design and implementation of remotely operated underwater vehicle using microcontroller

DESIGN AND IMPLEMENTATION OF REMOTELY OPERATED

UNDERWATER VEHICLE USING MICROCONTROLLER

A Project Submitted

By

1. Abir, Meraj Mustakim ID: 10-16284-1

2. Apu, Sajib Das ID: 10-16274-1

3. Biswas Prasun ID: 10-16290-1

4. Fattah, Md. Abu ID: 10-16304-1

Under the Supervision of

Dr. Md. Kamrul Hassan

Assistant Professor

American International University - Bangladesh

Department of

Electrical and Electronic Engineering

Faculty of Engineering

Summer Semester 2012-2013,

August, 2013


DESIGN AND IMPLEMENTATION OF REMOTELY OPERATED

UNDERWATER VEHICLE USING MICROCONTROLLER

A Project submitted to the Electrical and Electronic Engineering Department of the Engineering Faculty,

American International University - Bangladesh (AIUB) in partial fulfillment of the requirements for the

degree of Bachelor of Science in Electrical and Electronic Engineering.




4. Fattah, Md. Abu ID: 10-16304-1

Department of

Electrical and Electronic Engineering


Summer Semester 2012-2013,

August, 2013


© Faculty of Engineering, American International University-Bangladesh (AIUB) i

DECLARATION

This is to certify that this Project is our original work. No part of this work has been submitted elsewhere

partially or fully for the award of any other degree or diploma. Any material reproduced in this project has

been properly acknowledged.

Students’ names & Signatures

1. Abir, Miraj Mustakim

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

2. Apu, Sajib Das

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

3. Biswas Prasun

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

4. Fattah, Md. Abu

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

© Faculty of Engineering, American International University-Bangladesh (AIUB) ii

APPROVAL

The Project titled ―DESIGN AND IMPLEMENTATION OF REMOTELY OPERATED UNDERWATER

VEHICLE USING MICROCONTROLER‖ has been submitted to the following respected members of the

Board of Examiners of the Faculty of Engineering in partial fulfillment of the requirements for the degree

of Bachelor of Science in Electrical and Electronic Engineering on August, 2013 by the following

students and has been accepted as satisfactory.




4. Fattah, Md. Abu ID: 10-16304-1

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Supervisor

Dr. Md. Kamrul Hassan

Assistant Professor


American International University-

Bangladesh

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Prof. Dr. ABM Siddique Hossain

Dean



Bangladesh

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

External Supervisor

Dr. Md. Abu Bakar Siddiqui

Faculty



Bangladesh

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Dr. Carmen Z. Lamagna

Vice Chancellor


Bangladesh

© Faculty of Engineering, American International University-Bangladesh (AIUB) iii

ACKNOWLEDGEMENT

First, we would like to express our heartiest gratitude to our honorable supervisor Dr. Md. Kamrul

Hassan, Assistant Professor, Department of Electrical and Electronics Engineering, under Engineering

Faculty, American International University-Bangladesh (AIUB), who helped us with his knowledge and

guidance throughout the project. Because of his such guidance, invaluable assistance, abundant support

and inspiration with his brilliant insight we were able to finish our project successfully. Yet from the core

of our heart, we would like to thank him with immeasurable respect.

We would like to show our gratitude to Dr. Carmen Z. Lamagna, Vice Chancellor, American

International University-Bangladesh for her continuous encouragement and generosity during our years of

study.

We are also grateful to Prof. Dr. A.B.M Siddique Hossain, Professor and Dean, Faculty of Engineering,

who has shared his wisdom, experience and invaluable knowledge with us and provided us guidance from

time to time.

We would also like to thank Mr. Abdur Rahman, Assistant Professor and Head of the Department,

Faculty of Engineering, who helped us when we were in difficult situations and whose new rules and

regulations gave us the opportunity to work with comfort.

We are thankful to our respected external faculty Dr. Abu Bakar Siddiqui, Faculty of Engineering for

giving us support till the end of the project.

We would like to thank those who were directly or indirectly helped us in different stage of completing

this project.

We would also like to take this opportunity to thank our parents for their belief in us and their endless

moral support.

Lastly we are very much grateful to the Almighty for keeping us healthy and giving us strength to finish

this project.

1. Abir, Meraj Mustakim

2. Apu, Sajib Das

3. Biswas, Prasun

4. Fattah, Md. Abu

© Faculty of Engineering, American International University-Bangladesh (AIUB) iv

ABSTRACT

The main objective of our project is to design and implement a remotely operated underwater vehicle

(ROV) using microcontroller. Microcontroller is very suitable for programming for this project because it

is efficient and at the same time it is cost effective. The microcontroller is programmed in such a way that

it can control the ROV according to the received command from another microcontroller of the remote.

Every switch is assigned to send different command to the host module from the remote module. The host

acts accordingly after receiving command from the remote module and operates the motors. Temperature,

pressure and obstacle sensors are interfaced with the host module. A camera is attached with the host

module which captures and transmits constant video output to a monitor placed beside remote module. To

get a clear view of the underwater environment powerful LED is attached in front of the ROV. Full

functioning ROV can be used as an underwater observation device to work in aquatic environment that

are problematic and risky for human. It can collect water sample from certain depth of water. After further

modification it can be used for underwater heavy duty purpose. Microcontroller of model PIC16F877A is

used for system programming. UART protocol is used to conduct communication between two working

unit. This robot can roam underwater to a certain level.

© Faculty of Engineering, American International University-Bangladesh (AIUB) v

List of abbreviation

ROV - Remotely Operated underwater Vehicle.

AUV - Automated Underwater Vehicle.

BG - Buoyancy Gradient

BJT - Bipolar Junction Transistor.

COB - Center of Buoyancy.

COG - Center of Gravity.

CPU - Central Processing Unit.

FOV - Field of View.

TMS - Tether Management System.

HP - Horse Power.

PIC - Peripheral Interface Controller.

GLCD - Graphical Liquid Crystal Display.

IMU - Inertial Measurement Unit.

TFTLCD - Thin Film Transistor Liquid Crystal Display.

MCU - Microcontroller Controller Unit.

MOSFET - Metal Oxide Semiconductor Field Effect Transistor.

ADC - Analog to Digital Converter.

PWM - Pulse Width Modulator.

UART - Universal Asynchronous Receiver Transmitter.

USB - Universal Serial Bus.

© Faculty of Engineering, American International University-Bangladesh (AIUB) vi

TABLE OF CONTENTS

DECLARATION ....................................................................................................................................... I

APPROVAL .............................................................................................................................................. II

ACKNOWLEDGEMENT ....................................................................................................................... III

ABSTRACT ............................................................................................................................................. IV

LIST OF ABBREVIATION .............................................................................................................................. V

LIST OF FIGURES ..................................................................................................................................... X

CHAPTER 1 ................................................................................................................................................. 1

INTRODUCTION ........................................................................................................................................... 1

Introduction ................................................................................................................................ 1 1.1

CLASSIFICATION .............................................................................................................................. 1 1.2

Earlier Research .......................................................................................................................... 2 1.3

RECENT RESEARCH ......................................................................................................................... 3 1.4

FIGURE 1.1 ROV PHOCA .......................................................................................................................... 3

APPLICATION OF ROV .................................................................................................................... 3 1.5

Potential Benefits of the Project ................................................................................................. 4 1.6

Objective of this Work ............................................................................................................... 4 1.7

The primary objectives are listed below ............................................................................................ 4 1.7.1

The secondary objectives are following ............................................................................................. 5 1.7.2

ADVANTAGE OVER TRADITIONAL METHODS .................................................................................... 5 1.8

LIMITATION TO THE STUDY ............................................................................................................. 5 1.9

Overview of the Project .............................................................................................................. 6 1.10

CHAPTER 2 ................................................................................................................................................. 7

METHODOLOGY.......................................................................................................................................... 7

Introduction ................................................................................................................................ 7 2.1

Basic Principles .......................................................................................................................... 7 2.2

Archimedes Law ................................................................................................................................ 7 2.2.1

Newton’s Law ................................................................................................................................... 7 2.2.2

Hydrodynamics .................................................................................................................................. 8 2.2.3

Hull .................................................................................................................................................... 8 2.2.4

Pressure ............................................................................................................................................. 8 2.2.5

Buoyancy ........................................................................................................................................... 9 2.2.6

FIGURE 3.1 EFFECT OF BUOYANCY ON ROV .............................................................................................. 9

Density .............................................................................................................................................10 2.2.7

Relation of Buoyancy and Resistance with Density ..................................................................10 2.2.7.1

Conductivity .....................................................................................................................................10 2.2.8

Temperature ......................................................................................................................................11 2.2.9

Light Penetration ..............................................................................................................................11 2.2.10

SUMMARY ..................................................................................................................................... 11 2.3

CHAPTER 3 ............................................................................................................................................... 12

© Faculty of Engineering, American International University-Bangladesh (AIUB) vii

PROJECT SYSTEM DESCRIPTION ............................................................................................................... 12

Introduction .............................................................................................................................. 12 3.1

System Architecture ................................................................................................................. 12 3.2

Controlling Unit ................................................................................................................................12 3.2.1

Remote Module ........................................................................................................................12 3.2.1.1

Host Module .............................................................................................................................14 3.2.1.2

Propulsion System ............................................................................................................................14 3.2.2

Sensors .............................................................................................................................................15 3.2.3

Communication ................................................................................................................................16 3.2.4

Summary ..........................................................................................................................................16 3.2.5

CHAPTER 4 ............................................................................................................................................... 17

MODELING ............................................................................................................................................... 17

Introduction .............................................................................................................................. 17 4.1

Drag Force Calculation ............................................................................................................. 17 4.2

Buoyancy Estimation ................................................................................................................ 18 4.3

Summary ................................................................................................................................... 19 4.4

CHAPTER 5 ............................................................................................................................................... 20

COMPONENTS AND PROTOCOLS USED IN THIS PROJECT ........................................................................... 20

Introduction .............................................................................................................................. 20 5.1

Sensors ...................................................................................................................................... 20 5.2

DS18B20 Digital Thermometer Sensor ............................................................................................20 5.2.1

GH-311 Ultrasound Motion Sensor ..................................................................................................21

Water Level Sensor ..........................................................................................................................22 5.2.3

IMU ..................................................................................................................................................23 5.2.4

Linear regulator IC (MC78XX/LM78XX/MC78XXA) ........................................................... 23 5.3

Crystal Oscillator ...................................................................................................................... 24 5.4

Relay ......................................................................................................................................... 25 5.5

BC 547 (dc) .............................................................................................................................. 27 5.6

Irf540 Power MOSFET ............................................................................................................ 28 5.7

Bilge Pump Replacement Motor .............................................................................................. 28 5.8

Fuse ........................................................................................................................................... 29 5.9

Battery ...................................................................................................................................... 30 5.10

Pump ......................................................................................................................................... 30 5.11

Camera and Light ..................................................................................................................... 31 5.12

Propeller and Coupler ............................................................................................................... 31 5.13

Liquid Cristal Display(LCD) .................................................................................................... 32 5.14

TFT LCD Display ..................................................................................................................... 32 5.15

UART PROTOCOL ...................................................................................................................... 32 5.16

Summery ................................................................................................................................... 33 5.17

CHAPTER 6 ............................................................................................................................................... 34

MICROCONTROLLER ................................................................................................................................. 34

Introduction .............................................................................................................................. 34 6.1

© Faculty of Engineering, American International University-Bangladesh (AIUB) viii

Microchip PIC16F877A : Microcontroller Overview .............................................................. 35 6.2

Basic Working Units ................................................................................................................ 35 6.3

Central Processor Unit (CPU) ...........................................................................................................35 6.3.1

Memory ............................................................................................................................................35 6.3.2

ROM Memory ..........................................................................................................................35 6.3.2.1

EEPROM Memory ...................................................................................................................36 6.3.2.2

Random Access Memory ..........................................................................................................36 6.3.2.3

General-Purpose Registers ........................................................................................................36 6.3.2.4

Special Function Registers ........................................................................................................36 6.3.2.5

Some of its Main Features are Listed Below ............................................................................ 37 6.4

Special Microcontroller Features .............................................................................................. 37 6.5

PIC16f877A Pin Diagram ....................................................................................................... 38 6.6

Block Diagram of PIC16f877a ................................................................................................. 39 6.7

PIC16f877A Pin Configuration [19] ........................................................................................ 40 6.8

Summary ................................................................................................................................... 44 6.9

CHAPTER 7 ............................................................................................................................................... 45

PROGRAMMING AND APPLICATION OF THE SOFTWARE ............................................................................ 45

Introduction .............................................................................................................................. 45 7.1

The C Programming ................................................................................................................. 45 7.2

MikroC Pro Pic C Compiler .............................................................................................................46 7.2.1

Some Features of Mikroc_pro_PIC_v600.........................................................................................46 7.2.2

Single-click Debugging ............................................................................................................46 7.2.2.1

Faster, Better, More Productive ................................................................................................46 7.2.2.2

Design Develop Share ..............................................................................................................46 7.2.2.3

Library Manager .......................................................................................................................46 7.2.2.4

Edit Project ...............................................................................................................................47 7.2.2.5

Code Assistant ..........................................................................................................................47 7.2.2.6

Parameter Assistant...................................................................................................................47 7.2.2.7

Object Explorer .........................................................................................................................47 7.2.2.8

Active Comments .....................................................................................................................47 7.2.2.9

Quick Converter........................................................................................................................47 7.2.2.10

Code Folding ............................................................................................................................47 7.2.2.11

Software Simulator ...................................................................................................................48 7.2.2.12

Programming the Microcontroller ............................................................................................ 48 7.3

Introduction to Burner .............................................................................................................. 48 7.4

PICkit™ 2 Programming Software .......................................................................................... 49 7.5

Program Loading Steps ............................................................................................................ 50 7.6

Summary ................................................................................................................................... 51 7.7

CHAPTER 8 ............................................................................................................................................... 52

ROV SHELL, THRUSTER, CAMERA AND LIGHT HOUSING DESIGN AND CONSTRUCTION .......................... 52

INTRODUCTION .......................................................................................................................... 52 8.1

SHELL DESIGN ........................................................................................................................... 52 8.2

Shape ................................................................................................................................................52 8.2.1

THRUSTERS ................................................................................................................................ 54 8.3

© Faculty of Engineering, American International University-Bangladesh (AIUB) ix

Fabricating the Protective Propeller Cowling........................................................................... 54 8.4

SUMMARY ..................................................................................................................................... 56 8.5

CHAPTER 9 ............................................................................................................................................... 57

SOFTWARE SIMULATION OF THE SYSTEM ................................................................................................. 57

Introduction .............................................................................................................................. 57 9.1

Simulation ................................................................................................................................. 57 9.2

Simulating the Circuit of Remote Module ........................................................................................57 9.2.1

Simulating the Circuit of Host Module .............................................................................................58 9.2.2

Simulation of Serial Communication by Coupling the Remote and Host .........................................60 9.2.3

Summary ................................................................................................................................... 60 9.3

CHAPTER 10 ............................................................................................................................................. 61

CIRCUIT IMPLEMENTATION AND OPERATION ........................................................................................... 61

INTRODUCTION .......................................................................................................................... 61 10.1

