This document describes a graduate project submitted by Zainab Falaih Hasan Ulla Ahmed Ouda for the degree of Bachelor of Automated Manufacturing Engineering. The project involves designing and building a prototype of a black line tracking robot. The robot uses sensors and a microcontroller to follow a black line on a white surface and maneuver turns. It is intended to function autonomously within an automated factory environment. The document provides background on the project, acknowledges those involved in advising and supporting the work, and outlines the various chapters that will comprise the project report, including the robot design, hardware components, implementation details, results, and proposals for future work.

1. Republic of Iraq
Ministry of higher Education and Scientific Research
University of Baghdad
College of Al-Khwarizmi Engineering
Automated Manufacturing Engineering Department
ate Project TitleduGrad
Black Line Tracking Robot
By
Zainab Falaih Hasan Ulla Ahmed Ouda
Under Supervision
Dr. Hussein Tbena Kadhim Msc. Raghad Ahmed
June/2016

2. University of Baghdad
College of Al-Khwarizmi Engineering
Automated Manufacturing Engineering Department
Graduate Project Titled
Black Line Tracking Robot
Submitted for partial fulfillment of the degree of
Bachelor of Automated Manufacturing Engineering
By
Zainab Falaih Hasan Ulla Ahmed Ouda
SupervisionUnder
Dr. Hussein Tbena Kadhim Msc. Raghad Ahmed
Committee Certificate
June/2016

3. ‫ا‬ً‫م‬ْ‫ل‬ِّ‫ع‬ ‫ي‬ِّ‫ن‬ْ‫د‬ِّ‫ز‬ ِّ‫ب‬َ‫ر‬ ْ‫ل‬ُ‫ق‬َ‫و‬

4. Acknowledgments
We have received an amazing guidance from our supervisors "Dr. Hussien Tabeena" and "Msc. Raghad
Ahmed", we would like to convey our gratitude to them.
We would like to dedicate our project to all our "family members" for supporting us in all aspects of our lives
since we were born, without them we wouldn’t do anything.
We would like to thank all of our "lecturers" who were like candles in our way in every single information they
gave it to us from their knowledge.
At the end we would like to dedicate our project to all our "classmates" who shared with us everything and
supported us in the good and the bad times.

5. Abstract
This paper describes algorithm of line tracking robot (any contrasting colors) it’s a machine that can follow a
path. The path can be visible like a black line on a white surface (or vice-versa), the line follower robot is an
automated part of a fully automated factory which are considered to be the most flexible type of material handling
system, the vehicles’ working environment ranges from small offices with carpet floor to huge harbor dockside
areas, as it give many advantages in our lives.
The aim of this project is to build a prototype of a black line tracking robot that can move on a flat white surface
with visible black line to follow by its two driving wheels that connected to two DC gear motors and a third wheel
that make the vehicle to rotate 360°. The prototype is able to follow the black line on floor with the AVR
microcontroller to synchronize the orders from the sensors and for controlling the delay.
To follow the line, the microcontroller is attached to a sensor that continuously reflecting to the surface condition
by proximity sensor which control the movement and the direction of the vehicle which play role of stern and a
distance sensor which act like a brakes when necessary.
Therefore, this project involves designing and fabrication of the hardware and the software.
Keywords
Infrared detector, Mobile robots, Path planning, Line follower robot, Robot sensing system

6. I
Contents
Acknowledgments
Abstract
Chapter One: Introduction…………………...…………………………………………1
1.1 Line tracking robot definition………………...…………………………………….1
1.2 Literature review……………………………………..………………………….….1
1.3 Objective…………..………………………………………………………………..1
1.4 Scopes of project…………………..………………………………………………..2
1.5 Advantages……..…………………………………………………………………..2
1.6 Disadvantages………..……………………………………………………………..2
1.7 Applications…………..…………………………………………………………….3
Chapter Two: Robot Design……………………………………………………………4
2.1 Line tracking robot principle……..………………………………………………...4
2.2 Algorithm…..………………………………………………………………………5
2.3 Theory of differential steering system…………………..…………………………6
2.4 Path specification………… ………………………………………………………7
2.5 Methodology………..……………………………………………………………...7
Chapter Three: Hardware components………..………………………………………..8
3.1 Arduino Uno……..…………………………………………………………………8
3.2 The AVR microcontroller…..……………………………………………………...9
3.3 L298 dual H-bridge motor controller module………..…………………………...10
3.4 IR proximity sensor……………..………………………………………………...11
3.5 Carriage……..…………………………………………………………………….11
3.6 Batteries………………….……………………………………………………….12
3.7 Wires…..………………………………………………………………………….12
Chapter Four: Implementation………………………………………………………..13

