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“I hereby declare that I have read the content of this thesis and according to my
opinion, this thesis is sufficient in term of scope and quality for the purpose of
awarding a Bachelor‟s Degree of Engineering (Electrical - Mechatronics).”
THE WIRELESS FORKLIFT
ABDUL AZIZ BIN ABDUL RAHMAN
A thesis submitted in partial fulfillment of the requirements for the
degree of Bachelor of Engineering (Electrical - Mechatronics)
FACULTY OF ELECTRICAL ENGINEERING
UNIVERSITI TEKNOLOGI MALAYSIA
MAY 2010
ii
I declare that this thesis entitled “The Wireless Forklift” is the result of my own
research except as cited in the references. The thesis has not been accepted for any
degree and is not concurrently submitted in candidature of any other degree.
iii
Specially dedicated to:
My beloved father, Abdul Rahman Abd. Karim; mother, Ume Kalthom Rusdi; sister,
lecturers and all my friends for their eternal support, encouragement and inspiration
throughout my journey of education in Universiti Teknologi Malaysia.
May Allah bless us.
iv
ACKNOWLEDGEMENT
Alhamdulillah, thank you to Allah S.W.T because of His blessing, I finally complete
and finish my final year project successfully.
During the process to complete my project objective, I do a lot of research,
either by using internet, reading past year thesis, reference books or journals. With
the guidance and support from peoples around me, I finally complete the project due
to the time given. Here, I want to give credit to those who helped me to achieve
what I had achieved in my final year project.
Primarily, I wish to express my sincere appreciation to my supervisor, Dr.
Salinda bt. Hj. Buyamin for her guidance, critics, advices and motivation. Without
her continued support and interest, the project would not be like what it likes today.
I also want to thanks to my beloved parents because without them, I will not
be able to do well in my final year project. They did give me a lot of support, both
from money and moral support to help me continue for what I had started on.
Last but not least, my sincere appreciation also extends to all my colleagues
and others who provided assistance at various occasions involved either directly or
indirectly in completing this project. Their views and tips are useful indeed. From
my deepest heart thanks a lot to all.
May Allah S.W.T bless for the cooperation and support.
v
ABSTRACT
Forklift is a powered industrial truck used to lift and transport materials.
Forklift has become indispensable equipment in manufacturing and warehousing
operations. In order to reduce operational cost and improve productivity, an
automated forklift has been developed from growing number of suppliers.
Nowadays, robotic technologies have been developed rapidly in most countries
where it been used to replace humans in doing tasks or work especially in hostile
environment. Robotic are commonly related to automation which defined as the
process of following a predetermined sequence of operations with minimum or non
human intervention using specialized equipment and device that control and perform
the particular tasks. The progress on robotic, computer technology, sensor and
perception system has produced great advances in the field of forklift. This project
was implemented a mobile robot concept to the forklift. The mainly is about
designing and fabricating forklift which is operated by wireless controlled. The lift
and movement system of the forklift will be provided by miniature electric-powered
motor. This forklift can move forward, backward, turning right and left depend on
the signal from wireless module which is Bluetooth module and give the input signal
to the PIC16F877A which is act as a brain for this forklift to produce the output
signal to control the forklift movement. The objective of this project is to design the
forklift which includes the physical structure, electronic circuit, control and operating
system. The research on this field has great functions and benefits and can be
proceed in the future.
vi
ABSTRAK
Forklift merupakan salah satu trak industri berkuasa yang mempunyai lengan
bercabang yang digunakan untuk mengangkat dan menyusun barang. Kini forklift
telah dianggap sebagai peralatan yang amat penting untuk operasi di gudang dan
kilang. Untuk mengurangkan kos operasi dan meningkatkan produktiviti, forklift
automatik telah dibangunkan oleh banyak syarikat besar. Pada masa kini, teknologi
robotik telah membangun dengan pesatnya di kebanyakan negara untuk
menggantikan penggunaan tenaga manusia terutama di persekitaran kerja yang
merbahaya. Teknologi robotik yang berkaitan dengan automasi yang didefinisikan
sebagai proses separa-tentu digunakan untuk aplikasi yang akan meminimumkan
penglibatan manusia dalam melakukan tuga-tugas tertentu. Kemajuan robotik,
teknologi komputer, penderia dan sistem persepsi telah memberi kelebihan dalam
bidang forklift. Dalam projek ini, konsep robot mudahalih telah dilaksanakan pada
forklift yang mana membawa kepada kepentingan rekabentuk model forklift
mudahalih yang beroperasi dengan kendalian kawalan tanpa wayar. Sistem angkat
dan pergerakan forklif‟ ini berdasarkan motor kecil yang menggunakan kuasa bateri.
