Content uploaded by Riddhi Mohan Bora
Author content
All content in this area was uploaded by Riddhi Mohan Bora on Jun 08, 2022
Content may be subject to copyright.
Final Year B.Tech Project
Report
SWARM ROBOTICS :
Master-Slave Configuration through Radio
Communication
Submitted in partial fulfillment of
the requirements for the award of the degree of
Bachelor of Technology
in
Electrical Engineering
Submitted by
Roll No Names of Students
13-1-3-009 Riddhi Mohan Bora
13-1-3-044 Harshita Paul
13-1-3-102 Pema Tenzin
13-1-3-008 Pritom Das
11-1-3-085 Uttaran Warry
Under the guidance of
Dr B. K. Roy
Department of Electrical Engineering
National Institute of Technology Silchar
ELECTRICAL ENGINEERING
BRANCH
National Institute of Technology Silchar
Certificate
This is to certify that the following students of 8th Semester, Electrical Engi-
neering Department of National Institute of Technology, Silchar have carried
out the project work under my guidance. The project work is submitted
in partial fulfilment of the requirement for the award of Bechelor Degree in
Electrical Engineering. I wish them a bright future.
Roll No Names of Students
13-1-3-009 Riddhi Mohan Bora
13-1-3-044 Harshita Paul
13-1-3-102 Pema Tenzin
11-1-3-085 Uttaran Warry
13-1-3-008 Pritom Das
Dr B. K. Roy
Professor
Electrical Engineering Department
NIT, Silchar
Date:
Acknowledgment
A major task completing this project work has been eased with the ample
guidance of our respected guide Dr B. K. Roy, Electrical Engineering Depart-
ment of NIT silchar. Thus we are highly indebted for his guidance, direction
and co-operation at every stage of work which helped us to complete this
project in time.
Further we express our sincere gratitude and heartiest thanks to the whole
Electrical Department. Last but not the least we are also very thankful to
our friends who helped us in completing our projects with their technical
supports.
Above all, to the great Almighty, the author of knowledge and wisdom, for
his countless love; we thank you.
Riddhi Mohan Bora
Harshita Paul
Pema Tenzin
Uttaran Warry
Pritom Das
2
Abstract
Sometimes it is impossible to complete a given task by a single person or it
becomes quite difficult to that person to complete the work. In such cases,
there is a need of a team or group of members who can collaboratively work
and make the work of the person very much simple.
Swarm intelligence (SI) is the study of collective behavior in decentralized or
self-organized system. Using an artificial intelligence technique the concept
of SWARM ROBOTICS is based on the basis of grouping of multiple robots
or devices and perform a desired task. Swarm robotics is a new approach
to the coordination of multi-robot systems which consist of large numbers
of simple physical robots. This approach emerged on the field of artificial
swarm intelligence, as well as in the biological studies of insects, ants and
other fields in nature, where swarm behaviour occurs.
The three major advantages of SI Robotic approach, since SI systems have
the following properties:
1) Scalable: The control architecture of each robot is same irrespective
of the number of robots.
2) Flexible: The robots may be inserted or deleted to/from the environ-
ment; no requirement for any change in the task operation.
3) Robust: Not only due to unit redundancy but also through minimalist
unit design. Swarm robotics has varied applications in all fields like commu-
nication , military services, civil engineering, building construction, advance
medical issue, etc.
The project includes study of various fields in Electronic and Computer Sci-
ence such as Artificial Intelligence, Swarm Intelligence, Embedded System,
Wireless Communication( Radio Communication), Microcontroller, etc. The
project deals with radio frequency communication mechanism. The server or
master robot is guided by an algorithm that has already been programmed
and communicated with the client or slave robot through RF medium.
3
Once the program is flashed into the robots, they can automatically run
and perform their requisite tasks. Here the test task is to make the server to
follow a certain user defined path and the client to synchronized the move-
ment of the server. The schematic idea was given as an input to the master
robot which in response guided the slave one to move as per the master.
i
Contents
Acknowledgement 2
Abstract 3
1 Introduction 1
1.1 Motivation............................. 1
1.2 Swarm robotics -the concept . . . . . . . . . . . . . . . . . . . 1
1.3 Features and applications . . . . . . . . . . . . . . . . . . . . 2
1.4 Swarm robotics -the general idea . . . . . . . . . . . . . . . . 3
1.5 Robot and human analogy . . . . . . . . . . . . . . . . . . . . 3
2 Literature survey 4
2.1 Bio-Inspired sensor swarms . . . . . . . . . . . . . . . . . . . . 4
2.2 Under-sea sensor networks . . . . . . . . . . . . . . . . . . . . 5
2.3 Satelliteswarms.......................... 5
2.4 Some other observations . . . . . . . . . . . . . . . . . . . . . 6
3 Proposed work 7
4 General layout of the work 9
4.1 General idea about the system . . . . . . . . . . . . . . . . . . 9
4.2 General idea about the embedded development board . . . . . 10
4.3 Schematic diagram of the microcontroller unit . . . . . . . . . 11
5 System design 12
5.1 Familiarization with components . . . . . . . . . . . . . . . . 12
5.1.1 Microcontroller . . . . . . . . . . . . . . . . . . . . . . 12
5.1.2 Encoder .......................... 13
5.1.3 RF Transmitter( Tx) . . . . . . . . . . . . . . . . . . . 15
5.1.4 RF Receiver( Rx) . . . . . . . . . . . . . . . . . . . . . 15
5.1.5 Decoder .......................... 15
5.1.6 Voltage controller . . . . . . . . . . . . . . . . . . . . . 16