BLOCK DIAGRAM AND OPERATIONAL DESCRIPTION OF COMPLETE CIRCUIT .............................. 61 10.2

Description of the Block Diagram ....................................................................................................62 10.2.1

Test Connection of the Circuits ................................................................................................ 62 10.3

Speed control with PWM ..................................................................................................................62 10.3.1

Use of Optocoupler ...........................................................................................................................63 10.3.2

Bidirectional motor driver using relay ..............................................................................................63 10.3.3

Circuit Implementation on Bread Board ...........................................................................................64 10.3.4

Operation of Circuit .................................................................................................................. 65 10.4

Implementation on Vero Board ............................................................................................... 66 10.5

Planning a Vero Board Layout .........................................................................................................66 10.5.1

Placing Components on Vero Board .................................................................................................67 10.5.2

Dry Test .................................................................................................................................... 70 10.6

Wet Test .................................................................................................................................... 72 10.7

Static Wet Test .................................................................................................................................72 10.7.1

Dynamic Wet Test ............................................................................................................................73 10.7.2

TEST RESULTS ............................................................................................................................ 74 10.8

SUMMARY ..................................................................................................................................... 74 10.9

CHAPTER 11 ............................................................................................................................................. 75

DISCUSSIONS AND CONCLUSIONS ............................................................................................................. 75

DISCUSSIONS ................................................................................................................................. 75 11.1

LIMITATIONS ................................................................................................................................. 75 11.2

SUGGESTION FOR FUTURE WORK .................................................................................................. 76 11.3

CONCLUSIONS ............................................................................................................................... 77 11.4

REFERENCES ........................................................................................................................................... 78

APPENDIX ................................................................................................................................................. 80

CODE TO RUN THE REMOTE MODULE ...................................................................................................... 80

CODE TO RUN HOST MODULE .................................................................................................................. 84

© Faculty of Engineering, American International University-Bangladesh (AIUB) x

LIST OF FIGURES

FIGURE 1.1 ROV PHOCA .......................................................................................................................... 3

FIGURE 3.1 EFFECT OF BUOYANCY ON ROV ..................................................................................... 9

FIGURE 2.1 REMOTE MODULE OPERATING SEQUENCE. .............................................................. 13

FIGURE 2.1 REMOTE MODULE OF ROV ............................................................................................. 13

FIGURE 2.2 HOST MODULE OPERATING SEQUENCE ..................................................................... 14

FIGURE 2.3 DEGREES OF FREEDOM ................................................................................................... 15

FIGURE 5.1 GH-311 ULTRASOUND MOTION SENSOR ..................................................................... 22

FIGURE 5.2 IMU ....................................................................................................................................... 23

FIGURE 5.3 IC MC 7805 ........................................................................................................................... 24

FIGURE 5.4 CRYSTAL OSCILLATOR ................................................................................................... 25

FIGURE 5.5 12V 5 AMP RELAY ............................................................................................................. 26

FIGURE 5.6 BC547 IC ............................................................................................................................... 27

FIGURE 5.7 BILGE PUMP MOTOR ........................................................................................................ 29

FIGURE 5.8 FUSE ..................................................................................................................................... 30

FIGURE 5.9 WATER PUMP ..................................................................................................................... 30

FIGURE 5.10 LED LIGHT AND CAMERA ............................................................................................. 31

FIGURE 5.11(A) PROPELLER COUPLER FIGURE 5.11(B) PROPELLER .................................... 31

FIGURE 5.12 DISPLAY 2×16 LCD .......................................................................................................... 32

FIGURE 5.13 UART COMMUNICATION TIMING DIAGRAM. .......................................................... 33

FIGURE 6.1 INTERNAL BLOCK DIAGRAM OF MICROCONTROLLER .......................................... 34

© Faculty of Engineering, American International University-Bangladesh (AIUB) xi

FIGURE 6.2 PIC 16F877A PIN DIAGRAM ............................................................................................. 38

FIGURE 6.3 ARCHITECTURE OF PIC16F877A [18] ............................................................................. 39

FIGURE 7.1: TECHPIC ............................................................................................................................. 48

FIGURE7.2 PICKIT™ 2 PROGRAMMING SOFTWARE ...................................................................... 50

FIGURE 7.3 MANU BAR > TOOLS > CHECK COMMUNICATION ................................................... 50

FIGURE7.4 HEX FILE LOADED SUCCESFULLY ................................................................................ 51

FIGURE 7.5 PROGRAM LOADED SUCCESSFULLY ........................................................................... 51

FIGURE 8.1 TOP VIEW AND SIDE VIEW ............................................................................................. 53

FIGURE 8.2 SKETCH OF ROV ................................................................................................................ 53

FIGURE 8.3 HULL OF ROV ..................................................................................................................... 54

FIGURE 8.4 BILGE MOTOR AND PROPELLER UNIT ........................................................................ 54

FIGURE 8.5 BILGE MOTOR HOUSING ................................................................................................. 56

FIGURE 9.1 SIMULATION DIAGRAM OF REMOTE MODULE ........................................................ 58

FIGURE 9.2 SIMULATION DIAGRAM OF HOST MODULE .............................................................. 59

FIGURE 9.3 UART COMMUNICATION SIMULATION DIAGRAM .................................................. 60

FIGURE 10.1 BLOCK DIAGRAM OF THE COMPLETE CIRCUIT ..................................................... 61

FIGURE 10.2 PWM CONTROLLED MOTOR BLOCK DIAGRAM ...................................................... 62

FIGURE 10.3 OPTOCOUPLER BLOCK DIAGRAM .............................................................................. 63

FIGURE 10.4 BIDIRECTIONAL MOTOR DRIVER. .............................................................................. 63

FIGURE 10.5 CIRCUIT CONNECTION ON BREAD BOARD. ............................................................. 64

FIGURE 10.6 PLACING COMPONENT ON VERO BOARD (REMOTE MODULE) .......................... 67

© Faculty of Engineering, American International University-Bangladesh (AIUB) xii

FIGURE 10.8 FINALIZED REMOTE MODULE ..................................................................................... 68

FIGURE 10.9 FINALIZED HOST MODULE ........................................................................................... 69

FIGURE 10.10 FULL FUNCTIONAL CIRCUIT (1) ................................................................................ 69

FIGURE 10.11 FULL FUNCTIONAL CIRCUIT (2) ................................................................................ 70

FIGURE 10.12 FINAL APPEARANCE OF ROV (1) ............................................................................... 71



FIGURE 10.15 STATIC WET TEST OF ROV ......................................................................................... 73

FIGURE 10.16 DYNAMIC WET TEST OF ROV .................................................................................... 73

© Faculty of Engineering, American International University-Bangladesh (AIUB) 1

Chapter 1

Introduction

Introduction 1.1

A remotely operated underwater vehicle, conventionally known to us as ROV, is tethered robot

submarine, where operators control its movement, actions and other actions from a remote vessel. There is

another type of underwater vehicle AUV, which are autonomous and capable of operating itself

underwater to do specific task without any human assistance. ―ROV‖ the traditional abbreviation stands

for remotely operated vehicle, which is distinguished from remote controlled vehicles where as remote

controlled vehicles are operated on land or in the air. ROVs are unmanned, highly maneuverable and

controlled by human. For remote operation this are connected to the operating panel with a neutrally

buoyant tether or often when working in rough condition or in deeper water a load carrying umbilical

cable is used, along with a tether management system (TMS). The tether management system (TMS)

stores and deploys the ROV tether cable so that the ROV is decoupled from motion of the surface vessel

and is able to operate at a larger radius. Usually it’s a garage like device which hold the ROV during

lowering through the high current zone, or on larger work class ROVs (a separate assembly which sits on

top of the ROV). TMS serves by changing the length of tether through the effect of cable drag to

minimize where there are underwater current. Electrical power, video and data signals are carried back

and forth between operator and ROV by the umbilical cable which contains a set of cables. There are two

main categories of ROVs: observation and work classes. The work class subdivides into light and heavy,

which specifies their maximum working depth. The capability of reaching depth of heavy class ROVs are

greater than 3000 meters. This requires very large propulsion system to generate the forces required to

tow the length to tether required.

Classification 1.2

Submersible ROVs are normally classified into categories based on their size, weight, ability or power.

Some common ratings are

Micro - typically Micro class ROVs are very small in size and weight. Today’s Micro Class ROVs

can weigh less than 3 kg. These ROVs are used as an alternative to a diver, specifically in places

where a diver might not be able to physically enter such as a sewer, pipeline or small cavity.


Mini - typically Mini Class ROVs weigh in around 15 kg. Mini Class ROVs are also used as a

diver alternative. One person may be able to transport the complete ROV system out with them on

a small boat, deploy it and complete the job without outside help. Some Micro and Mini classes

are referred to as "eyeball" class to differentiate them from ROVs that may be able to perform

intervention tasks.

General - typically less than 5 HP (propulsion); occasionally small three finger manipulators

grippers have been installed, such as on the very early RCV 225. These ROVs may be able to

carry a sonar unit and are usually used on light survey applications. Typically the maximum

working depth is less than 1,000 meters though one has been developed to go as deep as 7,000 m.

Light Work class - typically less than 50 hp (propulsion). These ROVs may be able to carry some

manipulators. Their chassis may be made from polymers such as polyethylene rather than the

conventional stainless steel or aluminum alloys. They typically have a maximum working depth

less than 2000 m.

Heavy Work class - typically less than 220 hp (propulsion) with an ability to carry at least two

manipulators. They have a working depth up to 3500 m.

Trenching/Burial - typically more than 200 hp (propulsion) and not usually greater than 500 hp

(while some do exceed that) with an ability to carry a cable laying sled and work at depths up to

6000 m in some cases.

Submersible ROVs may be "free swimming" where they operate neutrally buoyant on a tether from the

launch ship or platform, or they may be "garaged" where they operate from a submersible "garage" or

―top hat" on a tether attached to the heavy garage that is lowered from the ship or platform. Both

techniques have their pros and cons; however very deep work is normally done with a garage [1].

Earlier Research 1.3

Remotely operated underwater vehicles (ROVs) were first developed in the mid-1950s by the Royal

Navy, became more and more common. At first they were used by different authorities to recover

torpedoes on the ocean floor and to clear mines. In the mid-1980s ROVs became an essential part of the

offshore oil and gas industry, since the pipes were placed deeper and further into the ocean. As we enter

the 21st century, ROVs are a commercial product that can be used for anything from exploration and

surveillance to rescue missions and maintenance. As the ROVs become more advanced, their price

increases. In the early 1980’s Dalhousie University, in partnership with the Bedford Institute of

Oceanography, launched numerous expeditions to recover and analyze basalts of the mid-Atlantic ridge.


Most of the drilling occurred near Mount Glooscap, named after a mythical first nation’s character from

Atlantic Canada. During this time exploration of mid-oceanic ridges was a topic of great interest [2].

Recent Research 1.4

In recent day’s different university, research organization, navy/marine corps and Business Corporation

are working on the development of ROV. They are emphasizing on building ROV that are capable of

doing heavy duty task like digging and underwater mining, conducting research in very deep underwater

environment etc.

For example, The ROV PHOCA will be an essential assistant in this context, being able to install, rebuild

as well as maintain scientific equipment at the sea floor. First sea trials for MoLab and the new ROV are

expected to take place in spring 2011. Another ROV ―Minerva‖ has been used in biological research and

sampling, testing of equipment and development of new research technology, archaeological surveys,

supplying ground truth in geological investigations, commissioned research and much else. She's also an

appreciated tool in many courses at NTNU.

Figure 1.1 ROV PHOCA Figure 1.2 MINERVA

Application of ROV 1.5

Oil & Gas Industry

Salvage, recovery and rescue

Chemical Industries

Cooling water intakes and outlets

Fish farms

Power stations: hydroelectric, nuclear


Corrosion and cathode measurements

Criminal investigations

Detection of objects (anti-collision / imaging sonar and side scan sonar)

Sample taking

Ships hulls, propellers and steering gears

Reservoirs / dams

Enclosures, pipes, cable

Diver observation and support

Environmental investigations

Investigating sunken objects (ships, wrecks, cars, motorbikes, airplanes etc.)

Destruction of mines [3].

Potential Benefits of the Project 1.6

1. This robot could be used to make detailed underwater map of the seafloor in a cost effective way.

2. It could be useful to our marine biologist to do underwater research and taking sample from

different level of sea.

3. After further modification and enhancement of upgraded technologies it has another area of

potential is to help in recovery from disasters by detecting drowned water vehicles in quickest

possible time.

Objective of this Work 1.7

The objective of our project was defined as follows

―To design and implement a small, low cost ROV, runs by water propulsion, powered by on board battery

and controlled by microcontroller.‖

The primary objectives are listed below 1.7.1

Our ROV must be able to move in forward and reverse direction.

It will be able to dive up to a depth of 5 meters.

It will be able to collect water sample at certain depth.


It will be able to work under water like capturing image and videos, detecting underwater objects

at primary level.

The secondary objectives are following 1.7.2

It will be able to measure the water level

Will be able to locate exact position of any object under water.

Tether Management System (TMS) will be added for better control

Advantage over traditional methods 1.8

There are some advantages of our ROV over traditional methods. Traditional ROVs are square and boxed

shaped, where as our design is torpedo shaped which gives some benefits.

This ROV has a streamline design which makes it less sufferer of water damping effects as most of

other ROV designs do.

This ROV has a design which is durable and can be repaired easily.

It has specially 5 thrusters, which makes is better speed, higher maneuverability

The ballast is placed so that the ROV always strives to stabilize itself.

Limitation to the study 1.9

Though our method of study has advantages still it has some limitations

Due to acceleration with the back thruster will cause an unwanted roll rotation, according to

Newton’s third law. This can cause problems, especially if the ROV uses on board camera for

observation. Due to the pendulum stability of our ROV, it will not turn over.

The thrusters may lose performance at higher speeds as it is in tunnel. It is difficult to remove the

on board circuits and recharge the batteries. To recharge batteries, the ROV have to be opened.


Overview of the Project 1.10

Chapter 1 describes about an introduction to this project and a brief description of different

consideration.

Chapter 2 gives system description design advantages and disadvantages. It also discuss about the system

architecture.

Chapter 3 discussed about the methodology, basic principles different types of aquatic conditions and

hydrodynamics.

Chapter 4 focuses on modeling, necessary theoretical calculations, drag force and buoyancy estimation.

Chapter 5 have detailed description about the components and protocol used to accomplish the project.

Chapter 6 gives detailed description about microcontroller, its pin and register and operation.

Chapter 7 discussed about the programming and application of MikroCPro PIC compiler and programing

the microcontroller with PICkitTM

programming software.

Chapter 8 discussed about the design and construction of ROV shell, thruster, camera and light housing.

Technique of waterproofing the ROV is also described here.

Chapter 9 discuss about the final software simulation of the system for real time application.

Gives brief discussion of the whole project and conclusion.

Chapter 10 gives circuit implementation, operation and block diagrams along with the test run of ROV.

Chapter 11 will reveal the discussions and limitations of the project. Then future suggestions. Lastly a

small conclusion of the whole project work is mentioned.


