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UNIVERSITI TEKNIKAL MALAYSIA
MELAKA
FACULTY OF ELECTRICAL ENGINEERING
BEKU 4983
FINAL YEAR PROJECT
AUTOMATED GUIDED VEHICLE
(AGV)
NAME
JULIE AIDAH BINTI JUSIN
B010810230
SUPERVISOR
EN. AZHAR BIN AHMAD
PANEL
CIK ARFAH BINTI AHMAD,
EN. SHAHRUDIN BIN ZAKARIA
“ I hereby declare that I have read through this report entitle “Automated Guided Vehicle
(AGV)” and found that it has comply the partial fulfillment for awarding the degree of
Bachelor of Electrical Engineering (Industrial Electronics)”
Signature : ………………………………………..
Supervisor’s Name : AZHAR BIN AHMAD
Date : ………………………………………..
AUTOMATED GUIDED VEHICLE (AGV)
Submitted By:
JULIE AIDAH BINTI JUSIN
B010810230
A report submitted in partial fulfillment of the requirement for the degree of Bachelor of
Engineering
Faculty of Electrical Engineering
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
JUNE 2012
I declare that this report entitle “Automated Guided Vehicle (AGV)” is the result of my own
research except as cited in the references. The report has not been accepted for any degree
and is not concurrently submitted in candidature of any other degree.
Signature : ……………………………………………
Name : JULIE AIDAH BINTI JUSIN
Date : ……………………………………………
ii
ACKNOWLEDGEMENT
In the name of Allah S.W.T, The Most Beneficial and The Most Merciful. It is with
deepest serve gratitude of the Al-Mighty that gives me strength and ability to complete my
final year project (FYP). I would like to take this opportunity to express gratitude to my
dedicated project supervisor, Mr. Azhar Bin Ahmad for guiding my final year project
tolerantly by sharing his valuable ideas and expertise. Not forgotten to any other UTeM
lecturer such as Mr. Zamani Bin Md. Sani, who spends his precious time to solve some
problem regarding to this final year project.
My sincere thanks go to all my friends who sincerely give their opinion and
continuous guidance throughout this FYP. Last but not least, I would like to express my
outmost gratitude to my lovely parents and sibling for giving a support direct or indirectly
during this project accomplishment progress. I appreciated for all of the co operations.
Once again, thank you very much.
iii
ABSTRACT
The construction of Automated Guided Vehicle (AGV) model has been created all
over the world. It gives many advantages in our lives and work just as a robot. It can done
it task without complaint. AGV is a system that moves following a line from one point to
another point regarding to it given task. This kind of technology can be found appliance at
factories, offices, hospitals and even houses. The aim of this project is enhance a simplest
circuit of AGV system that comes with low prices and user friendly. PIC16F877A
microcontroller is use to control all navigation during the operation of AGV system. The
advantage of this prototype is it has an ability to follow line on and can be further
developed to do more complicated task in real life. The microcontroller is attached to a
sensor that continuously reflecting to the surface condition. Therefore, this project involves
of designing and fabrication of the hardware and circuitry. The main importance in this
project is the algorithm to assembly language, embedded in the microcontroller. Then, the
H-bridge will be use as the DC motor drive. At the end of this project, the AGV can move
following the line regarding to the task that will be given.
iv
ABSTRAK
Pembinaan model AGV telah dicipta di seluruh dunia. Ia telah memberikan banyak
manfaat dalam kehidupan seharian kita dan bekerja sebagai robot. Ia boleh melakukan
tugas tanpa sebarang rungutan. AGV adalah satu sistem yang bergerak mengikut garisan
dari satu tempat ke tempat yang lain berikutan dengan tugas yang telah ditetapkan.
Teknologi ini boleh dilihat diaplikasikan di kilang-kilang, pejabat, hospital dan tidak
terkecuali di rumah. Matlamat utama projek ini adalah untuk menambah baik pulih litar
yang ringkas bagi sistem AGV yang telah sedia ada. Pengawal PIC16F877A digunakan
untuk mengawal semua pergerakan sistem AGV. Kelebihan sistem ini adalah ia bergerak
mengikuti garisan berpandukan pengesan dan mampu melakukan kerja yang rumit dalam
kehidupan sebenar. Pengesan akan disambungkan pada pengawal untuk mendapatkan
bacaan dan membolehkan AGV bergerak. Oleh itu, projek ini melibatkan penyambungan
litar dan pembinaan bahasa himpunan dan dimasukkan ke dalam sistem pengawal. H-
jambatan akan digunakan sebagai pemacu DC-motor. Pada akhir projek ini, AGV boleh
bergerak mengikut garisan berpandukan pengesan untuk melakukan tugas yang akan
diberikan.
