengeluaran kilang automotif ini kerana kebanyakan
aktiviti industri pembuatan disifatkan sebagai berulang, berbahaya dan berat. Proses
pengimpalan merupakan antara operasi pengeluaran kilang automotif yang banyak
bergantung kepada penggunaan aplikasi robotik. Ini disebabkan proses pengimpalan
memerlukan operasi yang berulangan dan berterusan. Selain itu, penggunaan robotik
juga membantu dalam meningkatkan kualiti hasil kerja pengimpalan. Projek ini
mengandungi dua tujuan. Pertamanya adalah untuk menganalisa
yang akan melaksanakan operasi pengimpalan ke atas struktur utama sesebuah
kereta. Tujuan yang kedua adalah untuk mencadangkan satu sistem pembuatan
robotik yang akan menjalankan proses pengimpalan dalam industri automotif.
Analisa kinematik, analisa perancangan laluan, pengaturcaraan robot dan simulasi ke
atas fungsi(fungsi robot akan dilaksanakan sepanjang kajian projek ini supaya satu
analisa lengkap tentang sistem pengeluaran robotik yang dicadangkan dapat
diungkapkan dengan tepatnya. Sebagai hasil kajian, pemahaman dalam proses
merekabentuk and analisa ke atas system pengeluaran robotic dalam industri
automotif akan dapat ditingkatkan. Hasil kajian ini juga diharapkan dapat
membangunkan satu sistem pengeluaran robotik yang mantap untuk kesesuaian
industri automotif.
ii
To my beloved family and friends.
iii
I would like to express my gratitude to my supervisor, Dr. Zamberi bin Jamaludin for
his support, encouragement, supervision and useful suggestions throughout this
research work. His continuous guidance enabled me to complete my study
successfully. I would also like to thank Mr. Muhammad Hafidz Fazli B. Md Fauadi,
my ex(supervisor for his encouragements and enthusiastic helps in the first part of
the study. I am truly grateful of their knowledge sharing and time spending in order
to help me to complete the project.
Besides, I am ever, indebted to my parents for their love and support throughout my
life. Although they did not contribute much in the information in the thesis, their
moral supports are more than enough for me to overcome all the challenges I met
during the study. I would also like to thank my brother for providing me a good
computer for me to use the software related and to complete my thesis. Without him,
my thesis could not be completed too.
I am truly grateful to some of my beloved friends that help me a lot in completing
this thesis. I appreciate all the help and advice given from them especially Mr. Lau
Ong Yee who had guided me about the direction of my thesis from the beginning and
Mr. Chan Seng Kiong who has overcome some of my doubts on several matters.
Their opinions and knowledge sharing helps me a lot when doing research on this
study. Not to forget, I appreciate the time shared and opinions exchanged with all my
lovely housemates especially during the rush hours to complete the thesis. Last but
not least, special thanks to individuals not mentioned that had been directly and
indirectly help me in this project. All your helps and supports are very well
appreciated. Thank you.
