UNIVERSITI TEKNIKAL MALAYSIA MELAKA

OBSTACLE AVOIDANCE METHOD FOR AUTOMATED GUIDED

VEHICLE (AGV)

This report submitted in accordance with requirement of the Universiti Teknikal

Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering

(Robotics and Automation) with Honours.

by

NASHRUL ADZIM B. NASHRUDDIN

FACULTY OF MANUFACTURING ENGINEERING

2009

DECLARATION

I hereby, declared this report entitled “Obstacle Avoidance Method For Automated

Guided Vehicle (AGV)” is the results of my own research except as cited in

references.

Signature : ………………………………………………..

Author’s name : ………………………………………………..

Date : ………………………………………………..

APPROVAL

This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a

partial fulfillment of the requirements for the degree of Bachelor of Manufacturing

Engineering (Robotics and Automation) with Honours. The member of the

supervisory committee is as follow:

(Signature of Supervisor)

…………………………………………..

(Official Stamp of Supervisor)

APPROVAL

This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a

partial fulfillment of the requirements for the degree of Bachelor of Manufacturing

Engineering (Robotics and Automation) with Honours. The member of the

supervisory committee is as follow:

(Signature of Principal Supervisor)

…………………………………………..

(Official Stamp of Principal Supervisor)

(Signature of Co-Supervisor)

…………………………………………..

(Official Stamp of Co-Supervisor)

i

ABSTRACT

From the previous industrial training, author has been involved in automated guided

vehicle (AGV) route construction. The interest of the AGV thus makes this report

happened. This report is mainly consists of a study, research, and development of

AGV programming and platform. The research starts with a literature review about

obstacle avoidance for AGV from previous researcher, studies from related books

and others. The development of AGV platform is done so that the obstacle avoidance

method programming can be shown in real situation. Mainly, a robot development

consists of three main parts: mechanical part, electrical and electronic part, and

programming part. As for mechanical part is a chassis design, shaft design and any

mechanical relevant part while for electronic part is a circuit design for sensor and

motor driver. The development for the AGV platform is used machining process

such as lathe, laser cutting, milling and non machining process such as fabrication.

The electronic circuit had been constructed and then attached to a microcontroller

which acts as the AGV’s main controller for the whole AGV movement.

Programming was done using C Language for the AGV path planning and obstacle

avoidance and it is based on rule-base expert system. The programme was compiled

in a form of hex file and was downloaded inside the peripheral interface controllers

(PIC). Thus AGV can move like autonomous robot and it will use all available

sensors such as line following and obstacle sensors to detects any guide tape or

obstacle. Rule-base system will be used as AGV decision making process. If it meets

with any obstacle in its way it will execute the rule base system to avoid the obstacle.

ii

ABSTRAK

Daripada pengalaman menjalani latihan industri penulis telah terlibat dengan projek

pembinaan jalan AGV. Oleh kerana minat terhadap AGV, maka terhasillah penulisan

ilmiah ini. Secara keseluruhan laporan ini mengandungi kajian dan pembangunan

platfom AGV. Kajian mengenai pengelakkan halangan AGV dimulakan dengan

melihat rujukan daripada penyelidik terdahulu melalui jurnal, pembelajaran daripada

buku berkaitan dan juga sumber ilmiah lain. Pembangunan platfom AGV adalah

berdasarkan pembinaan asas sebuah robot. Platfom AGV dibangunkan supaya

program pengelakkan halangan dapat ditunjukkan dalam keadaan sebenar. Secara

umumnya robot mengandungi tiga bahagian utama iaitu: bahagian mekanikal,

bahagian elektriakl dan elektronik dan juga bahagian pengaturcaraan. Untuk

bahagian mekanikal ianya meliputi rekabentuk casis dan juga shaf tayar. Bahagian

elektronik diberi penekanan mengenai rekabentuk litar untuk pengesanan dan

pengendali motor. Pengaturcaraan pula adalah untuk merancang pergerakan dan

pengelakkan halangan AGV. Pengaturcaraan telah menggunakan bahasa C dimana

bahasa C ini akan diubah kepada bentuk hex dan akan dimuat turunkan ke dalam PIC.