Kawalan pergerakan forklift ini ditentukan oleh isyarat yang diperolehi daripada
modul kawalan tanpa wayar iaitu modul Bluetooth yang memberi isyarat masukan
kepada PIC16F877A yang bertindak selaku „otak‟ utama yang memproses maklumat
dan memberi isyarat keluaran untuk mengawal operasi motor. Objektif projek ini
ialah untuk merekabentuk forklift termasuklah struktur fizikal, litar elektronik, sistem
dan kawalan operasinya. Penyelidikan dalam bidang ini mempunyai fungsi yang
hebat dan kebaikan serta dapat dilanjutkan di masa hadapan.
vii
TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF ABBREVIATIONS xiii
LIST OF APPENDICES xiv
1 INTRODUCTION 1
1.1 Project Background 1
1.2 Project Objective 1
1.3 Scope of the Project 2
1.4 Project Methodology 3
1.5 Thesis Structure 3
2 LITERATURE REVIEW 5
2.1 Industrial Forklift Truck 5
2.2 ATX-Series Omni-Directional Forklift 6
2.3 Massachusetts Institute of Technology (MIT)
Intelligent Robotics Forklift 8
viii
2.4 Unmanned Autonomous Forklift 9
2.5 LEGO® MINDSTORMS
® NXT Forklift 10
3 METHODOLOGY 12
3.1 Mechanical Structure Design 14
3.1.1 Base Body 16
3.1.2 Wireless Forklift‟s Fork Arm 17
3.1.3 Actuator 18
3.1.3.1 Tamiya Twin-Motor Gearbox DC
Motor 19
3.1.3.2 Hextronix HX5010 Servo Motor 20
3.1.4 Wheel and Castor 21
3.2 Electronic Circuit Design 22
3.2.1 Power Supply Circuit 25
3.2.2 Main Circuit 26
3.2.3 Motor Driver Circuit 29
3.2.4 Bluetooth Module 30
3.3 Software Programming Design 33
3.3.1 Controlling the Wireless Forklift
Movement 36
3.4 Summary of Chapter 3 37
4 RESULT AND DICUSSION 39
4.1 Result 39
4.1.1 The Wireless Forklift 39
4.1.2 Wireless Forklift‟s Movement 41
4.2 Discussion 42
5 CONCLUSION AND RECOMMENDATION 44
5.1 Conclusion 44
5.2 Recommendation 45
ix
REFERENCES 46
APPENDIX A 47
x
LIST OF TABLES
TABLE NO. TITLE PAGE
3.1 PIC16F877A microcontroller specification 29
3.2 KC21 Wirefree Bluetooth module function description 32
3.2 ASCII character corresponds to the specific command 36
xi
LIST OF FIGURES
FIGURE NO. TITLE PAGE
2.1 Typical industrial forklift overview 6
2.2 Airtrax ATX-3000 forklift 7
2.3 MIT intelligent robotics forklift 9
2.4 Clark CRX-10 forklift equipped with sensors 10
2.5 LEGO® MINDSTORMS
® NXT forklift 11
3.1 Methodology flow chart 13
3.2 Mechanical structure design overview 14
3.3 Complete mechanical design with dimension 15
3.4 A 3 mm A4 size acrylic 16
3.5 Forklift‟s base body size and dimension 17
3.6 Forklift‟s fork arm dimension 18
3.7 Tamiya twin-motor gearbox 19
3.8 Hextronix HX5010 twin bearing servo motor 21
3.9 Tamiya off-road tire 22
3.10 Tamiya ball castor 22
3.11 Electronic part configuration interfacing 23
3.12 Electronic circuit design schematic 24
3.13 Complete electronic circuit 25
3.14 7.4 volts rechargeable battery and 9 volts battery 26
3.15 Voltage regulator circuit 26
3.16 Microcontroller circuit 28
3.17 Pin diagrams for the PIC16F877A 28
3.18 Motor driver circuit 30
3.19 Bluetooth module 30
xii
3.20 KC Wirefree Bluetooth module system overview 32
3.21 KC21 Wirefree Bluetooth module 32
3.22 Software programming design flow chart 33
3.23 MikroC compiler interface 34
3.24 PICkit 2 programmer interface 35
3.25 USB ICSP PIC programmer 35
3.26 Flow chart for the wireless forklift control and
movement 37
4.1 The final wireless forklift design overview 40
4.2 The complete wireless forklift overview 41
4.3 The wireless forklift capable to lift-up a small object 42
xiii
LIST OF ABBREVIATIONS
RF - Radio Frequency.
PIC - Programmable Interface Controller.
MIT - Massachusetts Institute of Technology.
USA - United States of America.
PC - Personal Computer.
CSAIL - Computer Science and Artificial Intelligence Laboratory.
CAD - Computer Aided Design
DC - Direct Current
mm - millimeter
IC - Integrated Circuit
USB - Universal Serial Bus
USART - Universal Synchronous/Asynchronous Receiver/Transmitter
UART - Universal Asynchronous Receiver/Transmitter
PWM - Pulse Width Modulation
LED - Light Emitting Diode
ICSP - In-Circuit Serial Programming
ASCII - American Standard Code for Information Interchange
xiv
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Gantt Chart 1 and 2 47
1
CHAPTER 1
INTRODUCTION
1.1 Project Background
Mobile robot is about any robots that have ability to move from one place to
other place. Mobility increase robot effectiveness and portability. This project
named wireless forklift is an attempt to provide mobile robot with truly controlled by
wireless control. This project was implemented as same as the concept of the real
forklift that can move and capable to lift-up and place an object.
1.2 Project Objective
The first objective of this project is to create, design and build a forklift that
capable to lift-up and place an object. By applying the concept and characteristic
from the real forklift, a forklift can be fabricated and implemented as a project.
According to the concept, a forklift must have two arms likely fork in front of its
body to ensure it capable to lift-up an object.
2
After the characteristics of build concept were determined. The second
objective is to design an operating system for the forklift. The forklift can be control
by using wireless control. There are various types of wireless control modules can
be used for data sending that works in any application other than the control of
models for hobby and recreational purposes such as radio frequency (RF) module,
ZigBee module and Bluetooth module. In this project, Bluetooth module has been
used to control the forklift remotely from the laptop.