Chapter 2

Methodology

Introduction 2.1

In this chapter the methodology of designing of ROV is discussed. The word methodology means the

systematic research for an applied field of study, theoretical analysis of the methods to be used. The

principles and theoretical analysis related with the work is a part of it. It stereotypically covers concepts

like paradigm, theoretical model, phases and quantitative or qualitative techniques and analysis. It does

not set out to provide solutions but helps with the theoretical underpinning for understanding which set of

methods or so can be useful to apply in a specific case. For theoretical work, the development

of paradigms satisfies most or all of the criteria for methodology. This procedure is logical, rather than a

physical, array of related elements.

It has been defined also as follows

The analysis of the principles of methods, rules, and postulates employed by a discipline.

The systematic study of methods that are, can be, or have been applied within a discipline.

The study or description of methods.

Basic Principles 2.2

Some basic principles are related with operation of ROV. Those are mentioned below.

Archimedes Law 2.2.1

Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the

fluid displaced by the object.

Newton’s Law 2.2.2

Second law: The acceleration of a body is directly proportional to, and in the same direction as, the net

force acting on the body, and inversely proportional to its mass. Thus, F = ma, where F is the net force

acting on the object is the mass of the object and as the acceleration of the object.

Third law: When one body exerts a force on a second body, the second body simultaneously exerts a

force equal in magnitude and opposite in direction to that of the first body.


Hydrodynamics 2.2.3

Hydrodynamics is a sub discipline of fluid dynamics. It includes calculating force and moments on a

body. It describes different conditions based on some parameters like pressure, temperature, density, mass

etc. it also has relation with momentum equation for Newtonian fluid. This study also includes

compressible vs. incompressible, viscous vs. in viscid, steady vs. unsteady, laminar vs. turbulent flow

Newtonian vs. non Newtonian fluids are most important field of research of hydrodynamics. This factor

affects largely on a body in motion in water or any other fluid. Our ROV have to be able to operate on

different condition in water that varies due to change of weather or materials of water [4].

Hull 2.2.4

This is an important factor to design a ROV. Hull is related with the strength of the body of the ROV. It

depends on the material with which the body or shell is made. It also depends on the design. It is possible

to design a strong b body using comparatively less strong material. For example a sphere is more

sustainable and capable of handling more pressure from its surroundings than a cube made with same

material. Because if pressure is put on a single point it spreads over the body of the sphere and minimize

the pressure on a single point, thus gives better strength.

Pressure 2.2.5

Pressure is an important concern to be considered because it is related with the depth of operation of our

ROV. Pressure directly affects the speed of ROV. depending on the operating depth the strength of body,

power of the thrusters, design of the propeller, power needed, type of security measures, communication

system, lights , sensors and other components have to be designed. Depth of the water we are working in

and how our structure will handle the increasing pressure with depth is a key concern to design ROVS.

The column of air over every single square inch of surface weighs 14.7 lbs. at sea level. The metric

equivalent is 101 Kilopascals (kPa) or 101 mill bars. For every additional 33 feet (10 meters) you descend

into the ocean, pressure increases by an additional 14.7 lbs. per square inch (101 kPa). – One additional

atmosphere (ATM) of pressure.

Sea level = 1 atmosphere = 101 Kilopascals or 14.7lbs/square inch.

33 feet deep = 2 atmospheres = 202 kPa or 29.5 lbs./square inch of surface area

66 feet deep = 3 atmospheres = 303 kPa or 44.2 lbs./square inch of surface area


100 feet deep = 4 atmospheres =404 kPa or 59 lbs. /square inch of surface area

The answer to the question how does pressure affect an underwater robot?

The deeper the ROV goes, the more pressure exerted by the water column parts like motors and camera

casings. The deeper the ROV, the greater the pressure for water to enter these spaces and to compress

anything containing gas – even rigid form insulation [5].

Buoyancy 2.2.6

Buoyancy is a force which is exerted on upward direction by any fluid. This force opposes the weight of

any drowning object. Pressure increases as depth increases as a resultant effect of the increasing weight of

the overlying layers of fluid in a column of fluid. For this reason a column of fluid, or body submerged in

the fluid, experiences greater pressure at the bottom of the column than at the top. This difference in

pressure results in a net force that tends to accelerate an object upwards. The value of that force exerted is

proportional to the difference of pressure between bottom and top of column of water. This explains why

an object of higher density than that of the fluid in which it is submerged tends to sink. If the object is

either less dense than the liquid or is shaped appropriately (as in a boat), the force can keep the object

afloat.

Figure 3.1 Effect of buoyancy on ROV

There are two forces acting upon your Remotely Operated Vehicle in water: Buoyancy is upward pushing

force; Gravity is downward pushing force. Neutral Buoyancy is achieved when both forces are equal.

There are two imaginary centers COB and COG. COB stands for center of buoyancy and COG is center

of gravity. If these two forces are working on an object in water, COB should be always above the COG.

Otherwise it will make the ROV unstable and it will turn over.

BG (Buoyancy Gradient) is the distance between COB and COG. Stability of the ROV depends on BG

the greater the distance between the COB and the COG, the more stable the vehicle, the smaller the BG,

the less stable but the more maneuverable [6].


If COB and COG works on the same point the ROV will be highly maneuverable,

Two Important Physics Rules relating to ROV design

Floats must be located above heavier weights. (Stability is the issue here.)

Before ROV can sink, it must to float. An ROV shouldn’t sink when it is put in the water – it

should float – at least a little. For bottom crawling ROVs that are made to sink because their

purpose is to sit and work on the bottom should not float before is sinks.

Density 2.2.7

Mass per unit volume is the density of a material. Different materials usually have different densities, and

density may be relevant to buoyancy. Less dense fluids float on more dense fluids if they do not mix. If

the average density (including any air below the waterline) of an object is less than water it will float in

water and if it is more than water it will sink in water. The density of a material varies with temperature

and pressure. This variation is typically small for solids and liquids.

Relation of Buoyancy and Resistance with Density 2.2.7.1

Buoyancy is directly related with density. If density increases, buoyancy increases. That makes it harder

for the ROV to sink. If we make Gravity greater than Buoyancy it will allow the ROV to sink. So

depending on the fluid density of the work environment to overcome the buoyancy the ROV shell should

be designed.

The operation and movement and maneuverability of the ROV depend on the resistance of the water. The

resistance increases is proportional to the increase of density of water. So depending on the density the

power of thruster should be determined to operate properly under high and low resistance [7].

Conductivity 2.2.8

To drive electromechanical motors of thrusters or electrical pump motor of hydraulic thruster, .most of the

ROV use electrical power. Electricity used for power controls, underwater lights, cameras, different

sensors motorized tools such as robotic arms, etc. too. The electrical power can be supplied to the ROV

from outside by tether or battery can be mounted inside. Depending on the required amount of power

suitable method is have to be choose. We have to check if there is a leak into the electrical or electronic


Components of the ROV. Water conducts electricity and causes short circuits in the electronic

components - making them dysfunction. It’s bad enough with fresh water, but salt water in the ocean is

several times more conductive than freshwater. Consequently, a leak of water into any electrical or

electronic components is a tragedy that may irreparably fry all the electrical components of the ROV. The

other concern id safety as divers working in the vicinity of an electrical leak may be in grave danger.

Temperature 2.2.9

Water has a very high specific heat. It absorbs much amount of heat. It is good because water acts like a

very efficient heat sink. This property of water is used to keep ROV’s high power working thruster motors

cool. It shouldn’t operate for long time in air as they emerge high amount of heat and the motors can be

damaged.

Light Penetration 2.2.10

Water filters our light to a varying degree depending on the frequency (color) of the light. Color of light

would change gradually with depth because the shorter wavelength light is filtered first. Light is also

distorted .Water acts as a lens. This affects the way cameras sees underwater. It ends up in reduction of

the camera’s field of view (FOV or horizontal angle). The power of light necessary to work underwater

should be calculated as required for desired task.

Summary 2.3

In this chapter we discussed about some important factors of designing our ROV. Brief theoretical

discussion and methodology that are important aspect of planning and implementing the ROV is

discussed above in the chapter.


Chapter 3

Project System Description

Introduction 3.1

This chapter shows the general system architecture and design for the project. It also describes the

advantage of our design and its implications. The equipment that are being used and possible future

enhancement of equipment is also discussed.

System Architecture 3.2

The basic system is composed of four major parts.

Controlling unit

Propulsion

sensors

Communication

Controlling Unit 3.2.1

This control unit consists of two parts. They are remote module and host module.

Remote Module 3.2.1.1

The remote module is the main controlling and monitoring unit of the system. It controls host module

when to initiate a communication and when to end it. It can communicate with the host module. The

controlling unit is connected to the host module through two wire serial UART communication. As they

are connected with multiple components both host and remote module communication is not parallel. The

function of the remote module is to send different command to host module. It also receives data sent

from the host module and shows it on the LCD display to make the controlling easy and comfortable for

the operator.. The operating sequence of the remote module is given in figure 2.1

The main components of the remote module are MCU, different type of switches, variable resistors, a

GLCD display, a TFT monitor etc. There are 15 switches for different control command TFT monitor for

looking under water and controlling the maneuver of the ROV.A structural design of remote module is

given in figure 2.2


Figure 2.1 Remote module operating sequence.

Figure 2.2 Remote module of ROV

REMOTE INITIALIZED

BAUD RATE: 1280

ADDRESS HOST MODULE

GENERATE COMMAND BIT; TRANSMIT 7-BIT HOST ADDRESS & R/W BIT

WAIT FOR HOST

TO RESPOND

1

RECEIVE 8 BIT DATA FROM HOST MCU

TRANSMIT 8 BIT DATA TO HOST MCU

IF READ OPERATION IF WRITE OPERATION

DISPLAY OUTPUT IN GLCD VIA UART


Host Module 3.2.1.2

The host module senses the analog and digital outputs of the sensors. It uses ADC to sense analog output

from the sensors, temporarily stores the current data and then sends the data to the remote module, this

host module also receives data and command from the remote module and works accordingly by

executing the commands. For example: When it gets instructions from remote module, it can turn on or

off the thrusters and increase or decrease the duty cycle of a Pulse Modulated Signal (PWM) to change

the speed. The host operating sequence is shown in the following flow diagram.

Figure 2.3 Host module operating sequence.

Propulsion System 3.2.2

All commercially available ROVs use thrusters to provide propulsion. These are propellers attached to

either electrical or hydraulic motors. There are two types of propulsion system, water jets and propellers.

Commercially available ROVs use thrusters because of the efficiency difference between propellers and

water jets at low speeds. Water jets work by increasing the velocity of a relatively small mass of fluid by a

relatively large amount. Conversely, propellers work by increasing the velocity of a relatively large mass


of fluid by a relatively small amount. As a result, propellers are more efficient at low speeds and water

jets at higher speeds. For example: water jets are usually used in high-speed catamarans and propellers in

low speed ships.

There are six independent degrees of freedom, three translational and three rotational. The number of

required degrees of freedom dictates the maneuverability of the ROV and affects the configuration of

the water jets on it. The aim as stated in the specification is to maximize the maneuverability of the

ROV. Using five thrusters we achieved six degree of freedom. For example, six degrees of freedom can

be achieved using six pumps in a configuration [3].

Figure 2.4 Degrees of freedom

Sensors 3.2.3

A sensor is a device that responds to a physical stimulus like heat, light, sound, pressure, magnetism, or a

particular motion and transmits a resulting impulse for the purpose of measurement or operating a control

system. The systems consist of quite a number of sensors. These sensor usually measure temperature,

humidity, presence of particular gases, light intensity etc. from its surrounding environment. Job of the

host module is to manipulate the output of the sensor suitable for analog to digital conversion or for other

data sampling methods, then perform the conversion and store it temporarily. After that the remote

module will collect these converted sensor data when it is needed and use it for displaying purpose. These

are the data from the environment which needs to be observed, analyzed and according to the observation


some decisions will be taken by the computer and then commanded by the master to perform specific

actions to the slave devices.

Communication 3.2.4

Two wire serial communications is used for the communication between the remote module and host

module. The host module collects information from the remote module and sends this information to the

remote module for displaying purpose through the wire. The communication method used in the computer

bus is serial communication. Different kinds of serial communication can be used. Some of the popular

serial communication architectures are

RS-232

Universal Serial Bus (USB)

Ethernet

Serial Peripheral Interface (SPI) [8]

Among these communication architectures the USB, Ethernet are high speed communication systems.

Each communication method has its own communication protocol which differs from each other and is

somewhat complex. But the RS-232 is a very common serial communication method. It is easy to

implement but is a low-speed communication system. RS-232 is a low speed communication protocol.

On the other hand USB and Ethernet is high speed communication system. But in our project we used RS-

232 for serial communication because communication through Ethernet is complex and USB is only

effective and efficient for very short distance data transmission. On the other hand RS-232 is easy to

implement and can be used longer distance communication than USB, which is suitable for our project.

UART is a serial communication protocol that used two wire for communicating between two

microcontroller and a common ground. It’s a fast and simple process and very compatible for our project.

Summary 3.2.5

A brief idea about the system works and probable use of the sensors is provided in this chapter. The

discussion above helps us to decide how to proceed with and take decision to accomplish the project goal

in different steps.


Chapter 4

Modeling

Introduction 4.1

Modeling is a very important step of building the ROV. To accomplish the project in a systematic way it

is important to estimate some necessary steps for the ROV to work in the real life. Drag force calculation

and buoyancy estimation is two important step as these have direct relation with the ROV to work in

aquatic environment.

Drag Force Calculation 4.2

If a body is transitory through a fluid or medium then it faces retarding or opposing force this force is

called Drag Force. Drag force, or the force of fluid friction for a falling body, increases with speed. A

falling object will reach a speed at which the force of air friction will be equal to and opposite the force of

gravity. At that point, the object will no longer accelerate. Its speed will remain constant, and we call that

speed its terminal velocity.

In case operating an ROV or an AUV, it’s not the main concern how quickly the ROV can accelerate , the

important consideration is how fast it go the water current it is able to hold station in. for this reason the

ROV mass is not most important factor. We have to emphasize on the drag of the ROV.

Equation for calculating drag force:

(4.1)

(For seawater is around 1027kg/m^3 — but for a simplicity round this to 1000kg/m^3) [9].

To find drag force accurately the most important thing is accurate estimate for the Cd. For calculating the

Cd there are some rough estimation. A flat plate or a cable, for example, has Cd approximately around 1.2

if the ROV has a smooth outer shell. For open frame ROV’s the Cd will be around 2. For a ROV which

has a shape like torpedo, the Cd could be as low as 0.1 but probably more on the order of

0.3.Approximation of drag force of our ROV (considered highest possible value) is calculated in the

following table


Frontal area

A(m2)

Mass density of

water in (kg/m^3)

Speed

(m/s)

Cd

Drag force F

(Newton)

For horizontal motion :

π* r2 = π*0.762

2

= 0.01824

1000

1

0.5

(considered highest

possible value)

9.12

For vertical motion:

L*W=0.762*0.1524

=0.116112

1000

1

2.0

(considered highest

possible value)

116.128

.

The calculated drag force does not include the additional drag component of the umbilical cable.

Buoyancy Estimation 4.3

Buoyancy is the force that exerts on upward direction by any fluid. This force opposes the weight of any

drowning object. Pressure increases as depth increases as a resultant effect of the increasing weight of the

overlying layers of fluid in a column of fluid. For this reason a column of fluid, or body submerged in the

fluid, experiences greater pressure at the bottom of the column than at the top.