Hanya selepas itu barulah AGV dapat bergerak secara automatik sepenuhnya. AGV

akan menggunakan sensor garisan untuk mengesan garisan dan sensor halangan

untuk mengesan halangan sebagai panduan untuk bergerak. Pengelakkan halangan

AGV adalah berdasarkan penggunaan sistem berasaskan aturan. Pengawal mikro

atau PIC akan melaksanakan pengaturcaraan ini jika AGV terlibat dengan halangan

sewaktu bergerak ke tempat yang telah ditetapkan. Cara untuk AGV mengelak

halangan ini adalah berdasarkan sistem berasaskan aturan.

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ACKNOWLEDGEMENT

I would like to thank to ALLAH S.W.T because of His help author could finished

this report. I also like to thank my supervisor, En. Mohd Hisham b. Nordin because

of his supervision for the report writing and the PSM development progress. As for

ISUZU HICOM Malaysia Sdn. Bhd. (IHMSB), the place where author learned about

AGV, a great thank because allowing author to take AGV project as PSM project.

Last but not least to all author family, especially author’s parent and sibling whose

give a lot of support for this PSM project, IHMSB Engineering Department,

Production Engineering (PE) section, Kaizen branch (Engineering Workshop)

technician, ISUZU technician and anyone who is directly or indirectly involved in

this PSM project.