7. II
4.1 Main board schematic……..……………………………………………………...13
4.2 Sensor circuit…..………………………………………………………………….15
4.3 Motor interface and control circuit…………..……………………………………16
4.4 The H-bridge control hardware..………………………………………………….17
4.5 PMW specification & calculation…………..…………………………………….18
4.6 Voltage experiment…………..…………………………………………………...19
4.7 Process explanation…………..…………………………………………………...20
4.8 Flow chart…………………..……………………………………………………..21
4.9 Programming………………..…………………………………………………….22
4.10 Code……………………………………………………………………………...22
4.11 Final shape……………………………………………………………………….25
Chapter Five: Results & Conclusion……………………………………...…………..27
5.1 Results…..………..……………………………………………………………….27
5.2 Proposal for future work………………..…………………………………………27
References & resources..………..…………………………………………………….28

8. III
List of figures
FIGURE NAME PAGE NUM.
2.1 Sensor principle 4
2.2 The robot principle 5
2.3 Theory of differential steering system 6
2.4 The path 7
3.1 Arduino UNO 8
3.2 AVR microcontrollers 9
3.3 L298 Dual H-bridge motor controller module 10
3.4 The proximity sensor 11
3.5 Automation carriage 11
3.6 Batteries 12
3.7 Wires 12
4.1 Schematic main board 13
4.2 Complete circuit diagram 14
4.3 Circuit connections 14
4.4 Schematic of a single sensor 15
4.5 Relative voltage swing 16
4.6 Internal schematic of L298 17
4.7 The motor controller 17
4.8 Line tracking process 20
4.9 Rotating algorithm 21
4.10 Process flow chart 21
4.11 Programmable code 22
4.12 Linking motors to tires 25
4.13 Final shape 26
4.14 Black line tracking robot on path 26

9. 1
Chapter one
Introduction
1.1 Linetracking definition
The line tracking is a self-operating robot that detects and follows a line that is drawn on the floor. The path
consists of a black line on a white surface (or it may be reverse of that). The control system used must sense a
line and maneuver the robot to stay on course, while constantly correcting the wrong moves using feedback
mechanism, thus forming a simple yet effective closed loop System. The robot is designed to follow very tight
curves.[1]
1.2 Literaturereview
In this section some of the existing tools and technologies developed so far in the field line tracking robots are
reviewed. Hymavathi & Vijay Kumar (2011) presented a paper on Design of a double line tracking using IR
sensors, op-amp and 8051 Microcontroller. Arora & Mengi (2011) presented a paper on line follower using IR
sensors and S12X Microcontroller. These techniques have a major drawback that they are color dependent. The
voltages outputted by the sensors depend on the color sensed. Hence they are not flexible. Also these IR sensors
are affected by other IR radiations if present in the same environment. The placement of sensors is also dependent
on the dimensions of the path. Also IR sensors have a limited lifetime and it’s difficult to debug faults.[6]
1.3 Objective
In the industry carriers are required to carry products from one manufacturing plant to another which are usually
in different buildings or separate blocks. Conventionally, carts or trucks were used with human drivers.
Unreliability and inefficiency in this part of the assembly line formed the weakest link. The project objective is
to automate this sector, using carts to follow a line instead of laying railway tracks which are both costly and an
inconvenience.[1]

