High Speed Link Following Robot.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
HIGH SPEED LINE FOLLOWING ROBOT
This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering
(Robotic & automation) with Honours.
By
PARAMESWARA BIN ABDUL RAHMAN SUBRAMANIAM
FACULTY OF MANUFACTURING ENGINEERING 2009
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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJUK: High Speed Line Following Robot
SESI PENGAJIAN: 2008/ 09 Semest er 2
Saya PARAMESWARA B. ABDUL RAHMAN SUBRAMANIAM
mengaku membenarkan Laporan PSM ini disimpan di Perpust akaan Universit i Teknikal Malaysia Melaka (UTeM) dengan syarat -syarat kegunaan sepert i berikut : 1. Laporan PSM adalah hak milik Universit i Teknikal Malaysia Melaka dan penulis. 2. Perpust akaan Universit i Teknikal Malaysia Melaka dibenarkan membuat salinan
unt uk t uj uan pengaj ian sahaj a dengan izin penulis.
3. Perpust akaan dibenarkan membuat salinan laporan PSM ini sebagai bahan pert ukaran ant ara inst it usi pengaj ian t inggi.
4. **Sila t andakan (√)
SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarj ah keselamat an at au kepent ingan Malaysia yang t ermakt ub di dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang t elah dit ent ukan oleh organisasi/ badan di mana penyelidikan dij alankan)
(TANDATANGAN PENULIS) Alamat Tet ap:
No: 46, Lorong Perdana 6, Taman Selasih 2,
36400 Hut an Melint ang, Perak. Tarikh: 22 Mei 2009
Disahkan oleh: (TANDATANGAN PENYELIA) Cop Rasmi:
Tarikh: 22 Mei 2009
** Jika Laporan PSM ini SULIT at au TERHAD, sila lampirkan surat daripada pihak berkuasa/ organisasi berkenaan dengan menyat akan sekali sebab dan t empoh laporan PSM ini perlu dikelaskan sebagai SULIT at au TERHAD.
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DECLARATION
I hereby, declare this report entitled “High Speed Line Following Robot” is the result of my own research except as cited in references.
Signature :
Author’s Name : Parameswara b. Abdul Rahman Subramaniam
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APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfilment of the requirements for the degree of Bachelor of Manufacturing Engineering (Robotic & Automation) with Honours. The member of the supervisory committee is as follow:
(Signature of Supervisor)
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ABSTRACT
A line following robot is part of the Automated Guided vehicle which is widely used in the industry. However most robot available today is slower than what the user wants. This project wills concentre on build high speed line following robot. The construction of the robot will be divided into three categories which are mechanical, electrical and electronic and finally programming. The robot structure will be construction properly so that it really strong and rigid to withstand the force of operation. For electrical and electronic components only best and affordable components will be use on this robot to achieve best performance. Finally the programming will do so that no matter what kind condition the robot is, it still can function properly and achieve the goal.
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ABSTRAK
Robot mengikut garisan adalah tergolong dalam kategories kenderaan panduan automatik di mana ia digunakan meluas di industri. Namun robot yang terdapat dipasar kini adalah berkelajuan rendah berbanding dengan permintaan industri. Projek ini akan memfokus dalam menghasilkan robot mengikut garisan berkelajuan tinggi. Pembinaan robot ini terbahagi kepada tiga bahagian iaitu struktur mekanikal, eletrik dan elektronik dan akhir sekali pengatucaraan. Struktur robot ini akan dibina dengan kemas dan rapi supaya ia mampu beroperasi dalam keadaan teguh dan mampu menyerap daya ketika beroperasi. Untuk bahagian elektrik dan elektronik, robot ini akan menggunakan komponen yang murah dan terbaik supaya robot dapat beroperasi dengan jayanya. Akhir sekali, pengatucaraan robot ini akan dilakukan dengan baik sehingga robot ini mampu beroperasi walau apa jua keadaan yang dihadapi dan mencapai objectif.