Adzim

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TABLE OF CONTENT

Abstract i

Abstrak ii

Acknowledgement iii

Table of Content iv

List of Figures vii

List Abbreviations ix

1.0 INTRODUCTION 1

1.1 Project Introduction 1

1.2 Objective 2

1.3 Scope 2

1.4 Problem statement 3

1.5 Conclusion 3

2.0 LITERATURE REVIEW 4

2.1 What is AGV? 4

2.2 Types of AGV 5

2.3 Expert Systems 9

2.3.1 The Structure of Expert System 11

2.3.2 Knowledge Engineering 13

2.3.3 The Inference Engine 15

2.3.4 How Expert Systems Explain Their Reasoning 16

2.3.5 Confidence Estimates 17

2.4 Obstacle Avoidance Method 17

2.5 Conclusion 19

v

3.0 METHODOLOGY 20

3.1 Introduction 20

3.2 Development planning 21

3.2.1 PSM 1 Gantt Chart 21

3.2.2 PSM 2 Gantt Chart 22

3.2.3 Development Process Flowchart 23

3.2.4 Development Process Flowchart Explanation 24

3.2.5 Programming Flowchart for Path Planning and Obstacle Avoidance 25

3.2.6 Programming Flowchart for Path Planning and Obstacle Avoidance

Explanation 26

3.2.7 AGV Platform Drawing 27

3.3 Parts selection 28

3.3.1 Mechanical Structure Parts 28

3.3.1.1 Tire 28

3.3.1.2 Acrylic sheet for AGV Platform chassis 29

3.3.1.3 Aluminium Square Tube 30

3.3.2 Electrical and Electronic Parts 31

3.3.2.1 Multimeter 31

3.3.2.2 Battery 32

3.3.2.3 DC Motor 33

3.3.2.4 Microcontroller 34

3.3.2.5 Ultrasonic transducer 35

3.3.2.6 Infrared transducer 36

3.3.2.7 Light Emitting Diode (LED) 37

3.3.2.8 Transistor 38

3.3.2.9 Resistor 39

3.3.2.10 Potentiometer 40

3.3.2.11 Capacitor 41

3.3.2.12 Wire 42

3.3.2.13 Printed Circuit Board (PCB) 43

3.3.2.14 Voltage Regulator 44

3.3.2.15 Diode 45

3.4 Method of Manufacturing 46

3.4.1 Machining Method 46

vi

3.4.1.1 Laser Cutting Machine 46

3.4.1.2 Lathe Machine 48

3.4.1.3 Milling Machine 49

3.4.1.4 Horizontal Bandsaw Machine 50

3.4.2 Soldering Method 51

3.4.2.1 Soldering Iron 51

3.4.2.2 Solder Sucker 52

3.4.2.3 Flux core Solder 53

3.4.2.4 Wire Stripper 54

3.5 Method of Programming 55

3.5.1 C programming 55

3.5.1.1 Programming a PIC using C language 56

3.5.1.2 Compiler for C language 56

3.6 Conclusion 57

4.0 RESEARCH AND DEVELOPMENT 58

4.1 AGV platform development 58

4.1.1 Tire coupling design 59

4.1.1.1 Tire coupling machining process 61

4.1.2 AGV chassis design 63

4.1.2.1 AGV chassis fabrication 64

4.1.2.2 AGV chassis assembly 65

4.2 AGV electronic circuit development 66

4.2.1 Line sensor circuit 66

4.2.1.1 Line sensor circuit development 68

4.2.2 Obstacle sensor circuit 70

4.2.3 Motor driver circuit 74

4.3 Programming development 76

4.3.1 Operational flowchart for AGV 76

4.3.2 Programming flowchart for AGV 76

4.3.3 Write program using MPLAB IDE 79

4.3.4 Programming using C language 83

4.3.4.1 AGV logic input for programming 85

4.3.4.2 AGV programming writes in C language 86

vii

4.3.5 PIC programmer 86

4.4 Conclusion 92

5.0 RESULT AND DISCUSSION 93

6.0 CONCLUSION AND FUTURE WORK 107

REFERENCES 108

APPENDICES

A AGV Development Costing 110

B AGV Programming in C Language 111

viii

LIST OF TABLES

4.1 Logic input for AGV programming when both sensor high 85

4.2 Logic input for AGV programming when obstacle sensor low 85

ix

LIST OF FIGURES

2.1 Towing AGV. 6

2.2 Packmobile® 4 and Carrier AGVs 6

2.3 ADAM (Autonomous Delivery and Manipulation) developed by

RMT Robotics. 7

2.4 AGVs fork truck type. 7

2.5 Transcar Automated Guided Vehicle System (AGVs) used at Healthcare. 8

2.6 Automated tugger used for part delivery. 8

2.7 A basic schema for knowledge-based applications. 12

3.1 PSM 1 Gantt chart. 21

3.2 PSM 2 Gantt chart. 22

3.3 Flowchart for Development Process. 23

3.4 Flowchart for Path Planning and Obstacle Avoidance. 25

3.5 Drawing concept for AGV Platform. 27

