Design and Construction of
Remotely Operated Underwater Vehicle
Submit By;
Kasun Hasantha Kandearachchi
Gayashan De Alwis
Contents
1
Details of Team Members............................................................................................................. 3
2
Executive summary of the project ............................................................................................... 4
3
Report in Detail ............................................................................................................................. 5
3.1
Introduction ............................................................................................................................. 5
3.2
Objectives ............................................................................................................................... 5
3.3
Description of the work........................................................................................................... 6
3.3.1
Initial Calculations .......................................................................................................... 6
3.3.2
Dynamic Stability ......................................................................................................... 10
3.3.3
Tether Effects ................................................................................................................ 18
3.3.4
Vehicle Control ............................................................................................................. 19
3.3.5
Construction of the MAGURA II ................................................................................. 20
3.3.6
Designing Electrical and Electronic Schematics........................................................... 21
3.4
Material Selection ................................................................................................................. 23
3.4.1
Initial Material Selection ............................................................................................... 23
3.4.2
Finding Suitable Suppliers ............................................................................................ 23
3.4.3
Purchasing ..................................................................................................................... 23
3.5
Hull Construction .................................................................................................................. 24
3.5.1
Manufacturing Process .................................................................................................. 24
3.6
Manufacturing Mechanical accessories ................................................................................ 25
3.7
Final assembling ................................................................................................................... 25
3.8
Discussion results and observations ...................................................................................... 26
3.9
Other considerable facts ........................................................................................................ 27
4
Comments Regarding Project Implementation........................................................................ 28
5
Comments of the Head of the Department/ Institution regarding progress .......................... 28
6
Recommendation of the Dean of the Faculty and Vice Chancellor or Head of the Institution
28
2
1 Details of Team Members
Team Members –
1. Gayashan De Alwis ( Team Leader )
2. Kasun Hasantha Kandearachchi
Place where the project was carried out
3
2 Executive summary of the project
Constructing the ROV was a challenging task yet we undertake the challenge and able to finish
the task completely. Manufacturing processes was carried out in the three parallel processes.
Mechanical, electrical & Electronics parts where manufactured separately & tested individually
to maintain the overall quality control.
Once the prototype was manufactured complete ROV was tested continuously to test the
mechanical, electrical & electronic systems. During the testing we find many challenges like
finding suitable pool because most of the pool owner’s doesn’t like lend their pool for testing.
In the initial testing we have observed a design fault witch have increase the buoyancy of the
hull & it causes the ROV to float all the time. We have rectify this matter by removing the form
open that portion to the water so that it will reduce the buoyancy of the ROV. Even though this
processes rectify the problem we have add additional 2.8kg of balancing weight to bring the
ROV to the neutral buoyancy point.
We are really happy with the performance of the prototype continue our testing to optimized
the design.
4
3 Report in Detail
3.1 Introduction
Remotely operated underwater vehicles, commonly referred to as ROVs are used for a
variety of underwater operations particularly in situations when it is not practically possible
or when it is unsafe for a person to go and perform a task personally. ROVs, unlike remotely
controlled vehicles used on land which are basically radio controlled, are connected to a
mother vessel through a cable (umbilical cord) and are operated by a person sitting in the
mother vessel. Signals, power and data are transmitted through the cable. In Sri Lanka there
are no records of the use of ROVs by any institution/organization for exploration or
research. The high cost of foreign manufactured ROVs could be the main reason for the
absence of these vessels in Sri Lanka. Sri Lanka being an island can benefit immensely if
ROVs can be made available at an affordable cost. They can be used for seabed exploration
and research work that can lead to healthy financial returns. It is therefore clear that there
is a need for low cost ROVs in Sri Lanka.
A variety of designs are used in ROVs, but basically the vessel is designed to be neutrally
buoyant and are operated by electric motor driven equipment for maneuvering underwater.
The cost of a ROVs used for normal researching purposes are approximately 5 Million
rupees. Generally ROVs are designed to perform a variety of functions. A ROV designed
for research and seabed exploration may have facilities for sending live pictures from
underwater, collect samples from seabed, send data (temperature, depth, current etc.).
ROVs are also designed and equipped to perform specific underwater operations. As an
initial step it is decided to design and build a ROV that is fitted with a video camera and
temperature sensors and capable of transmitting underwater pictures and temperature data.
3.2 Objectives



Design Inspection Class ROV that can be controlled from a mother vessel with
power, data and signals transmitted through a cable link with facilities for providing
underwater pictures and temperature data which could be used for research studies
and also for preliminary underwater exploration work.
Construct the vessel using as far as possible locally available low cost material.
Test operate the ROV
5
3.3 Description of the work
3.3.1 Initial Calculations
3.3.1.1 Hydrostatic equilibrium
Any ROV has movement about six degrees of freedom. Three translations (surge, heave, and
sway along the longitudinal, vertical, and transverse (lateral) axes respectively) and three
rotations (roll, yaw, and pitch about these same respective axes). This section will address the
interaction between vehicle static and dynamic stability and these degrees of freedom.
Figure 1 Movement of an underwater vehicle
Magura II ROV is normally equipped to surge, heave and yaw. The system is constructed with
a high center of buoyancy and a low center of gravity to give the camera platform maximum
stability about the longitudinal and lateral axes.
Figure 2 Position of center of gravity and center of buoyancy
6