ii
5.1.7 DC motor driver . . . . . . . . . . . . . . . . . . . . . 17
5.1.8 IRsensors......................... 18
5.1.9 Comparator IC . . . . . . . . . . . . . . . . . . . . . . 19
5.1.10 TimerIC ......................... 20
5.1.11 DCMotors ........................ 20
5.1.12 Rotary potentiometer . . . . . . . . . . . . . . . . . . . 21
6 Working principle 23
6.1 Working of IR sensors . . . . . . . . . . . . . . . . . . . . . . 23
6.1.1 OP-amp.......................... 25
6.1.2 Motor and motor driver coordination . . . . . . . . . . 26
6.2 RF communication: concept and applications . . . . . . . . . 26
6.2.1 Some of the RF characteristics . . . . . . . . . . . . . . 27
6.2.2 Some of the significant applications of RF . . . . . . . 27
6.2.3 Design of RF circuit . . . . . . . . . . . . . . . . . . 28
7 Software specifications 30
7.1 Softwaretools........................... 30
7.1.1 Open source software . . . . . . . . . . . . . . . . . . . 30
7.1.2 ARMKeil microcontroller tool . . . . . . . . . . . . . . 30
7.1.3 AT89S52 IC programming software: ProgIsp . . . . . . 31
7.1.4 USBASP programmer . . . . . . . . . . . . . . . . . . 31
7.2 Algorithm and programming . . . . . . . . . . . . . . . . . . . 32
7.2.1 Master algorithm and programming . . . . . . . . . . . 32
7.2.2 Slave algorithm and programming . . . . . . . . . . . . 32
7.3 Flashing the code into the robots . . . . . . . . . . . . . . . . 32
7.3.1 Test the robots . . . . . . . . . . . . . . . . . . . . . . 32
8 Working of robot 36
8.1 The functional set up . . . . . . . . . . . . . . . . . . . . . . . 36
8.2 Result and discussion . . . . . . . . . . . . . . . . . . . . . . . 37
8.2.1 Training the master . . . . . . . . . . . . . . . . . . . 37
9 Cost analysis of this project 47
9.1 Swarm master robot cost . . . . . . . . . . . . . . . . . . . . . 47
9.1.1 Price corresponding to the items . . . . . . . . . . . . . 47
9.2 Swarm slave robot cost . . . . . . . . . . . . . . . . . . . . . . 48
9.2.1 Price corresponding to the items . . . . . . . . . . . . . 48
9.3 Some auxiliary item cost . . . . . . . . . . . . . . . . . . . . . 49
9.3.1 Price corresponding to the items . . . . . . . . . . . . . 49
iii
List of Figures
4.1 General layout of the sytem 1 . . . . . . . . . . . . . . . . . . 9
4.2 General layout of the embedded borad . . . . . . . . . . . . . 10
4.3 General layout of the microcontroller unit and its peripherals 11
5.1 Pin diagram of an AT89S52 IC . . . . . . . . . . . . . . . . . 13
5.2 Pin diagram of IC HT 12E-18DIP . . . . . . . . . . . . . . . 14
5.3 Data conversion from parallel to serial data . . . . . . . . . . . 14
5.4 Pin diagram of a transmitter IC . . . . . . . . . . . . . . . . . 15
5.5 Pin diagram of a receiver IC . . . . . . . . . . . . . . . . . . . 16
5.6 Pin diagram of IC HT 12D-18DIP-A . . . . . . . . . . . . . . 16
5.7 Pin diagram of a voltage controller IC and its connection . . 17
5.8 Pin diagram of an L293D IC and its connection with motors . 18
5.9 Circuit diagram of an IR sensor . . . . . . . . . . . . . . . . . 19
5.10 OP-amp : Inside a comparator . . . . . . . . . . . . . . . . . . 19
5.11 Pin diagram of a 555 timer IC . . . . . . . . . . . . . . . . . . 20
5.12 Voltage polarity for a clockwise rotation . . . . . . . . . . . . 21
5.13 Voltage polarity for an anticlockwise rotation . . . . . . . . . . 21
5.14 Circuit diagram of a rotary potentiometer . . . . . . . . . . . 22
6.1 IR sensor circuitry in the absence of OBSTACLE . . . . . . . 24
6.2 IR sensor circuitry in the presence of OBSTACLE . . . . . . . 24
6.3 working of an OP-amp . . . . . . . . . . . . . . . . . . . . . . 25
7.1 Program for the swarm master . . . . . . . . . . . . . . . . . 34
7.2 Program for the swarm slaver . . . . . . . . . . . . . . . . . . 35
8.1 The straight line track . . . . . . . . . . . . . . . . . . . . . . 37
8.2 The L-shaped track . . . . . . . . . . . . . . . . . . . . . . . . 38
8.3 Thezig-zagtrack ......................... 38
8.4 The circular track . . . . . . . . . . . . . . . . . . . . . . . . . 39
8.5 Thesquaretrack ......................... 39
8.6 Thesquaretrack ......................... 40
v
8.7 At the starting point . . . . . . . . . . . . . . . . . . . . . . . 40
8.8 Atrunningstage ......................... 41
8.9 At the turning point . . . . . . . . . . . . . . . . . . . . . . . 41
8.10 The deviantion from the track . . . . . . . . . . . . . . . . . . 42
8.11 At the starting point . . . . . . . . . . . . . . . . . . . . . . . 42
8.12Atrunningstage ......................... 43
8.13 At the turning point . . . . . . . . . . . . . . . . . . . . . . . 43
8.14 At the starting point . . . . . . . . . . . . . . . . . . . . . . . 44
8.15Atrunningstage ......................... 44
8.16 At the turning point . . . . . . . . . . . . . . . . . . . . . . . 45
8.17 At the starting point . . . . . . . . . . . . . . . . . . . . . . . 45
8.18Atrunningstage ......................... 46
8.19 At the turning point . . . . . . . . . . . . . . . . . . . . . . . 46
vi
Chapter 1
Introduction
1.1 Motivation
Swarm Robotics is a coordination of multi-robot systems according to the
control from the master bot or server bot. This approach emerged on the field
of Artificial Intelligence. As it is a very diverse field to work with we have
come up with the idea of this project. The concept of swarm is highly involved
in day to day life. It is very interesting to study about how artificially we can
implement our natural behaviours onto a machine. This is the key concept of
this project. New technologies are coming up very rapidly in today’s world.
So we think that Swarm Robotics along with wireless communication concept
is really a solid topic for research and innovation.