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DEDICATION
To my beloved parents
Abdul Rahman Subramaniam b. Abdullah Asiah bt. Sawal
And my supported siblings
Parimala Devi bt. Abdul Rahman Subramaniam Ashwani bt. Abdul Rahman Subramaniam
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ACKNOWLEDGMENTS
As the opening of the words, I would like to praise to ALLAH swt with His love and merciful I able to complete this project. Besides that, I would like to give my thanks and gratitude to Mr. Mohd Hisham b. Nordin, from Faculty of Manufacturing Engineering, UTeM for all his guidance and help throughout the entire time of this project being carried out. Without this guidance this project might not go as well as it is. The encouragement and motivation that was given to me to carry out my project are greatly appreciated.
I also would like to thank my family for undivided supports from the beginning of my exist in this world until now. I also would like to express my gratitude to Mr. Muhamad Asari b. Abdul Rahim and Mr. Shariman b. Abdullah for their continuous support and ideas. I would also like to express my gratitude to all the lecturers and technician who have guided and taught me over the years in UTeM. They have taught me invaluable knowledge which is prerequisite in completing this project.
Furthermore, I would like to express my heartfelt appreciation to our faculty Robocon 2009 crew who directly or indirectly helped me and gave their help and support toward my project especially, Norhalis, Muhamad Adam, Norris Ezwan, Aaron Aw Teik Hong and Song Chien Shyen.
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TABLE OF CONTENT
Declaration i
Approval ii
Abstract iii
Abstrak iv
Dedication v
Acknowledge vi
Table of Content vii
List of Tables xii
List of Figures xiii
List of Abbreviations xv
1. INTRODUCTION 1
1.1 Background 1
1.2 Problem Statement 2
1.3 Objective 2
1.4 Scope 3
1.5 Benefits of the Project 3
2. LITERATURE REVIEW 4
2.1 Introduction to Robot 4
2.1.1 Autonomous robot 8
2.1.2 Industrial robot 9
2.2 Mechanical Structure 10
2.2.1 Frame 10
2.2.1.1 ABS (Acrylonitrile butadiene styrene) 11
2.2.1.2 Acrylic 12
2.2.1.3 Polycarbonate 13
2.2.1.4 PVC (Polyvinyl Chloride) 14
2.2.1.5 Plywood 15
2.2.1.6 Extruded Aluminium 16
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2.2.2 Locomotion 18
2.2.3 Motor 19
2.2.3.1 AC motor 19
2.2.3.2 DC motor 20
2.2.4 Master Controller 24
2.2.4.1 PLC 24
2.2.4.2 Microcontroller 26
2.2.5 Electric and Electronic Components 27
2.2.5.1 Capacitor 28
2.2.5.2 Diode 29
2.2.5.3 Resistor 30
2.2.5.4 Transistor 32
2.2.5.5 Electronic Relay 33
2.2.6 Sensors 34
2.2.6.1 Proximity Sensor 35
2.2.6.2 Range Sensor 36
2.2.6.3 Tactile Sensor 37
2.2.7 Power Supply 38
2.2.7.1 Direct Current 39
2.2.7.2 Solar 40
2.2.7.3 Battery 41
2.3 Past Research 45
2.3.1 A Bot Board Plus Line Following Robot 45
2.3.2 Desktop Line Following Robot 47
2.3.3 Failurebot 50
3. METHODOLGY 53
3.1 Introduction 53
3.2 Research Tool 53
3.2.1 References Books 53
3.2.2 Journals and Articles 54
3.2.3 Internet 54
3.3 Project Planning 55
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3.3.2 Data Collection 56
3.3.3 Designing 56
3.3.4 Building 57
3.3.5 Analyze Robot Performance 57
3.3.6 Presentation and Report Writing 57
3.4 Selection of Components and Equipments 58
3.4.1 Motor 59
3.4.2 Sensor 59
3.4.3 Master Controller 60
3.4.4 Motor Driver 60
3.4.5 Battery 60
3.4.6 Voltage Regulator 61
3.4.7 Lathe Machine 61
3.4.8 Vertical Milling Machine 61
3.4.9 Drilling Machine 61
3.4.10 Horizontal Band Saw 62
3.4.11 Laser Cut 62
3.4.12 Soldering Station 62
3.4.13 Multimeter 62
3.5 System Block Diagram 63
3.6 Operational Flow Chart 64
3.7 Preliminary Design 65
3.7.1 Arrangement of the Sensor Cells 65
3.7.2 The Distance between the Drive Centre and the Sensor 66
3.8 Project Schedule 67
4. DESIGN AND DEVELOPMENT 69
4.1 Introduction 69
4.2 Mechanical Construction 69
4.2.1 Base 70
4.2.2 Lifting Mechanism 71
4.3 Electrical and Electronic components 74
4.3.1 LED-LDR Sensor Cells 74
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4.3.3 Comparator 76