Weight distribution for components
Number
1
2
3
4
5
6
7

Component
Hull
Main frame
Camera encloser with components
Batteries and electronics
Thrusters
Mounting brackets
External balancing weight
Total mass
Weight (kg)
16.72kg
1.8kg
1.1kg
1.5 kg
1.18 kg
2.4kg
2.8 kg
27.5kg
Neutral buoyancy equation for the ROV
Total weight of ROV = Total buoyancy force of fully submerged ROV
Therefore
Total buoyancy force of MAGURA II = 27.5 𝑥 9.8 = 269.5 𝑁
3.3.1.2 Transverse Stability
According to Archimedes’ principle, any body partially or totally immersed in a fluid is buoyed
up by a force equal to the weight of the displaced fluid. That is the main principle we use here.
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).There is one variable in the stability equation that is valid for surface vessels
with non-wetted area that is not considered for submerged vehicles. The point where the CB
intersects the hull centerline is termed the metacenter and its distance from the CG is termed
the metacentric height (usually written as GM). For ROV considerations, all operations are
with the vehicle submerged and ballasted very close to neutral buoyancy, making only the
separation of the CB and the CG the applicable reference metric for horizontal stability.
The equilibrium attitude of the buoyant body floating in calm water is determined solely by
interaction between the weight of the body, acting downward through its CG, and the resultant
of the buoyant forces, which is equal in magnitude to the weight of the body and acts upward
through the CB of the displaced water. If these two forces do not pass through the same vertical
axis, the body is not in equilibrium, and will rotate so as to bring them into vertical alignment.
The body is then said to be in static equilibrium.
7
If the moment of the buoyancy (or any other) force acts to rotate the vehicle about its CG
opposite to the direction of inclination, it is called a righting moment; If in the same direction,
it is called a heeling moment.
Righting moment of a ROV
Location of the CG (reference to mid plane) = 180𝑚𝑚 from the bottom
Location of the CB (reference to mid plane) = 350𝑚𝑚 from the bottom
Total weight =
269.5𝑘𝑔
BG = 350 − 180 = 170𝑚𝑚
Righting moment = 269.5 × 9.8 × 170 sin 𝜃 × 10−6 = 0.449 sin 𝜃
8
3.3.1.3 Water Density and Buoyancy
It is conventional operating procedure to have vehicles positively buoyant when operating to
ensure they will return to the surface if a power failure occurs. This positive buoyancy would
be in the range of 450 g for small ROVs
Pure water has a specific gravity of 1.00 at maximum density temperature of about 4◦C
(approximately 39◦F). Above 4◦C, water density decreases due to molecular agitation. Below
4◦C, ice crystals begin to forming the lattice structure.
Our ROV designed to float neutrally in pure water. Therefore we have to add additional weight
to the vehicle to bring it to neutral point.
Sea water density – 1030𝑘𝑔/𝑚3
Pure water density – 1000𝑘𝑔/𝑚3
Additional weight to float in sea water - 2.8 × 9.8 = 27.44𝑁
9
3.3.2 Dynamic Stability
3.3.2.1 Thrusters
We have used Blue robotics T100 underwater thruster to the design. T100 Thruster is a patentpending underwater thruster designed specifically for marine robotics. It’s high performing
with over 22 N of thrust and durable enough for use in the open ocean at great depths. A variety
of mounting options, simple control, and a low price tag make it the perfect thruster to choose
for our design.
The T100 is basically a brushless electric motor. The big difference is that this motor is
purpose-built for use in the ocean and was designed specifically for use on ROVs, AUVs, and
robotic surface vehicles. The T100 is made of high-strength, UV resistant polycarbonate
injection molded plastic. The core of the motor is sealed and protected with an epoxy coating
and it uses high-performance plastic bearings in place of steel bearings that rust in saltwater.
Everything that isn’t plastic is either aluminum or high-quality stainless steel that doesn’t
corrode.
Blue robotics T100 underwater thruster
Specification Table of T100
Performance
Kgf
N
Maximum Forward Thrust
2.36
23.14
Maximum Reverse Thrust
Minimum Thrust
1.85
18.14
0.10
Rotational Speed
0.01
300-4200 rev/min
10
Electrical
Operating Voltage
Max Current
Max Power
6-16 v
12.5A
135 W
Physical
Diameter
Weight in Air (with 1m cable)
Weight in Water (with 1m
cable)
100 mm
295 g
3.9 in
0.65 lb
120 g
0.26 lb
Propeller Diameter
76 mm
M3 x 0.5
19 mm
1.0 m
6.3 mm
3.0 in
Mounting Hole Threads
Mounting Hole Spacing
Cable Length
Cable Diameter
0.75 in
39 in
0.25 in
,/.
11
12
3.3.2.2 Thruster Placement and stability
External forces, however, do act upon the vehicle when it is in the water, which can produce
apparent reductions in stability. For example, the force of the vertical thruster when thrusting
down appears to the vehicle as an added weight high on the vehicle and, in turn, makes the
center of gravity appear to rise, which destabilizes the vehicle in pitch and roll. The center of
buoyancy and center of gravity can be calculated by taking moments about some arbitrarily
selected point.
Other design characteristics also affect the stability of the vehicle along the varying axis. The
so-called ‘aspect ratio’ (total mean length of the vehicle versus total mean width of the vehicle)
will determine the vehicle’s hull stability, as will thruster placement.
Aspect ratio for MAGURA ii = 640 / 370 = 1.72
Placement of side thrusters
Side thruster helps to move the ROV along the y- axis. Location of the each side thruster is
220mm from the longitudinal mid plane.
13
Location of the side thrusters are not parallel to the vertical axis. Each thruster create an 15°
angle towards the hull from the vertical axis.
Moment of side thruster around
Longitudinal mid plane = 𝑑 × 𝑇 cos 15°
= 220 × 10−3 × 23.14 cos 15° = 4.917 𝑁𝑚
Moment creates by both side thrusters take same value and opposite to each other. Therefore
these two moments get cancel.
Vertical component of side thrusters ( 𝑇 cos 15° ) moves the ROV up and down. Horizontal component
of the side thrusters ( sin 15°) helps ROV to stay stable around the Z- axis, while moving along the
vertical axis.
15°
𝑇 = 23.14𝑁
Vertical thrust component = 𝑇 cos 15° = 23.14 × cos 15° = 22.35𝑁
Horizontal thrust component = 𝑇 sin 15° = 23.14 × sin 15° = 5.98𝑁