The sum of the forces applied to the ROV and the weight forces should be equal to buoyant force applied

by the water. The density of the fluid is a important factor on how the forces will act on the ROV. Also,

another important aspect that will determine the success is the determination of the center of gravity of the

ROV. This cannot be calculated until the components are decided upon. Once the ROV reaches neutral

buoyancy we will be able to manipulate it through thrusters [10].

For neutral buoyancy the following equation must be used.

∑ device - W device

Fdevice is the downward force due to gravity and Wdevice is the upward force due to buoyancy.

In calculation FROV is the gravitational force which depends on the mass of the ROV ―M‖ and acceleration

due to gravity ―g‖. FW is the force due to the buoyancy of fluid which varies with different fluids. FW is

proportional to the density of the fluid ―ρ‖, mass of ROV ―M‖ and volume of water replaced by the body

of ROV ―VWD‖.


Calculations to find displacement volume that will make ROV neutrally buoyant

FROV = Mg FROV = weight of the ROV

FROV = 10.5 9.81 M= mass =10.5kg

= 103.005 N g= 9.81 m/s2

Fw =ρgVwd Fw = force of water

=1000 9.81*0.056 ρ = density

=136.31 N g= gravity

Vwd= volume displaced

= πr2l m3

=3.1416 0.07622 0.762 m3

= 0.056 m3

Based on the previous calculations the team determined that the ROV will not sink because, ROV is not

neutrally buoyant. To make it neutrally buoyant FROV must be equal to Fw

Mass estimation to make neutrally buoyant

FROV = 136.31 N = M× g

M= 13.89 kg.

The mass of the ROV must be at least 13.89 kg to sink in the water. So we need to attach 3.39 kg of

additional weight to the ROV.

Summary 4.4

In this chapter we made a rough calculation about the drag force and buoyancy. To give motion to a ROV

and to sink it under water these are some of the substantial worries. Depending on the result of this section

is helpful to set our work procedure like motor selection, power estimation, body shape of the ROV etc.


Chapter 5

Components and Protocols Used in this Project

Introduction 5.1

To be able to control a robot, a variety of electric and mechanical components are needed. In this project

the electronics mainly consist of a Host Module which comprehends a Microcontroller (PIC16F877A),

Relays, Motors, Bc-547 transistors, IRF540 power MOSFET, Fuses, Heat Sink, and a set of sensors.

There is also a Remote Module which also contains a Microcontroller (PIC16F877A), push buttons,

GLCD, control the host module. The most important devices will be described below Since electronics

usually are sensitive to water; a water-proof container is needed inside the underwater vehicle. In this

project, the main electronics are assembled in a plastic structure

Sensors 5.2

Different kinds of sensors were used to measure some physical quantity from the environment. Their

names and respective model no. are listed below

Table 5.1 Sensors model no and physical stimulus.

Physical Stimulus Sensor Model No.

Temperature DS18B20

Sonar GH311

Water Level Sensor WL

DS18B20 Digital Thermometer Sensor 5.2.1

The DS18B20 digital thermometer provides 9-bitto 12-bit Celsius temperature measurements and has an

alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20

communicates over a 1-Wire bus that by definition requires only one data line (and ground) for

communication with a central microprocessor. It has an operating temperature range of -55°C to +125°C

and is accurate to ±0.5°C over the range of -10°C to +85°C. In addition, the DS18B20 can derive power


directly from the data line (―parasite power‖), eliminating the need for an external power supply. Each

DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1-

Wire bus. Thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large

area. Applications that can benefit from this feature include HVAC environmental controls, temperature

monitoring systems inside buildings, equipment, or machinery, and process monitoring and control

systems [11].

Features

Unique 1- Wire® Interface Requires Only One Port Pin for Communication

Each Device has a Unique 64- Bit Serial Code Stored in an On-Board ROM

Multi drop Capability Simplifies Distributed Temperature-Sensing Applications

Requires No External Components

Can Be Powered from Data Line; Power Supply Range is 3.3V to 5.5V

Measures Temperatures from - 55° C to + 125° C (-67° F to + 257° F)

±3.5° C Accuracy from - 13° C to + 85° C

Thermometer Resolution is User Selectable from 9 to 12 Bits

Converts Temperature to 12- Bit Digital Word in 753 ms (Max

GH-311 Ultrasound Motion Sensor 5.2.2

The GH-311 ultrasonic Motion sensor provides precise, non-contact distance Measurements from about 2

cm (0.8 inches) to 3 meters (3.3 yards). It is very easy to connect to microcontrollers such as the BASIC

Stamp®, SX or Propeller chip, requiring only one I/O pin. The GH-311 sensor works by transmitting an

ultrasonic (well above human hearing angel) burst and providing an output pulse that corresponds to the

time required for the burst echo to return to the sensor. By measuring the echo pulse width, the distance to

target can easily be calculated [12].

Features

High Sensitivity, Reliability and Stability

Extreme-Temp resistant, moisture proof, shock & vibration-proof, etc.


Pin Definitions

GND Ground (Vss)

5 V 5 VDC (Vdd)

SIG Signal (I/O pin)

Figure 5.1 GH-311 Ultrasound motion sensor

Water Level Sensor 5.2.3

Global Water's WL433 Water Level Sensor submersible pressure transducer consists of a solid state

pressure sensor encapsulated in submersible stainless steel 13/16‖ diameter housing. The water level

gauge uses a marine grade cable to connect the water pressure sensor to the monitoring device. Each of

Global Water's pressure transducers has a two-wire 4-23 mA high level output, five full scales ranges, and

is fully temperature and barometric pressure compensated.

Feature

• High accuracy and reliability

• Completely submersible sensor and cable

• Compact, rugged design for easy installation

• Minimal maintenance and care

• Sensor compatible with most monitoring equipment

• - mA output

• Vented cable for automatic barometric compensation

• Multiple ranges available from ’ to ’

• Wet-wet sensor eliminates vent tube concerns

• Dynamic temperature compensation system

• Not affected by foam, wind or rain


IMU 5.2.4

IMU is a measurement device that can combine three different sensors into one measuring board. It

consists of a gyroscope (measures angular velocities), 3 accelerometers (measures the acceleration in each

direction) and a magnetometer (measures magnetic field). With this information, it is straight-forward to

use the Kalman filter to estimate the orientation of the device. In this way we can attain knowledge of the

orientation, rotation and linear motion of the ROV. Since the IMU came with a built in configured

Kalman filter.

Figure 5.2 IMU

Linear regulator IC (MC78XX/LM78XX/MC78XXA) 5.3

Description

The MC78XX/LM78XX/MC78XXA series of three terminal positive regulators are available in the TO-

220/D-PAK package and with several fixed output voltages, making them useful in a wide range of

applications. Each type employs internal current limiting, thermal shut down and safe operating area

protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over

1A output current. Although designed primarily as fixed voltage regulators, these devices can be used

with external components to obtain adjustable voltages and currents.

Features

• Output Current up to 1A

• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

• Thermal Overload Protection

• Short Circuit Protection

• Output Transistor Safe Operating Area Protection


Figure 5.3 IC MC 7805

Pin description

Pin no Function Name

1

Input voltage(5v-18v) input

2

Ground(0v) ground

3 Regulated output (varies with

different models)

output

Crystal Oscillator 5.4

A crystal oscillator is an electronic circuit that uses the mechanical resonance of a vibrating crystal of

piezoelectric material to create an electrical signal with a very precise frequency. This frequency is

commonly used to keep track of time (as in quartz wristwatches), to provide a stable clock for digital

integrated circuits, and to stabilize frequencies for radio transmitter and receivers. The most common type

of piezoelectric resonator used is the quartz crystal, so oscillator circuits designed around them become

known as ―crystal oscillators‖

When a crystal of quartz is properly cut and mounted, it can be made to distort in an electric field by

applying a voltage to an electrode near or on the crystal. This property is known as piezoelectricity. When

the field is removed, the quartz will generate an electric field as it remains to its previous shape, and this

can generate voltage. The result is that a quartz crystal behaves like a circuit composed of an inductor,

capacitor and resistor, with a precise resonance frequency. Quartz has the further advantage that its elastic

constants and its size change in such a way that the frequency dependence on temperature can be very

low. The specific characteristics will depend on the mode of vibration and the angle at which the quartz is

cut. For critical applications the quartz oscillator is mounted in a temperature- controlled container, called


a crystal oven, and can also be mounted on a shock absorbers to prevent perturbation by external

mechanical vibration [13].

Figure 5.4 Crystal oscillator

Relay 5.5

A relay is a kind of switch which is electrically operated. Mainly relays use an electromagnet to operate a

switching mechanism, but there are some other operating principles also. Where several circuits must be

controlled by one signal or where it is necessary to control a circuit by a low power signal, relay are used.

Relay gives complete electrical isolation between control and controlled circuit.

Contactor is a type of relay that can handle the high power required to drive or control an electric motor or

other loads. Instead of using a semiconductor device to perform switching, solid-state relays are used. The

relay also drives high power rated devices and machineries without damaging the control circuit.

Construction and operation of relay

Relays are amazingly simple device. There mainly 4 parts in every relay.

Electromagnet

Armature(that can be attach by electromagnet)

Spring

Set of electrical contacts.

A relay consists of two separate and completely independent circuits. The first is that the bottom and

drives the electromagnet, in this circuit, a switch is controlling power to the electromagnet. When the

switch is on, the electromagnet is on and it attracts the armature. The armature is acting as a switch in the

second circuit. When the electromagnet is energized, the armature completes the second circuit and turns

it on. When the electromagnet is not energized, the spring pulls the armature away and the circuit is not

complete.

Advanced and disadvantages of relay

The main advantages and disadvantages of relays are listed below:


Advantages:

Relays can switch AC and DC, transistor can only switch DC.

Relays can switch higher voltages than standard transistor.

Relays are often a better choice for switching large current.

Relays can switch many contacts at once.

Disadvantages:

Relays are bulkier than transistors for switching small currents.

Relays cannot switch rapidly (except reed relays), transistor can switch many times per second.

Relays use more power due to the current flowing through their coil.

Relays require more current than many ICs can provide, so a low power transistor may be needed

to switch the current for the relay’s coil.

Work of relay in our project

To drive the high power thruster

Controlling the direction of thruster

Operating the pumps and light.

For relay purchasing we generally have control over several variables

The voltages and current to active the armature.

The maximum voltage and current that can run through the armature contacts.

The number of armatures(generally one or two)

The number of contacts for armature.

Whether the contacts (if only one contact is provided) is normally open (NO) or normally closed

(NC).

Figure 5.5 12V 5 amp relay


BC 547 (dc) 5.6

BC547 is a (NPN) transistor. Used together with other electronic components, such as resistors, coils, and

capacitors, it can be used as the active component for switches and amplifiers. Like all other NPN

transistors, this type has an emitter terminal, a base or control terminal, and a collector terminal. In a

typical configuration, the current flowing from the base to the emitter controls the collector current. A

short vertical line, which is the base, can indicate the transistor schematic for an NPN transistor, and the

emitter, which is a diagonal line connecting to the base, is an arrowhead pointing away from the base.

There are various types of transistors, and the BC547 is a bipolar junction transistor (BJT).

Features of BC547

Material of transistor: Si

Polarity: NPN

Maximum collector power dissipation (Pc), W: 0.5

Maximum collector-base voltage |Ucb|, V: 50

Maximum collector-emitter voltage |Uce|, V: 50

Maximum emitter-base voltage |Ueb|, V: 6

Maximum collector current |Ic max|, A: 0.1

Maximum junction temperature (Tj), °C: 150

Transition frequency (ft), MHz: 300

Collector capacitance (Cc), pF: 6

Forward current transfer ratio (hFE), min: 110

Figure 5.6 BC547 IC


In our project we used bc547 to couple electrical circuit with microcontroller. The output pulse of

microcontroller passes through the BC547 and enables current flow. It also keep the microcontroller safe

by protesting the reverse biased current.

Irf540 Power MOSFET 5.7

IRF-540 is a power MOSFET. Power MOSFET is a specific type of metal oxide semiconductor field-

effect transistor (MOSFET) that can handle significantly high power levels than regular MOSFET, one of

the advantages of power MOSFET is high commutation speed and good efficiency at low voltages

Compared to the other power semiconductor devices. It is easy to use.

The power MOSFET is the most widely used low-voltage (that is, less than 200 V) switch. It can be found

in most power supplies, DC to DC converters, and low voltage motor controllers. To use various

MOSFETs together may occur in switching high currents or high voltage loads that becomes expensive

and impractical in both components and circuit board space.as a solution of this problem Power

MOSFET's were developed [14].

Features of IRF540

Advanced Process Technology

Ultra Low On-Resistance

Dynamic dv/dt Rating

175°C Operating Temperature

Fast Switching

Fully Avalanche Rated

In our project we used IRF540 to work along with PWM for speed control motor. Current passes through

the IRF540 as pulse come from microcontroller according to the PWM signal.

Bilge Pump Replacement Motor 5.8

Bilge pumps are specially made water resistant motor that used for removing water from the lowest

compartment inside the hull of a ship. As a safety measurement electric bilge pumps are designed to be

non-sparking. Electric bilge pumps are used with float switches that turn on the pump when the bilge fills

to a set level.

In our project we used the replacement motor of bilge pump to build our thrusters along with propellers.


We used 5 such motors. Ratings are given below:

Capacity

GPH

Number of motors

Current rating

A

Voltage rating

V

1000 2 4 12

750 3 3.5 12

Figure 5.7 Bilge pump motor

Fuse 5.9

Fuse is a type of low resistance resistor that provides overcurrent protection of circuit. It is a metal wire or

strip that is placed between a pair of electrical terminals, and enclosed by a non-combustible housing. It

melts when overcurrent flows and thus interrupts the circuit in which it is connected. By melting itself it

protects circuits from fault like Short circuit, overloading, mismatched loads or device failure. The fuse

element is made of zinc, copper, silver, aluminum, or alloys to provide stable and predictable

characteristics. The fuse ideally would carry its rated current indefinitely, and melt quickly on a small

excess. The bilge pump replacement motor used in our project draws high current. There are other

complex and valuable circuitry. So we used 4 amp fuse to protect the overflow in motors.


Figure 5.8 Fuse

Battery 5.10

In this project battery is a very significant aspect of consideration. Since the motors draws very high

current to run under water battery should be powerful enough to support with necessary power. It also

give the power to the circuits. In our project the energy source consists of two 10 Ah sealed lead-acid

battery that together provide for the motor, light and other circuit components in host module. We

used a (6V, 4.5Ah) power source to give power to the remote module.

Pump 5.11

Pump is a basically a motor placed in a closed and congested housing with two hole as input and output

path for water or air. In our project we used pump to collect water sample from certain level of water. We

used a jet pump of windshield wiper for this reason. It can exhaust water with high pressure which may be

dangerous for electrical circuit. So as a safety measure we changed the direction of water flow in the

motor and used the jet output path as input path of water.

Figure 5.9 Water pump


Camera and Light 5.12

Camera is an optical device that can capture image or video. It either stores or transmit the output as

image of video to another place. In our project we used camera and led light together to observe

underwater environment. The camera directly transmits the video to the TFT LCD monitor. It can easily

be stored if interfaced with a computer.