4.3.4 Comparator Development 76
4.3.5 Main Power Supply 77
4.3.6 Main Power Supply development 78
4.3.7 Electrical Wiring 79
4.3.8 Programming 80
5. RESULT AND DISCUSSION 81
5.1 Result 81
5.2 Discussion 83
6. CONCLUSION 84
6.1 Conclusion 84
6.2 Suggestion 84
REFERENCES 85
APPENDIX A 86
APPENDIX B 87
APPENDIX C 88
APPENDIX D 89
APPENDIX E 90
APPENDIX F 91
APPENDIX G 92
APPENDIX H 93
APPENDIX I 94
APPENDIX J 95
APPENDIX K 96
APPENDIX L 97
APPENDIX M 98
APPENDIX N 99
APPENDIX O 100
APPENDIX P 101
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APPENDIX R 103
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xii
LIST OF TABLE
2.1 The comparison of decimal and binary number 7
3.1 project planning for PSM 1 67
3.2 Project planning for PSM 2 68
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LIST OF FIGURES
2.1 The figure represents a switch that is works according to the 8 binary number
2.2 Robots doing vehicle underbody assembly (KUKA) 9
2.3 Spanners made of the ABS 11
2.4 Sample of flexi glass sheets 12
2.5 Sample of polycarbonate sheets 13
2.6 Sample of PVC pipes 14
2.7 Sample of plywood 15
2.8 Sample of extruded aluminium 16
2.9 Carbon fibre 17
2.10 One of the AC motor 19
2.11 Illustration on how the DC motor working principle 20
2.12 Stepper motor 22
2.14 One of the common PLC available in the market 24
2.15 Sample of PIC used in the market 27
2.16 A few of capacitor 28
2.17 Diode 29
2.18 Resistor and table of resistor value 31
2.19 Sample of transistor 32
2.20 Relay 33
2.21 Proximity sensor 35
2.22 Range sensor 36
2.23 Plate tactile sensor 37
2.24 Illustration on how the AC work on graph 39
2.25 Solar cells 40
2.26 Nickel cadmium battery 41
2.27 Nickel metal hydride that used on the RC cars 42 2.28 Lithium-ion battery that used in cellular phone 43
2.29 Illustration of the lead acid components 44
2.30 Bot board plus line following robot 45
2.31 Bot board plus line following robot 45
2.32 Desktop line following robot 48
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2.34 Flow chart of the robot controller 50
2.35 Front view of the Failurebot 5 51
2.36 Failurebot5 51
3.1 Project planning flow chart 55
3.2 System block diagram of the high speed line following robot 63 3.3 Operational flow chart of the high speed line following robot 64
3.4 Suggested sensor cells arrangement 65
3.5 The distance between the driver centre and the sensor cells 66
4.1 Band saw machine 70
4.2 The robot base 71
4.3 Lifting mechanism 72
4.4 Milling process on the rack gear 73
4.5 LED-LDR sensor cells 75
4.6 Comparator 77
4.7 Main Power Supply 78
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LIST OF ABBREVIATIONS
PIC - Programmable Integrated Controller BJT - Bipolar Junction Transistor
CPU - Centre Processing Unit IC - Integrated Circuit
ISO - International Standard Organization KUKA - Keller Und Knappich Hugsburg ABS - Acrylonitrile Butadiene Styrene
PS - Polystyrene
PVC - Polyvinyl Chloride
IUPAC - International Union of Pure and Applied Chemistry AC - Alternative Current
DC - Direct Current
ESC - Electronic Speed Controller BLDC - Brushless DC Motor
PLC - Programmable Logic Controller
I/O - Input / Output
MCU - Microcontroller
RAM - Random Access Memory
PC - Personal Computer
PSU - Power Supply Unit
NiCd - Nickel Cadmium NiMH - Nickel-Metal Hydrate NiOOH - Nickel Ox Hydroxide
C - Capacitive
Li-ion - Lithium Ion
LED - Light Emitting Diode LDR - Light Dependent Resistor SRS - Seattle Robotics Society PWM - Pulse Width Modulated PID - Proportional/Integral/Defence ADC - Analogue to Digital Converter
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xvi PCB - Polychlorinated Biphenyls PSM - Projek Sarjana Muda
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CHAPTER 1
INTRODUCTION
1.1 Background
In today’s modern world, more and more robot has been developed. Regardless of its purposes robot has become more popular in these past new years than it was before. Robot can be defined as a machine that resembles a human and does mechanical, routine tasks on command.