v
TABLE OF CONTENT
CHAPTER TITLE PAGE
DEDICATION i ACKNOWLEDGEMENT ii ABSTRACT iii ABSTRAK iv TABLE OF CONTENT v LIST OF FIGURE viii LIST OF TABLE x LIST OF APPENDICES xi 1 INTRODUCTION 1 1.1 Problem Statement 1 1.2 Objectives 2 1.3 Scope of Project 2 2 LITERATURE REVIEW 3 2.1 Control and path prediction of an Automated Guided Vehicle
Control (AGV)
3
2.2 Makespan Minimization of Machines and Automated Guided
Vehicles (AGV) Schedule using Binary Particle Swarm
Optimization
4
2.3 Automated Guided Vehicle (AGV) using 68HC11
Microcontroller
4
2.4 Development of control system for Automated Guided
Vehicle (AGV)
5
2.5 Carrying Robot (C-Bot) 6
2.6 Microelectronic (MicroC) 6
vi
2.7 Proteus 7 professional 7
3 METHODOLOGY 9 3.1 Title understanding 11
3.2 Literature review 11
3.3 AGV operation Development 11
3.3.1 Flow chart 11
3.3.2 Motor Driver 12
3.4 Programming Development
13
3.5 Software Implementation
15
3.6 Hardware Development
17
3.6.1 PIC16F877A Microcontroller 17
3.6.2 Power Supply Unit 18
3.6.3 Line Follower Sensor 19
3.6.4 IR Transmitter and Receiver 20
3.6.5 LCD Display 21
3.6.5.1 LCD pin layout 22
3.6.5.1 LCD pin connection 23
3.7 Testing 23
4 RESULT 25 4.1 Software Part 24
vii
4.2 Developed Prototype 25
4.3 Result And Outcome 26
4.3.1 Simulation 26
4.3.2 Hardware 27
4.3.2.1 Power Supply and Microcontroller Circuit 27
4.3.2.2 Line Follower Sensor Circuit 28
4.3.2.3 IR Sensor Circuit 29
4.3.2.4 Motor Driver Circuit 30
4.3.2.5 The prototype of AGV 30
5 ANALYSIS AND DISCUSSION 33 5.1 Analysis 33
5.1.1 Calibration of Line Follower Sensor 34
5.1.2 Calibration of PIC 35
5.1.3 Calibration of Motor Driver 35
5.2 Discussion 36
6 CONCLUSION AND RECOMMENDATION 37 6.1 Conclusion 37
6.2 Recommendation 38
REFERENCES 39 APPENDICES 41
viii
LIST OF FIGURE
FIGURE TITLE PAGE
2.1 AGV command architecture 3
2.2 C-Bot 6
2.3 Proteus Virtual System Modelling 8
3.1 Flow Chart of the Methodology 10
3.2 Flow Chart of the AGV 12
3.3 Basic connection of H-Bridge circuit 13
3.4 Programming Development 14
3.5 Generating HEX file 14
3.6 PIC16F877A circuit 15
3.7 Compiler in Proteus 16
3.8 The output of this project 16
3.9 Microcontroller reset circuit 18
3.10 Power Supply by using Voltage Regulator 19
3.11 The circuit of line follower sensor using four emitters and four
receivers.
20
3.12 IR Transmitter and Receiver 20
3.13 Common LCD pin diagram 22
3.14 LCD connection by using 4 bit 23
4.1 Block diagram for the whole system 25
4.2 Simulation of DC Motor 26
4.3 Combination circuit of Power Supply and PIC16F877A 28
4.4 Circuit of Line Follower Sensor 29
ix
4.5 IR Sensor 29
4.6 Motor Driver Circuit 30
4.7 Top view 31
4.8 Side view 31
4.9 Bottom view 32
4.10 Back view 32
x
LIST OF TABLE
TABLE TITLE PAGE
3.1 The list of component for basic circuit of PIC Microcontroller 18
3.2 LCD pin description 22
5.1 The movement of AGV’s motor 34
5.2 Aimed the sensor’s units on various materials 34
5.3 Output from PIC to L293D 35
5.4 Output from L293D to motor 35
1
CHAPTER 1
INTRODUCTION
This chapter will give a brief explanation about this project including the problem
statement, objectives also the scopes of the project. This project is to develop automated
guided vehicle (AGV) by using microcontroller.
1.1 Problem Statement
Automatic Guided Vehicles (AGV) has been using since the 1950's. First AGV
developed in 1954 by A.M.Barrett,Jr. The AGV used an overhead wire to guide a modified
towing truck pulling a trailer in a grocery warehouse. Then, commercial AGV were
introduced by Barrett. In 1973 Volvo developed automated guided vehicles to serve
assembly platforms for moving car bodies through its final assembly plants. Later, Volvo
marketed their unit load AGVs to other car companies. [5] Several important aspects of
AGV system problem should be acknowledged and need an in-depth research in order to
understand the problems. Nowadays, industries already used complicated control system of
AGV which it’s comes with high cost. So, by enhance and design a simplest AGV circuit
it will automatically comes with low prices. Then, in the industries, human workers will
take more movement to do their work. With the application of AGV system can ease the
strain on human workers by performing tiring task such as lifting and carrying heavy
material. In handle the heavy work, AGV is more effectively with no signs of creeping.
Therefore, the valuable knowledge on AGV construction is very significant to be studied
2
and be further implemented from the result of this project. It will come with many benefits
to our live and technologies.
