H3O 2014 Technical Report ,Faculty of Engineering at Helwan university

2. 1. Abstract
2. Mechanical Design
2.1 Frame
2.1.1 Design
2.1.2 Materials
2.1.3 Safety Features
2.2 Thrusters
2.2.1 motors & propellers specifications
2.2.2 Design
2.2.3 Motion
2.2.4 Isolation
2.2.5 Bullard Pull Test
2.2.6 Safety Features
2.3 Buoyancy & Stability
2.3.1 Buoyance
2.3.2 Stability
2.4 Gripper
2.4.1 Concept
2.4.2 Safety Features
2.4.3 Pneumatic diagram
2.5 Camera Mechanism
2.5.1 Design
2.5.2 Isolation
3. Electrical Design
3.1 Electrical diagrams
3.2 Isolation
4. Future Improvement
5. Challenges
5.1 Non-Technical
5.2 Technical
6. Budget
7. Reference

3. Team H3O which consists of five members constructs ROV that work on
exploring, documenting, identifying a newly discovered, unknown
shipwreck, scientific applications and removing trash and debris from the
shipwreck and surrounding area.
For performing ;that task we used ROV with 8 thrusters, multi-directional
Cameras, mechanical mechanisms and special software for achieving our
mission.
ROV design allows us to perform tasks in a high speed and performance,
easy maneuverability and very accurate vision.
We worked on achieving our task by concentrating on scientific base rather
than using very expensive components to achieve the value of
“High Performance … Low Cost”
Scientific concentration was not just for achieving low cost ROV; however to
learn everything about ROV world was our main target.
We introduce ourselves as entrepreneurs hoping to be mate chosen team
which performs the task professionally.
Team Members from left
To right:
 Omar Ihap
 Hisham Abdel-Hamid
 Hossam Younis
 Abdallah Basem
 Hesham Osman

4. 2.1 Frame
2.1.1 Design
On designing our ROV we considered
it to be open source to have applicable
for adding any additional parts.
ROV Dimensions:
 Length: 46.20 cm
 Width: 40.60 cm
 Height: 40 cm
We have chosen these dimensions to suit our components sizes.
As the skin friction drag will be related to the width and height and for that
both of them are small with respect to length.
2.1.2 Material
Besides pipes are most suited for structure as its cylindrical shape has low drag
We choose aluminum angles to help us in fixing our components also it has
small area which reduces drag.

5. 2.1.3 Safety Features
For achieving the highest level of safety we worked on three main
points for our frame: 1. Smoothing sharp edges
2. Caution taps on critical areas
3. Handles embedded into the frame
2.2 Thrusters
2.2.1 Motors & Propellers Specifications
 Motors:
 6 motors(48v-DC-1800rpm-full load
Current “4Amp”)
 2 motors (48v-DC-2000rpm-full load
Current “4.4 Amp”
 Propellers:
 3 Blade-50mm “diameter”- 42 pitch
2.2.1 Design
8 thrusters “4 Up & Down” – “4 forward
& Backward”
As a result of our calculations of thrusters
forces this number of thrusters is the
most suited for our performance.
And because of the difference in thruster forces
in the two directions we put each two thrusters “having
one function” in opposite directions to achieve equal-total force in the opposite
directions.

6. 2.2.2 Motion
Motor Up Down Forward Backward
Twisting
Left
Twisting
Right
1
F 
B 
2
F 
B 
3
F 
B 
4
F 
B 
5
F  
B  
6
F  
B  
7
F  
B  
8
F  
B  
Note:
 For moving left in curve we use motor 5 forward and motor 8 backward.
 For moving right in curve use motor 6 forward and motor 7 backward.