iv
Abstract
i
Abstrak
ii
Dedication
iii
Acknowledgement
iv
Table of Content
v
List of Tables
ix
List of Figures
x
List of Abbreviations
xii
1.1
Background
1
1.2
Problem Statements
3
1.3
Objectives
4
1.4
Scope of Study
4
1.5
Summary
4
2.1
Introduction
5
2.2
History of Robot
6
2.2.1 What is Robot?
6
2.2.2 Robot Timeline
6
2.3
8
Classification of Robots
2.3.1 Cartesian Robot
8
2.3.2 Cylindrical Robot
9
2.3.3 Spherical Robot
10
v
2.3.4 Articulated Robot
10
2.4
12
Basic Components of a Robot System
2.4.1 Manipulator
12
2.4.2 End – effector
12
2.4.3 Actuators
13
2.4.4 Sensory Devices
13
2.4.5 Controller
14
2.5
14
Robot Motion
2.5.1 Point to Point Control (PTP)
14
2.5.2 Continuous Path Control
16
2.6
17
Robot Applications
2.6.1 Welding
17
2.6.2 Spray Painting
18
2.6.3 Palletizing and Material Handling
19
2.6.4 Assembly Operations
20
2.7
Kinematics Analysis
21
2.7.1 Forward Kinematics
22
2.7.1.1 Rotation Transformations
22
2.7.1.2 Homogeneous Transformations
24
2.7.1.3 Denavit – Hartenberg Algorithm
26
2.7.2 Trajectory Planning
28
2.7.2.1 Trajectory Planning with Polynomials
29
2.7.2.2 Polynomials Trajectories with Via Points
29
2.8
Spot Welding
30
2.8.1 Spot Welding Robot
31
2.8.2 Robotic Welding System
32
2.9
33
Offline Programming and Simulation
2.9.1 Robotic Workspace Simulation Models
34
2.9.1.1 Create Part Models
35
2.9.1.2 Building Device Models
35
vi
2.9.1.3 Positioning Device Models in Layout
35
2.9.1.4 Defining Devices Motion Destination in Layout
36
2.9.1.5 Device Behavior and Programming
36
2.9.1.6 Executing Workspace Simulation and Analysis
36
2.9.2 Robot Simulation
37
2.10
Summary
37
3.1
Introduction
38
3.2
Planning of Study
38
3.3
Project Methodology
41
3.3.1 Problem Statements and Objectives
42
3.3.2 Research and Analysis of Study
42
3.3.3 Robot/Tool Selection
43
3.3.4 Kinematics Analysis
43
3.3.5 Workspace Design
44
3.3.6 Programming
44
3.3.7 Simulation
45
3.3.8 Discussions and Conclusion
45
3.4
Summary
45
4.1
Introduction
46
4.2
Workspace Design
46
4.2.1 Workstation
47
4.2.2 Spot Welding Robot
49
4.2.3 Assistant Handling Robot
50
4.2.4 Components to be Weld
51
4.3
Working Process of Workstation
52
4.4
Summary
55
vii
5.1
Introduction
56
5.2
Simulation Results
56
5.3
Programming of Robots Behaviour
59
5.3.1 Spot Weld Gun Class Module
59
5.3.2 Gripper Class Module
61
5.4
63
Kinematics Analysis
5.4.1 Forward Kinematics of Spot Welding Robot
63
5.4.2 Forward Kinematics of Assisting Robot
67
5.5
Path Planning
71
5.6
Summary
75
6.1
Introduction
76
6.2
Forward Kinematics
76
6.3
Path Planning
77
6.4
Workstation Arrangements
80
6.5
Spot Welding Process
84
6.6
Summary
86
7.1
Conclusions
87
7.2
Future Work and Recommendations
89
!"