3.6 Sponge tire. 28

3.7 Acrylic Glass for AGV Platform chassis. 29

3.8 Aluminium square tube. 30

3.9 Digital multimeter. 31

3.10 12 volt valve regulated lead-acid rechargeable battery. 32

3.11 12 volt geared dc motor. 33

3.12 PIC start up kit. 34

3.13 Both ultrasonic sensor transmitter and receiver. 35

3.14 A pair of IR detector and IR transmitter. 36

3.15 Variable colours and size of LED. 37

3.16 Typical transistor. 38

3.17 Variable value of resistor. 39

3.18 Typical potentiometer with variable resistive value. 40

3.19 Variable type and value of capacitor. 41

3.20 Variable hooked wire. 42

3.21 Parallel line PCB. 43

3.22 5 volt voltage regulator. 44

3.23 Diode 45

x

3.24 Laser cutting machine. 46

3.25 Lathe machine. 48

3.26 Milling machine. 49

3.27 Horizontal bandsaw machine. 50

3.28 Soldering iron. 51

3.29 Solder sucker. 52

3.30 Flux core solder inside a tube. 53

3.31 Automatic wire stripper. 54

4.1 Engineering drawing of tire coupling 60

4.2 Aluminium solid rod that have been cut to make tire coupling 61

4.3 Aluminium solid rod that has been done facing process 61

4.4 Turning process to the aluminium solid rod is done to form tire

coupling shape 61

4.5 Tire coupling with desire shape 61

4.6 Hole is drill to make the tire mounting hole screw 62

4.7 Hole is drill for motor shaft 62

4.8 Tire coupling 62

4.9 AGV chassis engineering drawing 63

4.10 Acrylic sheet is being cut using laser cutter machine 64

4.11 Parts of AGV chassis 64

4.12 Finished AGV frame 64

4.13 Assemble of motor to the AGV chassis 65

4.14 Half process of AGV chassis assembly 65

4.15 Complete AGV chassis 65

4.16 The basic voltage comparator 67

4.17 Line sensor circuit 67

4.18 Circuit that have been printed on OHP transparency paper 68

4.19 PCB is cut to the circuit size 68

4.20 Iron is used to transfer heat to the PCB for about 9 to 12 minutes 68

4.21 Ferric Chloride acid for etching process 69

4.22 Infrared transducer circuit is soldered with infrared

transmitter and receiver 69

4.23 Completed line sensor circuit 69

4.24 Voltage comparator circuit for line sensor 70

xi

4.25 Ultrasonic transducer 71

4.26 Ultrasonic transducer circuit that have been attached to the AGV 71

4.27 Oscillator circuit design using Proteus 72

4.28 Ultrasonic transmitter circuit from protoboard 73

4.29 Ultrasonic receiver circuit 73

4.30 Ultrasonic receiver circuit from protoboard 74

4.31 Motor driver circuit designed from Proteus 75

4.32 Motor driver circuit is soldered on the independent board 75

4.33 Operational flowchart for AGV 77

4.34 Programming flowchart for AGV 78

4.35 MPLAB IDE 79

4.36 A programming from C language 80

4.37 Project Wizard to start a new project 80

4.38 Select type of PIC to use for the project 81

4.39 Select toolsuite language 81

4.40 Name of the project and file location 82

4.41 Add an existing file 82

4.42 Summary of the new project 83

4.43 PIC programmer 86

4.44 USB cable 87

4.45 PIC programmer that has been connected to the PC 87

4.46 PIC16F877A insert to the ZIF socket 88

4.47 Build All the C source programming to get the hex file 88

4.48 Winpic800 version 3.55f 89

4.49 Open the hex file 89

4.50 PIC is detected from Winpic800 90

4.51 Setting configuration display 90

4.52 Setting to the configuration 91

4.53 Hex file have been burned inside the PIC16F877A 91

5.1 AGV fully function 93

5.2 Minimum distance of ultrasonic transducer to function properly 95

5.3 Maximum distance of ultrasonic detection 95

5.4 Minimum width of ultrasonic range detection is about 5mm 95

5.5 Obstacle sensor cannot detect object than thin as card 95

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5.6 A paper have been place horizontally in front of ultrasonic transducer 96