Here, the input and output for this project are already defined, so the last
objective is to develop the control system that will receive the input signal or
instruction for determine the process that it must execute to give out the desired
output. PIC microcontroller does fit the purpose to control all activities of the
wireless forklift and it has all the peripherals that needed.
1.3 Scope of the Project
The scope of this project will be the guidelines throughout this project to ensure
the project is conducted within it‟s intend objectives. At the end of the project, it
should be eventually achieved. The scopes are:
Design of the mechanical and electronic hardware to suit the software
programming.
The forklift is control by using wireless control.
The wireless forklift in conjunction to do a simple task such as moving and
lift-up an object using its fork arm.
3
1.4 Project Methodology
In the beginning of this project, some research on the background of a forklift
was conducted to get the concept and ideas. From these inputs, the objectives and
scope of the project were determined. Besides, the findings from the research of
theory and concept of forklift, as well as case studies of other models have been so
helpful to project development process and all of the relevant information‟s were
arranged for the literature review. The designing process of electronic circuit for
microcontroller circuit, voltage regulator circuit and motor driver circuit were carried
out after done some research. By studying the working system of a forklift, the
structure and mechanism of the forklift have been fabricated.
While the electronic and mechanical part was done, it is time to work on the
combination and arrangement of both parts. In the software part, the instruction for
control system of the wireless forklift was programmed which to be loaded into the
microcontroller. Then be able to do the testing and troubleshooting activity to the
workable forklift. During this activity, the limitation of the forklift‟s application can
be recognized. The details discussion of the methodology on hardware and software
implementation for this project will be discussed in Chapter 3.
1.5 Thesis Structure
This thesis basically discuss about the construction of the wireless forklift.
First chapter discuss on the introduction of the project. Second chapter discuss on
the literature review. While chapter three will focus on the research methodology
details on the mechanical, electronic and software design. Chapter four is about
4
result and discussion. Finally, chapter five will explain about the conclusion and
future recommendation.
5
CHAPTER 2
LITERATURE REVIEW
Conducting the literature review is done prior to undertaking the project.
This will critically provide as much information as needed on the technologies
available and methodologies used by other research counterparts around the world on
the topic. This chapter provides the summary of the literature reviews on topics
related to the wireless forklift.
2.1 Industrial Forklift Truck
Forklift as shown in figure 2.1 is a powerful industrial truck [1] that is to lift
and transport material by steel forks that are inserted under the load. Forklift is
commonly used to move loads and equipment that is stored on pallets. It was
developed in 1920 and has since become a valuable piece of equipment in many
manufacturing and warehousing operations. The most type of forklift is the counter
balance forklift. Forklifts are available in many types and different load capacities.
In the average warehouse setting, most forklifts have load capacities of around five
tons.
6
One of the most important aspects of operating forklift is the rear wheel
steering. Even though this helps to increase maneuverability in tight cornering
situations, it differs from the traditional experience of a driver with other wheeled
vehicles as there is no caster action. Another critical aspect of the forklift is the
instability. Both the forklift and the load must be considered a unit, with a varying
center of gravity with every movement of the load.
Figure 2.1: Typical industrial forklift overview.
2.2 ATX-Series Omni-Directional Forklift
Airtrax ATX-3000 [2] as shown in figure 2.2 is an industrial forklift that can
be travel in any directions and excellent in the applications requiring tight
maneuvering or transporting long loads sideways through standard sized door or
narrow aisle ways. The ATX‟s unique Omni-Directional allows it to travel in all
directions thus making it an ideal vehicle to work in tight spaces where turns are not
7
possible and finite control is important. This forklift features 48 volts transistor
controls technology, infinitely variable travel, lift and lower speeds, excellent
visibility, ergonomic controls and operator comfort.
The unique designs of the four independently driven wheels enable the
ATX‟s Omni-Directional capabilities. Each wheel is directly driven by individual
transaxles. The wheels consist of a large, heavy-duty hub with 12 uniquely designed
polyurethane rollers. The wheel and roller design provides the Omni-Directional
movement of the forklift based on the speed and direction of each wheels as
determined by the operator. Each roller incorporates bearings that do not require
periodic greasing or maintenance under most conditions. Since each roller rotates
freely, scrubbing against the floor is minimized while turning or moving sideways.
Figure 2.2: Airtrax ATX-3000 forklift.
8
2.3 Massachusetts Institute of Technology (MIT) Intelligent Robotics
Forklift [3]
The new United States of America (USA) army funded robotic forklift as
shown in figure 2.3 that can recognizes voice commands, can learn the layout of a
makeshift warehouse and operate out of doors has been built. It also may be able to
save lives on the war zone field and make the warehouse work more efficient at
home. But for the specific purposes, MIT with funded by USA army have been
develop robotic forklift that can be used in a war zone.
This semi-autonomous prototype forklift is able to familiarize itself with a
particular warehouse and then follow orders given by a remote human superior.
Footage from the robot‟s forward-looking video camera is displayed on a tablet
personal computer (PC), which serves as a wireless controller. The operator can
issue command with a stylus, tapping on a particular pallet where the forks should be
inserted, but the robot also responds to voice commands. The project is based at
MIT‟s Computer Science and Artificial Intelligence Laboratory (CSAIL) and is
funded by USA Army Logistics Innovation Agency for the purposes of military
application.
This MIT‟s robotics forklift is a modified 3 tone Toyota forklift, designed to
operate outdoor and indoor. This forklift using voice recognition and an array of
learning algorithms; tying words to places and places to actions with everything
positioned spatially. This forklift will be smarter than the average forklift. Besides
of operating autonomously, this forklift also can be controlled manually in presence
of human control. An operator can jump into the cockpit and take over the forklift.
