i

ABSTRACT

The present invention related to automated guided cart (AGC) particularly to cost-

effectiveness, light duty vehicle, which is specifically adapted for use in light

manufacturing shop floor. This AGC followed a magnetic guide taped on floor to

move goods or material from one point to another under PIC control. The AGC

system employ specifically designed carts, which are configured particularly to carry

components such as automobile chassis or assembly components in an automobile

assembly operation. Generally, the method to achieve the objectives, it consists of

designation stage, procurement preparation stage, material preparation stage,

fabrication stage, and examination stage. This project involved design and

development of the AGC system through the engineering skills via mechanical

calculation and analysis, material selection, electrical circuit design, and

programming of the PIC controller. In the implementation stage, a light duty AGC

produce and applicable to industrial environment to accomplished the project.

ii

ABSTRAK

Ciptaan projek berautomatik panduan kereta (Automated Guided Cart) terutamanya

untuk keberkesanan kos, kenderaan tugas ringan dan khususnya disesuaikan oleh

penggunaan dalam tingkat pembuatan ringan. AGC ini diikuti satu panduan yang

magnetik merakamkan di atas lantai untuk bergerak barangan atau bahan di

sepanjang lorong yang ditentukan. Ia dikawalkan oleh PIC mengawal untuk bergerak

dan pelbagai fungsi. Sistem AGC reka bentukan mengatur corak yang tatarajah

terutamanya untuk melaksanakan komponen-komponen ibarat casis kereta atau

komponen-komponen pemasangan dalam operasi automobil pemasangan.

Umumnya, kaedah untuk mencapai matlamat-matlamat, ia mengandungi peringkat

gelaran, ia itu, tahap persiapan pemerolehan, tahap persiapan bahan, peringkat

pembuatan, dan peringkat peperiksaan. Rekabentuk dan pembangunan AGC terlibat

dalam projek ini melalui kemahiran-kemahiran kejuruteraan adalah pengiraan dan

analisis mekanikal, pemilihan bahan, rekabentuk litar elektrik,dan pengaturcaraan

PIC mengawal. Untuk mencapaikan matlamat projek ini, dalam peringkat

pelaksanaan, AGC yang bertugasan ringan menghasilkan dan bersedia digunakan

untuk persekitaran perindustrian dicipta.

iii

ACKNOWLEDGEMENT

I would like to express my gratitude to all those who gave me the possibility to

accomplish this project of manufacturing engineering bachelor’s degree entitled

automated guided cart. I want to thank the Department Managemtnt Faculty of

Manufacturing of Universiti Teknikal Malaysia Melaka (UTeM), Prof. Dr. Mohd.

Razali b. Muhamad and giving me permission to commence this project in the first

instance, approved the title of project proposed. I have furthermore to thank the

Management of Project Sarjana Muda, Sivarao a/l Subramonian, and Head of

Department of Robotic and Automation, Dr. Zamberi bin Jamaludin who gave and

confirmed this permission and supported me to progressing with my project.

I am deeply indebted to my supervisor, Puan Nur Aidawaty bt. Rafan and principle

co-supervisor, Puan Silah Hayati bt. Kamsani from the Department of Robotic and

Automation of UTeM whose help, stimulating suggestions, technical information,

and encouragement helped me in all the time of project and writing of this report.

My colleagues from 4BMFA of UTeM supported me in my research work. I want to

thank them for all their help, support, interest and valuable hints. Especially I am

obliged to Mr. Lim, Lee Wai Keong, Tan Sia Peng for the great help in difficult

times and suggestions for improvement.

Especially, I would like to give my special thanks to my wife Karen whose patient love enabled me to complete this work.