10. 2
1.4 Scopes of project
• The robot must be capable of following a line.
• It should be capable of taking various degrees of turns
• It must be prepared of a situation that it runs into a territory which has no line to follow.
• The robot must also be capable of following a line even if it has breaks.
• The robot must be insensitive to environmental factors such as lighting and noise.
• The color of the line must not be a factor as long as it is darker than the surroundings.
1.5 Advantages
 Can be moved on the straight or arc-shaped railways to carry many different kinds of stuff.
 Different shape, size and weight can be carry.
 Flexible and intelligent.
 Time consuming.
 Used to reduce manufacturing and labor costs while increasing productivity and efficiency.
 Robot movement is automatic.
 It is used for long distance applications.
 Simplicity of building.
 Used in home, industrial automations etc.[8]
1.6 Disadvantages
 Follows a black line about 1 or 2 inches in width on a white surface.
 Simple robots with an additional sensors placed on them.
 Needs a path to run either white or black since the IR rays should reflect from the particular path.
 Slow speed and instability on different line thickness or hard angles.[8]

11. 3
Applications1.7
 Industrial Applications: These robots can be used as automated equipment carriers in industries replacing
traditional conveyer belts, automatic storage, packaging, use as a handling materials vehicle inside the
factories, in harbors with the aid of robotic arm can make completely automated system of loading and
unloading from the ships.
 Automobile applications: These robots can also be used as automatic cars running on roads with embedded
magnets.
 Domestic applications: These can also be used at homes for domestic purposes like floor cleaning etc.
 Guidance applications: These can be used in public places like shopping malls, museums etc. to provide
path guidance.
 Medical applications: As a wheel chair for patients to use it, can be used in walking stick for blind persons
which react as an alarm when get out of the way instead of the motor, efficient automatic transportation of
goods, the goods typically transported by ATLIS System include carts of dietary/food items, medical/surgical
supplies (case carts), linens, trash, regulated medical waste, pharmaceuticals, items for decontamination
centers, and general housekeeping items.[1]

12. 4
Chapter two
Robot design
2.1 Line tracking robot principle
The working of a line follower robot is pretty straight forward. These robots have the capability to detect a
black/dark line on a lighter surface depending on the contrast. They estimate whether the line underneath them is
shifting towards their left/right as they move over them. Based on that estimation they give respective signals to
the motors to turn left/right so as to maintain a steady center with respect to the line.
These robots usually use an array of IR (Infrared) sensors in order to calculate the reflectance of the surface
beneath them. The basic criteria being that the black line will have a lesser reflectance value (black absorbs light)
than the lighter surface around it. This low value of reflectance is the parameter used to detect the position of the
line by the robot. The higher value of reflectance will be the surface around the line. So in this linear array of IR
sensors, if the leftmost/rightmost IR sensor presents the low value for reflectance, then the black line is towards
the left/right of the robot correspondingly. The controller then compensates for this by signaling the motor to go
in the opposite direction of the line. [2]
Fig. (2.1) Sensor Principle

13. 5
Fig. (2.2) The robot principle
2.2 Algorithm
The robot uses IR sensors to sense the line, IR LEDs (Tx) and sensors (Rx), facing the ground has been used in
this setup. The output of the sensors is an analog signal which depends on the amount of light reflected back, this
analog signal is given to the comparator to produce 0s and 1s which are then fed to the uC.
1. L= left sensor which reads 0; R= right sensor which reads 0.
If no sensor on Left (or Right) is 0 then L (or R) equals 0;
2. If both sensors read 1 go to step 3,
Else,
If L>R Move Left
If L<R Move Right
If L=R Move Forward

14. 6
Go to step 4
3. Move clockwise if line was last seen on Right
Move counter clockwise if line was last seen on Left
Repeat step 3 till line is found.
4. Go to step 1.[3]
2.3 Theory of the differential steering system
The differential steering system is familiar from ordinary life because it is the arrangement used in a wheelchair.
Two wheels mounted on a single axis are independently powered and controlled, thus providing both drive and
steering. Additional passive wheels (usually casters) are provided for support. Most of us have an intuitive grasp
of the basic behavior of a differential steering system. If both drive wheels turn in tandem, the robot moves in a
straight line. If one wheel turns faster than the other, the robot follows a curved path. If the wheels turn at equal
speed, but in opposite directions,
the robot pivots.[8]
Fig. (2.3) Theory of differential steering system