7. 2.2.3 Isolation
We used glance, O-rings, plastic tubes and Artylon to isolate our motors and
that was tested under 8 bar pressure.
2.2.4 Bullard pole test
A test to measure the force of our thrusters practically which helped us to determine
number of thrusters required, also it effects on our design.
2.2.5 Safety Features
In order to achieve safety we used to main methods which are:
1. Caution Tapes: we used them to highlight critical areas in ROV and to help the diver
to have safe interaction with it under water if there.
2. Nozzles: used for protection of blades from any external effect and to protect divers
form it.
On the other hand it gives ROV more power in thrust.
2.3 Buoyancy & Stability

8. 2.3.1 Buoyancy
According to Archimedes’ principle, anybody partially or totally immersed in a fluid is
buoyed up by a force equal to the weight of the displaced fluid. If somehow one could
remove the body and instantly fill the resulting cavity with fluid identical to that
surrounding it, no motion would take place, the body weight would exactly equal that
of the displaced fluid.
We calculated the desired additional buoyancy which makes the ROV weight inside
water zero where any force applied on it could move it.
Additional Buoyancy = Total Buoyancy – Other ROV Components
Required Buoyancy
Total Buoyancy Required: We calculated it from the relation:
FB = FG
P x v x g = m x g
Where;
P : Density of water
V: Total Volume of ROV
G: Gravity
M: total mass of ROV

9. 2.3.2 Stability
The resultant of all of the weight forces on this displaced fluid is centered at a point
within the body termed the ‘center of gravity’ (CG).This is the sum of all the
gravitational forces acting upon the body by gravity. The resultant of the buoyant
forces countering the gravitational pull acting upward through the CG of the displaced
fluid is termed the ‘center of buoyancy’ (CB).
The two forces must pass through the same vertical axis otherwise the body is not in
equilibrium and will rotate so as to bring then into vertical alignment. The body is then
said to be in static equilibrium.
COM (X, Y, Z) = (M1*X1 + M2*X2 + M3*X3 + …….) / (M1 + M2 + M3…….)
COB (X, Y, Z) = (Fb1*X1 + Fb2*X2 + Fb3*X3 + …….) / (Fb1 + Fb2 + Fb3…….)
BG is defined as: it is the space between CB and CG.
Increasing BG will leads to increasing righting moment which helps in making ROV
more stable.
Also we consider the arm of twisting moment to be tall as possible to provide high
dynamic stability for the ROV.

10. 2.4 Gripper
2.4.1 Concept
It is a mechanical mechanism which used to grab and hold objects in order to take a
sample of it or to rescue it or any other tasks.
It has a lot of shapes and each one of them is used for a special task and with a certain
force.
A lot of systems could be used in order to move grippers’ mechanism one of them is
using motors and another one is pneumatic system which we decided to use in our ROV
as it gives us accurate performance and accurate force besides its very advanced
option of having a highly safe isolation.

11. 2.4.2 Safety Features
1. Caution Tapes
2. Smooth Edges
2.4.3 pneumatic diagram

12. 2.5 Camera Mechanism
2.5.1 Design
A perfect view is a must for the ROV to perform the task. So that we decide to make
mechanisms for ROV cameras to allow a perfect – wide view.
Before deciding what the cameras mechanisms are, we put our scenario of performing
the task to know the optimum way.
A front cam with three dimension moving allowance and a side cam with two
dimensions moving allowance was the best.
2.5.2 Isolation
The isolation of cameras and its mechanisms was by the same concept of thruster
motors isolation .. (Glands, o-rings, plastic pipes, Aclyric and Artylon)

13. 3.1 Electrical Diagrams

14. 3.2 Isolation
A new system of isolation was used for electrical components isolation. We use PVC
pipe with two end caps of Artylon from both sides of pipe providing pressure on the o-rings
with three tall bolts and nuts. Also (glands and plastic pipes) are used.
We tested our system under pressure of 8 bars to ensure its performance.