The purpose of this project was to apply principles of robotics to a real-world application. When developing a mobile robot, it becomes apparent just how complex it is to navigate freely and dynamically in space. With each new sensors or manipulator, the human body which is the ultimate mobile robot has and incredible number of sensor. To simplify this problem the designer can limit the robot to a predefined environment, such as our white paper with a black line. For some tasks this may be perfectly fine, such as a child’s toy robot or perhaps a coal bucket in a mining facility or the famous automatic lawn mover except that uses a wire instead of a black line.
By developing the sensors, hardware and software from scratch, the project enabled us to get a deeper understanding of what is required in the design of a mobile robot. The logic was performed using a PIC micro-controller, and motor was control was performed with power BJT’s. All the wiring was done using wire wrap. What the logic works down to is if the left sensor sees white, the car turns left; and if the right sensor sees white, it turns right. The system can be compared to a monorail, except the rail is a white line.
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1.2 Problem Statement
Line following robot used to help reduce cost of manufacturing and increase efficiency in a manufacturing system. However some line following robot not suite to be used in mass product factory, because the robot move so slow that even the human operator can transfer thing faster than the robot itself. This will result inefficient work.
Some of the line following robot are not suitable to move faster because the centre of gravity of the robot is too high. When the robot tries to move faster, it will cause the robot to trip over. When the robot move faster, sometime the robot fill just keep on going out of the line. This happen because the distance between the sensor and the floor not suitable. The sensors need to be close to the floor so that the sensor than work properly.
Another critical factor that affects the efficient of the robot is the distance between the sensors cells itself. The distance between sensors cells need to be perfect. If possible there should be at least 2 sensors cells that detect the line all the time, even though the robot is at the tight corner.
With this project of high speed line following robot, all problem stated above can be reduced or eliminated. With this robot the move of the product in the production line will be much faster and safe. At the same time it can reduce labour cost, because the robot is fully automatically operated.
1.3 Objectives
The main objective of this project is to develop a high speed line following robot which can follow the line at a high speed to reach it predetermined destination. Additional objective of this projects are:-
• To develop a robot with lower centre of gravity. • Design the position of the sensor cell.
• Develop a circuit with faster respond time. • Built the robot from lighter and stronger material.
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1.4 Scope
In order to develop a working robot that can follow line to a predetermine place, scope are required to assist and guide the development of the project. The scope should be identified and planned to achieve the objective of the project successfully on the time. The scopes for this project are:-
• To design and develop motor driver circuit that has low electrical noise level. • To design and fabricate a solid base structure of the robot.
• To design and develop sensor arrangement which can be operated at high speed movement.
1.5 Benefits of the Project
This high speed line following robot are being developed in order to assist the movement of the product from one station to another station in a huge factory that usually done by human. The benefits of this project are:-
• Eliminating the human power to move the products around the factory. • Preventing fatics to the operator.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction to robot
When we hear the word “robot”, we probably get a picture in our mind of a cleaver mechanical man, perhaps R2D2 or C3PO from the movie Start Wars. That is how most people think of robots, but the robots that really exist today are quite different from the robots of comic books, cartoons and science fiction films and books. Most are simply huge metal arms controlled by a computer. Others are large boxes that move along a track, perhaps carrying parts through a factory. Some are submarines that dive beneath the ocean to work on undersea pipelines or oil rigs or to search for old shipwrecks.
Robots come in many shape and sizes and have many different abilities. Basically, a robot is simply a computer with some sort of mechanical body designed to do a particular job. Usually, it is able to move and has one or more electronic senses. These senses are not nearly as powerful as our own senses of sight and hearing. However, scientists and engineers are working hard to improve robots. They are constantly coming up with ways to make them see, hear and respond to the environment around them.