15. 7
2.4 Path specifications
There are two colors chosen for the guide-path.
Guiding Color: very low reflection color (black) drawn on the ground, which form the path of the vehicle;
the basic width of the line is (200mm) which is a bit more than the space between the two sensors, this is to avoid
failures happening while turnings. In this case the sensor board may go out of the basis path and read the data
from the basic carpet of the shop floor which makes the plan unlikely and unpredictable.
Base Color: This color is a shiny color with high reflection (white) which the line follower sensor react with
to move the vehicle, it forms the basic platform of the factory or the place where the vehicle work in.[3]
Fig. (2.4) The path
2.5 Methodology
First we used the reflective optical sensors but when we experienced it the signal that gave us was too weak so
we used an amplifier circuit but also the signal wasn’t strong enough to operate and sense the line from a distance
,Then we changed the sensors into the IR proximity sensor and tested it by connecting it with the Arduino and
when we passed it over a white color path it gave us signal (1) and when we passed it over black path gave us
(zero) , then we started the hardware part of the project and the programing part using the C/C++ language and
finally it worked. For which we’re thankful for, as we have learnt much more in the processes.[3]

16. 8
Chapter three
Hardware component
3.1 ArduinoUno
The Uno is a microcontroller board based on the ATmega328P.It has 14 digital input/output pins (of which 6
can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an
ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it
to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. You can tinker
with your UNO without worrying too much about doing something wrong, worst case scenario you can replace
the chip for a few dollars and start over again. "Uno" means one in Italian and was chosen to mark the release
of Arduino Software (IDE) 1.0. The Uno board and version 1.0 of Arduino Software (IDE) were the reference
versions of Arduino, now evolved to newer releases. The Uno board is the first in a series of USB Arduino
boards, and the evolved to newer releases. The Uno board is the first in a series of USB Arduino boards, and
the reference model for the Arduino platform; for an extensive list of current, past or outdated boards see the
Arduino index of boards.[1]
Fig. (3.1) Arduino UNO

17. 9
3.2 The AVR microcontroller
Atmel's AVR® microcontrollers have a RISC core running single cycle instructions and a well-defined I/O
structure that limits the need for external components. Internal oscillators, timers, UART, SPI, pull-up resistors,
pulse width modulation, ADC, analog comparator and watch-dog timers are some of the features you will find in
AVR devices.
AVR instructions are tuned to decrease the size of the program whether the code is written in C or Assembly.
With on-chip in-system programmable Flash and EEPROM, the AVR is a perfect choice in order to optimize cost
and get product to the market quickly.[4]
Fig. (3.2) AVR microcontrollers

18. 10
3.3 L298 Dual H-bridgeMotor Controllermodule
H- Bridges are typically used in controlling motors speed and direction, but can be used for other projects such
as driving the brightness of certain lighting projects such as high powered LED arrays.
An H-Bridge is a circuit that can drive a current in either polarity and controlled by *Pulse Width Modulation (P
WM).Pulse Width Modulation is a mean in controlling the duration of an electronic pulse.[4]
Fig. (3.3) L298 Dual H-bridge Motor Controller module
3.4 IR Proximitysensor
The IR Proximity sensor is one of the most commonly used sensors you will find these in automatic taps,
automatic door opening, etc. This sensor works on the principle of IR reflectance.
There is an IR LED (white / light blue in color) that’s constantly emitting emitting IR light. The light when
reflected back falls on the IR Receiver) LED / Photodiode (the black / dark blue color led) this received signal
is then Already a member? Sign in processed by an Op-Amp and the Op-Amp gives a HIGH signal. So the sensor
module will give a HIGH signal if there is an object in front of the LED's. The range of sensing can be varied by
adjusting the potentiometer on the sensor module. The maximum range of this module is only a few cms, so don't
expect to use this as a distance sensor. The module will not work when pointed at black objects as black
color tends to absorb the IR light program to trigger the Buzzer every time the sensor gives a high signal.[2]