viii
2.1
Timelines of Robots
7
2.2
Four Arm Parameters
27
3.1
Gantt Chart of PSM I
39
3.2
Gantt Chart of PSM II
40
5.1
Arm Parameters of Spot Welding Robot
63
5.2
Arm Parameters for Assisting Robot
67
6.1
Welding Parameters
85
ix
1.1
Spot welding of a car body in an assembly line
2
1.2
Spot welding
3
2.1
Cartesian robot
9
2.2
Cylindrical robot
9
2.3
Spherical robot
10
2.4
Articulate robot
11
2.5
The PTP motion
15
2.6
The continuous path motion
16
2.7
Welding application
18
2.8
Robot spot welding car body
18
2.9
Spray painting
19
2.10
Palletizing
20
2.11
Material Handling
20
2.12
Assembly process of a car
21
2.13
Relationship of forward and inverse kinematics
21
2.14(a) Roll
22
2.14(b) Pitch
22
2.14(c) Yaw
23
2.15
A transformation that consists rotation and translation
24
2.16
The four values (θ, d, a, α) identified relating one joint to the next
26
2.17
Polynomial trajectories with via points
30
2.18
Spot welding
30
2.19
Process to determine robotic work space simulation
34
2.20
Robot simulation process
37
x
3.1
Methodology of the complete study
41
4.1
Arrangement of components in the workstation
48
4.2
Spot welding robot (ABB 6400 series)
49
4.3
End(effector of spot welding robot (C spot weld gun)
49
4.4
Assisting robot (ABB 6400 series)
50
4.5
Robot tool for pick and place
50
4.6
Car body
51
4.7
Roof of the car
51
4.8
Roof transferred by assisting robot while spot welding robots
52
ready in position
4.9
Welding route of both spot weld robots
53
4.10
Spot welding process ongoing while assisting robot holding the roof
53
4.11
Process flow of the spot welding process of car roof
54
5.1
Assisting robot grasping the roof
57
5.2
Assisting robot holding roof while spot welding robots move to first
57
welding position
5.3
Spot welding robots welding at the second path
58
5.4
Spot welding completed and parts transferred to next station
58
5.5
Coding for spot weld gun
60
5.6
Coding for gripper
62
5.7
Graph of distance versus time
74
5.8
Graph of speed versus time
74
5.9
Graph of acceleration versus time
74
6.1
Path planning for robots system
79
6.2
Working envelopes for spot welding robots
81
6.3
Working envelope for assisting robot
81
6.4
Working envelope for all three robots
82
6.5
Space for future allocation of new robot
83
xi
CAD (
Computer Aided Design
D(H
(
Denavit – Hartenberg
DoF
(
Degree of Freedom
GP
(
Geometry Points
ISO
(
International Organization for Standardization
PC
(
Personal Computer
PTP
(
Point to Point
RMS (
Robot Manufacturing System
RUR (
Rossum’s Universal Robots
UTeM (
Universiti Teknikal Malaysia Melaka
VBA (
Visual Basic for Applications
xii
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
In this chapter, sources from journals, case studies and articles related are
summarized. All the information obtained will act as a guideline or references for
this study field. Analysis and detail research are done from these information
obtained to compile in this report for better exposure and understandings.
Robots are capable of performing many different tasks and operations precisely and
do not require common safety and comfort elements need. However, it takes much
effort and many resources to take a robot function properly. Hence, various types of
research and studies need to be done from various reading materials and the global
search engine on all the related information required in this study field.
When it comes to robots, reality still lags science fiction. But, just because robots
have not lived up to their promise in past decades does not mean that they will not
arrive sooner or later. Indeed, the confluence of several advanced technologies is
bringing the age of robotics ever nearer; smaller, cheaper, more practical and cost&
effective.
5
2.2 History of Robot
2.2.1 What is Robot?
The Robot Institute of America (1979) defined a robot as a re&programmable, multi&
function manipulator designed to move material, parts or specialized devices through
variable programmed motions for performance of a variety of tasks. However, there
are many other definitions for robots where the encyclopedia defines a robot as a
stand – alone hybrid computer system that performs physical and computational
activities. In addition, robots are capable of performing many different tasks as it is a
multiple&motion device with one or more arms and joints.
Another definition given by the International Organization for Standardization (ISO)
in ISO 8373 states that robot is an automatically controlled, reprogrammable,
multipurpose, manipulator programmable in three or more axes, which may be either
fixed in place or mobile for use in industrial automation applications.
The acclaimed Czech playwright Karel Capek (1890&1938) made the first use of the
word ‘robot’. The word robot is originated from the Czech word
which means
slave laborer. The use of the word robot was introduced into his play R.U.R
(Rossum's Universal Robots) which opened in Prague in January 1921.
There are no an exact definition of robot which can satisfy everyone and many
people have their own definitions. However, it can be generally concluded that from
the above mentioned definitions, the programmable and re&programmable multi&
functions are the most important features of a robot system.