Figure 5.10 LED light and camera

Propeller and Coupler 5.13

Propeller is the part that couples with motor to build a thruster which provides with proper thrust force to

give motion to the ROV. The number and shape of the blades of the propeller is an important thing to

concern about to build a ROV thruster. To give proper strength propeller are connected with motor head

using adopter or propeller coupler. In our project we used 3 blade propellers.

Figure 5.11(a) Propeller coupler Figure 5.11(b) Propeller


Liquid Cristal Display(LCD) 5.14

LCD or liquid-crystal display is a flat panel electronic visual display or a video display that uses the light

modulating properties of liquid crystals. Computer monitors, televisions, watches, calculators,

and telephones, instrument panels etc. are some field of application of LCD. They do not suffer image

burn-in. LCDs are, however, susceptible to image persistence. LCD screen has better energy efficiency

and they are easily disposable. Its low electrical power consumption enables it to be used in battery-

powered electronic equipment.

In our project we used a 16 X 2 LCD to show the temperature of water and the output of obstacle and

pressure sensor.

Figure 5.12 Display 2×16 LCD

TFT LCD Display 5.15

TFT LCD stands for ―thin-film-transistor liquid-crystal display‖. It is a type of liquid-crystal

display (LCD) that uses thin-film transistor (TFT) for better quality of image. The advantage of this type

of display are high contrast, color saturation and luminance. It also offer the opportunity to increase

performance like anti-reflective screens and ultra-wide viewing angles etc.

TFT LCDs are used in appliances including televisions, computer monitors, PDA, navigation

systems and projectors.

UART Protocol 5.16

UART is a integrated feature in PIC16F877a microcontrollers. The remote module takes bytes of data and

transmits the individual bits in a sequence. At the host module, second UART re-assembles the bits into

complete bytes. In our project Communication is ―full duplex‖ that means both send and receive at the

same time. The sender MCU and receiver MCU must operate on same Baud Rate. In our project both


MCU operates at BAUD rate of 1280. It is possible to operate at a high BAUD rate of more than 9000.

But this is not suitable for long distance transmission.

In asynchronous transmission, the sender sends LSB first. When data is fully transmitted, an optional

parity bit is sent to the transmitter. This bit is usually used by receiver to perform simple error checking.

Lastly, Stop bit will be sent to indicate the end of transmission. A common reason for the occurrence of

Framing Error is that the sender and receiver clocks were not running at the same speed, or that the signal

was interrupted. MCU sends data using TX port and receives using RX port. Both MCU have a common

ground. [15]

Figure 5.13 UART communication timing diagram.

Summery 5.17

In our project we used TFT LCD display for showing the video feedback output of the camera from the

underwater environment.

In this chapter we discussed briefly about the important components used in our project. The purpose of

the components in the circuit is discussed too.


Chapter 6

Microcontroller

Introduction 6.1

Microcontroller is a small computer on a single integrated circuit that contains a processor core, memory,

and programmable input/output peripherals. It is a small package of simplified CPU, some amount of ram,

some amount of reprogrammable rom, some I/O ports in a single small chip. Program memory in the form

of NOR flash or OTP ROM is also often included on chip. Microcontrollers are designed for embedded

applications, in contrast to the microprocessors used in personal computers or other general purpose

applications.

Microcontrollers are mostly used in automatically controlled devices, such as automobile engine control

systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys and

other embedded systems. By reducing the size and cost compared to a design that uses a separate

microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally

control even more devices and processes. They are simple and at the same time efficient enough to be

used in many DIY (do it yourself) projects. Mixed signal microcontrollers are common, integrating analog

components needed to control non-digital electronic systems.

We used pic16F877A in our project.[14]

Figure 6.1 Internal block diagram of Microcontroller

http://en.wikipedia.org/wiki/Integrated_circuit

http://en.wikipedia.org/wiki/Input/output

http://en.wikipedia.org/wiki/NOR_flash

http://en.wikipedia.org/wiki/Programmable_read-only_memory

http://en.wikipedia.org/wiki/Microprocessor

http://en.wikipedia.org/wiki/Personal_computer

http://en.wikipedia.org/wiki/Embedded_system

http://en.wikipedia.org/wiki/Mixed-signal_integrated_circuit


Microchip PIC16F877A : Microcontroller Overview 6.2

The PIC16F887 is an excellent microcontroller which is one of the latest products of Microchip. It

features all the components which modern microcontrollers normally have. It has register based

architecture it comes with low price but wide range of application as well as high quality and easy

availability. It is a suitable option for applications such as: control of different processes in industry,

machine control devices, measurement of different values etc.

Basic Working Units 6.3

Central Processor Unit (CPU) 6.3.1

The CPU is manufactured with RISC technology an important factor when deciding which

microprocessor to use. RISC (Reduced Instruction Set Computer) gives the PIC16F887 some advantages:

The CPU can recognize only 35 simple instructions (In order to program some other microcontrollers it is

necessary to know more than 200 instructions by heart).

Except two and lasts 4 clock cycles (oscillator frequency is stabilized by a quartz crystal) the execution

time is the same for all instructions. The Jump and Branch instructions execution time is 2 clock cycles. It

means that if the microcontroller’s operating speed is 20MHz, execution time of each instruction will be

200nS, i.e. the program will be executed at the speed of 5 million instructions per second [15].

Memory 6.3.2

PIC16F877A microcontroller has 3 types of memory- ROM, RAM and EEPROM. All of them are briefly

discussed below separately, since each has specific functions, features and organization.

ROM Memory 6.3.2.1

To permanently save the program being executed, ROM memory is used. This is also called ―program

memory‖. The PIC16F887 has 8Kb of ROM (in total of 8192 locations). This ROM is made with FLASH

technology which gives the facility to change its contents by providing a special programming voltage

(13V).


EEPROM Memory 6.3.2.2

Alike ROM memory or ―program memory‖, the contents of EEPROM is permanently saved. Even if the

power goes off, it saves the data. But the difference with ROM is that the contents of the EEPROM can be

changed during operation of the microcontroller. That is why this memory (256 locations) is a perfect one

for permanently saving results created and used during the operation.

Random Access Memory 6.3.2.3

This is the most complicated part of microcontroller memory. In this case, it consists of two parts:

general-purpose registers and special-function registers (SFR).

Even though both groups of registers are cleared when power goes off and even though they are

manufactured in the same way and act in the similar way, their functions do not have many things in

common.

General-Purpose Registers 6.3.2.4

For storing temporary data and results created during operation, General-Purpose registers are used. For

example, if the program performs a counting, it is necessary to specify the address of some general

purpose register and assign it a new function. The microcontroller can execute that program because it

now knows what and where the ―sum’’ is and which must be incremented. Each program variable must be

Pre-assigned some of general-purpose register.

Special Function Registers 6.3.2.5

Special-Function registers are also RAM memory locations, but unlike general-purpose registers, their

purpose is predetermined during manufacturing process and cannot be changed. Since their bits are

physically connected to particular circuits on the chip (A/D converter, serial communication module, etc.),

any change of their contents directly affects the operation of the microcontroller or some of its circuits.

For example, by changing the TRISA register, the function of each port A pin can be changed in a way it

acts as input or output. Another feature of these memory locations is that they have their names (registers

and their bits), which considerably facilitates program writing. Since high-level programming language

can use the list of all registers with their exact addresses, it is enough to specify the register’s name in

order to read or change its contents.


Some of its Main Features are Listed Below 6.4

RISC architecture

Only 35 instructions to learn

All single-cycle instructions except branches

Operating frequency 0-20 MHz

Precision internal oscillator

Factory calibrated and software selectable frequency range of 8MHz to 31 KHz

Power supply voltage 2.0-5.5V

Consumption: 220uA (2.0V, 4MHz), 11uA (2.0 V, 32 KHz) 50nA (stand-by mode)

Power-Saving Sleep Mode

Brown-out Reset (BOR) with software control option

35 input/output pins

High current source/sink for direct LED drive

software and individually programmable pull-up resistor

Interrupt-on-Change pin

8K ROM memory in FLASH technology

Chip can be reprogrammed up to 100.000 times

In-Circuit Serial Programming Option

Chip can be programmed even embedded in the target device

256 bytes EEPROM memory

Data can be written more than 1.000.000 times

368 bytes RAM memory

A/D converter:

14-channels

10-bit resolution

3 independent timers/counters[16]

Special Microcontroller Features 6.5

100,000 erase/write cycle Enhanced Flash program memory typical

Data EEPROM Retention > 40 years

Self-reprogrammable under software control


In-Circuit Serial Programming™ (ICSP™) via two pins

Single-supply 5V In-Circuit Serial Programming

Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation

Programmable code protection

Power saving Sleep mode

Selectable oscillator options

In-Circuit Debug (ICD) via two pins [17]

PIC16f877A Pin Diagram 6.6

Figure 6.2 PIC 16f877A pin diagram


Block Diagram of PIC16f877A 6.7

Figure 6.3 Architecture of PIC16F877A [18]


PIC16f877A Pin Configuration [19] 6.8

Name Number

DIP

Functio

n Description

RE3/MCLR/VPP

1 RE3 General purpose input Port E

MCLR Reset pin. Logic level on this pin resets

microcontroller.

Vpp Programming voltage

RA AN ULPWU/C IN -

RA General purpose I/O port A

AN A/D Channel input

ULPWU Stand-by mode deactivation input

C IN Comparator C or C negative input

RA AN C IN - 3 RA Genaral purpose I/O port A

AN A/D channel

C IN

-

Comparator C or C negative input

RA2/AN2/Vref- /CVref C in+ RA2 GENERAL PURPOSE I/O PORT

AN2 A/D CHANNEL 1

Vref- A/D NEGATIVE VOLTAGE REF

CVref COMPARATOR VOLTAGE REF. OUTPUT

C2IN+ COMPARATOR C2 POSITIVE INPUT

RA3/AN2/VREF+/CIN+ 5 RA3 GENERAL PURPOSE I/O PORT A

AN3 A/D CHANNEL 3

VREF+ A/D POSITIVE VOLTAGE REFERENCE INPUT

CIN+ COMPARATOR C1 POSITIVE INPUT

TOCKI TIMER TO CLOCK INPUT


C1OUT COMPARATOR C1 OUTPUT

RA5/AN4/SS/C2OUT 7 RA5 GENERAL PURPOSE I/O PORT A

AN4 A/D CHANNEL 4

SS SPI MODULE INPUT(SLAVE SELECT)

C2OUT COMPARATOR C2 OUTPUT

RE0/AN5 8 RE0 GENERAL PURPOSE I/O PORT E

AN5 A/D CHANNEL 5

RE1/AN6 9 RE1 GENERAL PURPOSE I/O PORT E

AN6 A/D CHANNEL 5

RE2/AN7 10 RE2 GENERAL PURPOSE I/O PORT

AN7 A/D CHANNEL 5

VDD 11 + POSITIVE SUPPLY

VSS 12 - NEGATIVE SUPPLY

RA7/OSC1/CLKIN 13 RA7 GENERAL PURPOSE I/O PORT E

OSC1 CRYSTAL OSCILLATOR INPUT

CLKIN EXTERNAL CLOCK INPUT

RA6/OSC2/CLKOUT 14 RA6 GENERAL PURPOSE I/O PORT E

OSC2 CRYSTAL OSCILLATOR INPUT

CLKO FOSC /4 OUTPUT

RC0/T1OSO/T1CK1 15 RC0 GENERAL PURPOSE I/O PORT E

T1OSO TIMER T1 OSCILLATOR OUTPUT

T1CK1 TIMER T1 CLOCK INPUT

RC1/T1OSO/TICK1

1

RC1/ GENERAL PURPOSE I/O PORT E

T1OSO TIMER T1 OSCILLATOR OUTPUT

TICK1 TIMER T1 CLOCK INPUT

RC2/P1A/CCP1 17 RC2 GENERAL PURPOSE I/O PORT E


P1A PWM MODULE OUTPUT

/CCP1 CCP1 AND PWM MODULE I/P

RC3/SCK/SCL 18 RC3 GENERAL PURPOSE I/O PORT E

SCK MSSP CLOCK I/O IN SPI MODE

SCL MSSP CLOCK I/O IN I2C MODE

RD0 19 GENERAL PURPOSE I/O PORT E




RC4/SDI/SDA 23 RC4 GENERAL PURPOSE I/O PORT E

SDI MSSP DATA INPUT IN SPI MODE

SDA MSSP DATA I/O IN I2C MODE

RC5/SD0 24 RC5 GENERAL PURPOSE I/O PORT E

SD0 MSSP DATA OUTPUT IN SPI MODE

RC6/TX/CK 25 RC6 GENERAL PURPOSE I/O PORT E

TX/ USART ASYNCHRONOUS OUTPUT

CK USART SYNCHRONOUS CLOCK

RC7/RX/DT 26 RC7 GENERAL PURPOSE I/O PORT E

/RX USART ASYNCHRONOUS INPUT

DT USART ASYNCHRONOUS DATA


RD5/P1B 28 RD5 GENERAL PURPOSE I/O PORT E

P1B PWM OUTPUT

RD6/P1C 29 RD6 GENERAL PURPOSE I/O PORT E

P1C

PWM OUTPUT


RD7/P1D 30 RD7 GENERAL PURPOSE I/O PORT E

P1D PWM OUTPUT

VSS 31 GROUND

VDD 32 POSITIVE SUPPLY

RB0/AN12/INT 33 RB0 GENERAL PURPOSE I/O PORT E

AN12 A/D CHANNEL 12

INT EXTERNAL INTERRUPT

RB1/AN10/C12INT3 34 RB1 GENERAL PURPOSE I/O PORT E

AN10 A/D CHANNEL 10

C12INT3 COMPARATPR C1 OR C2 NEGATIVE INPUT

RB2/AN8 35 RB2 GENERAL PURPOSE I/O PORT E

AN8 A/D CHANNEL 10

RB3/AN9/PGM/C121N2 36 RB3 GENERAL PURPOSE I/O PORT E

AN9 A/D CHANNEL 10

PGM PROGRAMMING ENABLE PIN

C121N2 COMPARATPR C1 OR C2 NEGATIVE INPUT

RB4/AN11 37 RB4 GENERAL PURPOSE I/O PORT E

AN11 A/D CHANNEL 10

RB5/AN13/TIG 38 RB5 GENERAL PURPOSE I/O PORT E

AN13 A/D CHANNEL 10

TIG TTIMER T1 EXTERNAL INPUT

RB6/ICSPICLK 39 RB6 GENERAL PURPOSE I/O PORT E

ICSPICLK SERIAL PROGRAMMING CLOCK

RB7/ICSDAT 40 RB7 GENERAL PURPOSE I/O PORT E

ICSDAT PROGRAMMING ENABLE PIN


Summary 6.9

The PIC16f877A microcontroller has been discussed in this chapter. This chapter clarifies that a

microcontroller is a miniature version of computer but it is special in the sense that it carries out a specific

function unlike computers. Different features of the microcontroller are described here. The overall

architecture along with the function of its different parts is provided in this chapter.


Chapter 7

Programming and Application of the Software

Introduction 7.1

Machines cannot understand human language. It only understands binary 0 and1. But writing a long code

in 0s and 1s is very difficult for humans. So another language that is in between this two language is used.