19. 11
Fig. (3.4) The proximity sensor
3.5 Carriage
Contain three tires used in the project taken from baby carriage, two of them are attached to the motors and the
third is restricted in movement only rotate forward and backward. Three tires are used instead of four to lessen
the friction while turning because there is no steering to rotate the tire.[3]
Fig. (3.5) Automation carriage

20. 12
3.6 Batteries
The vehicle is powered by two (9 volts) batteries as a primary source of an electrical energy for the motors and
as a power supply for the Arduino.
Fig.(3.6) 9v batteries
3.7 Wires
Fig. (3.7) Wires

21. 13
Chapter four
Implementation
4.1 Main board schematic
Each of the hardware is dissected and was designed/implemented separately for their functional and later
incorporated as one whole application. This helped in the debugging processes. In similar fashion the separate
modules forming the ensemble will be explained separately.
Fig. (4.1) Schematic main board

22. 14
Fig. (4.2) Complete circuit diagram
Fig. (4.3) Circuit connections

23. 15
4.2 Sensor circuit
The resistance of the sensor decreases when IR light falls on it. A good sensor will have near zero resistance in
presence of light and a very large resistance in absence of light, we have used this property of the sensor to form
a potential divider. The potential at point ‘2’ is R sensor / (R sensor + R1). Again, a good sensor circuit should
give maximum change in potential at point ‘2’ for no-light and bright-light conditions. This is especially important
if you plan to use an ADC in place of the comparator. To get a good voltage swing, the value of R1 must be
carefully chosen. If R sensor = a when no light falls on it and R sensor = b when light falls on it. The difference
in the two potentials is:
Vcc * { a/(a+R1) - b/(b+R1) }……….(1)
Fig. (4.4) Schematic of a single sensor

24. 16
Fig. (4.5) Relative voltage swing
Relative voltage swing = Actual Voltage Swing / Vcc……….(2)
= Vcc * { a/(a+R1) - b/(b+R1) } / Vcc
= a/(a+R1) - b/(b+R1)
4.3 Motor interface and control circuit
The L298 Motor Driver has 4 inputs to control the motion of the motors and two enable inputs which are used for
switching the motors on and off. To control the speed of the motors a PWM Waveform with variable duty cycle
is applied to the enable pins. Rapidly switching the voltage between Vs and GND gives an effective voltage
between Vs and GND whose value depends on the duty cycle of PWM. 100% duty cycle corresponds to voltage
equal to Vs, 50 % corresponds to 0.5Vs and so on.
Many circuits use L293D for motor control, I chose L298 as it has current capacity of 2A per channel @ 45V
compared to 0.6 A @ 36 V of a L293D. L293D’s package is not suitable for attaching a good heat sink, practically
you can’t use it above 16V without frying it. L298 on the other hand works happily at 16V without a heat sink,
though it is always better to use one.

25. 17
Fig. (4.6) Internal Schematic of L298
4.4 The H-bridgecontrol hardware
Fig. (4.7) The motor control

26. 18
The entire motor control circuitry is shown in the above figure along with the internal circuitry of the L298 motor
control IC. The table below clearly indicated the operation of the IC.
Table (1)
The total number of directional control signals required is 4; but as it can be observed in the above table, IN1 &
IN2 are complimentary (and so is IN3 & IN4) that is, both the inputs have to take the opposite states for a safe
operation. This is done by connecting DL to IN1 and L D to IN2. The same is done to IN3 & IN4. Now we have
1 directional control per motor. The ENABLE of each motor section is given PWM inputs to further improve on
the control. Now, each motor has a direction control and a speed control. The clamping diodes are built into the
chip which prevent the back EMF generated by the motors to harm the H-bridge.
4.5 PWM Specification & Calculation
The L293D chip can operate on PWM signals up to 5kHz, which was decided to be used.
..........(3)
1/5kHz = [(PR2) + 1] × 4 × (1/4MHz) × 1
200μs = [(PR2) + 1] × 1μs
PR2 = 200-1 = 199 ≈200
Three speeds are used for the line following robot and their corresponding duty cycles are 0%, 50% & 96%.
These calculations are shown below.