iv

TABLE OF CONTENT

Abstract i

Abstrak ii

Acknowledgement iii

Table of Content iv

List of Tables vi

List of Figures vii

List of Abbreviations viii

1. INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 2

1.3 Objectives 4

1.4 Scope 5

2. LITERATURE REVIEW 6

2.1 Vehicle Guided Technology 6

2.1.1 Imbedded Guided Wires 6

2.1.2 Paint Strips Guidance 7

2.1.3 Self Guided Vehicle 8

2.2 Mechanical Review 8

2.2.1 Material in Mechanical Design 9

2.2.2 Electrical Motors 13

2.2.3 Kinematic of Gears 18

2.3 Electrical Review 20

2.3.1 Sensors 20

2.3.2 PIC Microcontroller 23

3. METHODOLOGY 26

3.1 Methodology Flow Chart of project AGC 26

3.2 Functions of the Cart 27

v

3.3 Design Requirement 28

3.4 Evaluation Criteria 29

3.5 DC Motors 30

3.6 Drive Mechanism 30

3.7 Frame 31

3.8 PIC Microcontroller 33

3.9 Sensors 35

4. DESIGN AND DEVELOPMENT 38

4.1 DC Motor Selection 38

4.2 Drive Mechanism 40

4.2.1 Gear Geometry Computation 41

4.2.2 Shaft Design 42

4.2.3 Bearing Selection 44

4.3 Frame Design 45

4.3.1 Technical Drawing 48

4.4 Motor Drive Circuit Board Designation 51

4.5 Microcontroller Electronic Circuit Designation 53

4.6 Magnetic Sensor 54

5. RESULT AND DISCUSSION 56

5.1 Mechanical Structure 56

5.2 Controller 58

5.2.1 Microcontroller Electronic Circuit Board 58

5.2.2 Microchip Pin Assignment 61

5.2.3 Motor Control Electronic Circuit Board 62

5.3 Magnetic Sensor Electronic Circuit Board 64

5.4 PIC Comment Programs 67

5.4.1 Microcontroller Language (C Language) 67

5.4.2 Program Burning 71

vi

6. CONCLUSION AND RECOMMENDATION 74

6.1 Conclusion 74

6.2 Recommendation 75

REFERENCE 76

APPENDIX A

APPENDIX B

APPENDIX C

APPENDIX D

APPENDIX E

APPENDIX G

vii

LIST OF TABLES

1.1 Comparison of the Methods of Material Handling.

2.1 Uses of Some Steels

2.2 Aluminum Alloy Groups

2.3 Common Aluminum Alloys and Their Uses

2.4 AC Motor Voltage.

2.5 AC Motor Speeds for 60 Hertz Power

2.6 DC Motor Voltage Ratings

3.1 Characteristics of the Material Elements.

3.2 Alloy Steel and Aluminum General Physical Properties.

3.3 Microcontrollers Device Overview and Its Properties

3.4 Microcontroller Features As Guide to Selection

3.5 Characteristics and the Features of Unipolar Type Magnetic Sensors.

3.6 Characteristics and the Features of Bipolar Type Magnetic Sensors.

4.1 Summary of the Comparison between Desired Value and Selected Value.

4.2 Pin assignment and its function.

4.3 General electrical and magnetic specifications.

5.1 Result comparison from designed specification to actual specification

viii

5.2 DIP switch operation direction

5.3 Logic function of the motor driver

LIST OF FIGURES

1.1 Production Layout Illustrated the Material Handling System in Present Practice.

2.1 Plan View of an Exemplary Embodiment of the Information Sensing

Portion of the Guided System.

2.2 The Diagrammatical Perspective View of the AGV Adapted to Move

Automatically Along an Optically Defined Path for Carrying a Load From

a Starting Point to an Arrival Point.

2.3 A Diagrammatic Side Elevation View of a Self Guided Vehicle

2.4 Single-phase AC Power and Three-phase AC Power

2.5 General Form of Motor Performance Curve

2.6 Pair of Spur Gears. The Pinion Drives the Gear

2.7 Hall-Effect Principle With No Magnetic Field Present

2.8 Hall-Effect Principle With Magnetic Field Presents

2.9 Circuit of an IR Emitter and IR Phototransistor

2.10 Circuit and Diagram of an Infrared Reflectance Sensor.

3.1 Basic Draft of the Options for the Drive Mechanism of Automated Guided

Cart.

3.2 Design Concept of the Frame of the Automated Guided Cart.

3.3 Comparison of the Properties between Alloy Steel and Aluminum.

ix

3.4 Force Distributed on the Cart.

4.1 Design Sketch of the Drive Mechanism (Single Stage Gear System) and

Its Main Components.

4.2 Power Flow Through the Gear.

4.3 Direction of Force Distribution on Gear.

4.4 Graphical Representative of Force, Shearing Force and Bending Moment

of the Gear.