2.2.2 Robot Timeline
Table 2.1 shows that robot has been evolved greatly since it has been from the first
development from the respective inventor.
6
Table 2.1 : Timelines of Robots (http://en.wikipedia.org, 2008)
Year
Significance
Robot Name
Inventor
1206 First programmable humanoid robots
Boat with four
robotic
musicians
Al&Jazari
1495 Designs for a humanoid robot
Mechanical
knight
Leonardo da Vinci
Digesting Duck
Jacques de
Vaucanson
1738
Mechanical duck that was able to eat, flap its
wings, and excrete
1800s
Japanese mechanical toys that served tea, fired
arrows, and painted
1921
First fictional automatons called "robots"
appear in the play
1930s
Humanoid robot exhibited at the 1939 and 1940
Elektro
World's Fairs
1948 Simple robots exhibiting biological behaviors
toys
Rossum's
Universal
Robots
Elsie and Elmer
Hisashige Tanaka
Karel Čapek
Westinghouse
Electric
Corporation
William Grey
Walter
First commercial robot, from the Unimation
1956 company founded by George Devol and Joseph Unimate
Engelberger, based on Devol's patents
George Devol
1961 First installed industrial robot
Unimate
George Devol
1963 First palletizing robot
Palletizer
Fuji Yusoki Kogyo
1973
First robot with six electromechanically driven
Famulus
axes
KUKA Robot
Group
1975
Programmable universal manipulation arm, a
Unimation product
Victor Scheinman
PUMA
At year 1989, the first biped walking robot which was able to walk on a terrain
stabilized by trunk motion was developed by Kato which is named, WL12RIII
(Jaeger, 2004). It could walk at a rate of 2.6 seconds, up and down stairs. Then robots
revolved to another form where Honda creates P2, the first major step in creating
their ASIMO in year 1996. P2 is the first self®ulating, bipedal humanoid robot
created.
7
At year 2002, Honda creates the Advanced Step in Innovative Mobility (ASIMO). It
is intended to be a personal assistant. It recognizes its owner's face, voice, and name.
ASIMO can read email and is capable of streaming video from its camera to a PC.
While at year 2005, The Korean Institute of Science and Technology (KIST), creates
HUBO, and claims it is the smartest robot in the world. This robot is linked to a
computer via a high&speed wireless connection; the computer does all of the thinking
for the robot (Jaeger, 2004).
2.3 Classification of Robots
Industrial robots are categorized by the first three joint types which are the
prismatic/translational (linear) joint and rotational joints. These two types of joint is
the most current used in industrial robots. There are four different types of robot
configurations which are :
a) Cartesian
b) Cylindrical
c) Spherical
d) Articulated
2.3.1 Cartesian Robot
This type of robot has the first three joints corresponding to the major axes which are
all prismatic (PPP) as shown in Figure 2.1. This type of robot is commonly used for
positioning tools such as dispensers, cutters, drivers and routers (Parker, 2008). The
primary applications of this robot are in material handling, machine loading and
printer board construction. The advantages of Cartesian robot are that the
configuration and design are simple, motion control in Cartesian space can be easily
carried out and large work envelop. The robot will be easier to visualize and have
better inherent accuracy than most other types besides easier to be program offline.
On the other hand, the limitations of this type of robot are that it is not space efficient
and the external frame can be massive.
8
importance in automotive factories. Factories are well suited for robotic automation
because many tasks in the manufacturing tend to be repetitive, dangerous and heavy.
Among the most widely used robotic assisted operation in the automotive industry is
welding process. This is due to the nature of welding operation itself where the job is
normally done under repetitive and continuous condition. Besides, utilization of
robot would also increase welding accuracy consistently. There are two main goals
of this project. The first goal is to analyze articulated robots that would execute spot
welding process on the car body. Second goal is to propose the design of a suitable
robotic manufacturing system (RMS) to execute spot welding operation for
automotive
industry.