1.2 Swarm robotics -the concept
Swarm robotics is implementation of swarm intelligence. Swarm intelligence
(SI) is an artificial intelligence technique based on the study of collective
behavior in decentralized, self-organized systems. Swarm robotics is a new
approach to the coordination of multi-robot systems which consist of large
numbers of simple physical robots [1]. It is supposed that a desired collective
behavior emerges from the interactions among the robots and interactions of
robots with the environment. This approach emerged on the field of artificial
swarm intelligence, as well as the biological studies of insects, ants and other
fields in nature, where swarm behaviour occurs. The main objective of swarm
robotics is to reduce the work load and increase the efficiency of the system.
1
1.3 Features and applications
The swarm robotics is a very important and efficient development in the ar-
tificial intelligence field. It has enormous applications in modern technology
era.
Some of the applications are as follows:
i) Disaster Rescue Missions
ii) Demand Cheap Designs
iii) Mining
iv) Agricultural work
v) Defence and Military works
vi) Swarms of micro-aerial vehicles
vii) Nano and micro swarm robots can be used in human surgery or health
care
viii) Also some artists use swarm robotic techniques to realize new forms
of interactive art
Some of the features as follows:
i) It is inspired but not limited by the emergent behavior observed in so-
cial insects, called swarm intelligence
ii) Relatively simple individual rules can produce a large set of complex
swarm behaviors
iii) A key-component is the communication between the members of the
group that build a sys-tem of constant feedback
iv) The swarm behavior involves constant change of individuals in coop-
eration with others, as well as the behavior of the whole group
v) Unlike distributed robotic systems in general, Swarm robotics emphasizes
2
on a large number of robots, and promotes scalability. It may be done by
using only local communication. The local communication for example, can
be achieved by wireless transmission systems, like radio frequency or infrared
vi) Both miniaturization and cost are key factors in swarm robotics. These
are the constraints in building large groups of robotics; therefore the sim-
plicity of the individual team member should be emphasized. This should
motivate a swarm-intelligent approach to achieve meaningful behavior at
swarm level, instead of the individual level
1.4 Swarm robotics -the general idea
In general language, we can say that a ’swarm’ is nothing but a number of
similar geological phenomena or features occurring closely within a given pe-
riod or place. As for example, we can see a lot of swarm activities in nature
itself. Such as:
i) Bird flying together in coordination forming shape
ii) Ant moving in coordination
iii) Bee coordination
iv) Fish swim together in a certain pattern and many more
1.5 Robot and human analogy
It gets very interesting when we are trying to visualize the correlation be-
tween a human behaviour and an artificial-programmed human, called robot.
These are some easily observable and explainable characters that both hu-
man and robots are similar:
i) Human eye function resembles to IR sensors
ii) Human brain function resembles to microcontroller or microprocessor
iii) Human movable parts like hand and legs resemble to robotic arm or
link, motors, etc
3
Chapter 2
Literature survey
Swarm Intelligence( SI) was first presented by Gerardo Beni, Suzanne Hack-
wood, and Jing Wang [5] when they were researching the properties of mim-
icked, self-arranging operators in the structure of cellular robotic systems.
The three noteworthy advantages of the SI Robotics approach are:
1) Scalable: The control design of every robot is same, regardless of the
quantity of robots
2) Flexible: The robots might be embedded or erased to/from the surround-
ings, no necessity for any adjustment in the errand operation
3) Robust: Not just because of unit repetition additionally through mod-
erate unit plan
2.1 Bio-Inspired sensor swarms
[2] Joseph Fronczek and Nadipuram Prasad of New Mexico State University
distinguished the basic requirement for innovations for rapidly finding and
repairing of the weight spills in contained situations like the International
Space Station. The area, seclusion and repair of climatic weight breaks are
one of the fundamental crises on which the team of the Space Station is con-
sistently prepared. In the event that the group neglects to address the weight
spill in the designated time, they are told to desert the station by means of the
escape module. Such breaks can come from two or three sources. Mistakes
can happen amid the operation of the ISS Environmental Control and Life
Support System( ELCSS - a system of valves and channeling used to make
4
a vacuum situation inside the ISS for the reasons for logical tests). What’s
more, effects from space trash are a danger to the barometrical trustwor-
thiness of the Station. While disappointments in the ECLSS are every now
and again due to a fizzled part that are effortlessly recognized yet spills hap-
pening because of garbage effect are frequently capricious. So by utilizing
mechanical sensor swarms, that can rapidly find and repair weight releases,
basic time can be accommodated the groups to make perpetual repairs.
2.2 Under-sea sensor networks
In spite of the fact that the utilization of kept an eye on and unmanned
frameworks in remote sea investigation has yielded an abundance of learning
about leading up to now obscure maritime procedures [4], the creators have
recognized an absence of advancements to watch creatures and procedures
without aggravating them as they move with the normal movement of the
seas [3]. They propose this can be expert through the improvement of an
independent, free-gliding submerged gadget that can team up or connect with
other such gadgets through an acoustic submerged system [3,4]. Networked
swarms of the proposed free-skimming sensors could make three-dimensional
guide beach front dissemination. These maps could give scientists better
comprehension of different wonders, for example, the spread of poisons and
the development of planktonic groups.
2.3 Satellite swarms
The arrangement set forth in the paper proposed by Owen Brown of Defense
Advanced Research Projects Agency( DARPA) and Paul Eremenko of Booz
Allen Hamilton includes the utilization of free-flying modules in group circles
sharing force and information through a remote system. This makes a virtual
satellite [5]. This would empower a swarm of satellites where a fizzled( or
enhanced) segment can be substituted without the requirement for complex
meet or docking. Envision enlarging processor assets, control era, or payload
capacities on the fly on a transitory or changeless premise basically by adding
modules to the swarm. A satellite swarm could scatter to keep away from
different satellites or enemy munitions.
5
2.4 Some other observations
As of late numerous perceptions and improvements are being made in the
Swarm Robotics field. Swarm robots were utilized to build a 20 feet high
tower, made out of 15,000 blocks that weighted 1.1 lbs each, hence giving a
window into the possible future of architecture and construction. A task that
would have taken people half a month to finish, these little robots finished it
in just three days. The robots were controlled by computers with complex
algorithms and motion sensors. They could recognize and adjust to any
normal unsettling influences, for example, turbulence and either acclimate
to the issues or prematurely abort the assignment completely.