5.7 Ultrasonic transducer can reflect a wave if the object

is below the transducer 96

5.8 A paper is wavy in front of the ultrasonic transducer 96

5.9 Toolbox is placed in front of AGV as obstacle 96

5.10 Masking tape as obstacle in front of AGV 97

5.11 Obstacle from aluminium sheet 97

5.12 Obstacle in diagonal position 97

5.13 Line sensor of AGV that use four pair of infrared transducer 98

5.14 Two LEDs is light up indicates that line sensor

sensing a straight aluminium line 99

5.15 Right LED is light up indicates that line sensor sensing

right position of aluminium line 99

5.16 AGV move forward follow the aluminium line approaching

to a right turning 100

5.17 AGV making a right turning 101

5.18 AGV making left turning 101

5.19 Ultrasonic beam pattern 102

5.20 Behaviour of light during reflection 104

5.21 Smooth surface of aluminium line 105

5.22 Aluminium line surface is wavy and not flat 105

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LIST OF ABBREVIATIONS

AC - Alternate Current

ADAM - Autonomous Delivery and Manipulation

AGV - Automated Guided Vehicle

BORIS - Block Oriented Simulation System

CPU - Central Processing Unit

D.C. - Direct Current

DMM - Digital Multimeter

EEPROM - Electrical Erasable-programmable Read Only Memory

FMS - Flexible Manufacturing System

HICOM - Heavy Industry Company of Malaysia

I / O - Input / Output

Ga/As - Gallium Arsenide

GaAsP - Gallium Arsenide Phosphide

GaP - Gallium Phosphide

IHMSB - ISUZU HICOM Malaysia Sdn. Bhd.

IR - Infrared

LBM - Laser Beam Machining

LED - Light Emitting Diode

MCU Microcontroller unit

MDI - Multiple Document Interface

MF - Maintenance Free

PCB - Printed Circuit Board

PE - Production Engineering

PIC - Peripheral Interfaces Controllers

PID - Proportional Integral Differential

RAM - Random Access Memory

ROM - Read Only Memory

RPM - Revolution per Minute

VOM - Volt / Ohm Meter

VRLA - Valve Regulated Lead Acid

1

CHAPTER 1

INTRODUCTION

1.1 Project Introduction

This project is about a research and development of AGV programming and platform.

The programming is developed using suitable language such as C program and

assembly language. Mostly the programming consists of path planning and obstacle

avoidance method. Obstacle avoidance is based on rule-base expert system. The

developed AGV platform is a basic platform where it is suitable for a study of path

planning and obstacle avoidance programming. The program will be compiled into

hex files and downloaded into peripheral interface controllers (PIC) and the PIC will

be attached to a microcontroller. The AGV platform had been developed based on a

basic robot parts such as mechanical part, electrical and electronic part, and

programming part. To develop the AGV platform, the use of suitable machine for

machining process and non machining process like fabrication was made compulsory.

As for AGV circuit, basic electronics component such as resistor, transistor,

capacitor, potentiometer and others has been used. After the entire robot parts finish

being assembled to form the AGV platform, it had been test for the obstacle

avoidance program and the program had been observed to work in the real situation.

2

1.2 Objective

Objectives of this project:

To learn and understand what is Automated Guided Vehicle (AGV).

To develop basic mobile robot platform represented as AGV.

To develop electronics circuit for AGV.

To develop AGV programming for obstacle avoidance method.

1.3 Scope

Scope that is covered for this project:

Mechanical design for AGV platform.

Mechatronics for AGV circuits.

Sensors for AGV.

Programming language for PIC.

3

1.4 Problem statement

From the industrial training experienced, author has been involved in a kit delivery

project for chassis A and B assembly line at Isuzu HICOM Malaysia Sdn. Bhd. The

project is mainly involved in constructing a guide tape made for two automated

guided vehicle (AGV) which the company bought from Japan. These two AGVs

were modified at Engineering Workshop so that it becomes a towing AGV. The main

task of the AGV is to deliver a kit dolly rack that is filled with assembly components

for HICOM Perkasa truck and ISUZU D-MAX pickup. However, there are a few

problems and shortage encounter by both AGV such as being hitting by a transverser,

can’t move backward, do not move automatically after an operator from the

assembly line pick the rack, non path planning programming, non obstacle avoidance

programming, non sequence programming and missing guide tape on the floor. All

of these problems sometimes delay the delivery routine. Operators have to replace

the delivery task if any of the problems occurred to the AGV. Since the company

reduces the workman power, the used of AGV is really necessary and reliable for

delivery task. AGV is a costing mobile robot where a basic AGV can cost for almost

RM5000 for industrial applications. Thus to reduce the cost, the company is planning

to build its own AGV from scratch (refer Appendix A for project cost).