1.2 Objective
The main objective of this project is:
i. To find information about circuit of AGV system and PIC programming
ii. To design and enhance a simplest circuit for AGV application by using PIC
microcontroller.
iii. To construct and develop the prototype of the circuit design.
1.3 Project Scopes
The scopes of this project are:
i. Design and development of AGV system.
ii. PIC microcontroller control all the navigation of the AGV operation
iii. Produce one complete system that can be user friendly.
3
CHAPTER 2
LITERATURE REVIEW
In this chapter will explain about the literature reviews that been reviewed. In order
to design and construct of AGV system, research in AGV need to be performed. This
chapter would discuss the previous studies of AGV that have been developed. This
literature review section will also provide knowledge and understanding the application of
the AGV system.
2.1 Control and path prediction of an Automated Guided Vehicle Control (AGV)
This journal discuss about the development of an AGV. The navigation of the AGV
will be control by Programmable Logic Control (PLC) module as shown in the figure
below.
Figure 2.1: AGV command architecture
4
The position and orientation of the AGV will determined by the parameters of the
motion are driving speed and steering angle. The input from both left and right rear wheel
and analog output signal are interfaced with PLC module. Then, the steering and driving
command signal can be calculated. The PLC convert the digital output to analog signal to
drive amplifier of the driving motor and steering motor as shown in figure 4.1. The DC
motor are been using in this project. [1]
The developed algorithm is based on memorised path and kinematics determination
of the movement. The vehicle position and deviation are calculated from rear wheels
rotation measurement. The steering and driving command are determined from this
deviation. Localization of AGV by Kaman filtering algorithm is presented. Overall
structure of designing AGV is described. Control of AGV motion is implemented by using
PID control scheme. Displacement axis and steering axis are separated to implement the
motion control. [1]
From this review that has been examined can be concluding that this kind of AGV
has an ability to estimate and adjust the error sources during it position and orientation
along the defined path. However, there is no safety that has been developing for this kind
of technology in this project such as to detect any obstacle.
2.2 Makespan Minimization of Machines and Automated Guided Vehicles (AGV)
Schedule using Binary Particle Swarm Optimization
This paper discuss about the implementation of Flexible Manufacturing System
(FMS) to the AGV task. FMS is a high automated machine cell that controlled by a
computer system. At the factory, the AGV need to do more than one task. So, this study is
based on minimizing the total completion time of the AGV by using Binary Particle
Swarm Optimization (BPSO). The algorithm is developing to control the navigation of the
5
AGV by using MATLAB software. Among the elements in the implementation of AGV is
task scheduling. The efficient of scheduling will reduce the cost of delivery. [2]
As the conclusion, the schedule of AGV can be minimizing by using BPSO. The
BPSO managed to provide a better optimization solution particularly for simultaneous
scheduling of machines and automated vehicles in production environment. This kind of
method can be implementing in the simple development of AGV’s project.
2.3 Automated Guided Vehicle (AGV) using 68HC11 Microcontroller
This project is about an AGV prototype can move on a flat surface with its two
driving wheels and a free wheel. The prototype will be control by M68HC11
microcontroller which it acts as main brain that will control all the navigation and
responses to the environment. This project just develops for line follower. The ability to
follow line on floor was an advantage of this prototype as it can be further developed to do
more complicated task in real life. It using voltage sensor to detect the line. [4]
Therefore, this project involves both of designing and fabrication of the hardware
and circuitry. The key study in this project is the algorithm designed in assembly language,
embedded in the microcontroller. This prototype is able to move on a flat surface and move
along black line on a white surface, depending on how much of the darkness and
brightness of the surface as well as the width of the line.
The microcontroller MC68HC11 can be use to control all the navigation of this
prototype. The microcontroller is the important part that makes this prototype has quite a
simple circuitry, as it already has complete internal circuitry in the chip. The line follower
sensor and the DC motors are very reliable and suitable for the prototype. As the sensors
gives continuous input to the microcontroller about the surface physical variables. There is
no safety for the prototype of this project that has been installed.
6
2.4 Development of control system for Automated Guided Vehicle (AGV)
This project was focused on development of the control system for Automated
Guided Vehicle (AGV). It concentrates on developing the control system for the AGV
operation, movement and loading & unloading mechanism. The objectives of this project
are to develop the control system parts involving by using the electronic circuit system and
computer programming. The wired guided navigation will communicate with the computer
to the AGV to ensure the AGV work proper according to its operation. Subsequently, this
kind of project needs to be fabricating each of the electronic com9ponents to become one
complete circuit. All the computer programmings are building by using Code Blocks
software, the compiler which is compatible with electronic components and Visual Basic
software. Afterwards, Visual Basic 6 is used in this project to create user friendly interface
which is better than C interface (Command Prompt). [6]
2.5 Carrying Robot (C-Bot)
Figure 2.2: C-Bot
This kind of robot is was one of type of AGV application. It was designed to move
in linear or curved route. C-Bot has a gripper tat function as gripping the work piece. It
uses a high torque of servo motor for both function of gripping and vertical movement.
7
Then, it also uses dual motor drive system where both of the motor were coupled directly
to the wheel. The safety bumper is use to detect any obstacle that come in front of its way.