Specialists all through Sheffield foundations made robots whose employment
was to just push an object over the floor, starting with one side then onto the
next. They could likewise sort out themselves by need in the wake of being
scattered in a room. Dr Roderich Gross, leader of the Natural Robotics Lab,
in the Department of Automatic Control and Systems Engineering at the
University of Sheffield, says that swarm robots could be used in military hunt
and-rescue missions in regions unfit for people, in miniaturized scale solution
by using nanobots, and in industry to make it more productive and safe.
Swarm robots can likewise be utilized to assist in disastrous circumstances.
For example after a current cataclysmic event, the swarm could communicate
with each other and people by sharing what they observe [6]. A venture of
swarm robots called Symbrion( Symbiotic Evolutionary Robot Organisms) is
as of now being taken a shot at to join the robots together as one. This could
be helpful for a cataclysmic event, for example, flood, in which the swarm
robots join together to make a raft. Despite the fact that the breakdown
rate of swarm robots is high, it is not of much risk, since numbers are high,
if one robot malfunctions it doesn’t influence the rest.
6
Chapter 3
Proposed work
After a lot of discussion and going through various technical papers, we have
come up with a new idea. The aim of the project entitled with Swarm
robotics: Master and Slave configuration through Radio Communication is
to build two robots which would perform a task given by the user on a certain
platform. The tasks include as i) to follow a user define path and ii) obstacle
avoider.
The project includs the study of various fields in Electronic and Computer
Science such as Artificial Intelligence, Swarm Intelligence, Embedded System,
Wireless Communication( Radio Communication), Microcontroller, etc. The
project deals with radio frequency communication mechanism. Where the
server or master robot is guided by a certain algorithm that has already been
programmed and communicated with the client or slave robot through RF
medium.
Once the program is flashed onto the robots, they can automatically run
and perform their requisite tasks. Here the test task is to make the server to
follow a certain user defined path and the client to synchronize the movement
of the server. The schematic idea was given as an input to the master robot
which in response guides the slave one to move as per the master.
The whole idea of the project is to make it wireless and automatic in nature.
Another aspect is to complete the whole the project with a low expense .
In our B.Tech career, we have come across various technical subjects where
we learn so many concepts, ideas and theoretical Knowledge. The bright
side of this project is that we really can see the utilization of those theo-
retical concepts and ideas in a practical platform. Ideas from various fields
have been brought together in this project. For example, Microcontroller(
7
from MPMC), ICs( from Digital Electronics), Motor Driver circuit( from
Power Electronics), Swarm Robot( from Artificial Intelligence), Radio Com-
munication( from Analog and Digital Communication), DC motor( from Ma-
chines),etc. So we can say that it is a very useful and versatile project.
8
Chapter 4
General layout of the work
4.1 General idea about the system
Figure 4.1: General layout of the sytem 1
9
4.2 General idea about the embedded devel-
opment board
Figure 4.2: General layout of the embedded borad
10
4.3 Schematic diagram of the microcontroller
unit
Figure 4.3: General layout of the microcontroller unit and its peripherals
11
Chapter 5
System design
5.1 Familiarization with components
5.1.1 Microcontroller
The second trend in microprocessor technology is the integration of various
supporting chips( memory, I/O, etc.) with the Microprocessor Unit( MPU)
on a single chip known as Microcontrollers( MCUs). They are used primarily
to perform dedicated functions. They are used as independent controllers in
machines or as slaves in distributed processing. Generally, they include all
the essential elements of a computer on a single chip: MPU, Read Write(
R/W) memory, ROM, I/O ports and other supporting chips such as A/D,
D/A converters, timers, serial communication modules, etc. Typical example
of widely used MCU is Intel 8051 and its various versions manufactured by
different companies, like 89S52 by Atmel company.
Some salient features of a microcontroller:
i) It accepts variables from user program
ii) Stores them temporarily onto its RAM
iii) Performs ALU and again store the results in RAM
iv) Store the final results in ROM and when it is asked to give O/P, it
will give the desired result
About 89S52 IC:
12
i) It is a low power, high performance CMOS 8-bit microcontroller with
8 Kbytes of In-System-Programmable( ISP) flash memory
ii) As basic features it has:
a) 40 pins and 256*8 bit internal RAM
b) 32 programmable I/O lines
c) Three 16 bit Timer/Counter
d) 4 ports which act as both I/O and O/P way. It is very essential for
programming purposes
Figure 5.1: Pin diagram of an AT89S52 IC
5.1.2 Encoder
It is an electronic device which can convert information from one format to
another for the purpose of standardization, security and compression of data.
Another most important use of an encoder is to convert parallel data into
13
serial data. The main benefit is that it needs fewer connecting channels,
and complexity will be greatly reduced. It makes the data transmission very
effective between a transmitter and receiver.
Here we are using an encoder IC HT 12E-18DIP, which is shown in Fig.5.2
Figure 5.2: Pin diagram of IC HT 12E-18DIP
Figure 5.3: Data conversion from parallel to serial data
14
5.1.3 RF Transmitter( Tx)
Typically, it has an oscillator which generates the frequency and amplify
the signal to increase the power which is to be sent through antenna. The
generating frequency from the Tx is 433.92 MHz( approx. 434 MHz). As
we already have known that the encoder will produce the serial data out of
different parallel data, so the transmitter will send out the serial data to air
through the antenna.
Figure 5.4: Pin diagram of a transmitter IC
5.1.4 RF Receiver( Rx)
It is connected just next to the decoder. It receives the serial signal coming
from the Tx antenna and send the same to the decoder which will retrieve
the original signal. Like the Tx, the Rx also has an oscillator which generates
a frequency of 433.92 MHz.
5.1.5 Decoder
This is an electronic device which changes or converts the the code( or bits)
into a set of signals. Here in our project, the main purpose of using a decoder
is to convert the serial data( which has been received by the Rx from the
15
Figure 5.5: Pin diagram of a receiver IC
Tx) into parallel data.