Kinematics
analysis,
path
planning
analysis,
robot
programming and also simulation of the working robots will be carried out
throughout the studies in order to analyze the entire robot manufacturing system that
will be proposed. By conducting this study, the process of designing and analysis the
robot manufacturing system for automotive industry can be deeply understood. The
outcomes of this study could be used to establish a RMS in automotive industry.
i
Penggunaan robot dalam industri automotif telah banyak berkembang atas
kepentingannya dalam kilang(kilang automotif. Automasi robotik merupakan
penyelesaian yang baik untuk pengeluaran kilang automotif ini kerana kebanyakan
aktiviti industri pembuatan disifatkan sebagai berulang, berbahaya dan berat. Proses
pengimpalan merupakan antara operasi pengeluaran kilang automotif yang banyak
bergantung kepada penggunaan aplikasi robotik. Ini disebabkan proses pengimpalan
memerlukan operasi yang berulangan dan berterusan. Selain itu, penggunaan robotik
juga membantu dalam meningkatkan kualiti hasil kerja pengimpalan. Projek ini
mengandungi dua tujuan. Pertamanya adalah untuk menganalisa
yang akan melaksanakan operasi pengimpalan ke atas struktur utama sesebuah
kereta. Tujuan yang kedua adalah untuk mencadangkan satu sistem pembuatan
robotik yang akan menjalankan proses pengimpalan dalam industri automotif.
Analisa kinematik, analisa perancangan laluan, pengaturcaraan robot dan simulasi ke
atas fungsi(fungsi robot akan dilaksanakan sepanjang kajian projek ini supaya satu
analisa lengkap tentang sistem pengeluaran robotik yang dicadangkan dapat
diungkapkan dengan tepatnya. Sebagai hasil kajian, pemahaman dalam proses
merekabentuk and analisa ke atas system pengeluaran robotic dalam industri
automotif akan dapat ditingkatkan. Hasil kajian ini juga diharapkan dapat
membangunkan satu sistem pengeluaran robotik yang mantap untuk kesesuaian
industri automotif.
ii
To my beloved family and friends.
iii
I would like to express my gratitude to my supervisor, Dr. Zamberi bin Jamaludin for
his support, encouragement, supervision and useful suggestions throughout this
research work. His continuous guidance enabled me to complete my study
successfully. I would also like to thank Mr. Muhammad Hafidz Fazli B. Md Fauadi,
my ex(supervisor for his encouragements and enthusiastic helps in the first part of
the study. I am truly grateful of their knowledge sharing and time spending in order
to help me to complete the project.
Besides, I am ever, indebted to my parents for their love and support throughout my
life. Although they did not contribute much in the information in the thesis, their
moral supports are more than enough for me to overcome all the challenges I met
during the study. I would also like to thank my brother for providing me a good
computer for me to use the software related and to complete my thesis. Without him,
my thesis could not be completed too.
I am truly grateful to some of my beloved friends that help me a lot in completing
this thesis. I appreciate all the help and advice given from them especially Mr. Lau
Ong Yee who had guided me about the direction of my thesis from the beginning and
Mr. Chan Seng Kiong who has overcome some of my doubts on several matters.
Their opinions and knowledge sharing helps me a lot when doing research on this
study. Not to forget, I appreciate the time shared and opinions exchanged with all my
lovely housemates especially during the rush hours to complete the thesis. Last but
not least, special thanks to individuals not mentioned that had been directly and
indirectly help me in this project. All your helps and supports are very well
appreciated. Thank you.