In the prototype, there were three wheels with two independently controllable wheels at the
front and a free unpowered caster at the back. [3]
2.6 Microelectronic (MicroC)
MikroC is a powerful, attribute rich growth tool for PIC microcontroller. It is
designed to present the programmer with the easiest possible solution for developing
applications for fixed systems, without compromising performance or control. This kind of
software is easy to built programming compare to the other software. While develop the
programming, this software will show if there is any error. The operation of the AVG is
design in the C language and imbedded in the PIC microcontroller. PIC and C fit together
well which PIC is the most popular 8-bit chip in the world, used in a wide variety of
applications, and C prized for its efficiency, is the natural choice for developing embedded
systems. [7]
MikroC allows quickly developing and deploying complex applications. First, write
C source code using the built-in Code Editor (Code and Parameter Assistants, Syntax
Highlighting, Auto Correct, Code Templates, and more. Then, use the included mikroC
libraries to considerably speed up the development: data acquisition, memory, displays,
conversions, communication. Practically all P12, P16, and P18 chips are supported. After
that, monitor the program structure, variables, and functions in the Code Explorer.
Generate commented, human-readable assembly, and standard HEX compatible with all
programmers. The program flow should be tnspect and debug executable logic with the
integrated Debugger and get detailed reports and graphs: RAM and ROM map, code
statistics, assembly listing, calling tree, and more. [7]
8
2.7 7 professional
Proteus is a zero-power research operated at the Paul Scherrer Institute,
Switzerland. High degree of flexibility in study about the wide range of a different system
is one of its main characteristics. At present, it is being used to provide an extended
integral database for the validation of modern light water reactor fuel designs. [8]
Figure 2.3: Proteus Virtual System Modelling
Figure 2.3 shows one the Proteus Virtual System Modelling (VSM) application.
VSM combines mixed mode SPICE circuit simulation, animated components and
microprocessor models to facilitate co-simulation of complete microcontroller based
designs. The most exciting and important feature of Proteus VSM is its ability to simulate
the interaction between software running on a microcontroller and any analog or digital
electronics connected to it. The micro-controller model sits on the schematic along with the
other elements of the product design. It simulates the execution of the object code
(machine code), just like a real chip. [8]
9
CHAPTER 3
METHODOLOGY
In order to complete the final year project, a methodology has been organized to
ensure the progress of the project running well and as a strategy to overcome problems.
Project methodology also describes the procedures and methods been used to achieve the
objectives of the project. Methodologies of this project are title understanding, literature
review, comparisons, development programming, development of AGV operation,
development for hardware and testing. Figure 3.1 show the flow chart of the methodology
of the project.
The most highlighted method in this methodology is programming and hardware
development. For software part are focus on circuit design, simulation and programming.
Circuit designs consist of PIC circuit and power supply circuit. The circuit is design in
Proteus 7.7 professional. MicroC software is to write a programming by using c language
and compile it with PIC16F877A in the Proteus. Other than that, this project also using
LCD to display the movement of the AGV prototype. Thus, the software part should be
solve first before proceed to next step where the hardware part to generate the value of
power.
Then, in hardware part Hardware part are focus on distribution board circuit,
component assemble and circuit soldering. The main component used to construct this
project is PIC 16F877A, Line follower (IR transmitter and receiver) sensor, analog
distance sensor and LCD.
10
Flow Chart:
Figure 3.1: Flow Chart of the Methodology
YES NO
Automated
Guided Vehicle
ENERGY
STORAGE
ROTARY SHORT
BREAK SYSTEM
COMBINED
SHORT BREAK
AND
GENERATING
SET SYSTEMS
ROTARY UPS
SYSTEMS
ROTARY UPS
SYSTEM
WITHOUT
INTERRUPT
ION
WITH
INTERRUPT
ION
GENERATING
SET SYSTEM
FLYWHEEL
ENERGY
STORAGE
NO ENERGY
STORAGE
Start
Literature review
AGV Operation Development
Programming Development
Testing
End
Hardware Development
Software Implementation
11
3.1 Title understanding
This title of project has been proposed to supervisor and has been approve. Then,
verify the objective and scope of this project. The problem statement has been stated to
identify the significance of this project.
3.2 Literature review
Study about the background of this project by refers to the similar project and any various
sources like references book, journal and any information from the internet that related to
the project.
3.3 AGV Operation Development
This chapter will elaborate on motor drive, flow chart and simulation circuit. Motor
driver will discuss about the operation of the motor whether the motor will move forward
or reversed. The flow chart will tell about concept studying in this project. While, motor
driver will discuss about how the motor is operation. Circuit simulation will demonstrate
the operation of the circuit in the computer.
3.3.1 Flow chart
As below figure 3.2 below is a flow chart that constructed for this project.
The operation will start by switch on and the sensor will starts operating. If sensor
senses magnetic or colour tape, the motor will start energized. Then, the AGV will
move forward or backward. If there any obstacle or blockage exist while the AGV
was moving, the ultrasonic sensor will detect and cut of the circuit and stop the
12
motor for a moment. When the motor is stop, the alarm will turn on. The AGV will
not back to it operation until the blockage is remove. After the blockage is remove,
the AGV will start over the flow from motor energized and will go through it
destination if there is no blockage.