There no switches or buttons to hit, seat-occupancy sensors kick in and the machine
relinquishes autonomous control. The sort of semi-autonomous control might be the
key to functional artificial intelligence.
9
Figure 2.3: MIT intelligent robotics forklift.
2.4 Unmanned Autonomous Forklift [4]
The vehicle to be automated in this project is a standard industrial forklift
CRX-10 as in figure 2.4 produced by the CLARK company. The forklift body is
mounted on four wheels includes two caster wheels at the front side and one small
caster wheel at the right rear side without any ability of steering or traction and one
main wheel at the left rear side for driving and steering of the forklift. The
dimension of the forklift is 2680 mm x 1170 mm x 2260 mm and its velocity is
limited up to 10 km/h both for empty or loaded operations. To achieve autonomy,
the forklift is modified so that all the necessary sensors and a PC for steering and
driving motors are attached. The main requirement in automating the forklift is to
provide the ability for dual operations that is unmanned mode and manual mode.
The motion command for the unmanned forklift is generated based on the
information of its pose provided by several sensors. The absolute pose of the forklift
in the global reference coordinate is determined on a given map based on the data
from ultrasonic satellite and gyro sensor. The present pose and speed of the forklift
10
from its initial point is calculated using the data from wheel encoder and gyro sensor.
The information about the forklift environmental is obtained by using vision, laser
range finder and sonar sensors. Based on the current pose, speed and the information
about the change on its working environment, the position of the forklift with respect
to its goal point on the reference frame can be calculated. The control command to
actuate the motion of the forklift is then generated by considering the trajectory on
the goal pose and the safety of its motion. The control inputs for the forklift consist
of linear and angular velocities. The appropriate control signal is determined by an
action selection algorithm based on the tasks that needs to be accomplished by the
autonomous forklift.
Figure 2.4: Clark CRX-10 forklift equipped with sensors.
2.5 LEGO® MINDSTORMS
® NXT Forklift [8]
This forklift as shown in figure 2.5 can drive around and steer on the carpet
or hard floors, lift loads that are placed on the pallet frames 6 inches straight up, set
them gently down on top of shelves or other platforms and take them back down.
The forklift can be program to do automatic tasks using the rotations sensors in the
motors and the ultrasonic sensor on the top or working with Bluetooth connection
11
between computer and NXT, then it can be drive by wireless remote control from
computer keyboard using free Bluetooth vehicle remote program provided by Anders
Soborg. Two NXTs can be control it by using Bluetooth with the dial remote
control.
Figure 2.5: LEGO®
MINDSTORMS® NXT forklift.
12
CHAPTER 3
METHODOLOGY
This project is divided into two parts. First is the hardware design and second is
the software design. This project activity must be done step by step in order to
achieve it target. It begins with the searching and collecting information from the
various sources such as journals, books, past year thesis and internet. The review is
about mechanical structure design, electronic circuit design and software
programming design.
The project was begun by finding the idea and concept related to this project
title. The wireless forklift depending on how it will be programmed should
implement all the behaviors like moving and lift-up an object. A survey concerning
prices, availability and choices had been done on the material and components that
will be used. The circuitry, data sheet and others information were gathered, seeking
for the most appropriate selection of components. Then, research on mechanical
design where how does base body and others mechanical part look alike. Just after
completing the design of mechanical and electronic part, it proceeds to developing
the software in C programming. Troubleshoot will always be done as long as there is
an error in final testing to get the final output and result. Figure 3.1 shows the
research methodology flow chart for completing this project.
13
Figure 3.1: Methodology flow chart.
FYP REPORT
FINAL
TESTING
YES
NO
TROUBLESHOOT & FINE TUNING
SOFWARE DEVELOPMENT & INTERFACING
MECHANICAL & ELECTRICAL PARTS ARRANGEMENT
WIRELESS CONTROL MOTOR DRIVER MAIN CONTROLLER
DESIGN ELECTRONIC CIRCUIT
FABRICATE MECHANICAL STRUCTURE
WIRELESS
FORKLIFT
BACKGROUND & LITERATURE STUDIES SCOPE OBJECTIVE
IDEA & CONCEPT
14
3.1 Mechanical Structure Design
Figure 3.2: Mechanical structure design overview.
15
Figure 3.3: Complete mechanical design with dimension.
The design of wireless forklift is mainly inspired from the figure 3.2 and
figure 3.3 that have been constructed and developed using Google SketchUp version
7.1. It was used as CAD tool to design the mechanical structure because it is free
and offer simplicity to the user. The main objective in this chapter is to converse the
forklift design, material and approach to construct the mechanical structure. This
forklift structure was built to capable moving in several directions such as forward,
backward, turn right and turn left; and do simple task to lift-up an object using its
fork arm. In order to do that, a few designs of the mobile robot and forklift has been
studied.
This wireless forklift was built consists of base body, aluminum fork arm,
actuators, wheels and castor. Most of these parts are built from raw material and
some are modified to congruent with this project. In other hand, most of the material
used is aluminum and acrylic.
ELECTRONIC CIRCUIT PART
WHEEL
CASTOR
FORK ARM
SERVO MOTOR
DC MOTOR
BASE BODY
16
The wireless forklift are powered by 7.4 volts rechargeable battery and 9
volts battery; one servo motor needed for the fork arm in order to lift-up an object;
two DC motor and castor for moving and stability of the base. The body and the fork
arm of the wireless forklift were built up using aluminum and acrylic.