27. 19
For 0% duty cycle the value to be loaded is obviously zero,
For 50 % duty cycle,
PWM duty cycle = 200μ s
100
× 50 = 100μs .
100 μ s = [DCx] •0.25μs • 1
DCx = 400 = 110010000b
Thus, clear the bits DCxB1 & DCxB0 and load 1100100b i.e. 100 into the CCPRxL
register.
For 96 % duty cycle,
PWM duty cycle = 200μ s
100
× 96 = 192μs .
192 μ s = [DCx] •0.25μs • 1
DCx = 768 = 1100000000b
Thus, clear the bits DCxB1 & DCxB0 and load 11000000b i.e. 192 into the CCPRxL register.
4.6 Voltage experiment
Orientation Voltage at node A Voltage at node B INFERENCE
Both sensors on white 3.5v 3.5v Robot not moving
Left sensoron white and right
sensoron black
0v 3.5v Robot drifted to right
Left sensor on black and right
sensor on white
3.5v 0v Robot drifted to left
Both sensors on black 0v 0v Robot moving
Forward
Table (2)

28. 20
4.7 Process explanation
Fig. (4.8) Line tracking process
As shown in the figure above, is a typical situation involved. At every sampled time the commands executed by
the microcontroller is also shown. From the above figure, it should be clear about the software requirements.
If no line is seen, the microcontroller just follows the previous action. This process is continued till either 5
seconds elapse or a line is reached. If a line is not reached within 5 seconds (software controlled), the
microcontroller shifts into “line find” mode. In this mode, the robot takes a right turn and starts rotating about a
fixed point. The radius is continuously incremented every second. Thus the robot follows the path of a spiral.
This process is continued till either a line is reached or till the robot has achieved a maximum radius of curvature
(is traveling in straight line) when the
Process is reset and the robot is made to turn in the starting circle, but now at a different point. This is the
algorithm with minimum complexity considering speed requirements.

29. 21
Fig. (4.9) Rotating algorithm
4.8 Flow chart
Fig. (4.10) Process flow chart

30. 22
4.9 Programming
We used C++ language for programming using the Arduino application
Fig. (4.11) Programming code
4.10 Code
float Kp=0,Ki=0,Kd=0;
float error=0, P=0, I=0, D=0, PID_value=0;
float previous_error=0, previous_I=0;
int sensor[5]={0, 0, 0, 0, 0};
int initial_motor_speed=100;
void read_sensor_values(void);
void calculate_pid(void);
void motor_control(void);
void setup()

31. 23
{
pinMode(9,OUTPUT); //PWM Pin 1
pinMode(10,OUTPUT); //PWM Pin 2
pinMode(4,OUTPUT); //Left Motor Pin 1
pinMode(5,OUTPUT); //Left Motor Pin 2
pinMode(6,OUTPUT); //Right Motor Pin 1
pinMode(7,OUTPUT); //Right Motor Pin 2
Serial.begin(9600); //Enable Serial Communications
}
void loop()
{
read_sensor_values();
calculate_pid();
motor_control();
}
void read_sensor_values()
{
sensor[0]=digitalRead(A0);
sensor[1]=digitalRead(A1);
sensor[2]=digitalRead(A2);
sensor[3]=digitalRead(A3);
sensor[4]=digitalRead(A4);
if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==0)&&(sensor[4]==0)&&(sensor[4]==1))
error=4;
else if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==0)&&(sensor[4]==1)&&(sensor[4]==1))
error=3;
else if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==0)&&(sensor[4]==1)&&(sensor[4]==0))
error=2;
else if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==1)&&(sensor[4]==1)&&(sensor[4]==0))
error=1;