These languages are called high level language. The codes written in the high level language are then

translated into the machine language using software. Then this instruction can be executed by the

computer. This chapter discusses the high-level programming language that has been used to write the

codes, the software that converts it into machine language and finally burn into the microcontroller.

The C Programming 7.2

C is a general purpose computer programming, developed between 1969 and 1973 by Dennis Ritchie at

the bell telephone laboratories for use with the UNIX operating system. Although c was designed for

implementing system software, it is also widely used for developing portable application software.

C is one of the most widely used programming languages of all time and there are very few computer

architecture for which a c compiler does not work. C has greatly influenced many other popular

programming languages, most notably C++, which began as an extension of c.

C is an imperative (procedural) system implementation language. It was designed to be compiled using

relatively straight forward compiler, to provide low level access to memory, to provide language

constructs that map efficiently to machine instructions and to require minimal run-time support. C has

been useful for much application that had for formerly been coded in assembly language. For this reason

this language has become available on a very wide range of platforms, from embedded microcontrollers to

super computer.

In this project, the code is written in c language. The source program is well commenter and easy to

understand. First the resister mane is defined specifically for PIC16f877A and then variables were

declared [20].


MikroC Pro Pic C Compiler 7.2.1

C was designed as a programming language not as a compiler target language. Since we know that the

code must be translated into machine language, we need a compiler to do this task. The compiler we are

using is called mikroc_pro_pic_v600 c compiler. This compiler converts the source program into hex

code which is downloaded to the microcontroller.

MikroC pro PIC is a complete set of tools designed for rapid and efficient software development for PIC

microcontroller. Hence for using to compile codes for PIC16F877A this software in best option [20].

Some Features of Mikroc_pro_PIC_v600 7.2.2

MikroC is a full-featured ANSI C compiler that is available for six different microcontroller architectures

(in this case, for PIC 12/16/18). It features an intuitive IDE, a powerful compiler with advanced SSA

optimizations, lots of hardware and software libraries, and additional tools

Single-click Debugging 7.2.2.1

MikroC PRO for PIC has native support for the MikroICD In-Circuit Debugger feature of the fast USB

2.0 MikroProg-PIC programmer (in both on-board and standalone versions). MikroICD is a separate DLL

module which supports Step-over, Step-Into, Step-Out, Run, and Run-to-Cursor debugging operations.

Also, the debugger supports standard and advanced breakpoints.

Faster, Better, More Productive 7.2.2.2

MikroC PRO for PIC comes equipped with fully functional software tools that can boost efficiency.

Design Develop Share 7.2.2.3

The Drag-and-drop development environment of the program ensures that we need to spend less time for

programming, allowing focusing on functionality and design.

Library Manager 7.2.2.4

It offers the mechanism to use any available library in project easily. If it is just clicked on the checkboxes

of the libraries the code will be available instantly. The Library Manager is programmed to allow easy

usage of third-party libraries installed with Package Manager Software.


Edit Project 7.2.2.5

Edit Project gives full overview of the configuration bits in each chip. Edit Project includes predefined

schemes of oscillator settings for most widely used microcontrollers.

Code Assistant 7.2.2.6

The ―Code Assistant‖ feature helps by providing function names and let syntax write itself correctly. Code

Assistant in MikroC PRO for PIC also suggests correct names of constants, URLs, Active Comments, and

variables.

Parameter Assistant 7.2.2.7

It has a listed function parameters which helps to easily identify the desired function.

Object Explorer 7.2.2.8

The Project Explorer window leads to projects and displays all of the included examples by default.

Double-click opens the project and sets it as active. It is possible to quickly switch between the programs

and have stable RAM consumption.

Active Comments 7.2.2.9

It’s a unique feature of MikroC PRO for PIC. Any comment can be used as a multimedia event hook and

images, files, URLs etc. can be used as active comment.

Quick Converter 7.2.2.10

Quick Converter can convert binary, float, HEX and Radix 1.15 formats within these as necessary. It also

can displays ASCII values of command bytes.

Code Folding 7.2.2.11

If code outgrows the size of screen, it fold those completed blocks, and work in a clearer surrounding.


Software Simulator 7.2.2.12

If allows to go through your code and monitor the values of your variables, searching for bugs and errors

via Software Simulator. Instead of executing the code on real hardware, it simulates code flow on PC.

Programming the Microcontroller 7.3

The codes to program the microcontroller was written using the Micro PRO C software in C programming

language. Then the code was converted to *.hex file. Than the program loader circuit TECH PIC was

connected to the computer. Generated HEX file (*.hex) was loaded using PICKIT 2.6. It was ensured the

simulated code was accurate and loaded to the microcontroller successfully.

Introduction to Burner 7.4

TechPIC trainer kit by www.techshopbd.com is a clone of pickit 2 with some extra function.

Figure 7.1: TechPIC


Features:

1) ZIF Socket for PIC IC, with accessible I/O, grouped by PORT.

2) On board Programmer.

3) USB connector, connection with PC.

4) Crystal Oscillator (Default 16MHz). It’s replaceable.

5) External Supply Socket (5V).

6) SPI Pinout.

7) ISP Pinout.

8) USART Pinout.

9) I2C Pinout.

10) Seven Segment Display Interfacing.

11) LCD Interfacing Connector.

12) LCD Contrast.

13) ADC Interfacing.

14) Push Button (x2) Interfacing.

15) I/O Expander.

16) RESET Circuitry.

17) 8 LEDs for general use.

18) 5-way Tactile Switch Interfacing.

19) Buzzer Interfacing.

20) PS/2 Interfacing.

21) Infrared Interfacing.

22) 1-Wire Communication Interfacing.

23) Power Switch.

24) Vcc-GND power pin [21].

PICkit™ 2 Programming Software 7.5

We used the software PICkit™ 2 to burn the code into the PIC16F877a microcontroller. Steps of burning

a code into the microcontroller are given below.


Figure7.2 PICkit™ 2 Programming Software

Program Loading Steps 7.6

Plugin the PIC kit 2 clone Development Board into Pc

Manu bar > tools > check communication

File > import HEX > select HEX file(*.hex)> click open

Command bar> write

Check if the programming is successful.

Figure 7.3 Manu bar > tools > check communication


Figure7.4 HEX file loaded succesfully

Figure 7.5 Program loaded successfully.

Summary 7.7

This chapter introduces the fundamental software and working procedure that has been used in this project

in order to load the program in the microcontroller. We also described the program burning steps with

necessary diagram of the every important steps.


Chapter 8

ROV Shell, Thruster, Camera and Light Housing Design and Construction

Introduction 8.1

Design of shell, thruster, camera and light housing and its manufacture is describe through this chapter.

The design and manufacture of skeleton or structure of a ROV, is an important portion of this project. In

this chapter there will be a brief description of factors, process of design and manufacture the whole ROV,

with locally available elements and materials.

Shell Design 8.2

Shell is the body structure and the main housing of the ROV. The design must be efficient and robust.

Shape 8.2.1

ROVs come in all shapes and sizes depending on what they are designed to do but all ROVs have a few

structures in common. ROVs have a rigid frame that must withstand high pressure and extreme

temperatures as deep sea temperatures can range from near freezing to over 400 degrees Celsius. Mounted

to the frame are motors to provide propulsion, floatation and ballast that combine to provide neutral

buoyancy, and a tether or umbilical cord linked to the ship that provides power and is used to control

movement. Other equipment such as lights, cameras, sensors, and collecting devices are often attached as

well. We designed our ROV shape as torpedo. The frontal area of torpedo shape ROV is less so the drag

factor is also less which gives the ROV more speed and maneuverability.

Drawing

First of all, we need to sketch a rough design we want, to scale, on paper. During design we count on

some points

Dimensions

Materials

Buoyancy

Drag

Stability


Location of thrusters

Location of required tools

Location of camera and tether attachments

Then we draw it on AUTOCAD design software with perfect scale. We draw it from two perspective

i. Plan view (looking down on the ROV from above)

ii. Side elevation (looking at the ROV from the side),

Figure of ROV (CAD design)

Figure 8.1 Top view and side view

Figure 8.2 Sketch of ROV


Making

To build the body of the ROV we used PVC pipe. It is a 2.5ft long PVC pipe of 6 inch diameter and 6mm

thickness. The front side is wide open and the other side is reduced to 2 inch diameter by giving heat. The

head is made with a glass and a PVC casing. This two parts are coupled together to make a waterproof

body. We drilled a few holes to insert the cables and sensors.

Figure 8.3 HULL of ROV

Thrusters 8.3

Thrusters are mainly electrically powered motors connected with propeller. The bilge pump is actually a

ready-made DC motor in a watertight housing. After removing the unnecessary parts of the bilge pump

we attached the propeller with the extension of the armature using the propeller coupler.

Figure 8.4 Bilge motor and propeller unit

Fabricating the Protective Propeller Cowling 8.4

A protective cowling or shroud for the propellers is an essential next step. It is a safety measure for the

deck crew handling the ROV and a method of keeping the propeller from damaging itself or whatever it’s

hitting and avoiding getting the prop fouled from other materials like tether or lines and competition

structures. To construct the cowling we need:


A 3‖ to 2‖ PVC pipe and a short length of 2‖ PVC pipe. Generally we have to cut two sections out

of each of these parts such that the remaining prongs overlap. We cut the reducer coupling by

mounting in on a piece of 2‖ pipe and then in a moveable vice such as used on a drill press. We

pushed the small end ring (2‖) of the pipe into the band saw blade. We made sure that the blade

must bisect the small ring (across its diameter) and penetrated into the cone shape until it reaches

the larger ring (3‖).

Now we rotated the whole pipe about 20 degrees (2.5 cm) in either direction, and position it

exactly as above. We repeated the cut across the diameter of the smaller ring. Now we have four

cut slots into the smaller ring. It leaves two segments of the arc much larger than the other two.

Then we rotated the whole vice 90 horizontally, such that the 3‖ pipe and the pipe coupling are

now perpendicular to the band saw blade. Then went to cut down the plane of the large ring, where

it meets the cone section of the adapter….but only through the larger arc segment. We were very

careful not to cut the smaller arc segments.

Once that was done, the large arc segment was pulled from the reducer. We did the same thing on

the opposite side of the reducer. The piece on the left (above) is what we had left. We’re 2/3s

done. Then we took a 20-30cm length of 2‖ PVC pipe and mounted it was in the drill press vice.

We measure off a 4.5 cm from the end and marked it with a scratch or a white grease pencil and

pointed the end of the pipe at the band saw blade position it such that the blade would cut across

the maximum width (the diameter) of the pipe. Exactly as with the reducer, we made a cut across

the diameter into the end of the pipe, rotated it about 200 and then made another cut. The end of

the pipe then had four cuts which defined four segments of the circumference. Two opposite

segments were about 2.0 cm long. Those were the segments which will remain after the next cuts.

Again, like the reducer, rotate the whole vice 900

horizontally, such that the 1-½‖ ABS is now

perpendicular to the band saw blade. Cut out the two longer arc segments at about 4.5 cm from the

end, being careful not to cut the smaller arc segments. The piece on the right (in the photo above)

is what you have left. Almost done! Now you can join the two parts of the thruster cowling

together. (see photo right) The bilge pump motor cartridge fits tightly into the 1-½‖ ABS pipe. The

propeller and brass hub can now be installed on the motor’s drive shaft and the whole unit can be

glued together with ―transition‖ cement. (ABS to PVC). The finished design is shown below


Figure 8.5 Bilge motor housing

Summary 8.5

This is one of the most important part of the project to make the HULL/ body structure of the ROV. Hull

is the container of the internal circuitry. The motors are attached with the body. It must be ensured that the

body is water proof. In this chapter we discussed about the procedure of building a waterproof HULL for

our ROV.


Chapter 9

Software Simulation of the System

Introduction 9.1

In this chapter the model derived in Chapter ―Modeling‖ will be evaluated by simulations. The different

tests that have been used will be described, followed by some results and recommendations. With the

intention of obtain accuracy of the model, trial the system and test the controller a variety of tests are

needed. Here are three types of tests that have been run: Dry tests, static wet tests and dynamic wet tests.

Simulation 9.2

In order to verify the model derived in chapter ―modeling‖ and estimated the real time working procedure

a model was created in PROTEOUS as a test workbench.

Its main purpose is

• Verify that the model behaves reasonable.

• Estimate the necessary model upgrades and changes.

• To understand solutions and ideas for implementing the circuit.

• The system block. This block simulates the system’s behavior for a given input signal.

• The controllers. With the help of the switch it is possible to understand the behavior of the controller.

Simulating the Circuit of Remote Module 9.2.1

The circuitry for the remote consists of pulse switch, microcontroller, LCD, TFT LCD. The pulse switch

and the LCD has been interfaced with the microcontroller unit. The tasks of the remote are to send

command to the host module and to receive feedback and to process the data too. The LCD shows output

of sensors after receiving and processing through microcontroller.

When a pulse switch is pressed, for every individual switch connected to different pin of the

microcontroller different character is generated. That’s means every generated character has different

ASCII value. It sends the ASCII code to microcontroller of the host module for further action. Total 15

switch are connected to Microcontroller as input pin. 12 of them turns on/off and controls the direction of

movement of the motors. 2 of them controls speed of motor. 1 switch used to completely shut down the

device.


Figure 9.1 Simulation diagram of remote module

Simulating the Circuit of Host Module 9.2.2

The main consisting parts of the circuitry of the host module of several relays, microcontroller,

optocoupler, power MOSFET, heat sink BJT, sensor etc. The sensors and motor driver circuits has been

interfaced with the microcontroller unit. The tasks of the host is to receive command from the remote

module and to behave accordingly by switching on different motors, light and pump. It also sends the

retrieved data of the sensors to the remote module to show in the LCD.

When a pulse switch is pressed in the remote module it sends the ASCII value to microcontroller of the

host module. Host module receives the data and execute further action.