Robotics is the science of studying and creating robots. It is a very broad and interesting science because like human, robots have many fascinating aspects. It is also a new science. Although people have been imagining and writing stories about robots for many years, robotics has been a real science only since the 1970’s. (Ming Xie, 2003).
Why do we need robots? First, they are hardworking and reliable. They can do dangerous work or work that is very boring or tiring for human. They can work around the clock without complaining and without needing rest, food and vacations.
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And robots can go places that human can not, such as the surface of the Mars, deep under the ocean or inside the radioactive part of a nuclear power plant.
First, a robot must have a body of some kind. Science fiction robots are made to look human, but the appearance of the real robots today are like giant arms bolted to the floor. The robot itself stay in one place while the arms moves to perform a task, such as painting an automobile door or picking up parts moving by on a conveyor belt. Other robots, called mobile robots, move about. For example, robot arts carry materials inside a factory or delivery mail in an office building.
Like the scarecrow in the Wizard of Oz, a robot also needs a brain. This is really what sets a robot apart from all other machines used by people. A robot’s brain is a computer and it controls everything the robot does.
As we may know if we have used computers, they are good at computing; that is, doing rote tasks like adding a column of numbers or processing words. However, they can’t really think as a human does. For a robot to be really useful, it must have some sort of intelligent. The intelligent is contained in the program, the set of instructions that it follows. Most robots today are not very intelligent, but researchers are constantly working to make computers and therefore robots, smarter. An exciting new science has grown up in recent years around the idea of creating machines that can mimic human intelligent. This science is called artificial intelligent, or AI for short. (Stadler, W. 1995).
Just as human have sense organs such as eyes and ears, robots need sensors. A robot might have electronic eyes to find it way around and see what it is doing; electronic ears to hear commands and noises, safety touch sensors to stop it if it accidentally bumps into anything. These are some of the many types of sensors used by robots. A robot might also need a voice to speak to its owner. Speech synthesizer chips can be programmed and controlled by a computer to speak in a voice that almost human. Many robots need some type of hand, usually called a manipulator or gripper, to do their jobs. Sometimes different tools, such as a screwdriver or a drill, are attached directly to the robot’s wrist. Other types of gripper use magnets and vacuums to pick up hold different objects.
The computer is perhaps the most important part of a robot, since it is the computer’s “brain” that makes a robot different from other machine. Over the last several years, computers has become smaller and smaller. This is what has made possible the many recent advances in robotics, since robots can now carry their brains around with
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them. This was not possible when computers were the size of a large room only about 25 years ago. Computers can seem like very complicated machines, but they are actually based on simple ideas.
All computers today have the same basic part or hardware. The main part, where most of the actual computing is done, is the central processing unit (CPU). It carries out the instructions of the computer program, or software and directs actions of all the other component of the computer. The CPU is made up of one or more plastic board holding lots of electrical connectors and sockets. Cables are attached to the connectors from other parts of the computer. Integrated circuit, or IC’s, are plugged into the sockets. The IC’s are tiny chips, so small they could fit on the tip made mostly of silicon (a common element found in sand and rocks) and contains thousands of small switches.
A second important part of computers is the memory. This is where the CPU stores the data that it needs or the answers to the problems it works on. Memory is also a small chip, usually made of silicon within a plastic covering. Computer memory is different from human memory in two main ways. A computer’s memory can hold a definite limited amount of information and no more. To add new data means that come of the old data must be erased. Secondly, a computer’s memory doesn’t forget over time and only forgets when told to do so. Some types of memory, however, lose the information they are processing when the power is turned off.
A computer needs a way to move information in and out of its brain. One familiar input device is the keyboard. It is used by human to type information into the computer. Joysticks and paddles other inputs device.
An output device is where the computer sends information out to the user or asks questions about what it should do next. It can be the computer’s monitor (screen), a printer or a storage device like a disk drive.
The basic parts of a computer are the central processing unit (CPU), memory, a keyboard or other input device and a screen or other output device. Sounds simple, doesn't it? But how does the computer know how to add and subtract, and how can its memory remember the answers it computes? We know that the computer doesn't have a real brain inside. It fact, it is made up mostly of plastic, metal and silicon. Yet, a computer acts in many ways as though it does have a real brain.