Figure 3.2: Flow Chart of the AGV.
3.3.2 Motor Driver
The motor driver is used to drive the motors of the robot. Since even a small
motor requires high current to operate, the high current could certainly causing
damage to the microcontroller if the motor is connected directly to the
microcontroller. Then, normally the motor driver or a relay is required to prevent
13
the reverse current and protect the microcontroller chip. The resistor 10kΩ of the
motor driver circuit is also used to limit the rush current. The microcontroller is
lacks of sufficient current to drive the motors, so the driver is needed to energize
the stator of the motor. The drivers for DC motors are H-Bridge circuit as well as
L293D. For this project, the H-Bridge driver circuit is the best solution to be
interface with the dc motors.
Figure 3.3: Basic connection of H-Bridge circuit
The circuit in figure above show the basic connection of H-bridge circuit. It
consists of motor, 2 supply rails and 4 switches. Any of the circuit can be close at
any time and just 3 combination of the switch close will turn on the motor. If the
A1 and A2 switches are turn on, the current will flow in one direction through the
motor, causing the motor turn on. Then, if the B1 and B2 switches are turn on, the
current will flow in the opposite direction through the motor, causing it to spin in
the opposite direction. If all the switches are turn off, there is no current flow
through the motor and it free to spin.
3.4 Programming Development
C language is use to develop the programming of PIC microcontroller. The
programming must be learn and analyze to get the output of project. The software
14
development includes the process of determining which communication port of
microcontroller that will interface with other component. It is also the important part
towards the completion of this project. The software of use is such as PIC Compiler,
MicroC and etc. The coding that has been developed need to convert to HEX file, so that it
can be burn into the PIC16F877A microcontroller.
Figure 3.4: Programming development
Figure 3.5: Generating HEX file
15
3.5 Software Implementation
In software development there are three stages needed to complete this whole
project. In the first stages MicroC is software that is needed to make a coding as the
programmed to define the value of the sensor will detect. To obtain this result, in the
programming also contain to convert current load that is analog to digital (ADC). This
MicroC using 10 bit which has higher resolution that means the step size between one
digital levels to the next one are smaller.
In the second staged, Proteus is the software that used to design the PIC16F877A as
a main circuit that required to this whole project. In this software is contain the LCD
Display and Motors as function to display the result that will obtain through the
programming that already been created. Figures below show the step of software
implementation before go the last step that is hardware development.
Figure 3.6: PIC16F877A circuit
17
3.6 Hardware Development
The hardware development consists of the process of developing the components
and parts to be assembled and at last become the final product of the prototype. It is the
important part of the project that determines the successful of the project. There are two
type of sensor that has been use on this AGV prototype. First is infrared and second is
analogue distance sensor.
3.6.1 PIC16F877A Microcontroller
Generally, there are numerous control methods to control a robot. The
methods are ranged from classical method like PI controller, PD controller and PID
controller to artificial intelligence such as Fuzzy Logic, Genetic Algorithm and
Neural Networks. Microprocessor and microcontroller are also can be use to control
robots which acts just like the brain for the robot. The brain that controls this
prototype is the PIC16F877A 40 pins PIC microcontroller. The PIC16F877A can
control the entire DC motors and the behaviour of the line-following sensor.
Microcontroller also can be recognized as computer-on-a-chip optimized to
control electronic devices which consist of CPU, ROM, RAM, I/O port and timer
embedded together inside the single chip. It can follows instructions, read
information, communicates, measures time and switches things on and off and also
does other things too depending on the model. It is often criteria to be considered to
which microcontroller to be used, such as the microcontroller should meet the
computing needs for the task at cost efficiency and also has simple architecture and
language. Figure below show the identified hardware requirements the following is
a summary of required material for prototype implementation.
18
Figure 3.9: Microcontroller reset circuit
Table 3.1: The list of component for basic circuit of PIC Microcontroller
Quantity References Value 1 Resistor 1k 1 Resistor 10k 2 Capacitor1 30pF 1 Capacitor2, Capacitor3 0.1µF 1 LCD Display JHD1602A 1 Microcontroller PIC16F877A 1 Crystal Oscillator 20MHz 1 Push Button Switch Sensor
3.6.2 Power Supply Unit
The microcontroller is powered up by a low voltage value ranging from 0V
to the maximum 5V. It will cause to the internal circuitry damage to the
microcontroller 16F877A if it is directly connected to a high value of supply
voltage. In this project, the voltage regulator is very important to turn the 9V supply
from the adapter to a constant 5V, to power on the microcontroller. This regulator
19
is already interfaced on the motor driver board that is a smart enough connection.
The 6V of voltage value supplied by four of 1.5V batteries is just to power on the
dc motors and this 6V is not connected directly to the microcontroller. The basic
connection of voltage regulator to turn any input voltage to a constant 5V value is
as shown by Figure 3.10 below.