15. No one stay on its level and all people deserve to rich a higher point of improvement
and that is the most important thing which takes our think.
On the way to achieve this target we are working on all branches that help to achieve
improvement:
1. Improving our control:
We are working on it in order to reach the highest way of control of all parts of our
ROV in order to enhance its performance so we are studying automatic control
methods like Arduino, PLC and micro controller which will make the difference in
improving our ROV performance.
2. Freezing fly system:
On the way to enhance our ROV motion we thought of that system which will help us
in having more control on our motors motion and performance.
3. Study:
To be will qualified for reach our improvements we must study theories and rules which
make us achieve that task so we are now working on more than learning programs
with our doctors in faculty to prepare and enhance our technical knowledge.
4. Thoughts Publicity:
One of targets we are aiming to is to increase publicity of ROV world and its formation
through not only engineering student’s community but also school students in order to
prepare a generation able to form an ROV that performs tasks under water
professionally.
5. Marketing Strategies:
To achieve our target in forming world class ROVs we have to perform marketing
strategies that make market believe in our thoughts and funds our work which will
helps us in achieving our target in a very small period of time.

16. 5.1 Non – technical challenges
Old coute says that “Road of success is not full of flowers” and for that we believe that
if we want to success and reach our goals we have to work hardly for that.
Our failure in ROV 2013 competition was our first step on the road of success as we
decided to have much better performance in 2014 competition and not only
performance but also win the title and represent Egypt in international competition.
For this target we start work on solving failure we faced in 2013 competition a week
after the end of the regional competitions and a new problem has faced us as number
of participants and members working on achieving that target were so small so we
have decided to publish more our thoughts between our colleagues.
Robotics crew helped us in that way by organizing very huge event in both faculties of
engineering Helwan Uni. And faculty of engineering Mattareya Branch.
The publicity does not stop on community of engineering students only but also we
spread our targets and thoughts in market by having the chance of exhibiting our
work in Cairo ICT exhibition which supported our targets a lot.
We also have participated in YIA competition which is powered Nahdet ElMahrousa
“one of the well-known foundations” and we presented their work.
Events that we participated in helped us more to increase number of students
interested in ROV world and helped us in reaching a lot of targets that we were
dreaming to reach once.
In Regional Competition this year we are working to prove to all people that our
failure last year was the start of our success.

17. 5.2 Technical challenges
face a lot of technical challenges during working on the MATE ROV competition
4. We can talk about isolation as an example. It was hard to make that system of
We
201
isolation.
We begin with wax passing through silicon and pipes. We get some information from
every try and finally we formed our system of isolation and also by the help of research.

18. 6. Budget.
Categories Component Price /each L.E N.O Items Total Price L.E
Mechanical DC Motors* 40 8 320
Small DC
Motors
30 3 90
Oil Seals 5 15 75
Coupling 5 8 40
Screws and
Nuts
- - 100
Aluminum Rods 75 2 150
Artylon and
Machining
- - 1800
PVC - - 130
Propellers* 60 8 480
Pneumatic
Valves*
80 2 160
Pneumatic
pistons*
50 4 200
Pneumatic
Accessories
- - 50
Pneumatic
hoses
- - 100
O-Rings - - 200
Acrylic sheet - - 50
Electrical Electrical
Wires
- - 1000
Joystick - - 30
Electrical
Glands
- - 100
DC-DC
converter
- - 210
Relays* 6 50 300
Others Team T-shirts* 5 40 200
Wasted Money - - 785
Total 6000
Note: “*” Is donated by Robotics Student Organization –Helwan University

19. 7. References.
1)ROV Manual ISBN: 978-0-7506-8148-3 Author: Robert D. Chris
2)HOMEBUILT ROVs http://homebuiltrovs.com
3)Tecnadyne http://Tecnadyne.wordpress.com
4)Robotics Channel http://youtube.com/theroboticsorg
5) Robotics Page http://fb.com/theroboticsorg
5)MATE Center http://www.marinetech.org
#Moral_thanks
For Eng.Mohamed Abd elrahman.
Eng.Rmay ebeid
Eng.Abd Elhameed Saleh.
Eng.Abd Elrahman Ashraf.
Eng.Essam Alaa.
#Robotics_Student_Organization
#H3O