3.1.1 Base Body
In order to have a smooth surface on the base of the wireless forklift, acrylic
was used to make this base shaped. As in figure 3.4, a 3mm A4 size of acrylic was
choose because of it tough, light and elastic characteristic. Other than, acrylic is also
reliable because of its cheap in price and easy to cut and shape it. While, in figure
3.5 shows a base body for the wireless forklift looks like as well as its size and
dimensions.
Figure 3.4: A 3 mm A4 size acrylic.
17
Figure 3.5: Forklift‟s base body size and dimension.
3.1.2 Wireless Forklift’s Fork Arm
Aluminum was used in this project to built most of the component in order to
obtain a light forklift. It is important to achieve the target so that the DC motor
which will drive the forklift is able to move smoothly. Hence, the fork arm for the
forklift was built from the aluminum. There are several type of aluminum that had
been used such as curtain rail, aluminum bar and L-shape aluminum. In this project,
aluminum was used because of its price and easy to cut and combine. The aluminum
was combined and connected to each other by using screw and nuts. The fork arm of
the wireless forklift was attached with the base by using the L-shape aluminum.
Figure 3.6 shows forklift‟s fork arm design and its dimensions.
18
Figure 3.6: Forklift‟s fork arm dimension.
3.1.3 Actuator
In order to ensure the wireless forklift is properly function, the actuators is
the part for the forklift will be move and capable to lift-up an object. For this project,
the actuators that had been used were DC motor and servo motor.
19
3.1.3.1 Tamiya Twin-Motor Gearbox DC Motor
Motor are inductive devices since they draw much more current at startup
than when they are running at a steady speed. Generally, a DC motor has two
terminals on it. If the positive and negative leads from the power source such as
battery are connected to the terminals of the motor, the motor will spin in one
direction. If the connection is swapped, the motor will spin in the opposite direction.
Figure 3.7 shows the twin-motor gearbox DC motor used in this project. The
Tamiya twin-motor gearbox is a small plastic gearbox. It contains two small DC
motor that drive separate 3 mm hexagonal output shafts. There are two possible
configuration options of standard speed with a high-speed 58:1 gear ratio or with a
slower speed 203:1 gear ratio. Either way, the motors can provide plenty of power to
drive any small robot. In this project, the gearbox will be assembled for use with a
low speed configuration because of the stability consideration for the wireless
forklift. The two low-voltage DC motors in the twin-motor gearbox run on 3-6 volts.
The 3 mm hexagonal shaft is compatible with Tamiya‟s wheel.
Figure 3.7: Tamiya twin-motor gearbox.
20
3.1.3.2 Hextronix HX5010 Servo Motor
A servo is a motor that is attached to a position feedback device. It consists
of several main parts that are motor and gearbox; a position sensor; an error
amplifier; a motor driver and a circuit to decode the requested position. Standard
servo motor is designed to receive electronic signals that tell what position to hold.
These motors can be programmed to move it shaft to a specific angle where the shaft
can turn from 0 degree to 180 degree if given the right signal. The microcontroller
will generated a pulse of varying length approximately every 20 milliseconds. The
pulse is normally between 1 and 2 milliseconds long. The length of the pulse is used
by the servo to determine the position it should rotate to. The pulse width however
must be accurate to ensure that the position of the servo is accurately set. Since the
targeted object will be a small object, then the torque produced by the servo motor is
much enough to lift-up and hold the object.
In this project, one modified Hextronix HX5010 servo motor had been used
as the actuator for the wireless forklift‟s fork arm application. This servo motor had
been modified to ensure it can rotate 360 degree like a DC motor but it still can be
functional as a standard servo motor with servo control output. The HX5010 servo
motor as in figure 3.8 was used instead of its simple and cheapest hobby servo.
Modifying servo is simple but required a lot works to do. To ensure it can rotate 360
degree, a small black plastic disk with a rectangular hole in the middle should be
removed and a small stopper should be cut at the output shaft gear.
Hextronix HX5010 twin bearing servo motor basic specifications:
Dimensions : 40 x 20 x 38 mm
Weight : 39 g
Speed : 0.16 sec/60 deg.
21
Stall torque : 6.5 kg
Dead bandwidth : 4 us
Voltage : 4.8 – 6volts
Figure 3.8: Hextronix HX5010 twin bearing servo motor.
3.1.4 Wheel and Castor
Two wheels of Tamiya off-road tire and Tamiya ball castors were attached to
the base of the forklift to achieve its stability to move. The wheels was attached to
the right and left side of the twin-motor gearbox DC motor chassis which is place at
the back of the forklift. Meanwhile the two castors is place at the front of the forklift
as replacement of the front wheels. Figure 3.9 shows the wheel and figure 3.10
shows the castor looks like.
22
Figure 3.9: Tamiya off-road tire.
.
Figure 3.10: Tamiya ball castor.
3.2 Electronic Circuit Design
This subtopic enlightens the electronic part of the wireless forklift as
illustrated in figure 3.11. While as shown in figure 3.12 is the all electronic parts
schematic design using ISIS software. Figure 3.13 shows the complete soldered
electronic circuit based on the schematic design. All circuit involved and the
connections between devices will be explained. The electronic part is divided into
four parts consists of power supply circuit, main circuit, motor driver circuit and
Bluetooth module. Power supply circuit includes of 5 volts and 6 volts voltage
regulator. The main circuit consists of PIC16F877A microcontroller circuit and its
peripherals. Meanwhile the interface circuit consists of the motor driver circuit and
Bluetooth module. Those electronic circuits part are done on the donut board. As
overall, there are four part of electronic circuit total. They were connected by
rainbow wire to make the connection neat and easy.