iv
Abstract
i
Abstrak
ii
Dedication
iii
Acknowledgement
iv
Table of Content
v
List of Tables
ix
List of Figures
x
List of Abbreviations
xii
1.1
Background
1
1.2
Problem Statements
3
1.3
Objectives
4
1.4
Scope of Study
4
1.5
Summary
4
2.1
Introduction
5
2.2
History of Robot
6
2.2.1 What is Robot?
6
2.2.2 Robot Timeline
6
2.3
8
Classification of Robots
2.3.1 Cartesian Robot
8
2.3.2 Cylindrical Robot
9
2.3.3 Spherical Robot
10
v
2.3.4 Articulated Robot
10
2.4
12
Basic Components of a Robot System
2.4.1 Manipulator
12
2.4.2 End – effector
12
2.4.3 Actuators
13
2.4.4 Sensory Devices
13
2.4.5 Controller
14
2.5
14
Robot Motion
2.5.1 Point to Point Control (PTP)
14
2.5.2 Continuous Path Control
16
2.6
17
Robot Applications
2.6.1 Welding
17
2.6.2 Spray Painting
18
2.6.3 Palletizing and Material Handling
19
2.6.4 Assembly Operations
20
2.7
Kinematics Analysis
21
2.7.1 Forward Kinematics
22
2.7.1.1 Rotation Transformations
22
2.7.1.2 Homogeneous Transformations
24
2.7.1.3 Denavit – Hartenberg Algorithm
26
2.7.2 Trajectory Planning
28
2.7.2.1 Trajectory Planning with Polynomials
29
2.7.2.2 Polynomials Trajectories with Via Points
29
2.8
Spot Welding
30
2.8.1 Spot Welding Robot
31
2.8.2 Robotic Welding System
32
2.9
33
Offline Programming and Simulation
2.9.1 Robotic Workspace Simulation Models
34
2.9.1.1 Create Part Models
35
2.9.1.2 Building Device Models
35
vi
2.9.1.3 Positioning Device Models in Layout
35
2.9.1.4 Defining Devices Motion Destination in Layout
36
2.9.1.5 Device Behavior and Programming
36
2.9.1.6 Executing Workspace Simulation and Analysis
36
2.9.2 Robot Simulation
37
2.10
Summary
37
3.1
Introduction
38
3.2
Planning of Study
38
3.3
Project Methodology
41
3.3.1 Problem Statements and Objectives
42
3.3.2 Research and Analysis of Study
42
3.3.3 Robot/Tool Selection
43
3.3.4 Kinematics Analysis
43
3.3.5 Workspace Design
44
3.3.6 Programming
44
3.3.7 Simulation
45
3.3.8 Discussions and Conclusion
45
3.4
Summary
45
4.1
Introduction
46
4.2
Workspace Design
46
4.2.1 Workstation
47
4.2.2 Spot Welding Robot
49
4.2.3 Assistant Handling Robot
50
4.2.4 Components to be Weld
51
4.3
Working Process of Workstation
52
4.4
Summary
55
vii
5.1
Introduction
56
5.2
Simulation Results
56
5.3
Programming of Robots Behaviour
59
5.3.1 Spot Weld Gun Class Module
59
5.3.2 Gripper Class Module
61
5.4
63
Kinematics Analysis
5.4.1 Forward Kinematics of Spot Welding Robot
63
5.4.2 Forward Kinematics of Assisting Robot
67
5.5
Path Planning
71
5.6
Summary
75
6.1
Introduction
76
6.2
Forward Kinematics
76
6.3
Path Planning
77
6.4
Workstation Arrangements
80
6.5
Spot Welding Process
84
6.6
Summary
86
7.1
Conclusions
87
7.2
Future Work and Recommendations
89
!"