4.5 Force Distortion on the Frame of the Cart.

4.6 Graphical Representative of Force, Shearing Force and Bending Moment

of the Frame.

4.7 COSMOSX Analysis of the Aluminum Square Hollow Bar (20x20x1/4)

4.8 Assembly CAD Drawing of the AGC.

4.9 Frame CAD Detail Dimension Drawing.

4.10 Detail CAD Drawing of the Drive Mechanism.

4.11 Pin connection of the dual-bridge microchip Multiwatt15

4.12 Full-bridge circuit electronic circuit diagram.

4.13 Design circuit of the microcontroller board associated with the burner

function.

4.14 Mechanism of turning performed by three magnetic sensors.

4.15 Dimension of the magnetic sensor.

4.16 Designation of the magnetic sensors circuit

5.1 Top view of the structure of Automated Guided Cart

5.2 Dimension of the Automated Guided Cart

5.3 Gear mechanism using spur gear system to drive the cart

5.4 Microcontroller electronic circuit board

5.5 Dual Interchange Pin (DIP) Switch

5.6 Voltage regulator 7805

5.7 Microchip 16F877A pin assignment to the programming.

5.8 Motors controller electronic circuit board.

5.9 Result from the testing on the PWM signal generation.

5.10 Magnetic sensor circuit board.

x

5.11 Typical output characteristics with various values of external bias resistors.

5.12 Solid-state sensor response graph.

5.13 PIC 16F877A pin-out descriptions.

5.14 New project and its setting in microC.

5.15 Source code build into machine code (.hex file).

5.16 Detection of the microchip 16F877A.

5.17 Burning operation of .hex file to microchip.

5.18 Finish burn of the microchip.

LIST OF ABBREVIATIONS

AC - Alternative Current

ADC - Analog Digital Convertor

AGC - Automated Guided Cart

AGV - Automated Guided Vehicle

AGVS - Automated Guided Vehicle System

AISI - American Iron and Steel Institute

CAD - Computer Aided Drawing

CCP - Capture and Compare Module

CPU - Central Processing Unit

DC - Direct Current

DIP - Dual Interchange Pin

EEPROM - Electrically Erasable Programmable Read-only Memory

FMS - Flexible Manufacturing System

GND - Ground

I/O - Input / Output

IC - Integrated Circuit

IDE - Integrated Development Environment

IR - Infra-Red

JIT - Just In Time

LED - Light Emitting Diode

NEMA - National Electrical Manufacturers Association

xi

PIC - Programmable Intelligent Computer

PWM - Pulse Width Modulation

R - Resistor

RAM - Random Access Memory

RPM - Radius per Minute

SCR - Silicon Controlled Rectifier

UNS - Unified Numbering System

USART - Universal Asynchronous Receiver / Transmitter

USB - Universal Serial Bus

1

CHAPTER 1 INTRODUCTION

This chapter introduced the general information regarding to this title of project and

problem statement to state reason to develop the research and implementation of

Automated Guided Cart. Brief declaration of Automated Guided Cart discussed.

1.1 Introduction

Automated guided vehicle system (AGVS) is a material handling system that uses

independently operated, self-propelled vehicles guided along defined pathways

(Groover, 2008). The vehicles are powered by on-board batteries that allow many

hours of operation. An AGV is suitable applies on automating material handling in

batch production and flexible manufacturing system.

In this project, automated guided cart (AGC) developed in the application of material

handling to light duty industry as assembly line applications, storage and distribution

and logistics. There are three main tasks to carry out the project, which are

mechanical structure, controlling electronic circuit components and comments

programming. From designation, material selection, implementation and evaluation

stages, discussed.

2

1.2 Problem Statement

Material handling equipment is usually assembled into a system. The system must be specified and configured to satisfy the requirement of a

particular application. It depends on the materials to be handled, quantities and distance to be move, type of production facility served by the

handling system, and other factors, included available budget.