Here we are using a decoder IC HT 12D-18DIP-A, which is shown in the
Fig.5.6
Figure 5.6: Pin diagram of IC HT 12D-18DIP-A
5.1.6 Voltage controller
Voltage regulator IC maintains the output voltage at a constant value. 7805,
a voltage regulator integrated circuit( IC) is a member of 78xx series of fixed
linear voltage regulator ICs used to control voltage fluctuations. An IC 7805
16
provides +5 volt regulated power supply with a provision to add heat sink
as well. As we normally have 9 volt batteries and the requirement of voltage
level is 5 volt throughout the circuit( except the DC motor), we need a volt-
age controller.
Figure 5.7: Pin diagram of a voltage controller IC and its connection
5.1.7 DC motor driver
It is a 16 pin IC which can control a set of two motors simultaneously in any
directions. It is a typical IC which allows the DC motor to rotate on either
directions clockwise or anticlockwise. That is the main advantage of using
this driver, because using only one IC we can control two DC motors which
reduces cost and circuitry complexity as well.
The motor driver that we are using here is L293D. Inside the IC it has H-
bridge. H-bridge is a circuit which allows the voltage to be flown in either
direction. Simple we can say that it provides a four quadrant operation. As
you know voltage need to change its direction for being able to rotate the
17
motor in clockwise or anticlockwise direction.
The Pin diagram of L293D IC and the motor connection is shown below:
Figure 5.8: Pin diagram of an L293D IC and its connection with motors
5.1.8 IR sensors
As the term suggests, it is a device which reacts to a physical, chemical or
biological conditions. It senses and detects. In other words, it can also be
defined as a detector. It gives a primary sensed signal to the signal con-
ditioning unit which generates a meaningful signal that can be studied for
analysis. This meaningful signal is in the form of mV or mA. It can sense
temperature, sound, speed, vibration, light and many more.
Here we have used two IR sensors which can sense infrared( IR) light. The
working principle of an IR sensor will be described clearly in a subsequent
section.
The pin diagram and connection of an IR sensor is given below.
18
Figure 5.9: Circuit diagram of an IR sensor
5.1.9 Comparator IC
It is nothing but an OP-amp. As we know that the output comes from IR
sensors is analog in nature. But we need to send all the parallel data from the
master to the slave in a manner of serial data. So for this purpose, we need
a comparator which can change the analog form of data into a discrete form.
The logic behind the conversion of digital from analog with a comparator is
described in the next subsection clearly.
The comparator IC that we are using in this project is an IC LM324. The
pin diagram is shown in Fig.5.10.
Figure 5.10: OP-amp : Inside a comparator
19
5.1.10 Timer IC
The timer IC is an integrated circuit( chip) used in a variety of timer, pulse
generation, and oscillator applications, etc. A 555 can be used to provide
time delays, as an oscillator, or as a flip-flop element. Derivatives provide
two or four timing circuits in one package.
Here in this project, we are using a 555 timer IC. The pin diagram of a
555 IC is shown in Fig.5.11.
Figure 5.11: Pin diagram of a 555 timer IC
5.1.11 DC Motors
Well known to all, this is an electrical machine which converts the electrical
energy to mechanical energy in rotational motion form. There are various
kind of motors available in market. Like Induction motor, DC brushed mo-
tor, DC BLDC( Brush-less DC) motor, Stepper motor, Servo motor, etc.
Here for this project, we particularly use DC brushed motor which is inter-
nally attached with a mechanical gear arrangements to maintain a low RPM.
The motor that we are using in our project is also called ”DC geared BO-1
motor”. As already mentioned that to control the direction of such motor,
the use of a DC motor driver is must. The operational idea of how the di-
rection of rotation of the motor is controlled by the driver is described in an
upcoming section.
20
The simple-connections diagram of the motor and battery is shown below.
From this diagram, the change in the direction of rotation with the change
in voltage polarity can be understood.
Figure 5.12: Voltage polarity for a clockwise rotation
Figure 5.13: Voltage polarity for an anticlockwise rotation
5.1.12 Rotary potentiometer
This is a very simple component but plays a very vital role in this project.
There are various kind of potentiometers. Among them linear and rotary are
the common ones. Rotary potentiometer is very convenient to use in such
project. The function of the potentiometer here is to set the reference voltage.
NB: After flashing the program onto the robots, the robots need to be cali-
brated which is being done with the help of this tiny component. There are
4 POTs in each robot.
The simple digram of a rotary potentiometer is shown in Fig.5.14.
21
Figure 5.14: Circuit diagram of a rotary potentiometer
22
Chapter 6
Working principle
6.1 Working of IR sensors
We can see in figure 5.9, the circuit diagram of an IR sensor. It will be good
if we know the function of each element in the circuit. The circuit consists
of two resistors, one IR diode and one photo diode.
Basic difference among diode, photo diode and IR diode.
Diode: Conducts in forward bias and does not conduct in reverse bias con-
dition.
Photo diode: Conducts in forward bias and even conducts in reverse bias
when it is exposed to the light.
IR diode: An IR LED( infrared light emitting diode) is a solid state lighting
device that emits light in the infrared range of the electromagnetic radiation
spectrum. IR LEDs allow for cheap, efficient production of infrared light,
which is electromagnetic radiation in 700 nm to 1mm range.
From the figure 6.1:
When there is no obstacle, the IR light which is emitting from the IR diode
does not reflect back to the photo diode. So there will be no conduction
through the photo diode. Hence, this branch acts like an open circuit. As a
result, due to some amount of voltage drop( in the 330 Ohm branch) in the
output terminal, voltage level will be reduced to 3.3 Volt.
23
Figure 6.1: IR sensor circuitry in the absence of OBSTACLE
Figure 6.2: IR sensor circuitry in the presence of OBSTACLE
From the figure 6.2:
When there is an obstacle, the IR light which is emitting from the IR diode
gets reflected back to the photo diode. So there will be conduction through
the photo diode branch. Hence, this branch acts like a short circuit. As a
result, due to some amount of voltage drop( in the 330 Ohm branch as well as
in the 10KOhm branch) in the output terminal, voltage level will be reduced
to 1.2 volt.
Some key points need to be taken care of such as:
24
i) The O/P from IR sensors is analog in nature
ii) I/P required by microcontrollers should be digital
iii) Analog to digital conversion is very much necessary. So OP-amp is used
for this purpose, which is inside the IC LM324
6.1.1 OP-amp
Figure 6.3: working of an OP-amp
Output voltage range is 1.2 volt to 3.3 volt in our case.