Figure 3.10: Power Supply by using Voltage Regulator
3.6.3 Line Follower Sensor
The Line Follower sensor uses a pair of IR sensors that aimed downwards
close to the floor. Each pair consists of transmitter and receiver, so the light from
the transmitter is reflected back by a light coloured surface and absorbed by a dark
coloured surface and the receiver is responding to the amount of light reflected
back.
20
Figure 3.11: The circuit of line follower sensor using four emitters and
four receivers.
From the figure above, the LM324N was use as the comparator. The
emitter will transmit while the receiver will detect the light that has been
transmitted. The receiver will act as switch. When it receive high input (max.
5v), it will send input to the comparator. Then comparator will send input to the
PIC. The PIC will read 5V (min. 3.3V and max. 5V) as high or ‘1’ and 0V
(below 3.3V will declared as 0V) as low or ‘0’.
3.6.4 IR Transmitter and Receiver
Figure 3.12: IR Transmitter and Receiver
21
IR transmitter and receiver are built to detect any obstacle in the front of the
AGV when it moves in the surface. In this pair of infra red sensors, when the
transmitter emits IR ray, as long as the receiver receives the ray, the electricity will
flow in the receiver. Of course in this, the electricity if not measure by ON or OFF
like the hand analogy. There is a range from full current to zero current. The current
can be any value from zero to the maximum depending on the strength of the IR
ray. The stronger the ray, the more current will pass through.
To connect, 5 volts voltage supply, 330 Ohm Resistor and 4.7k Ohm
resistor. The signal are getting is analogue voltage. When the ray is present,
meanings the ‘switch’ is closed, therefore signal will be close to 0V. If the ray is
absents, the ‘switch is opened; therefore the signal will close to 5V.
3.6.5 LCD Display
LCD (liquid Crystal Display) is a passive device that uses light modulating
properties of liquid crystals. By applying the power to LCD, light will transmitted
through liquid crystal in different direction compared to the when there is no power
supplied. LCD display is specifically designed and manufactured to be used with
microcontrollers. It cannot be active by using standards IC circuits. There are many
types of LCD for instance alphanumeric LCD and graphic LCD. Alphanumeric can
display a large number of character and symbols for examples, alphabet (A, B, x, y,
z, &) and number (0, 1, 2….., 9). While graphic LCD can display shape for
examples laptop screen and television screen.
22
3.6.5.1 LCD pin layout
There are a lot of types of LCD display which can be founded in
market nowadays such as with backlight, without backlight and various type
of colours display. Usually LCD with one controller have 14 pins or 16 pins
which have two extra pins for back light LED connection. The pins diagram
for common LCD displays is shown in Figure 2.4 and Table 2.1 shows the
pin description for LCD display.
Figure 3.13: Common LCD pin diagram
Table 2.1: LCD pin description
23
3.6.5.2 LCD pin connection
There are two types of LCD connection which are eight bit and four
bit connection. In this project 4 bit connection of LCD display has been
used. 4 bit connection that has two libraries consist of LCD library and LCD
custom library then has 4 pin data bus. The similarity of 8 bit connection
and 4 bit connection, they have three pin of Vss, Vdd and Vee and also three
pin of RS, RW and EN. The figure below shows the connection 4 bit of
LCD.
Figure 3.14: LCD connection by using 4 bit
3.7 Testing
After design and development done, the project will be testing to get the expected
result. If the objectives not achieves then the circuit need to study again. The prototype will
test at the breadboard before transfer the circuit and solder it on the strip board. The
prototype will be test on the surface with black and white paper.
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CHAPTER 4
RESULTS
This chapter will explained and discusses about the results obtained from what was
done on the designing process of this AGV’s prototype.
4.1 Software Part
The software used in the implementation of this project is Proteus 7.7 Professional
software and C Compiler software (CCS). Proteus 7.7 professional is used to build circuits
and perform simulations while CCS is to make programming for the mobile robot
microcontroller.
To obtain a constant power supply for PIC either from batteries or AC/DC adaptor,
a power supply circuit with fixed output voltage has been designed. The output voltage of
power supply circuit will be supplied to the input of PIC circuit. For activate outputs from
the PIC, the voltage and current level must adhere to the PIC’s level. Generally, the
maximum PIC voltage accepted is 5 Volts and the PIC can produce an output of 20mA of
current per pin (PIC 16F877A).
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4.2 Developed Prototype
Figure 4.1: Block diagram for the whole system
The detail block diagram shows all the important parts of this prototype. The
microcontroller unit controls all the circuitry and operation. The microcontroller is the
PIC16F877A 40 pin. There are two power sources, the 9V from adapter and the 6V
batteries. Since the microcontroller operating voltage is 5V, the 9V from the batteries is
powered down to 5V by the voltage regulator 7805 that also maintain the fixed 5V to the
microcontroller.