Figure 1.1: Production layout illustrated material handling system in present practice (Perodua, 2007)

Station #401

Side Member Transferred From Station #201/2 with Overhead Conveyor System

Roof and Cowl-Top Transferred from Sub-Assy Station #304 Coaster Return Conveyor

Plate Fender Transferred with Overhead Conveyor

Shell part (doors, hoods and screws) delivery manually

Station #301

3

In current practice, progress of welding to form a Main Body of KENARI (station

#301) presently is perform in a completely automated process line as shown in

Figure 1.4. In the #301 process, it involved robot welding and the main body delivery

automatically by the conveyor. When the main bodies proceed to the station #401,

which is assembles of the doors and hood. Screws and nuts, doors and hoods are

delivery manually by the tow tractor from the storage. Due to the tow tractor delivery

not in time, downtime of the operation occurred. Furthermore, extra cost of man

power and diesel needed to perform delivery process.

Every point affects the manufacturing cost. Especially man power operated required

labor costs and petrol and diesel consumption due to prices crisis increment.

Therefore, a reasonable adjustment and development required to encounter these

circumstances.

There are several alternatives to modification from manual supply to automated

supply to the station #401, which are automated guided cart system and conveyor

system.

Table 1.1: Comparison of material handling methods

Automated Guided Cart

Manual Transport

Conventional Conveyor

System Initial Investment Cost

Cart & Magnetic / Wire Tape Installation

Fork Lifter / Towing Truck

Building Construction and Modification

Labor, Maintenance and Power Consumption Costs

Labor Cost = 0 Maintenance = Average A Month Once Power Consumption = Electrical Powered

Labor Cost = Each per Transports Maintenance = Average 6 Month Once Power Consumption = Fuel Consumption

Labor Cost = 0 Maintenance = Average 2 Month Once Power Consumption = Electrical Powered

Productivity & efficiency

High Medium High

Material Flow (JIT System & FMS)

Point to Point Point to Point Station to Station

4

To implement automation to a process, several facts and consideration stated as

following based on the problems indicated, summarized of the AGC system

responded to its problems are:

• Cost effectiveness and Labor Free: Automated Guided Carts are in fact, required

no labor other than periodic and remedial maintenance. They can operate 24

hours a day without supervision, injuries, pensions, vacations or sick days.

Furthermore, electrical power drives the movement of AGC is much more

environment friendly and zero fuel consumption needed depend to fork lifter and

towing truck.

• Space Efficient: AGC require little more space than the material they are carrying

and since they are mobile and equipped with on-board safety equipment, they can

co-exist with people, manual material handling and processes such as assembly.

• Increase productivity while reduce costs: A prime for cost saving in

manufacturing is through in-process inventory reduction and facilities

investment. Simply by adding or removing the AGC from the line, assembly

production rate can be adjustable. This fits to company which applied Just-In-

Time System and Flexible Manufacturing System. In an addition, the load

handling is easy to modify to fits the materials or products needed to carries.

Therefore, it protecting the initial investment of the product.

1.3 Objectives

(a) To develop and produce a cost-effectiveness and flexible autonomous

Automated Guided Cart (AGC).

(b) To develop and produce an Automated Guided Cart which is controlled by

Programmable Intelligent Computer (PIC) Microcontroller.

(c) To develop and produce an Automated Guided Cart, which is, could be applied

into industrial environment included safety aspects.

5

1.4 Scope

(a) Design and fabricate the structure of the Automated Guided Cart.

When the materials selected to be used for the frame fabrication, dimensions design

and draw through computer aided design (CAD) drawing or technical drawing

prepared for the assisting to the fabrication stage. There is also needed to inspect the

function of the frame is supportable.

(b) Design and develop the controller of the Automated Guided Cart PIC

microcontroller.

In electrical construction, PIC microcontroller is the main component to control the

function of the AGC. In the programming stage, several hardware needed to be

prepared, they are: (1) burning circuit that transferring the source codes to computer

and convert to machine codes and load into the PIC microchip, (2) programming

software used to complies the source code, (3) computer used as the input and output

module between the microchip and the designed source code.

(c) Design the electrical circuit of the motor driver circuit board and magnetic circuit

board.

For the electrical circuit, it required to design and develops a workable electronic

circuit board that is able to interface to the microprocessor circuit board. Selection to

the magnetic sensors that meet to the microprocessor as input devices needed.

6

CHAPTER 2 LITERATURE REVIEW

In this chapter, the review of information is to support the knowledge and skills

before started the project. There are two major section contained, which are

mechanical section, and electrical section. Due to the information, it ensure the

research and development of the project accomplish.