To find the answer, we must take a close look at how we understand numbers. We have ten digits in our number system: 0,1,2,3,4,5,6,7,8,9. Digit is a fancy word for a
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CHAPTER 1
INTRODUCTION
1.1 Background
In today’s modern world, more and more robot has been developed. Regardless of its purposes robot has become more popular in these past new years than it was before. Robot can be defined as a machine that resembles a human and does mechanical, routine tasks on command.
The purpose of this project was to apply principles of robotics to a real-world application. When developing a mobile robot, it becomes apparent just how complex it is to navigate freely and dynamically in space. With each new sensors or manipulator, the human body which is the ultimate mobile robot has and incredible number of sensor. To simplify this problem the designer can limit the robot to a predefined environment, such as our white paper with a black line. For some tasks this may be perfectly fine, such as a child’s toy robot or perhaps a coal bucket in a mining facility or the famous automatic lawn mover except that uses a wire instead of a black line.
By developing the sensors, hardware and software from scratch, the project enabled us to get a deeper understanding of what is required in the design of a mobile robot. The logic was performed using a PIC micro-controller, and motor was control was performed with power BJT’s. All the wiring was done using wire wrap. What the logic works down to is if the left sensor sees white, the car turns left; and if the right sensor sees white, it turns right. The system can be compared to a monorail, except the rail is a white line.
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1.2 Problem Statement
Line following robot used to help reduce cost of manufacturing and increase efficiency in a manufacturing system. However some line following robot not suite to be used in mass product factory, because the robot move so slow that even the human operator can transfer thing faster than the robot itself. This will result inefficient work.
Some of the line following robot are not suitable to move faster because the centre of gravity of the robot is too high. When the robot tries to move faster, it will cause the robot to trip over. When the robot move faster, sometime the robot fill just keep on going out of the line. This happen because the distance between the sensor and the floor not suitable. The sensors need to be close to the floor so that the sensor than work properly.
Another critical factor that affects the efficient of the robot is the distance between the sensors cells itself. The distance between sensors cells need to be perfect. If possible there should be at least 2 sensors cells that detect the line all the time, even though the robot is at the tight corner.
With this project of high speed line following robot, all problem stated above can be reduced or eliminated. With this robot the move of the product in the production line will be much faster and safe. At the same time it can reduce labour cost, because the robot is fully automatically operated.
1.3 Objectives
The main objective of this project is to develop a high speed line following robot which can follow the line at a high speed to reach it predetermined destination. Additional objective of this projects are:-
• To develop a robot with lower centre of gravity. • Design the position of the sensor cell.
• Develop a circuit with faster respond time. • Built the robot from lighter and stronger material.
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3
1.4 Scope
In order to develop a working robot that can follow line to a predetermine place, scope are required to assist and guide the development of the project. The scope should be identified and planned to achieve the objective of the project successfully on the time. The scopes for this project are:-
• To design and develop motor driver circuit that has low electrical noise level. • To design and fabricate a solid base structure of the robot.
• To design and develop sensor arrangement which can be operated at high speed movement.
1.5 Benefits of the Project
This high speed line following robot are being developed in order to assist the movement of the product from one station to another station in a huge factory that usually done by human. The benefits of this project are:-
• Eliminating the human power to move the products around the factory. • Preventing fatics to the operator.
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4
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction to robot
When we hear the word “robot”, we probably get a picture in our mind of a cleaver mechanical man, perhaps R2D2 or C3PO from the movie Start Wars. That is how most people think of robots, but the robots that really exist today are quite different from the robots of comic books, cartoons and science fiction films and books. Most are simply huge metal arms controlled by a computer. Others are large boxes that move along a track, perhaps carrying parts through a factory. Some are submarines that dive beneath the ocean to work on undersea pipelines or oil rigs or to search for old shipwrecks.
Robots come in many shape and sizes and have many different abilities. Basically, a robot is simply a computer with some sort of mechanical body designed to do a particular job. Usually, it is able to move and has one or more electronic senses. These senses are not nearly as powerful as our own senses of sight and hearing. However, scientists and engineers are working hard to improve robots. They are constantly coming up with ways to make them see, hear and respond to the environment around them.
Robotics is the science of studying and creating robots. It is a very broad and interesting science because like human, robots have many fascinating aspects. It is also a new science. Although people have been imagining and writing stories about robots for many years, robotics has been a real science only since the 1970’s. (Ming Xie, 2003).