RA0/AN02

RA1/AN13

RA2/AN2/VREF-/CVREF4

RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP216

RC2/CCP117

RC3/SCK/SCL18

RD0/PSP019

RD1/PSP120

RB7/PGD40

RB6/PGC39

RB538

RB437

RB3/PGM36

RB235

RB134

RB0/INT33

RD7/PSP730

RD6/PSP629

RD5/PSP528

RD4/PSP427

RD3/PSP322

RD2/PSP221

RC7/RX/DT26

RC6/TX/CK25

RC5/SDO24

RC4/SDI/SDA23

RA3/AN3/VREF+5

RC0/T1OSO/T1CKI15

MCLR/Vpp/THV1

U1

PIC16F877A

D7

14

D6

13

D5

12

D4

11

D3

10

D2

9D

18

D0

7

E6

RW

5R

S4

VS

S1

VD

D2

VE

E3

LCD1LM016L

50%

RV1

5k

+5v

D5

1N4733A

+5v

VI1

VO3

GN

D2

U27805

+12v

R9

1k

+5v

X10

CRYSTAL

C1222pf C1

22pf

To the Receiver circuit

+5vR11k

R12221k

R21k

R331k

R41k

R551k

R61k

R771k

R81k

R1031k

R111k

R1221k

R131k

R1441k

R151k

R1661k

C2

100uf

RXD

RTS

TXD

CTS

93%

RV2

1k

+5v


R

Figure 9.2 Simulation diagram of host module

RA0/AN02

RA1/AN13

RA2/AN2/VREF-/CVREF4

RA4/T0CKI/C1OUT6

RA5/AN4/SS/C2OUT7

RE0/AN5/RD8

RE1/AN6/WR9

RE2/AN7/CS10

OSC1/CLKIN13

OSC2/CLKOUT14

RC1/T1OSI/CCP216

RC2/CCP117

RC3/SCK/SCL18

RD0/PSP019

RD1/PSP120

RB7/PGD40

RB6/PGC39

RB538

RB437

RB3/PGM36

RB235

RB134

RB0/INT33

RD7/PSP730

RD6/PSP629

RD5/PSP528

RD4/PSP427

RD3/PSP322

RD2/PSP221

RC7/RX/DT26

RC6/TX/CK25

RC5/SDO24

RC4/SDI/SDA23

RA3/AN3/VREF+5

RC0/T1OSO/T1CKI15

MCLR/Vpp/THV1

U1

PIC16F877A

RL1OMIH-SH-105D

RL2OMIH-SH-105D

D1

1N4007

D2

1N4007

Q1BC547

Q2BC547

R1

10kR310k

+12v

RL3OMIH-SH-105D

RL4OMIH-SH-105D

D3

1N4007

D4

1N4007

Q3BC547

Q4BC547

R2

10kR410k

+12v

RL5OMIH-SH-105D

RL6OMIH-SH-105D

D5

1N4007

D6

1N4007

Q5BC547

Q6BC547

R5

10kR610k

+12v

RL8OMIH-SH-105D

D8

1N4007

Q8BC547

R810k

+12v

RL7OMIH-SH-105D

D7

1N4007

Q7BC547

R710k

+12v

D9LED-RED

X10

CRYSTAL

C1122pf C1

22pf

R9

10k

+5v

C22200uf

C30.1uf

Q9 IRF540

+12v

Q10

IRF540

Q11

IRF540

Q12

IRF540

A

K

C

E

1

2

4

3

U3

PC817

+12v

R1010k

R1110k

To Obstacle detecting sensor

To the Remote control circuit

28.0

3

1

VOUT2

U2

LM35


Simulation of Serial Communication by Coupling the Remote and Host 9.2.3

Figure 9.3 UART communication simulation diagram

Summary 9.3

The experiments and test done in this section ensures the ROV is a full functional ROV. Different type of

run time error may occur. In the test period final checking is done to find if there any trouble. If any

problem found which can cause malfunction of the device and can harm the device, immediate steps for

recovery are taken to ensure maximum safety for the ROV.

MCLR/VPP1

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA3/AN3/VREF+5

RA4/T0CKI6

RA5/AN4/SS/LVDIN7

RE0/RD/AN58

RE1/WR/AN69

RE2/CS/AN710

OSC1/CLKI13

RA6/OSC2/CLKO14

RC0/T1OSO/T1CKI15

RC2/CCP117

RC3/SCK/SCL18

RD0/PSP019

RD1/PSP120

RD2/PSP221

RD3/PSP322

RD4/PSP427

RD5/PSP528

RD6/PSP629

RD7/PSP730

RC4/SDI/SDA23

RC5/SDO24

RC6/TX/CK25

RC7/RX/DT26

RB0/INT033

RB1/INT134

RB2/INT235

RB3/CCP2B36

RB437

RB5/PGM38

RB6/PGC39

RB7/PGD40

RC1/T1OSI/CCP2A16

MC1

PIC18F452

MCLR/VPP1

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA3/AN3/VREF+5

RA4/T0CKI6

RA5/AN4/SS/LVDIN7

RE0/RD/AN58

RE1/WR/AN69

RE2/CS/AN710

OSC1/CLKI13

RA6/OSC2/CLKO14

RC0/T1OSO/T1CKI15

RC2/CCP117

RC3/SCK/SCL18

RD0/PSP019

RD1/PSP120

RD2/PSP221

RD3/PSP322

RD4/PSP427

RD5/PSP528

RD6/PSP629

RD7/PSP730

RC4/SDI/SDA23

RC5/SDO24

RC6/TX/CK25

RC7/RX/DT26

RB0/INT033

RB1/INT134

RB2/INT235

RB3/CCP2B36

RB437

RB5/PGM38

RB6/PGC39

RB7/PGD40

RC1/T1OSI/CCP2A16

MC

PIC18F452

VCC

R2

10k

R310k

Master Slave

D7

14

D6

13

D5

12

D4

11

D3

10

D2

9D

18

D0

7

E6

RW

5R

S4

VS

S1

VD

D2

VE

E3

LCD1LM016L


Chapter 10

Circuit Implementation and Operation

Introduction 10.1

In this chapter the process of building the complete circuit and final attachment with the body is

described. At first we have implemented the circuit on bread board at first stage of testing. We checked

for error and troubles. After solving the error found at the primary stage, we finally implemented the

circuit in Vero board and made the connection carefully by soldering. Then we implemented it inside the

hull of ROV. We checked if there any possibility of leaking of water. Setting up the battery inside the

hull, mounting camera and LED light was done at this stage. Finally we tested it in dry, static wet and

dynamic wet environment.

Block Diagram and operational description of Complete Circuit 10.2

Figure 10.1 Block diagram of the complete circuit

REMOTE

MODUDEL

HOST

MODULE

Command

switches

LCD

Display

Monitor

Thrusters Pump

Light

Movement

Thermal

Sensor

Sonar

Sensor


Description of the Block Diagram 10.2.1

This block diagram shows the elementary working procedure, direction of command flow between the

MCUs (microcontroller unit) and relation of MCUs and other parts of circuit. As shown in the block

diagram the remote module consists of a MCU, a GLCD and a TFT LCD display. The MCU is connected

to MCU of host module. The host module consists of MCU, motor, pump, camera and LED lights. The

communication between the remote module and the host module is a bidirectional process. The MCU of

remote module send signal to the host module when switch is turned on. The MCU of host module

receives the signal and either make its different pin high or low to turn on/ off the motor, pump and LED.

On the other hand this also takes the reading of the sensors and sends to the MCU of remote module. The

MCU of remote module receives the data and shows it on the GLCD. The video feed of the camera is sent

from the host module and the TFT LCD display of the remote module shows the image of video.

Test Connection of the Circuits 10.3

There are some major types of circuits that are being controlled by the microcontroller in the host module.

Those are described briefly below with diagram.

Speed control with PWM 10.3.1

Figure 10.2 PWM controlled motor block diagram

From the diagram above we see the motor is connected to ground and source through a MOSFET.

MOSFET has 3 parts gate (G), drain (D) and source(S). The MOSFET allows current to flow from drain

to source if voltage is given to the gate (G). The MOSFET is normally off. When microcontroller give

pulse to the gate of the MOSFET it enables current to flow through the circuit and let the motor rotate.

The MOSFET has very fast switching property. If duty cycle of the PWM (provided from the

microcontroller) is small the MOSFET is ON for less time hence the motor gains less speed. Thus If the

duty cycle increase motor gains more speed due to inertia


Use of Optocoupler 10.3.2

Figure 10.3 Optocoupler block diagram

The power MOSFET used in our project need at least 8V to work on full mode. But the output pin of a

microcontroller can provide 5V at most. Practically we get less than 5V output from the microcontroller

pin. To overcome the problem we use optocoupler. Optocoupler has to main part, a light emitting diode

and a photo activated BJT. The gate of the MOSFET is connected with to a 12 V source through the photo

activated BJT. Current flow to the gate of the MOSFET if the base of the BJT is activated by IFR light.

The output pin of the microcontroller is connected to IFR diode. Microcontroller output enables the IFR,

IFR enables the BJT as a sequence current from 12V source activate the MOSFET.

Bidirectional motor driver using relay 10.3.3

Figure 10.4 Bidirectional motor driver.


To drive a motor in clockwise and counter clockwise direction we made the circuit of the given diagram

above using two relay which are connected with output pin of microcontroller through BJTs. when pin A

is high it turn on the BJT and adjacent path is activated by current flow from 6V voltage source hence

switch Sa is turned on to rotate in clockwise direction. Similar process activates the Sb when pin B is high

and rotates the motor counterclockwise.

Circuit Implementation on Bread Board 10.3.4

Figure 10.5 Circuit connection on bread board.

Before placing the component on the Vero board and soldering real time functionality of all the circuits

are needed to be tested. We implemented the components on bread board as a step of testing performance.

Depending on the result of test run we conducted troubleshoot and after final correction and necessary

modification we placed.


Operation of Circuit 10.4

The circuit get ready to work after giving connection with power source. A 9V DC battery is the power

source of the remote module. It provide with power to the MCU of the remote controller, the switches,

crystal oscillator, the LCD that shows output of the sensors. To continue the serial communication with

the host module necessary power is also provided from the 9V battery to the remote module. The task of

the remote module is to send command data bit to the host module to switch on/off the motors and let

them rotate in clockwise and counterclockwise direction. It also receives output from the sensors attached

with the host module and show in the LCD display.

Two 12V-10Ah batteries are connected in parallel connection. It provides with the necessary power to the

host module to run the motors, LED lights, MCU, video camera, pump, sensors and all other components

of the circuit of the host module. The task of the host module is to receive the command form the remote

module. The MCU is programmed to get the bits and to make different pin high according to the

command received. The camera captures images or video

To execute a full command the device have to work in a few stages in combination. At first both of the

remote and host module are connected with power source. At this stage the MCUs, motors, sensors and

displays are ready to operate. After pressing every switch MCU gets different input. To turn on a motor,

―ON‖ switch is pressed on the remote module and the MCU generate a character inside it. Than it send the

character into bits and send it to the host module through TX port using UART communication protocol.

The MCU in host module receives the command bits through the RX port, which is connected to the TX

port of the remote module. After receiving the command bit. it analysis it. The MCU of the host module

is programmed to switch on/off different pin according to the command of the remote module. When it

make a pin high the motor driver circuit start to run the motor. The output pin that drives the motors are

connected through optocoupler, power MOSFET and relay. When output pin is high in enables the

optocoupler. The optocoupler provides the required 8V voltage to the power MOSFET. The MCU cannot

give more than 5V output theoretically, partially it gives less than 5V which are not enough to turn on the

power MOSFET. Using optocoupler this problem is solved. When the power MOSFET is ON it let the

current flow to the motor and the motor starts. Using two single pole single throw relay bi-directional

motor can be made.


Implementation on Vero Board 10.5

Vero board is a circuit prototyping board between solder less breadboards and printed PCBs. It allows to

make a more permanent circuit and more reliable connections than with breadboard. It consists of strips of

metal on a side of a board and a grid of holes that allows to solder most types of non-surface mount ICs,

resistors, capacitors etc. on it. Some of the Vero board has copper layer on one side and some has on both

sides. Vero board holes are drilled on 0.1 inch (2.54mm) centers. This spacing allows components having

pins with 0.1 inch spacing to be inserted.

Planning a Vero Board Layout 10.5.1

Converting a circuit diagram to a Vero board layout is not straightforward because the arrangement of

components is quite different. Concentration is most important for the connections between components,

not their positions on the circuit diagram. The layout should be planned with a pencil and paper or suitable

computer software before attempting to solder any part of the circuit.

Steps to follow for planning a layout:

The IC holder should be place near the center of the planning sheet. It is helpful to number the

pins.

Breaks should be marked in each track under the IC holder with cross(X). It prevents connection

of wrong pin together.

The power supply tracks +Vs and 0V should be marked carefully

Then the wire links should be added. The links can be both vertical and horizontal because all the

holes of the Vero board are isolated.

Components should be added which will be mounted on the Vero board such as switch, resistor,

capacitor etc. through wires.

The plan should be checked very carefully. A good way to do this is to work round the IC pin-by-

pin. So all the connections and components connected to Pin 1 and then pin2 and so should check.

Finally, the plan should check again and a neat copy should be made which will be fully labeled

with all the component reference or values.


Placing Components on Vero Board 10.5.2

Components are placed on the non-copper side of the board; the Vero board is turned over and the

components leads are soldered to the copper tracks. In our project we used two Vero boards. Both the

Vero boards’ holes are separated by both horizontally and vertically. On Vero board we placed the

microcontrollers, resistors, capacitors, switches, relays, MOSFETs connecting ports etc.

Figure 10.6 Placing component on Vero board (remote module)


Figure 10.7 Placing component on Vero board (host module)

Figure 10.8 Finalized remote module


Figure 10.9 Finalized host module

Figure 10.10 Full functional circuit (1)


Figure 10.11 Full functional circuit (2)

Dry Test 10.6

The dry tests are executed on land in order to test some basic functionality in a controlled environment.

During dry tests motors cannot be driven for longer than a minute, because motors may be damager due to

overheating caused by high current flow through the armature.

To conduct dry test of the circuits we check for the following measurements:

every motor runs individually accurately

All motors runs perfectly

The remote communicate with the host perfectly.

Lights, sensors, camera and other circuitry operates sound in dry environment.

Check for troubles before final assembly.


Figure 10.12 Final appearance of ROV (1)




Wet Test 10.7

Wet test are procedure to test the functionality of the circuits inside the hull of the ROV after primary

assembly. To find out the troubles and malfunction within wet environment, when ROV is static, is the

goal of conducting wet test.

Static Wet Test 10.7.1

The static wet tests are implemented in a small pool to check basic functionality and behavior of the

device. The test-environment is displayed in Figure 6.8. These tests are preparation steps for the dynamic

wet tests. To check safety of circuit from leakage using leakage sensor is the most important step of static

wet test. ROV Needs to be thoroughly tested before using it in a larger pool, where if something goes

wrong the entire ROV can be destroyed.

To conduct static wet test we check for following measurements

Checking the controls, to observe that the ROV moves the way it should.

External affect the ROV by rotating it.

Depending on the result from the tests above, changes to the contributions from different if

necessary.

Stress testing to figure out possible faulty situations and observe how the system is reacting in

those situations.


Figure 10.15 static wet test of ROV

Dynamic Wet Test 10.7.2

The experiment was conducted in a pool where the ROV can make most motion. It’s the final step of

checking the functionality of the ROV. To find out how it behaves during full functional mode is the main

goal of the test.

Some situations that are tested are:

Driving motors with full speed for a longer period of time.

Sending as much commands from the remote as possible.

Check the sensors.

Driving a motor and pulling the Ethernet cable to simulate a loss of connection.

The data collected has to be examined to see if the behavior could cause a problem at the DWTs.

Figure 10.16 Dynamic wet test of ROV


Test results 10.8

Test types Description Result

Dry test To check all circuit and component function Successful

Static wet test To check for leakage in ROV body Successful

Dynamic wet test To check balance and maneuverability of ROV Successful

Sample collection Collecting water sample at different depth Successful

Video output To check the video feed of camera Successful

sensors Testing the sensors functionality Partially successful

Summary 10.9

The experiments and test done in this section ensures the ROV is a full functional ROV. Different type of

run time error may occur. In the test period final checking is done to find if there any trouble. If any

problem found which can cause malfunction of the device and can harm the device, immediate steps for

recovery are taken to ensure maximum safety for the ROV.


Chapter 11

Discussions and Conclusions

Discussions 11.1

The main objective of this chapter is to discuss the result of the project based on completion of the project.

What part was successful, why some things were not successful, the future scope for improvement of

function and what were the limitations will be included in this chapter.