23
Figure 3.11: Electronic part configuration interfacing.
DC MOTOR
Tamiya Twin
Gear Motor
MOTOR
DRIVER
L293D
MICROCONTROLLER
PIC16F877A
USART
SERVO MOTOR
HX5010
BLUETOOTH
MODULE
KC Wirefree
+5V Voltage
Regulator
LM7805
POWER
SUPPLY
CIRCUIT
+6V Voltage
Regulator
LM7806
24
Figure 3.12: Electronic circuit design schematic.
25
Figure 3.13: Complete electronic circuit.
3.2.1 Power Supply Circuit
The electronic circuit for the forklift must have power to be operated. Due to
that, the power supply circuit was built so that it can power up the circuit that needs
power such as microcontroller, motor driver, actuators and Bluetooth module. The
main source of the power supply circuit is supplied from 7.4 volts rechargeable
battery and 9 volts battery as in figure 3.14 shows. This power supply circuit
consists of 5 volts and 6 volts voltage regulator as mention in figure 3.15. The main
component of both regulators is the IC LM7805 and IC LM7806 voltage regulator.
26
The components that use 5 volts as a power supply are PIC16F877A
microcontroller, L293D motor driver and Bluetooth module. For the 6 volts, the
actuators includes DC motor and servo motor was used it as a power supply.
Figure 3.14: 7.4 volts rechargeable battery and 9 volts battery.
Figure 3.15: Voltage regulator circuit.
3.2.2 Main Circuit
The main part of the main circuit is the PIC16F877A microcontroller. Beside
that it includes other circuitry for the microcontroller operation and function such as
27
reset circuit, oscillator circuit and USB programmer circuit. The microcontroller‟s
ability to store and run unique programs makes it extremely versatile. In order to
construct a forklift, the microcontroller is usually used to act as a brain for the
forklift. The microcontroller control and monitor various input and output devices
such as DC motor, servo motor and Bluetooth module.
In this project, microcontroller acting as a brain for the forklift will be used to
generate signals to move the DC motor to desired location after receive some input
signal. Besides that, it is also used to perform such movement to that the fork arm
can lift-up an object and hold it. In this project, the PIC16F877A microcontroller
was chosen to be used as a brain and to controls actions of the wireless forklift, so
that the forklift can act accordingly after processing the inputs signals received. This
microcontroller was chosen because of it small in size, provides enough input and
output ports and supports more functions such as USART. Furthermore, a
comprehensive set of development tools, application notes and datasheets are also
available to download. The connection of the circuit is shown in figure 3.16.
Meanwhile, figure 3.17 shows the pin diagrams for the microcontroller. Then, table
3.1 shows the specification that includes in the PIC16F877A microcontroller that has
been chose as a main brain in this project.
28
Figure 3.16: Microcontroller circuit.
Figure 3.17: Pin diagrams for the PIC16F877A.
29
Table 3.1: PIC16F877A microcontroller specification.
3.2.3 Motor Driver Circuit
Motor driver circuit as shown in figure 3.18 is use for the connection between
DC motor and microcontroller. The function of motor driver is to protect
microcontroller and also the DC motor if any bad condition happen such as current
or voltage flow through the circuit exceed allowed. This can save the
microcontroller from exceed current or voltage flow. For the L293D motor driver, it
requires both 5 volts and 6 volts to supply to the control connection and motor
connection respectively. With using motor driver, speed of the DC motor can be
controlled by using pulse width modulation (PWM) from the microcontroller.
30
Figure 3.18: Motor driver circuit.
3.2.4 Bluetooth Module
Figure 3.19: Bluetooth module.
31
In this project, Bluetooth module that has been used was the KC Wirefree
Bluetooth module. Figure 3.19 shows the Bluetooth module was attached to the
circuit connection. This Bluetooth module offer simple and compact Bluetooth
platform for embedded application. This device has been designed for operate in 5
volts. With minimum interface, it is ready to connect to microcontroller for
embedded Bluetooth development. Furthermore, on board USB to UART converter
offer easy and reliable communication to PC for functionality test or even creating
Bluetooth wireless connection. Figure 3.20 shows the Bluetooth module system
connection overview. While for the figure 3.21 shows the KC21 Wirefree Bluetooth
module and its function as describe in table 3.2.
It has been designed with capabilities and features of:
USB plug and play UART function
5volts powered
5Vvolts UART interface, ready for microcontroller interface
Default baud rate of 115.2Kbps
Compact and easy and reliable platform
As USB Bluetooth dongle
As serial port replacement (wireless)
Dimension: 72mm x 39mm
32
Figure 3.20: KC Wirefree Bluetooth module system overview.
Figure 3.21: KC21 Wirefree Bluetooth module.
Table 3.2: KC21 Wirefree Bluetooth module function description.
LABEL FUNCTION
A KC21 Wirefree Bluetooth module.
B 5 ways header pin for external power supply and interface to
microcontroller.
C USB B type socket.
D On board 3.3 volts power indicator LED. It is green color.
E Two LED indicators for USB‟s transmitter and receiver status.
F On board reset button for KC21 Wirefree Bluetooth module.
33
3.3 Software Programming Design
Flow chart for the basic process of the software programming design is
illustrated in figure 3.22.