1.5 Conclusion

It can be concluded that, to develop an AGV platform there are few things to be

considered such as how the AGV should be created and designed in terms of

mechanical structure, electronics circuit, and programming for path planning and

obstacle avoidance. Not only that, the field of AGV study also covered many areas

like flexible manufacturing system (FMS) and Intelligent Manufacturing System

(IMS).

4

CHAPTER 2

LITERATURE REVIEW

2.1 What is AGV?

Automated guided vehicle, or AGV, are intended to be the most flexible conveyer

system possible: a conveyer which doesn’t need a continuous belt or roller table.

Ideally an AGV would be able to pick up a bin of parts or manufactured items and

deliver them as needed. For example, an AGV might receive a bin containing an

assembled engine. It could then deliver it automatically across the shop floor to the

car assembly area which needed an engine. As it returned, it might be diverted by the

central computer and instructed

However, navigation is complex. The AGV has to know where it is, plan a path from

its current location to its goal destination, and avoid colliding with people, other

AGVs, and maintenance workers and tools cluttering the factory floor. This proved

too difficult to do, especially for factories with uneven lighting (which interferes with

vision) and lots of metal (which interferers with radio controllers and on-board radar

and sonar). Various solutions converged on creating a trail for the AGV to follow.

One method is to bury a magnetic wire in the floor for the AGV to sense.

Unfortunately, changing the path of an AGV required ripping up the concrete floor.

This didn’t help with the flexibility needs of modern manufacturing. Another method

is to put down a strip of photochemical tape for the vehicle to follow. The strip

unfortunately is vulnerable, both to wear and to vandalism by unhappy workers.

Regardless of the guidance method, in the end the simplest way to thwart an AGV

was to something on its path. If the AGV did not have range sensors, then it would

5

be unable to detect an expensive piece of equipment or a person put deliberately in

its path. A few costly collisions would usually lead to the AGV’s removal. If the

AGV did have range sensors, it would stop for anything. A well placed lunch box

could hold the AGV for hours until a manager happened to notice what was going on.

Even better from disgruntled worker’s perspective, many AGVs would make a loud

noise to indicate the path was blocked. Imagine having to constantly remove lunch

boxes from the path of a dumb machine making unpleasant siren noises.

From the first, robots in the workplace triggered a backlash. Many of the human

workers felt threatened by a potential loss of jobs, even though the jobs being

mechanized were often menial or dangerous. This was particularly true of

manufacturing facilities which were unionized. One engineer reported that on the

first day it was used in a hospital, a HelpMate Robotics cart was discovered pushed

down the stairs. Future models were modified to have some mechanisms to prevent

malicious acts (Murphy 2000).

2.2 Types of AGV

AGVS Towing Vehicles were the first type introduced and are still a very

popular type today. Towing vehicles can pull a multitude of trailer types and

have capacities ranging from 3628 kilogram to 27215 kilogram.

AGVS Unit Load Vehicles are equipped with decks, which permit unit load

transportation and often automatic load transfer. The decks can either be lift

and lower type, powered or non-powered roller, chain or belt decks or custom

decks with multiple compartments.

AGVS Pallet Trucks are designed to transport palletized loads to and form

floor level; eliminating the need for fixed load stands.

AGVS Fork Truck has the ability to service loads both at floor level and on

stands. In some cases these vehicles can also stack loads in rack.

6

Light Load AGVS are vehicles which have capacities in the neighbourhood of

226 kilogram or less and are used to transport small parts, baskets, or light

loads though a light manufacturing environment. They are designed to

operate in areas with limited space.

AGVS Assembly Line Vehicles are an adaptation of the light load AGVS for

applications involving serial assembly processes (Transbotic 2008).

Figure 2.1: Towing AGV (ISUZU HICOM Malaysia Sdn. Bhd. 2008).

Figure 2.2: Packmobile® 4 and Carrier AGVs (Bell and Howell Company 2000).

7

Figure 2.3: ADAM (Autonomous Delivery and Manipulation) developed by RMT Robotics (RMT

Robotics Ltd. 2008).

Figure 2.4: AGVs fork truck type.