viii
2.1
Timelines of Robots
7
2.2
Four Arm Parameters
27
3.1
Gantt Chart of PSM I
39
3.2
Gantt Chart of PSM II
40
5.1
Arm Parameters of Spot Welding Robot
63
5.2
Arm Parameters for Assisting Robot
67
6.1
Welding Parameters
85
ix
1.1
Spot welding of a car body in an assembly line
2
1.2
Spot welding
3
2.1
Cartesian robot
9
2.2
Cylindrical robot
9
2.3
Spherical robot
10
2.4
Articulate robot
11
2.5
The PTP motion
15
2.6
The continuous path motion
16
2.7
Welding application
18
2.8
Robot spot welding car body
18
2.9
Spray painting
19
2.10
Palletizing
20
2.11
Material Handling
20
2.12
Assembly process of a car
21
2.13
Relationship of forward and inverse kinematics
21
2.14(a) Roll
22
2.14(b) Pitch
22
2.14(c) Yaw
23
2.15
A transformation that consists rotation and translation
24
2.16
The four values (θ, d, a, α) identified relating one joint to the next
26
2.17
Polynomial trajectories with via points
30
2.18
Spot welding
30
2.19
Process to determine robotic work space simulation
34
2.20
Robot simulation process
37
x
3.1
Methodology of the complete study
41
4.1
Arrangement of components in the workstation
48
4.2
Spot welding robot (ABB 6400 series)
49
4.3
End(effector of spot welding robot (C spot weld gun)
49
4.4
Assisting robot (ABB 6400 series)
50
4.5
Robot tool for pick and place
50
4.6
Car body
51
4.7
Roof of the car
51
4.8
Roof transferred by assisting robot while spot welding robots
52
ready in position
4.9
Welding route of both spot weld robots
53
4.10
Spot welding process ongoing while assisting robot holding the roof
53
4.11
Process flow of the spot welding process of car roof
54
5.1
Assisting robot grasping the roof
57
5.2
Assisting robot holding roof while spot welding robots move to first
57
welding position
5.3
Spot welding robots welding at the second path
58
5.4
Spot welding completed and parts transferred to next station
58
5.5
Coding for spot weld gun
60
5.6
Coding for gripper
62
5.7
Graph of distance versus time
74
5.8
Graph of speed versus time
74
5.9
Graph of acceleration versus time
74
6.1
Path planning for robots system
79
6.2
Working envelopes for spot welding robots
81
6.3
Working envelope for assisting robot
81
6.4
Working envelope for all three robots
82
6.5
Space for future allocation of new robot
83
xi
CAD (
Computer Aided Design
D(H
(
Denavit – Hartenberg
DoF
(
Degree of Freedom
GP
(
Geometry Points
ISO
(
International Organization for Standardization
PC
(
Personal Computer
PTP
(
Point to Point
RMS (
Robot Manufacturing System
RUR (
Rossum’s Universal Robots
UTeM (
Universiti Teknikal Malaysia Melaka
VBA (
Visual Basic for Applications
xii
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
In this chapter, sources from journals, case studies and articles related are
summarized. All the information obtained will act as a guideline or references for
this study field. Analysis and detail research are done from these information
obtained to compile in this report for better exposure and understandings.
Robots are capable of performing many different tasks and operations precisely and
do not require common safety and comfort elements need. However, it takes much
effort and many resources to take a robot function properly. Hence, various types of
research and studies need to be done from various reading materials and the global
search engine on all the related information required in this study field.
When it comes to robots, reality still lags science fiction. But, just because robots
have not lived up to their promise in past decades does not mean that they will not
arrive sooner or later. Indeed, the confluence of several advanced technologies is
bringing the age of robotics ever nearer; smaller, cheaper, more practical and cost&
effective.
5
2.2 History of Robot
2.2.1 What is Robot?
The Robot Institute of America (1979) defined a robot as a re&programmable, multi&
function manipulator designed to move material, parts or specialized devices through
variable programmed motions for performance of a variety of tasks. However, there
are many other definitions for robots where the encyclopedia defines a robot as a
stand – alone hybrid computer system that performs physical and computational
activities. In addition, robots are capable of performing many different tasks as it is a
multiple&motion device with one or more arms and joints.
Another definition given by the International Organization for Standardization (ISO)
in ISO 8373 states that robot is an automatically controlled, reprogrammable,
multipurpose, manipulator programmable in three or more axes, which may be either
fixed in place or mobile for use in industrial automation applications.