2.1 Vehicle Guided Technology

The guidance system is the method by which AGC pathway is defined and cart is

controlled to follow the pathways. In this section, it discusses three technologies that

are common used for the vehicle guidance: (1) imbedded guided wires, (2) paint

strips, and self-guided, and (3) self-guided vehicles.

2.1.1 Imbedded Guided Wires

A guided system for a self-guided vehicle features an electrical conductor and

permanent magnets embedded together in an elongate groove formed in a vehicle

supporting surface such as a factory or warehouse floor. The electrical conductor

provides steering guidance while the permanent magnets embedded with the

conductor provide other information without distorting the magnetic field of the

electrical conductor. To prevent such distortion, the permanent magnets are selected

for their low magnetic permeability and high electrical resistivity. Magnetic field

sensors are provided on the vehicle for determining exact position of the vehicle

7

along its path of travel by sensing deviation, or lack thereof, with respect to such

permanent magnets. (Laid, 1987)

Figure 2.1: Plan view of an exemplary embodiment of the information sensing portion of the guided

system. (Laib, 1987)

2.1.2 Paint Strips Guidance

The self-propelling vehicle is adapted to carry a load and has steering-wheels and a

central driving-wheel as well as optical detectors designed to read an optical track

laid out on the ground and furnishing passive driving signals, the vehicle also being

provided with an ultrasonic emitter-receiver assembly working as a radar and

operative to detect obstacles along the path of movement of the vehicle.

(Deplante, 1982)

Figure 2.2: The diagrammatical perspective view of the AGV adapted to move automatically along an

optically defined path for carrying a load from a starting point to an arrival point. (Deplante, 1982)

Hall-effect sensor

Floo Permanent magnet

Magnetic field

8

2.1.3 Self Guided Vehicle

A navigation system for use in a self-guided material handling vehicle provides

guidance during operation in areas having densely stacked rows of containers and

reduces the potential of deviation of the self-guided vehicle from the desired path

travel. A laser-signaling device is mounted on the vehicle and rotatable about an axis

of the rotation extending generally perpendicularly to the longitudinal axis of the

self-guided vehicle. The laser-signaling device is adapted to delivery a light beam

signal at the first preselected angle relative to the axis of rotation of the laser-

signaling device, at a second different preselected angle relative to the axis of

rotation. Receiving devices a reflection of the light beam signal and delivers a

position signal in response to the light beam signal received. The navigation system

is particularly suited for use in automation storage and retrieval systems.

(Wible, 1990)

Figure 2.3: A diagrammatic side elevation view of a self guided vehicle (Wible, 1990)

2.2 Mechanical Review

Design of automated machine always consists of two major elements, which is

mechanical and electrical element. In mechanical design, it creates device or system

to satisfy specific needs. Mechanical devices typically involve moving parts that

transmit power and accomplish specific pattern of motion. Mechanical systems are

composed of several mechanical devices.

9

2.2.1 Material in Mechanical Design

It needed to specify suitable material for each component of a mechanical device

before further designation. The initial efforts in specifying a material for a particular

component of a mechanical design should be directed to the basic kind of material to

be used. Function of the component, kinds and magnitudes of loads it will carry, and

the environment in which it will operate should be specified. (Mott, 2002)

Machine elements are often made from one of the metals or metal alloys such as

steel, aluminum, cast iron, zinc, titanium or bronze. Strength, elastic, and ductility

properties for metals usually determined and considered in the stage of design.

(a) Carbon and Alloy Steel

Steel is possibly the most widely used material for machine elements because of its

properties of high strength, high stiffness, durability and relative ease of fabrication.

Many types of steel are available.

The term steel refer to an alloy of iron, carbon, manganese, and one more other

significant elements. Carbon has very strong effect on the strength, hardness, and

ductility of any steel alloy. The other elements affect hardenability, toughness,

corrosion resistance, machinability, and strength retention at high temperature. The

primary alloying element present in the various alloy steels are sulfur, phosphorus,

silicon, nikel, chromium, molybdenum, and vanadium. (Mott, 2002)

General Form of Designation

The AISI uses a four-digit designation system for carbon and alloy steel as shown

above. The first two digits indicate the specific alloy group that indentified the

primary alloying element other than carbon in steel. The last two digits indicate the

amount of carbon in the steel (Mott, 2002).

Carbon content Specific alloy in the group Alloy group: indicates major alloying elements

AISI X X XX