Why do we need robots? First, they are hardworking and reliable. They can do dangerous work or work that is very boring or tiring for human. They can work around the clock without complaining and without needing rest, food and vacations.
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And robots can go places that human can not, such as the surface of the Mars, deep under the ocean or inside the radioactive part of a nuclear power plant.
First, a robot must have a body of some kind. Science fiction robots are made to look human, but the appearance of the real robots today are like giant arms bolted to the floor. The robot itself stay in one place while the arms moves to perform a task, such as painting an automobile door or picking up parts moving by on a conveyor belt. Other robots, called mobile robots, move about. For example, robot arts carry materials inside a factory or delivery mail in an office building.
Like the scarecrow in the Wizard of Oz, a robot also needs a brain. This is really what sets a robot apart from all other machines used by people. A robot’s brain is a computer and it controls everything the robot does.
As we may know if we have used computers, they are good at computing; that is, doing rote tasks like adding a column of numbers or processing words. However, they can’t really think as a human does. For a robot to be really useful, it must have some sort of intelligent. The intelligent is contained in the program, the set of instructions that it follows. Most robots today are not very intelligent, but researchers are constantly working to make computers and therefore robots, smarter. An exciting new science has grown up in recent years around the idea of creating machines that can mimic human intelligent. This science is called artificial intelligent, or AI for short. (Stadler, W. 1995).
Just as human have sense organs such as eyes and ears, robots need sensors. A robot might have electronic eyes to find it way around and see what it is doing; electronic ears to hear commands and noises, safety touch sensors to stop it if it accidentally bumps into anything. These are some of the many types of sensors used by robots. A robot might also need a voice to speak to its owner. Speech synthesizer chips can be programmed and controlled by a computer to speak in a voice that almost human. Many robots need some type of hand, usually called a manipulator or gripper, to do their jobs. Sometimes different tools, such as a screwdriver or a drill, are attached directly to the robot’s wrist. Other types of gripper use magnets and vacuums to pick up hold different objects.
The computer is perhaps the most important part of a robot, since it is the computer’s “brain” that makes a robot different from other machine. Over the last several years, computers has become smaller and smaller. This is what has made possible the many recent advances in robotics, since robots can now carry their brains around with
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them. This was not possible when computers were the size of a large room only about 25 years ago. Computers can seem like very complicated machines, but they are actually based on simple ideas.
All computers today have the same basic part or hardware. The main part, where most of the actual computing is done, is the central processing unit (CPU). It carries out the instructions of the computer program, or software and directs actions of all the other component of the computer. The CPU is made up of one or more plastic board holding lots of electrical connectors and sockets. Cables are attached to the connectors from other parts of the computer. Integrated circuit, or IC’s, are plugged into the sockets. The IC’s are tiny chips, so small they could fit on the tip made mostly of silicon (a common element found in sand and rocks) and contains thousands of small switches.
A second important part of computers is the memory. This is where the CPU stores the data that it needs or the answers to the problems it works on. Memory is also a small chip, usually made of silicon within a plastic covering. Computer memory is different from human memory in two main ways. A computer’s memory can hold a definite limited amount of information and no more. To add new data means that come of the old data must be erased. Secondly, a computer’s memory doesn’t forget over time and only forgets when told to do so. Some types of memory, however, lose the information they are processing when the power is turned off.
A computer needs a way to move information in and out of its brain. One familiar input device is the keyboard. It is used by human to type information into the computer. Joysticks and paddles other inputs device.
An output device is where the computer sends information out to the user or asks questions about what it should do next. It can be the computer’s monitor (screen), a printer or a storage device like a disk drive.
The basic parts of a computer are the central processing unit (CPU), memory, a keyboard or other input device and a screen or other output device. Sounds simple, doesn't it? But how does the computer know how to add and subtract, and how can its memory remember the answers it computes? We know that the computer doesn't have a real brain inside. It fact, it is made up mostly of plastic, metal and silicon. Yet, a computer acts in many ways as though it does have a real brain.
To find the answer, we must take a close look at how we understand numbers. We have ten digits in our number system: 0,1,2,3,4,5,6,7,8,9. Digit is a fancy word for a