NOTE: i) +V and -V are the analog inputs to OP-amp
ii)Case 1: +V is greater -V then O/P will be +Vsat
Case 2: +V is less than -V then O/P will be -Vsat
iii) In our case, +Vsat is 5 volt and -Vsat is 0 volt
iv) Now we can see that depending upon the O/P voltage level of IR sensor,
the OP-amp gives us only two set of O/P’s. These are 5 volt and 0 volt on
the basis on that above mentioned conditions (Case 1 and Case 2). So it
behaves like a discrete signal now
25
6.1.2 Motor and motor driver coordination
From the figure : 5.8
Significance of these pins:
i) 1A 2A :: I/P from the microcontroller to the L293D IC for Motor A
ii) 3A 4A :: I/P from the microcontroller to L293D IC for Motor B
iii) 1Y 2Y :: O/P to Motor A
iv) 3Y 4Y :: O/P to Motor B
Logic Table:
Logic Table
Signal to 1Y
(2Y)
Signal to 2Y
(4Y)
Motor actions
0 0 Motor Stops
0 1 Motor runs in
clockwise direc-
tion
1 0 Motor runs in
anticlockwise di-
rection
1 1 Motor moves
in forward
direction
6.2 RF communication: concept and appli-
cations
i) Radio waves are an electromagnetic waves that travels at the same speed
of light, like any EM radiations
26
ii) The frequency range of radio frequency( RF) in EM spectrum is about 3
KHz to 300 GHz
iii) The radio waves are widely used for radio broadcasting, mobile com-
munications, satellite communication and many more
6.2.1 Some of the RF characteristics
i) Low power: typically transmits with less than 1 mW of power
ii) Good operating range operating between distances of 1 cm to 100 Km
iii) Supports data rate up to 1-2 Mbps
iv) Penetrates walls
v) Does not require a direct transmission path
vi) As it deals with very high frequency (in MHz range); noise effect is very
less
vii) Due to high frequency transmission efficiency is good
6.2.2 Some of the significant applications of RF
i) RF contactless smart cards
ii) Wireless data terminals
iii) Wireless fire protection systems
iv) Biological signal acquisitio.
v) Hydrological and meteorological monitoring
vi) Robot remote control
NB: The application of RF is wide with any wireless communication and
control being a probable area of applications with our imagination is our
only bound.
27
6.2.3 Design of RF circuit
To design RF circuit we need:
i) Encoder: usually all the data which are received from the circuit are
parallel in nature. That means multiple bits of data are generated in the
circuit simultaneously. For transmitting all these data to the receiver end
we need proper channel and antenna. It is not advisable or efficient to send
these parallel data directly to the receiver end. The encoder first encoded all
those parallel multiple bits into serial data and then through the transmitter(
Tx) are sent. Serial communication reduces the number of channels required
to transmit multiple bits and hence performance quality and security both
increase.
For our project, as already mentioned earlier we have used pre-programmed
IC HT 12E 18DIP. Pin diagram is mentioned in the previous chapter. Spec-
ifications of Pins:
Pin A0-A7: Address switch to select an appropriate receiver
Pin 9 and 18: Ground and 5 Volt dc supply respectively
Pin 16 and 15: Oscillator which is used to generate the required 433.93 MHz
frequency
Pin 10-13: 4 bits parallel data are collected by these pins
Pin 17: The pin which is used to send the serial encoded data to transmitter(
Tx)
Pin 14: Enable the O/P pins from MCU
ii) Transmitter( Tx): The RF transmitter is typically a device with an os-
cillator which generate the requisite frequency and amplify the power of the
incoming signal which is later on sent through the antenna.
The Pin diagram is shown in the previous chapter. Specifications of the pins:
Pin 1: Ground
Pin 2: The serial data from encoder is received by this pin
Pin 3: Vcc 5 volt dc supply is provided to that pin
Pin 4: RF antenna is to be connected at this pin through this antenna the
data is being sent to air
iii) Receiver( Rx): The RF receiver has a slightly complex structure than
to the RF transmitter to tackle the issues of sensitivity and selectivity. Com-
28
pared to Tx; Rx has 8 pins( Pin diagram is already mentioned) and an
oscillator which also generates the same frequency as Tx. The specifications
of the Pins:
Pin 1, 6, and 7: Ground
Pin 4, 5: Supply 5 volt dc
Pin 2: Digital data output pin
Pin 3: Linear data output pin
Pin 8: The antenna is connected to this pin to collect the signals which are
being sent from Tx
The Rx is directly connected to the RF decoder to convert the received
serial data into the original parallel data form for the microcontroller on the
slave( client) robot.
iv) Decoder: unlike encoder the purpose of using the decoder is to convert
the serial data into the original parallel data format.
The RF decoder which we have used in this project, is a pre-programmed IC
HT 12D -18 DIP-A.
Specifications of the pin:
Pin A0-A7: Address pins which are used to select the appropriate trans-
mitter
Pin 9 and 18: Ground and 5 volt dc supply respectively
Pin 16 -15: Oscillator which generates 433.92 MHz frequency
Pin 14: This pin is used to receive the serial data from transmitter
Pin 17: This pin is connected to LED which indicates the receiving signal
Pin 10-13: Input from receiver to MCU
29
Chapter 7
Software specifications
7.1 Software tools
7.1.1 Open source software
Open-source software( OSS) is the computer software whose source code
is made available in the public domain. Further it may be licensed with a
license in which the copyright holder provides the rights to study, change and
distribute the software to anyone and for any purpose. Open-source software
is very often developed in public domain with collaborative manner. Open-
source software is the most prominent example of open-source development
and often compared with( technically defined) user-generated content or(
legally defined) open-content movements [7].
7.1.2 ARMKeil microcontroller tool
ARMKeil development tools for the 8051 microcontroller architecture sup-
port every level of software developer from a professional applications engi-
neer to a student just learning about embedded software development.