The project is taken to build a remotely operated underwater robot that will be able to move in vertical

and horizontal direction, sense temperature, detect presence of obstacle send video feed to work as an

observation robot. It’s not easy undertaking to construct a project with an errant success. So far we have

done most of the parts came out successful. We have built a complete circuitry with two parts (remote and

host) which are full functional in communicating and operating flawlessly. It is able to detect temperature

and obstacle. The operation of motor is successfully controlled by the circuits to move the ROV

underwater and to collect sample from certain level of water.

In this project a lot of time have been used up on hardware executions and finding errors. The shortage of

data and experience of working with the electronics has been a drawback that we have worked hard to

eliminate. The batteries used in the ROV is not for play. If the wrong circuits are short-circuited, the ROV

circuits could burnt. The quality of the design of the electronics should be investigated by future projects.

In spite of some limitation the prototype ROV is functional.

Due to the decision to use a structural shell, the necessity for an internal framework is less. It is capable

to tow a large amount of tether from the ROV. As the primary thrust has been upgraded and the

hydrodynamics optimized

Limitations 11.2

Due to limitation of time and resource we couldn’t designed and built the body structure of the

ROV perfectly.

All the motors are functional as expected but when working underwater environment the ROV

but, due to imperfect balance of the hull the ROV can’t move perfectly.


The tether used is not very suitable for real life application of the ROV. Strong yet flexible tether

should be used for the ROV to operate underwater.

Power consumption is a major issue in this project. As the motors and light, camera need large

amount of power the ROV can’t be operated for a long time.

Radio frequency don’t work well in underwater environment specially when its necessary to

communicate from two different medium. We had to use tethered communication instead of using

radio signal.

It has a very high risk of damage due to water leakage.

Sometimes the sensors may give wrong result.

Most of the necessary equipment are not available in the local market. That’s why we bought

components from abroad. For this reason we couldn’t use many necessary and suitable sensors and

components that could be used to make a versatile, more functional and efficient ROV.

Project requires very costly equipment that have been a major impediment for completion of the

project.

The project was designed as a miniature prototype for limited purpose due to limitation of

resource.

Suggestion for Future Work 11.3

As it is a basic experimental project there are possibility of various modifications and enhancement of

new sensors to make improvement in this project.

With full implementation of the software USART, calibration commands could be sent from the

PC to the sensor via the PIC to remove the need for access to the sensor/camera box. This would

greatly ease on location calibration of the ROV. In that case the ROV could be controlled from the

PC and the video feed could be seen in the PC monitor.

When it’s controlled by PC MATLAB simulation could be used to auto detection of objects by

image analysis. Hence with the help of other sensors it could be an automated device.

To simplify communications, only orientation data is read from the sensor. The sensor also

outputs error information and this could be transmitted via the PIC to the PC for the user’s

information.

Lots of other useful sensors could be used in this ROV to enhanced performance. Like gyroscope

would help it to maintain its balance while moving underwater.


Robotic arm could be attached to perform underwater operation like repairing parts in submarine

cable, oilrig or hull of ship. X-ray could be used to detect fracture and imperfection on HULL of

ship or underwater oil/gas pipe or submarine cable.

High powered motor could be used to do underwater heavy excavation with the help of high

powered AC supply.

If viewing an object in the water is impractically slow sideways then perhaps extra cameras could

be placed on the beam of the ROV, or a retracting camera, which could be extended outside the

hull and rotated after transit to the required destination. These are just a few considerations for

further work.

Conclusions 11.4

This project was intended to design and implement a simple and low cost Remotely Operated Underwater

Vehicle (ROV). To implement this project, we used microcontroller as platform and local raw materials

for low cost. Our challenge was to design a ROV in such a way that its components will be able to collect

data from sensors and operate in underwater environment. We succeeded in building a small and low cost

ROV. The price is compared with similar observation ROVs and, bearing in mind this is a prototype, the

chance for reduced costs in bulk production is considerable. In spite of some limitation our designed ROV

may be helpful to work as an underwater observation robot. Our project has much more scope for future

research and development. After further modification and enrichment of available technology it can be

used for commercial purpose.


REFERENCES

[1] Patrik Johansson and Jacob Bernhard, Advanced Control of a Remotely Operated Underwater Vehicle,

ISRN : LiTH-ISY-EX--12/4599—SE

[2] (2013) EXPLORATORIUM website [Online] Available

http://www.exploratorium.org/snacks/descartes_diver.htm

[3] HG Greene, DS Stakes, DL Orange, JP Barry and BH Robison. (1993). "Application of a remotely

operated vehicle in geologic mapping of Monterey Bay, California, USA.". In: Heine and Crane (eds).

Diving for Science...1993. Proceedings of the American Academy of Underwater Sciences (13th

annual Scientific Diving Symposium). Retrieved 2008-07-11.

[4] C Harrold, K Light and S Lisin. (1993). "Distribution, Abundance, and Utilization of Drift

Macrophytes in a Nearshore Submarine Canyon System.‖ In: Heine and Crane (eds). Diving for

Science...1993. Proceedings of the American Academy of Underwater Sciences (13th annual

Scientific Diving Symposium). Retrieved 2008-07-11.

[5] Reed JK, Koenig CC, Shepard AN, and Gilmore Jr RG (2007). "Long Term Monitoring of a Deep-

water Coral Reef: Effects of Bottom Trawling.".In: NW Pollock, JM Godfrey (Eds.) the Diving for

Science…2007. Proceedings of the American Academy of Underwater Sciences (Twenty–sixth annual

Scientific Diving Symposium). Retrieved 2008-07-11.

[6] TM Shank, DJ Fornari, M Edwards, R Haymon, M Lilley, K Von Damm, and RA Lutz. (1994).

"Rapid Development of Biological Community Structure and Associated Geological Features at

Hydrothermal Vents at 9-10 North, East Pacific Rise". In: M DeLuca (ed). Diving for Science...1994.

Proceedings of the American Academy of Underwater Sciences (14th annual Scientific Diving

Symposium). Retrieved 2008-07-11.

[7] (2013) SeaPerch website. [Online]. Available https://seaperch.org

[8] (2010) MATE's ROV Competitions website [Online]. Available:

http://www.marinetech.org/rov_competition/

[9] ―MC78XX/LM78XX/MC78XXA Data sheet‖ [Online] Available :

http://www.engineersgarage.com/electronic-components/7806-ic

[10] (2010) National Underwater Robotics Challenge website. [Online]. Available:

https://sites.google.com/site/nationalunderwaterrobotics/

[11] (2011) ALLTRANSISTORS website[Online] Available :

http://alltransistors.com/transistor.php?transistor=2340


[12] (2013) ELECTRONICS-TUTORIALS website [Online] Available http://www.electronics-

tutorials.ws/transistor/tran_7.html

[13] (2010) ROV Program Team Manual Under Water Robotics website [Online] Available:

http://www.marinetech.org/files/marine/files/MIROV2MANUAL.pdf

[14] (2008) Remotely Operated Vehicle Operations and Procedures Manual [Online] Available:

http://www.uncw.edu/nurc/

[15] (2010) M.A.T.E ROV competition [Online] Available: http://substack.net/doc/rov-2010-tech-

report.pdf

[16] (2011) Implementation of Underwater ROV as Coastal Surveillance Modules [Online] Available:

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2178084

[17] http://www.marinetech.org/nine_degrees/expedition.html?phase=log&date=942912000&base=expo94

2864462&picnum=0

[18] Douglas J, Gasiorek J, Swaffield J, ―Fluid Mechanics‖3rdEdition Longman Group Limited, Reprinted

1996

[19] Given, D. ―ROV Review‖(5thEdition) 1993-1994 ISBN 0-9623145-3-6

[20] Peter P, Chris L, Dainis N, ―Dalhousie University ROV Project ‘Liquid Death’ ‖ [Online] May 21,

2005. [Cited: December 1, 2008.]

www.optics.rochester.edu/workgroups/agrawal/publications/papers/paper_2005_05.pdf.

[21] David Small Wood ―A new Remotely Operated Underwater Vehicle for Dynamics and Control

Research‖ [Online] [Cited: September 19,1999 ]11th

international symposium on Unmanned

Untethered Submersible Technology , Durhum NH , September 19 1999


APPENDIX

Code to Run the Remote Module

char uart_rd;

char message1[] = "Temp.:-";

char message2[] = "Obstacle ";

char message3[] = "No Obstacle";

char *tempC = "000.0"; // Variables to store temperature values

unsigned long tempinC;

unsigned long temp_value;

void Display_Temperature() {

temp_value = ADC_Read(0);

temp_value = temp_value*244;

tempinC = temp_value/10; // convert Temp to characters

if (tempinC/10000)

tempC[0] = tempinC/10000 + 48;

else tempC[0] = ' ';

tempC[1] = (tempinC/1000)%10 + 48; // Extract tens digit

tempC[2] = (tempinC/100)%10 + 48; // convert temp_fraction to characters

tempC[4] = (tempinC/10)%10 + 48; // Extract tens digit

Lcd_Out(1, 8, tempC);

Delay_ms(500); // print temperature on LCD

}

void main() { // Disable analog comparators

ADCON0=0b10000101;

ADCON1=0b01000001;

CMCON = 7; // Turn off comparators

INTCON = 0;

TRISA = 0b111111; // RA4/T0CKI input, RA5 is I/P only

PORTA = 0b000000;


TRISE = 0b111;

PORTE = 0b000;

TRISB = 0b00000011;

PORTB = 0b00000000;

TRISC = 0b10011111;

PORTC = 0b00000000;

TRISD = 0b11111111;

PORTD = 0b00000000;

UART1_Init(1200); // Initialize UART module at 9600 bps

Delay_ms(1000); // Wait for UART module to stabilize

//UART1_Write_Text("Start");

Lcd_Init(); // Initialize LCD

Lcd_Cmd(_LCD_CLEAR); // Clear display

Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor off


Lcd_Out(1,1,message1); // Write message1 in 1st row

Lcd_Chr(1,15,223); // Print degree character

// different LCD displays have different char code for degree

// if you see greek alpha letter try typing 178 instead of 223

Lcd_Chr(1,16,'C');

while (1) { // Endless loop

Display_Temperature();

delay_ms(100);

if (UART1_Data_Ready()) { // If data is received,

uart_rd = UART1_Read(); // read the received data,

}

if(RB0_bit)

{

UART1_Write_Text("G");

}

if(RB1_bit)

{

UART1_Write_Text("D");


}

if(RD7_bit)

{

UART1_Write_Text("F");

}

if(RD6_bit==1)

{

UART1_Write_Text("E");

}

if(RD5_bit==1)

{

UART1_Write_Text("J");

}

if(RD4_bit==1)

{

UART1_Write_Text("I");

}

if(RD3_bit==1)

{

UART1_Write_Text("B");

}

if(RD2_bit==1)

{

UART1_Write_Text("A");

}

if(RD1_bit==1)

{

UART1_Write_Text("N");

}

if(RD0_bit==1)

{

UART1_Write_Text("O");

}


if(RC0_bit==1)

{

UART1_Write_Text("H");

}

if(RC1_bit==1)

{

UART1_Write_Text("M");

}

if(RC2_bit==1)

{

UART1_Write_Text("L");

}

if(RC3_bit==1)

{

UART1_Write_Text("K");

}

if(RC4_bit==1)

{

UART1_Write_Text("C");

}

if(uart_rd==65){

Lcd_Out(2,1,message2);

//delay_ms(500);

}

if(uart_rd==66){

Lcd_Out(2,1,message3);

//delay_ms(500);

}

// Delay_ms(100); // Wait for UART module to stabilize

}

}


Code to Run Host Module

unsigned short current_duty;

char uart_rd;

m1on()

{

rb7_bit=1;

delay_ms(8000);

rb7_bit=0;

}

lighton()

{

rb6_bit=1;

//Delay_ms(100);

}

lightoff()

{

rb6_bit=0;

//Delay_ms(100);

}

m2up()

{

rb4_bit=0;

rb5_bit=0;

delay_ms(40);

rb4_bit=1;

rb5_bit=0;

}

m2off()

{

rb4_bit=0;

rb5_bit=0;


//Delay_ms(100);

}

m2down()

{

rb4_bit=0;

rb5_bit=0;

delay_ms(40);

rb4_bit=0;

rb5_bit=1;

}

m3up()

{

rb3_bit=0;

rb2_bit=0;

delay_ms(40);

rb3_bit=1;

rb2_bit=0;

}

m3off()

{

rb3_bit=0;

rb2_bit=0;

//Delay_ms(100);

}

m3down()

{

rb3_bit=0;

rb2_bit=0;

delay_ms(40);

rb3_bit=0;

rb2_bit=1;

}

m4up()


{

rb0_bit=0;

rb1_bit=0;

delay_ms(40);

rb0_bit=1;

rb1_bit=0;

}

m4off()

{

rb0_bit=0;

rb1_bit=0;

//Delay_ms(100);

}

m4down()

{

rb0_bit=0;

rb1_bit=0;

delay_ms(40);

rb0_bit=0;

rb1_bit=1;

}

moff()

{

PORTB = 0b00000000;

//Delay_ms(100);

}

void m5up()

{

current_duty = current_duty + 15;

PWM1_Set_Duty(current_duty);

Delay_ms(40);

}

void m5down()


{

current_duty = current_duty - 15;


Delay_ms(40);

}

void main() {

ADCON1 = 7; // all ADC pins to digital I/O

CMCON = 7; // Turn off comparators

TRISA = 0b000001; // RA4/T0CKI input, RA5 is I/P only

PORTA = 0b000000;

TRISE = 0b000;

PORTE = 0b000;

TRISB = 0b00000000;

PORTB = 0b00000000;

TRISC = 0b10000000;

PORTC = 0b00000000;

TRISD = 0b00000000;

PORTD = 0b00000000;

UART1_Init(1200); // Initialize UART module at 9600 bps


PWM1_Init(1000); // Initialize PWM1 module at 5KHz

Delay_ms(1000);

current_duty = 0;

PWM1_Start();


while(1)

{

if (UART1_Data_Ready()) { // If data is received,

uart_rd = UART1_Read(); // read the received data,

}

if(uart_rd==66){

m1on();


}

if(uart_rd==68){

lighton();

}

if(uart_rd==67){

lightoff();

}

if(uart_rd==71){

m2up();

}

if(uart_rd==70){

m2off();

}

if(uart_rd==69){

m2down();

}

if(uart_rd==74){

m3up();

}

if(uart_rd==73){

m3off();

}

if(uart_rd==72){

m3down();

}

if(uart_rd==77){

m4up();

}

if(uart_rd==76){

m4off();

}

if(uart_rd==75){

m4down();


}

if(uart_rd==79 && current_duty <255){

m5up();

}

if(uart_rd==78 && current_duty > 0){

m5down();

}

if(uart_rd==65){

moff();

}

if(RA0_bit)

{

UART1_Write_Text("A");

delay_ms(40);

}

if(RA0_bit == 0)

{

UART1_Write_Text("B");

delay_ms(40);

uart_rd = 0;

} } }

design and implementation of remotely operated underwater vehicle using microcontroller

Documents

abu id

biswas prasun id

meraj mustakim id

operated underwater

degree of bachelor

miraj mustakim

partial fulfillment

honorable supervisor