The line follower sensor acts as input to the microcontroller, so that the
microcontroller will respond to the physical variables that it receives and make appropriate
feedback according to the program inside. The left and right motors are the dc motors that
PIC16F877A
MICROCONTROLLER
PORTA
/ADC
PORTB
PORTC
ANALOG DISTANCE
SENSOR
LINE FOLLOWER
SENSOR
MOTOR DRIVE
6V
BATTERY
RIGHT
MOTOR
LEFT
MOTOR
VOLTAGE
REGULATOR
9V
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function as the output for the microcontroller and there are motor drivers that prevent the
6V and high current from causing damage to the microcontroller. The dc motors operates
in 6V batteries. Both of the dc motors of the prototype provide the mechanical movement
for the prototype.
The batteries are used instead of external power supply to let the prototype to move
smoothly without any difficulties. It is more suitable to use batteries instead of external
power supply although the motors use more voltage power to the developed prototype.
4.3 Result And Outcome
The result and outcome divided in this project development divided into simulation
and hardware.
4.3.1 Simulation
Figure 4.2: Simulation of DC Motor
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Figure above show the simulation of two DC motor by using PIC16F877A
and L293D as the driver. In this simulation the IR sensor has been replace with
logic toggle and the analog distance sensor replace by 1kΩ of variable resistor. The
logic toggle will give ‘1’ as high and ‘0’ as low condition. The 1kΩ variable
resistor will give input voltage to the PIC until the certain value of voltage that
receive will stop the motor and turn on the led at port c. LCD has been connecting
to the PIC to show the movement of the robot. As shown at the figure 4.2, both of
the dc motor is moving forward and at the LCD is appearing ‘Robot Forward.
Simple programming has been developed to run the motor forward, reverse
and stop. In this simulation, the aim is to control the DC motor speed. The PWM is
importance to control the speed of motor. In this coding, the maximum value1 and
value2 are 225(in decimal) or 5V. The duty cycle for motor1fwd change to 125 or
2.45V and motor2fwd change to 250 or 4.9V. The AGV required some basic wiring
for the circuit to run. PIC16F877A was used as the microcontroller for the AGV
and PIC circuit required some basic circuit to run the circuit. The simplest test run
circuit requires a 5 volt direct current (DC) power supply, a pull-up resistor to the
reset (MCLR) pin, a reset switch, an oscillator/crystal and capacitors.
4.3.2 Hardware
4.3.2.1 Power Supply and Microcontroller Circuit
From the Fig. 4.3 above, shows the connection between power
supply and PIC16F877A. Before the circuit has connected to the real circuit,
all the port of PIC has been check whether it can function or not. Then, it
will apply with the rest of the circuit.
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Figure 4.3: Combination circuit of Power Supply and PIC16F877A
4.3.2.2 Line Follower Sensor Circuit
Fig. 4.4 shows the circuit of the circuit of Line Follower Sensor.
The voltage that flow to the transmitter is 4.5V while to the receiver is
1.10V. When a piece of white paper put in front of the IR sensor, current
will flow to the led and the led will turn on. The led will show which of the
sensors have detect the line. After that, the comparator will send input to the
PIC16F877A Microcontroller.
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Figure 4.4: Circuit of Line Follower Sensor
4.3.2.3 IR Sensor Circuit
In this project, IR sensor will be put in front of the body of the AGV
prototype to sense an obstacle as shown in figure 4.5.
Figure 4.5: IR Sensor
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4.3.2.4 Motor Driver Circuit
Figure 4.6: Circuit of Motor Driver
The figure 4.6 shows the circuit of driver motor that has been
develop. The Vss is connected to 5V of voltage supply while the Vs are
connected to 6V. If the Vss and Vs was connect parallel, there is not enough
current to run the motor. This is because, two motor needed higher starting
current. The capacitor functions as to constant the flowing current to the
motor.
4.3.2.5 The prototype of AGV
The body of the AGV prototype is been constructed by using control
car body and cardboard. DC motor also use the motor that already install in
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the control car. The chassis of the AGV is design by using the green
cardboard and has been combined by using glue gun. The alarm that
attached in the circuit is come with LED and BUZZER. The LCD also put
at the top of the prototype to show the AGV movement. The Figures below
show top, side, bottom and back view of the prototype.
Figure 4.7: Top view
Figure 4.8: Side view
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CHAPTER 5
ANALYISIS AND DISCUSSION
This chapter discusses about analysis and discussion on the result obtained of the project.
5.1 Analysis
In the simulation by using Proteus 7 professional, the PIC16F877A has been used.
This type of PIC has 5 I/O which are PORTA, B, C, D and E. It also has 8 analog to digital
converter (ADC). This project uses two type of sensor on its application and one of the
sensors is analog, so the input (analog) needs to convert to digital. This is because
microcontroller just can read digital input. The main voltage of PIC is 0-5V. The IR sensor
actually also give analog output, but the analog output has been convert to digital input
before give signal to the PIC.
During test the circuit of AGV prototype, the PIC only will define digital input
voltage at range between 0V until 3.2V as ‘0’ and voltage at range between 3.3V until 5V
as ‘1’. While for analogue input, the voltage to trigger PIC is range between 0V until 5V.
The motor movement of the AGV is depends on the line following sensor programming.
The movement of the robot is shown in Table 5.1. ‘1’ is defining as ON while ‘0’ is OFF.