The acclaimed Czech playwright Karel Capek (1890&1938) made the first use of the
word ‘robot’. The word robot is originated from the Czech word
which means
slave laborer. The use of the word robot was introduced into his play R.U.R
(Rossum's Universal Robots) which opened in Prague in January 1921.
There are no an exact definition of robot which can satisfy everyone and many
people have their own definitions. However, it can be generally concluded that from
the above mentioned definitions, the programmable and re&programmable multi&
functions are the most important features of a robot system.
2.2.2 Robot Timeline
Table 2.1 shows that robot has been evolved greatly since it has been from the first
development from the respective inventor.
6
Table 2.1 : Timelines of Robots (http://en.wikipedia.org, 2008)
Year
Significance
Robot Name
Inventor
1206 First programmable humanoid robots
Boat with four
robotic
musicians
Al&Jazari
1495 Designs for a humanoid robot
Mechanical
knight
Leonardo da Vinci
Digesting Duck
Jacques de
Vaucanson
1738
Mechanical duck that was able to eat, flap its
wings, and excrete
1800s
Japanese mechanical toys that served tea, fired
arrows, and painted
1921
First fictional automatons called "robots"
appear in the play
1930s
Humanoid robot exhibited at the 1939 and 1940
Elektro
World's Fairs
1948 Simple robots exhibiting biological behaviors
toys
Rossum's
Universal
Robots
Elsie and Elmer
Hisashige Tanaka
Karel Čapek
Westinghouse
Electric
Corporation
William Grey
Walter
First commercial robot, from the Unimation
1956 company founded by George Devol and Joseph Unimate
Engelberger, based on Devol's patents
George Devol
1961 First installed industrial robot
Unimate
George Devol
1963 First palletizing robot
Palletizer
Fuji Yusoki Kogyo
1973
First robot with six electromechanically driven
Famulus
axes
KUKA Robot
Group
1975
Programmable universal manipulation arm, a
Unimation product
Victor Scheinman
PUMA
At year 1989, the first biped walking robot which was able to walk on a terrain
stabilized by trunk motion was developed by Kato which is named, WL12RIII
(Jaeger, 2004). It could walk at a rate of 2.6 seconds, up and down stairs. Then robots
revolved to another form where Honda creates P2, the first major step in creating
their ASIMO in year 1996. P2 is the first self®ulating, bipedal humanoid robot
created.
7
At year 2002, Honda creates the Advanced Step in Innovative Mobility (ASIMO). It
is intended to be a personal assistant. It recognizes its owner's face, voice, and name.
ASIMO can read email and is capable of streaming video from its camera to a PC.
While at year 2005, The Korean Institute of Science and Technology (KIST), creates
HUBO, and claims it is the smartest robot in the world. This robot is linked to a
computer via a high&speed wireless connection; the computer does all of the thinking
for the robot (Jaeger, 2004).
2.3 Classification of Robots
Industrial robots are categorized by the first three joint types which are the
prismatic/translational (linear) joint and rotational joints. These two types of joint is
the most current used in industrial robots. There are four different types of robot
configurations which are :
a) Cartesian
b) Cylindrical
c) Spherical
d) Articulated
2.3.1 Cartesian Robot
This type of robot has the first three joints corresponding to the major axes which are
all prismatic (PPP) as shown in Figure 2.1. This type of robot is commonly used for
positioning tools such as dispensers, cutters, drivers and routers (Parker, 2008). The
primary applications of this robot are in material handling, machine loading and
printer board construction. The advantages of Cartesian robot are that the
configuration and design are simple, motion control in Cartesian space can be easily
carried out and large work envelop. The robot will be easier to visualize and have
better inherent accuracy than most other types besides easier to be program offline.
On the other hand, the limitations of this type of robot are that it is not space efficient
and the external frame can be massive.
8