This software is developed for solving complex problems related to embedded
systems. It’s a very user friendly software and easy to understand. As we are
dealing with AT89S52 microcontroller, so while we need to flash the program
onto the system first it has to be converted into hexadecimal file( .hex file),
which is done by the Keil software.
i) When starting a new project, we need to select the microcontroller from
the device database and the Vision IDE sets all compiler, assembler, linker,
and memory options for the project
30
ii) Numerous example programs are included to help one to get started with
the most popular embedded 8051 devices
iii) The Keil Vision debugger accurately simulates on-chip peripherals( IC,
CAN, UART, SPI, Interrupts, I/O Ports, A/D Converter, D/A Converter,
and PWM Modules) of 8051 device. Simulation helps us to understand hard-
ware configurations and avoids wastage of time on setting up a problem. Ad-
ditionally, with simulation, we can write and test an application before the
target hardware is available
iv) When we are ready to begin the testing of our software application with
the target hardware, we can use the MON51, MON390, MONADI, or Flash-
MON51 Target Monitors, the ISD51 In-System Debugger, or the ULINK
USB-JTAG Adapter to download and test program code on our target sys-
tem [8]
7.1.3 AT89S52 IC programming software: ProgIsp
This is an application which is widely used to falsh the HEX File( .hex file
which is created by the Keil software) into the destination ICs.
Some special features of this applications are:
i) It doesnot require any installation in the computer
ii) We just need to download the ’progIsp.exe’ extension file
iii) It has wide range of compatibility with different microcontrollers and
chips( approx. 150)
7.1.4 USBASP programmer
USBASP, the programmer for AVR( i.e. ATmega, ATTiny) and AT89S51/52.
This is ISP type programmer. It means it will program AVR microcontroller
keeping it in-application-circuit. Here in our project, we use USBASP for
AT89S52 microcontroller [9].
Some special features:
i) There are six main pins of an USBASP( for AT89S52), such as MISO,
31
MOSI, RST, Vcc, Gnd, SCK
ii) It is compatible with ATX, ATtinyX, ATmegaX serieses
iii) It is designed for serial communication with the target
iv) Construction is not so complex and it does not draw any power from
external source. The power is drawn from the laptop itself
v) Works under multiple platforms like Linux, Mac OS X and Windows
7.2 Algorithm and programming
7.2.1 Master algorithm and programming
Algorithm for the master or server robot is shown in the Fig.7.1:
7.2.2 Slave algorithm and programming
Algorithm for the slave or client robot is shown in the Fig.7.2:
7.3 Flashing the code into the robots
7.3.1 Test the robots
After flashing the code, remove the USBASP programmer from the system
and for which the following steps are needed:
i) Put the sensors in S3 and S4 pins in the port P1( for the path follower
algorithm)
ii) Provide power supply separately to the motors and the microcontroller
board
iii) Check all connections and switch the power on for both the robots PS:
At this point do not supply the power to the motors
iv) Now we could see that at the receiver end, the yellow LED is glowing
and while we press the RST( Reset) button in transmitting end in the mas-
ter robot that LED blinks. It means the data is being successfully transferred
32
from server to client
At this point we are ready to go
v) Now set up the master robot in the test arena and give power supply
to the motors in both the robots
33
Figure 7.1: Program for the swarm master
34
Figure 7.2: Program for the swarm slaver
35
Chapter 8
Working of robot
8.1 The functional set up
Procedure:
i) First remove the battery and IR sensor connection from both master and
slave robot
ii) Then using the Keil software program the robots and upload the .hex
file using progIsp onto the master and slave
iii) Then connect the battery and IR sensors to the respective ports iv) Next
switch it on
v) The most important part is to calibrate the POT in such a way that
when white surface is detected by the IR sensor the respective LED goes
OFF and when black surface is detected by the IR sensor the respective
LED goes ON
vi) We are ready to go now
Some important points to be remembered:
i) The IR sensors should be placed in such a position below the robot where it
can easily detect the reflected light from the surface. If this is not so, it may
happen that the master robot cannot detect its path and moves in wrong way
ii) It should be noted that while switching the master and slave robot ON
36
both the Tx and Rx LED glow and when we press the RST button in mas-
ter, the yellow colour LED in Rx also blinks. It is very necessary to notice,
which means that the data is being transferred and the Rx receives it. If the
LED does not respond it means there must be something wrong in the system
iii)The addressing switch in encoder and decoder must be in same orientation
iv) IR sensors must be connected to S3 and S4 pins
8.2 Result and discussion
8.2.1 Training the master
Objective: To make the master track the user defined track auto-
matically with the help of IR sensor
Case 1: The straight track:
Figure 8.1: The straight line track
37
Case 2: The L-shaped track:
Figure 8.2: The L-shaped track
Case 3: The zig-zag track:
Figure 8.3: The zig-zag track
38
Case 4: The circular track:
Figure 8.4: The circular track
Case 5: The sqare track:
Figure 8.5: The square track
39
Objective: To make the slave robot follow the movement of the
master robot through RF wireless communication
Case 1: The straight track:
Figure 8.6: The square track
Case
2:
The
L-shaped
track:
Figure 8.7: At the starting point
40
Figure 8.8: At running stage
Figure 8.9: At the turning point
41
Figure 8.10: The deviantion from the track
Note: The deviation angle of the slave robot from the desired track
is shown above in the figure.