Figure 3.22: Software programming design flow chart.
There are two types of software and hardware was used for the programming
part. MikroC compiler as in figure 3.23 was used to compile the C code to the .hex
code and PICkit 2 programmer as in figure 3.24 which used to load the program into
the microcontroller by using Cytron USB ICSP PIC programmer as shown in figure
3.25.
DOWNLOAD TO MICROCONTROLLER
IN .hex FORMAT
START
DESIRED FORKLIFT MOVEMENT
TEST FORKLIFT
MOVEMENT
WRITING PROGRAM
COMPILE USING mikroC
END
failed
ok
34
MicroC is a powerful, feature rich development tool for PIC microcontroller
develop by mikroElektronika. It is designed to provide the programmer with the
easiest possible solution developing applications for embedded systems, without
compromising performance or control. PIC and C fit together well. In this project,
C language was used in programming this wireless forklift. So, the mikroElekronika
(MikroC) software is needed to compile the C language into machine code before
programmed into microcontroller.
PICkit 2 is software that used in this project to load the .hex file into the
microcontroller. This software will be used together with the programmer which
being called Cytron USB ICSP PIC programmer. The Cytron USB ICSP PIC
programmer is the low cost reliable and user friendly PIC USB programmer
solutions for user to program popular flash PIC microcontroller which include
PIC12F, PIC16F and PIC18 family.
Figure 3.23: MikroC compiler interface.
35
Figure 3.24: PICkit 2 programmer interface.
Figure 3.25: USB ICSP PIC programmer.
36
3.3.1 Controlling the Wireless Forklift Movement
Bluetooth module was used as a cable-replacement. It allows microcontroller
to communicate with laptop and let user control the wireless forklift. Every
commands send from laptop transmit from Bluetooth dongle to the Bluetooth module
on the forklift. Commands send from laptop are ASCII codes. Every command
owns their unique ASCII characters. Table 3.3 below lists all the command used.
Table 3.3: ASCII character corresponds to the specific command.
ASCII Character Specific Command
„w‟ Moving Forward
„s‟ Moving Backward
„a‟ Turn Left
„d‟ Turn Right
„o‟ Fork Arm Up
„l‟ Fork Arm Down
„q‟ Stop the Forklift
For the next stage, after the connection for the wireless control was
established. If user turns switch „ON‟ of wireless forklift, it will be online and wait
the input from user to press the keyboard button on laptop‟s keyboard. For example,
if user presses the „w‟ button the keyboard, the wireless forklift will move forward.
This ASCII character „w‟ will be send to the microcontroller via Bluetooth
connection and allow the forklift to move forward. The use of ASCII character is
due to its simplicity and faster execution time. Microcontroller only need to process
a character rather than a words, that later could affect the rate of data transfer and
processing. Each movement or action owns a unique ASCII character. This unique
ID character used to separate each process from others for programming simplicity
and to avoid the misunderstanding during program execution. Figure 3.26 show the
flow chart algorithm for the wireless forklift control and movement.
37
Figure 3.26: Flow chart for the wireless forklift control and movement.
3.4 Summary of Chapter 3
Chapter 3 describes the research methodology for this project consists of
mechanical structure design, electronic circuit design and software programming
design. For the mechanical structure design it shows the wireless forklift‟s structure.
The main part consists of the base, forklift‟s fork arm, actuator, wheel and castor.
This subtopic discussed on how to build the forklift and material selection. It is
essential to locate the DC motor and castor appropriately since it will influence the
balance of the forklift itself.
START
Select COM port
Wait for
user input
Get ONLINE
OFFLINE
ONLINE
Keyboard
button
YES
Button press
Keyboard
button
Keyboard
button press
NO
‘o’
‘q’
‘d’
‘a’
‘s’
‘w’
‘l’
UP
STOP
TURN RIGHT
TURN LEFT
BACKWARD
FORWARD
DOWN
38
For the electronic circuit design, several circuits had been built such as power
supply circuit, main circuit, motor driver circuit and Bluetooth module. The last part
is focusing more on the software development of the wireless forklift programming
whereby it starts on writing the program using C language programming. In this
project for the software development, MikroC compiler and its development tools
include PICkit 2 and USB PIC programmer was discussed.
39
CHAPTER 4
RESULT AND DISCUSSION
The final accomplishment and result of the project shall be explained in this
chapter. This chapter discusses on the result, analysis and problems that are
encountered throughout the completion of the wireless forklift. After the
development and completion of the forklift, it will then be evaluated in order to
measure the effectiveness and to ensure whether it had met the outlined objectives
successfully. By the methodology as discussed in the previous chapter, this project
has made remarkable result and achievement.
4.1 Result
4.1.1 The Wireless Forklift
Figure 4.1 depict the final design of the wireless forklift. It consist of
electronic circuit includes voltage regulator, motor driver, microcontroller and
Bluetooth module; mounted DC motor and servo motor; and forklift‟s fork arm.
40
While as mention in figure 4.2 shows the complete mechanical structure of the
wireless forklift.
Figure 4.1: The final wireless forklift design overview.
DC MOTOR
FORK ARM
ELECTRONIC CIRCUIT
SERVO MOTOR
41
Figure 4.2: The complete wireless forklift overview.