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Table 5.1: The movement of AGV’s motor
Line Following Sensor
Movement
Left Middle 1 Middle 2 Right
0 1 1 0 Forward
0 0 1 1 Right
0 0 0 0 Stop
5.1.1 Calibration of Line Follower Sensor
The calibration for Line Follower sensor is to identify what kind of material the
sensor will detect. Table 4.1 below shows the result from the calibration.
Table 5.2: Aimed the sensor’s units on various materials
Situation Voltage (V)
Aimed the sensor’s units downwards close to white
surface of a piece of paper. 3.60
Aimed the sensor’s units downwards close to black
surface 0.00
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5.1.2 Calibration of PIC
The line following sensor will detect the line and send the signal to the PIC. PIC
will trigger when the input is high or ‘1’. Then, the PIC will send the signal to the motor
driver.
Table 5.3: Output from PIC to L293D
Sensor
Detection Input 1 (V) Input 2 (V) Input 3(V) Input4(V)
0110 4.67 0.10 0.18 0.03
0011 4.67 0.00 4.54 0.12
0000 0.00 0.00 0.00 0.00
5.1.3 Calibration of Motor Driver
The PIC will send signal to trigger the L293D. The input of the L293D depends
on the sensor detection.
Table 5.4: Output from L293D to motor
Sensor
Detection Output1 (V) Output2(V) Output3(V) Output4(V)
0110 5.04 0.23 0.20 -0.03
0011 5.04 0.00 4.04 -0.12
0000 0.00 0.00 0.00 0.00
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5.2 Discussion
Generally, this project includes hardware and software parts. For the first final year
project (FYP 1) it more focus on software part and learn AGV’s controller programming
by CCS C Compiler software. Controller programming parts throw down the gauntlet
because it never used previously, so it needs to start from basic and give full attention and
reasonability on the controller programming part to achieve the project objective. This is
because the controller is most important part inside the robot it acted like brain. Then, in
the FYP 2 is more focusing in hardware development.
During complete this project, there are many problems occur. Firstly, the IR sensor
cannot detect the line. There are short circuit while test the sensor. The input and output
voltage are the same. After get some advice from supervisor, the problem of the sensor has
been solved. The problem is the leg of receiver did not same with the leg of the transmitter.
For normal leg of led, the short leg will be negative while the other leg will be positive.
But for receiver, the short leg will be positive.
Another problem of the circuit is the motor driver. The motor driver cannot run the
motor. During testing, the 3V-12V DC motor has been used. Firstly, the motor driver just
gets one supply. But after the output voltage is low, the Vs have been connecting to
different supply but command ground. By using power generator, the motor can be run.
But then when the circuit has been solder to the bread board, all the circuit did not function
accept the line following sensor. Troubleshooting has been done to fine the main problem
of the circuit.
Then, the analogue distance sensor also has been burn. This kind of sensor is easily
damage. The transmitter did not function even there is supply. So, by solve this problem
analogue distance sensor been replace with IR sensor which is can sense white and black
colour only.
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CHAPTER 6
CONCLUSION AND RECOMMENDATION
6.1 Conclusion
As for conclusion, this project’s objective to build an Automated Guided Vehicle
prototype is has been done. This prototype is able to move on a flat surface and move
along white line on a black surface. Understanding in C language is very important in order
to do programming that can control all the navigation of AGV. PIC16F877A
microcontroller can be use to control all the navigation of this prototype. The
microcontroller is the important part that makes this prototype has quite a simple circuitry,
as it already has complete internal circuitry in the chip. The line following sensor and the
DC motors are suitable for the prototype while the wheel is not suitable for the movement
of the AGV. As the sensors gives continuous input to the microcontroller about the surface
physical variables. Then, the IR sensors that use as substitute to Analogue Distance Sensor
also function to detect an obstacle. By separately each circuit, it will more easy to
troubleshoot the circuit. This project has been build with equipment that not suitable for it
functions, but the main objective that is move along white line is done. During done this
project, the simulation in Proteus is only 70 percent same with the hardware development.
The cost of this project is also effective and there are much profitable aspects if this
prototype is developed in the future. Hope the idea of this project can be used for other
creation of AGV system.
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6.2 Recommendation
World of engineering is always looking for the best solution for every problem
exist to ensure a better future. As for this project, lots of development and improvement
can be made to ensure better outcome. There are many ideas and suggestions can be added
towards developing this prototype in the future as this prototype could be as one of all the
AGVs around the countries that help in human living.
As one of the suggestions is that, this prototype can be attached with more sensors
to make it could work in much more complex task. There are many sensors nowadays, and
the choices of sensors could be varied, but the selection of sensors must be applicable to
this prototype. This model’s chassis could be adjusted to make it suitable for future task,
and some other components could also be added. The adjustment may consider the factors
of desired function to be built to the prototype, making it look more smart, interesting, and
commercial.
Other than that, the microcontroller PIC chip can be change to other type such as
PLCC that could save the space of the board and also seem to look smarter. Therefore, this
prototype has the potential and could be the basic to the future adjustment of this prototype
to work in the workplaces or in helping the residents to do their housework.
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