32. 24
else if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==1)&&(sensor[4]==0)&&(sensor[4]==0))
error=0;
else if((sensor[0]==0)&&(sensor[1]==1)&&(sensor[2]==1)&&(sensor[4]==0)&&(sensor[4]==0))
error=-1;
else if((sensor[0]==0)&&(sensor[1]==1)&&(sensor[2]==0)&&(sensor[4]==0)&&(sensor[4]==0))
error=-2;
else if((sensor[0]==1)&&(sensor[1]==1)&&(sensor[2]==0)&&(sensor[4]==0)&&(sensor[4]==0))
error=-3;
else if((sensor[0]==1)&&(sensor[1]==0)&&(sensor[2]==0)&&(sensor[4]==0)&&(sensor[4]==0))
error=-4;
else if((sensor[0]==0)&&(sensor[1]==0)&&(sensor[2]==0)&&(sensor[4]==0)&&(sensor[4]==0))
if(error==-4) error=-5;
else error=5;
}
void calculate_pid()
{
P = error;
I = I + previous_I;
D = error-previous_error;
PID_value = (Kp*P) + (Ki*I) + (Kd*D);
previous_I=I;
previous_error=error;
}
void motor_control()
{
// Calculating the effective motor speed:
int left_motor_speed = initial_motor_speed-PID_value;
int right_motor_speed = initial_motor_speed+PID_value;

33. 25
// The motor speed should not exceedthe max PWM value
constrain(left_motor_speed,0,255);
constrain(right_motor_speed,0,255);
analogWrite(9,initial_motor_speed-PID_value); //Left Motor Speed
analogWrite(10,initial_motor_speed+PID_value); //Right Motor Speed
//following lines of code are to make the bot move forward
/*The pin numbers and high, low values might be different
depending on your connections */
digitalWrite(4,HIGH);
digitalWrite(5,LOW);
digitalWrite(6,LOW);
digitalWrite(7,HIGH);
}
4.11 Finalshape
We assembled all the parts tires to carriage, connected the motors to the tires and to the motor driver, the Arduino
kit was placed with glue on the cart and at last the electrical kit with the micro controller of the Arduino
Fig. (4.12) Linking motors to tires

34. 26
Fig. (4.13) Final Shape
Fig. (4.14) Black line tracking robot on its path

35. 27
Chapter five
Results & Conclusion
5.1 Results
In general, LTR was tested employing all the navigational strategies discussed in this paper. Observation
made for every proposed strategy show that the robot is capable of navigating the line with no difficulties at
all. Introducing ambient lighting to the test pitch does not affect the line following capability. The same can
be said in terms of junction navigation algorithms.
 When the both sensors read 3.5V the robot stopped.
 When the right sensor read 3.5V and the left sensor read 0V the robot turned left.
 When the right sensor read 0V and the left sensor read 3.5 V the robot turned right.
 When the both sensors read 0V the robot moved forward.
Unexpected problems didn't take it in consideration:
 It was supposed to use 5 sensors instead of two but because of the market limitations we had to work
with just two and that caused us troubles in movement accuracy.
 We had batteries problem we couldn’t find rechargeable batteries so we had to use less efficiency
batteries which drains fast.
 We switched the sensors from color sensor to proximity sensor because it didn’t give us enough voltage.
5.2 Proposal for future work
Many developing can achieve to the project like:
 A camera to help in monitoring the way.
 Adding fork- lift or robotic arm for automatic loading and unloading.
 Add wiper for cleaning.
 We can use more sensors to increase the accuracy or use the PID control to increase the flexibility and
control the errors.

36. 28
References & Resources
Books:
[1] Bajestani, S.E.M., Vosoughinia, A., “Technical Report of Building a Line Follower Robot” International
Conference on Electronics and Information Engineering
[2] M. Zafri Baharuddin, Izham Z. Abidin, S. Sulaiman Kaja Mohideen, Yap Keem Siah, Jeffrey Tan Too
Chuan,"Analysis of Line Sensor Configuration fo or the Advanced Line Follower Robot",University Tenaga
Nasional.
[3] Miller Peter , “Building a Two Wheeled Balancing Robot”, University of Southern Queensland, Faculty of
Engineering and Surveying. Retrieved Nov 18, 2008.
[4] Priyank Patil , “AVR Line Following Robot,” Department of Information Technology K. J. Somaiya College
of Engineering Mumbai, India. Retrieved Mar 5, 2010.
[5] Digital logic and computer design by M. Morris Mano - Prentice – Hall of India PVT limited
Digital Systems Principles & applications by Ronald J. Tocci Sixth Edition - Prentice – Hall of India PVT limited
Links:
[6] The Seattle Robotics Society Encoder library of robotics articles
http://www.seattlerobotics.org/encoder/library.html
[7] Dallas Personal Robotics Group. Most of these tutorials and articles were referred.
http://www.dprg.org/articles/index.html
[8] Go Robotics.NET, this page has many useful links to robotics articles.
http://www.gorobotics.net/articles/index.php
[9] Carnegie Mellon Robotics Club. This is the links page with lots of useful resources
http://www.roboticsclub.org/links.html