The video link: ://drive.google.com/open?id=0Bwx2tGBAgEW W I 3aW 5UMj F DcV U
Case 3: The zig-zag track:
Figure 8.11: At the starting point
42
Figure 8.12: At running stage
Figure 8.13: At the turning point
43
The video link::
//https://drive.google.com/open?id=0Bwx2tGBAgEOW RY QzhhbGY xbDA
Case 4: The circular track:
Figure 8.14: At the starting point
Figure 8.15: At running stage
44
Figure 8.16: At the turning point
The video link: :
//https://drive.google.com/open?id=0Bwx2tGBAgEOW RY QzhhbGY xbDA
Case 5: The square track:
Figure 8.17: At the starting point
45
Figure 8.18: At running stage
Figure 8.19: At the turning point
The video link: :
//https://drive.google.com/open?id=0Bwx2tGBAgEOW RY QzhhbGY xbDA
46
Chapter 9
Cost analysis of this project
9.1 Swarm master robot cost
9.1.1 Price corresponding to the items
For Swarm robot or server robot
Item name Item quantity Item price( INR)
BO1 motor 2 255
IR sensors 2 129
6F22 9V battery 2 40
USBASP pro-
grammer
1 365
Embedded
development
board
1 399
Encoder 1 125
RF Tx 1 135
7805 IC 1 30
Multimeter 1 276
47
9.2 Swarm slave robot cost
9.2.1 Price corresponding to the items
For swarm slave or client robot
Item name Item quantity Item price( INR)
BO1 motor 2 255
6F22 9V battery 2 40
USBASP pro-
grammer
1 365
Embedded
development
board
1 399
Decoder 1 125
RF Rx 1 135
7805 IC 1 30
48
9.3 Some auxiliary item cost
9.3.1 Price corresponding to the items
Some auxiliary items
Item name Item quantity Item price( INR)
U Clamps 2*2 200
Pin connec-
tors( Male and
female)
approx 20 265
Screws
3mm*60mm
6*2 –
Screws
3mm*30mm
6*2 185
Screws
3mm*45mm
6*2 –
Nuts 6*2 –
Insulation tape 3 40
Screw driver 2 175
Double tape 8 150
Wire strippers 1 95
Wooden plank
12*12
2*2 180
Spare battery 8*2 240
Total price( aproximately)= 4,600 INR
49
Chapter 10
Conclusion and future work
The project included study of various elds in Electronic and Computer Sci-
ence such as Articial Intelligence, Swarm Intelligence, Embedded System,
Wireless Communication( Radio Communication), Microcontroller, etc. The
project deals with radio frequency communication mechanism. Where the
server or master robot is guided by a certain algorithm that has already been
programmed and communicate with the client or slave robot through RF.
As it has already been mentioned that in the B.Tech career we have been
taught enormous technical subjects where we learnt so many concepts, ideas
and theoretical knowledge. A bright side of this project is that we really can
see the utilization of those theoretical concepts and ideas in a practical plat-
form. Not only from one subject, have ideas from various elds been brought
together in this project.
In comparison to other modules RF module costs a little bit less. Our whole
project costs around 7000 INR. But as it had been discussed with different
Robotic Organizations in India, we found that other module costs more than
11,000 INR( minimum).
The software platform( ARMkeil and progIsp) which is used for our project
is very user friendly and compatible with more than 150 Chips and micro-
controller. The programming is done on embedded-C language, which is an
another advantage as we can easily program and re-program our master robot
according to our required task.
The concept of swarm robotics has various applications in enormous fields like
industry, military, medical-science and many more. Though swarm robotics
is in its research stage, we can see the future when using this concept less
50
number of robots can complete an assigned task collectively in less amount
of time which also in turn increases the efficiency and the output at same
time reducing the cost. As a concluding remark it can confidently be said
that swarm robotics is such a versatile area of artificial intelligence where lot
of research and innovations can be done.
Some of the future implementations that we can add to this project are
as follows:
i) Here we have considered only line follower algorithm based robot. For
better improvisation we can use algorithm of obstacle avoider
ii) Here for this project due to our low budget we went for RF( Rx, Tx)
module. Instead for better accuracy we could have used Zigbee-Bluetooth
Module, GPS module, etc. So as a future work for better performance we
can go for other kind of system designing techniques
iii) We have used several tracks in our project with dierent shapes; as for ex-
amples: straight track, Zig-Zag track, L-shaped, circular, square and hexag-
onal path. To study the response of the system in depth we can go for more
complex tracks, which involves better understanding of the required algo-
rithm and the hardware parts
iv) Instead of IR sensors, we can use various types of sensors and techniques;
such as ultrasonic sensors, image processing, etc
Some of the technical aspects which need a detailed study:
i) The RF module used in our project is only capable of maintaining the
working range unto 20 meters. This imposes a limited range barrier on the
working of the project. Hence, a detailed study is required to overcome this
range barrier
ii) One of the main problems that we have faced is the 9 Volt batteries
which are being used for the master robot discharge very quickly. So for the
working period of the project we had to use a couple of 9 Volt batteries which
cost an ample amount of money. So this is a good observation where we can
optimize the usage of batteries, hence the cost
iii) Calibration is a vital part in this project. Calibration of the master
robot means to adjust the POT( 1,2,3,4) in such a way that the POT-3 and
51
POT-4 LEDs are ON while the IR sensor senses a ’black path’ and the LEDs
are OFF while the IR sensor senses a ’white path’. If this is so the robot will
conduct its task perfectly. But if there is something wrong in the calibration,
the movement of the robot will be unpredictable
52
References
[1] Swarm Robotics-wikipedia.org.
[2] Bio-Inspired Sensor Swarms to Detect Leaks in Pressurized Systems,
Fronczek, J.W.; Prasad, N.R., Man and Cybernetics, 2005 IEEE Inter-
national Conference on Volume 2, 10-12 Oct. 2005 Page(s): 1967 - 1972
Vol. 2 Digital Object Identifier 10.1109/IC-SMC.2005.1571435.
[3] Sensor Networks of Freely Drifting Autonomous Underwater Explorers,
J. Jaffe, C. Schurg-ers, WUWNet 06: Proceedings of the 1st ACM inter-
national workshop on Underwater Net-works September 2006 Publisher:
ACM.
[4] Distributed Surveillance Sensor Network( DSSN), SPAWAR Sys-
tems Center, San Diego, June 2006., http://www.nosc.mil/robots/
undersea/dssn/dssn.html
[5] E. Bonabeau, M. Dorigo, and G. Theraulaz. Swarm Intelligence: From
Natural to Artificial System. Oxford University Press, New York, 1999.
[6] Chiraag Nataraj , Sanjeev Reddy , Mark Woods , B. Samanta , and
C. Nataraj.Swarm Robotics,The American Society of Engineering Ed-
ucation Annual Conference, Louisville, KY, June 2010, Paper No. AC
2010-1655.
[7] http://www.nosc.mil/robots/undersea/dssn/dssn.html
[8] http://www.keil.com
[9] http://www.fischl.de/usbasp/
53