4.1.2 Wireless Forklift’s Movement
The development for the wireless forklift is successfully designed. The
wireless forklift was able to move forward, backward, turn right and turn left as
follow the microcontroller‟s program. The forklift was able to move in flat room‟s
floor without any obstacles avoidance. As the result, the process for main function
for the wireless forklift is to move in any forward, backward, turn right and turn left
direction and lift-up an object using its fork arm. As shown in figure 4.3, the
wireless forklift is capable to lift-up a small object with a weight around 100 grams
and dimensions of 6 x 7 x 11 cm.
42
Figure 4.3: The wireless forklift capable to lift-up a small object.
4.2 Discussion
Although this project is successfully implemented, there are some
challenging parts throughout this project. The first challenging part is the electronic
circuit. The first design of the electronic circuit was designed as an integrated circuit
or in the hand, all the electronic circuit are done in one donut board. After
completing the circuit, there are some problems on the circuit as it is not functioning
well. Some troubleshooting has been done vigorously to the circuit. But, it is still
not function. As time constrains, the best solution must be find. As the best
solution, the circuits were divided into several parts and can be connected by using
rainbow wire. Then it is work and function. To attach the electronic circuit to the
forklift‟s base, the circuit is combine to each other by implemented the layer concept.
As a result, the electronic circuit in the forklift is four layer circuits.
The second challenging part is to design the forklift‟s fork arm. By using the
curtain rail and several aluminum parts, the fork arm has been design. But, the arm
is not stable and its motion to lift-up an object is not smooth. As a solution to this
43
problem, one short ruler has been attach to the fork arm and tight it with thread to
ensure the arm is not collides with the curtain rail which act as a platform to the arm
to move up and down. And some grease has been swept to the arm to make it move
smoothly.
The last challenging part is the Bluetooth connection. Troubleshooting has
been done severally. However, the Bluetooth is not functioning well. Then, more
improvement can be done in the future.
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CHAPTER 5
CONCLUSION AND RECOMMENDATION
5.1 Conclusion
The project has been successfully carried out to create, design and build the
wireless forklift. The wireless forklift was capable to lift-up a small object at some
destination by using wireless control from Bluetooth module. This wireless control
is control remotely from the laptop. Several electronic circuits consists of LM7805
and LM7806 voltage regulator, PIC16F877A microcontroller, L293D motor driver
and Bluetooth module were successfully integrated into the wireless forklift and all
the electronics circuit is functioning. The wireless forklift has capability to lift-up an
object to the destination with capability of movement direction of forward,
backward, turn right and turn left. As a conclusion, the wireless forklift is
successfully designed, implemented and tested.
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5.2 Recommendation
Some modification can be implemented to enhance the capability of the
wireless forklift. On the mechanism part, more powerful high torque DC motor and
servo motor should be applied with a lighter body structure to enhance the forklift
movement and stability to lift-up an object. Addition of a camera as a vision system
so that the footage from the forklift‟s forward looking can be display on a laptop. In
addition, several sensors can be installs to the forklift such as infra-red sensor and
distance sensor in order to make it more efficient and can be moving as an
autonomously forklift. For the wireless control, it is suggested to use the difference
wireless control such as RF controller and ZigBee controller. Besides that, it is also
suggested that the programming of the wireless Bluetooth were reconstructed to
make it more efficient. An optimize solution is always a better way. It is hope for
this forklift can be reconstructed with some modification to improve the abilities and
provide benefits in the future.
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REFERENCES
1. Illinois Department of Commerce and Economic Opportunity. Forklift Safety
Guide. State of Illinois (USA): Safety Guide brochure. 2008
2. Airtrax Corp. ATX-Series Omni-Directional Forklift. New Jersey (USA):
Product brochure. 2006
3. David Chandler. Robo-Forklift Keeps Humans out of Harm‟s Way. Proc. of
the MIT Tech Talk. 2009. 53 (13): 5
4. Tua Augustinus Tamba, Bonghee Hong and Keum-Shik Hong. A Path
Following Control of an Unmanned Autonomous Forklift. Proc. of the
International Journal of Control, Automation and Systems. 2009. 7 (1): 113-
122
5. Nuzrul Fahmi bin Nordin. Mobile Robot Localization. Bachelor Degree
Thesis. Universiti Teknologi Malaysia; 2009
6. Siow Li Hon. Development of a Bluetooth Network Based LCD Messaging
System. Bachelor Degree Thesis. Universiti Teknologi Malaysia; 2009
7. Farrah Hayana binti Desa. Unmanned Hovercraft. Bachelor Degree Thesis.
Universiti Teknologi Malaysia; 2009
8. http://www.nxtprograms.com/forklift
9. http://www.kcwirefree.com
10. http://www.cytron.com.my
11. http://www.microchip.com
12. http://www.societyofrobots.com
13. http://www.forklifttrux.co.uk/forklifts
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APPENDIX A
GANTT CHART 1 and 2
48
GANTT CHART 1
WEEK 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
FYP Briefing Session
Student-Supervisor Name List
Identifying Topic For Project
Background Study & Literature Review
Project Proposal & Progress Evaluation 1
Preparing For Presentation
Progress Evaluation 2
FYP1 Seminar
Hardware Design & Planning
Parts & Components Purchasing
Report Writing
Progress Evaluation 3
FYP1 Report
Software Design & Planning
49
GANTT CHART 2
WEEK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Complete Hardware & Prototype
Progress Evaluation 1
Main Controller Circuit
Software Programming & Interfacing
Progress Evaluation 2
Troubleshoot & Fine Tuning
Progress Evaluation 3
FYP2 Seminar & Demo
Report Writing
Final Thesis Draft
Thesis Submission & Compilation