37. 29
‫ملخص‬‫البحث‬
‫هذا‬‫البحث‬‫يشمل‬‫انجاز‬‫روبوت‬‫متتبع‬‫للمسار‬‫االسود‬(‫او‬‫اي‬‫لون‬‫متباين‬,)‫الروبت‬‫المتتبع‬‫للمسار‬‫االسود‬‫هوعباره‬
‫عن‬‫ماكنه‬‫قادره‬‫على‬‫تتبع‬‫اي‬‫مسار‬,‫ممكن‬‫ان‬‫يكون‬‫المسار‬‫ظاهر‬‫كاللون‬‫االسود‬‫على‬‫سطح‬‫ابيض‬(‫او‬‫العكس‬,)
‫هذا‬‫الروبت‬‫هو‬‫جزء‬‫مؤتمت‬‫من‬‫اي‬‫مصنع‬‫مؤتمت‬‫الذي‬‫من‬‫الممكن‬‫ان‬‫يعتبر‬‫اهم‬‫جزء‬‫في‬‫نظام‬‫نقل‬‫المواد‬,
‫الروبوت‬‫يعمل‬‫في‬‫نطاقات‬‫واسعه‬‫من‬‫المكاتب‬‫الصغيره‬‫ذات‬‫االرضيات‬‫المفروشه‬‫وحتى‬‫الموانئ‬‫الضخمه‬
‫والذي‬‫يوفر‬‫لنا‬‫الكثير‬‫من‬‫الفوائد‬‫في‬‫حياتنا‬.
‫الهدف‬‫من‬‫المشروع‬‫هو‬‫بناء‬‫نموذج‬‫مصغر‬‫عن‬‫الروبوت‬‫المتتبع‬‫للمسار‬‫االسود‬‫والذي‬‫يستطيع‬‫التحرك‬‫على‬
‫ارضيه‬‫بيضاء‬‫ذات‬‫خط‬‫ظاهر‬‫اسود‬‫ليتبعه‬‫بواسط‬‫ه‬‫عجلتين‬‫مربوطين‬‫بماطورين‬‫وعجله‬‫ثالثه‬‫متحرره‬‫تتمكن‬‫من‬
‫الدوران‬063‫درجه‬.
‫النموذج‬‫قادر‬‫على‬‫تتبع‬‫هذا‬‫الخط‬‫بواسطه‬‫مايكروكونترولر‬‫ليتمكن‬‫من‬‫مزامنه‬‫االوامر‬‫من‬‫المتحسسات‬‫وال‬‫تحكم‬
‫بالمهله‬.
‫التباع‬‫الخط‬‫االسود‬‫المايكروكونترولر‬‫يربط‬‫مع‬‫المتحسسات‬‫التي‬‫تستمر‬‫باستقبال‬‫االشارات‬‫المنعكسه‬‫تبعا‬‫ل‬‫حاله‬
‫السطح‬‫بواسطه‬‫متحسسات‬‫القرب‬‫التي‬‫تتحكم‬‫بحركه‬‫واتجاه‬‫العربه‬‫والتي‬‫تلعب‬‫دورا‬‫مهما‬‫حتى‬‫كمكابح‬‫عند‬‫الحاجه‬.
‫لذلك‬,‫المشروع‬‫يشمل‬‫تصميم‬‫وصنع‬‫والمعدات‬ ‫للبرمجيات‬.