Total diving thrust = 22.35 × 2 = 44.7𝑁
Total submerge thrust = ROV using reverse thrust of the T-100 thruster to submerge.
therefore maximum submerge thrust for a each thruster will be 18.14 × cos 15°
Maximum submerge thrust = 18.14 × cos 15° × 2 = 35.04𝑁
14
Placement of stern thrusters
Stern thrusters using to move the ROV forward and backward. Also it is using to rotate ROV
around the y – axis. Rotation of the ROV establishing by changing force direction of a one
stern thruster.
Location of the each stern thruster is 280mm from the vertical mid plane and 75mm from the
longitudinal mid plane. Each of stern thrusters creates 30° of angle with the horizontal axis.
This angle helps ROV to create some dynamic stability while it moving forward and
backwards. Also it creates good rotational moment for the vehicle around the y-axis (or CG)

For the forward thrust
Horizontal thrust component = 𝑇 cos 30° = 23.14 × cos 30° = 20.03𝑁
Vertical thrust component = 𝑇 sin 30° = 23.14 × sin 30° = 11.57𝑁

For the reverse thrust
Horizontal thrust component = 𝑇 cos 30° = 18.14 × cos 30° = 15.7𝑁
Vertical thrust component = 𝑇 sin 30° = 18.14 × sin 30° = 9.07𝑁



Total forward thrust = 20.03 × 2 = 40.06 𝑁
Total reverse thrust = 15.7 × 2 = 31.4 𝑁
Rotational moment around the CG
= [23.14 × (75 cos 30° + 280 sin 30° )] + [18.14 × (75 cos 30° + 280 sin 30° )]
= 8460.4 𝑁𝑚𝑚 = 8.46 𝑁𝑚
15
3.3.2.3 Point of Thrust/Drag
Another critical variable in the vehicle control equation is the joint effect of both the point of
net thrust (about the various axis) and the point of effective total drag.
There are two basic types of drag with regard to all bodies:
1. Skin friction drag
Friction drag is created by the frictional forces acting between the skin and the water. The
viscous shear drag of water flowing tangentially over the surface of the skin contributes to the
resistance of the vehicle. Essentially this is related to the exposed surface area and the velocities
over the skin. Hence, for a given volume of vehicle hull, it is desirable to reduce the surface
area as much as possible.
An important factor determining the condition of flow about a body and the relative effect of
fluid viscosity is the ‘Reynolds number’. The Reynolds number can be calculated by the
following formula
𝑅𝑒 =
𝜌𝑉𝑙 𝑉𝑙
=
𝑚
𝑣
𝜌 = density of sea water = 1030 𝑘𝑔/𝑚3
𝑉 = velocity of flow. = 1𝑚𝑠 −1
𝑚 = coefficient of viscosity.
𝑣 = m/p=kinematic viscosity 9 × 10−4
𝑙 = a characteristic length of the body = 560𝑚𝑚
Velocity of flow is equal to design velocity. This value can be taken as 1𝑚𝑠 −1
𝑅𝑒 =
𝑉𝑙
1 × 560 × 10−3
=
= 622.22
𝑣
9 × 10−4
This value is between the 10 and 2000. Therefore flow passing on the ROV is laminar flow.
Skin friction drag of the ROV takes a low value due to the laminar flow.
16
2. Form drag
A second effect of the viscous action of the vehicle’s hull is to reduce the pressure recovery
associated with non-viscous flow over a body in motion. Form drag is created as the water is
moved outward to make room for the body and is a function of cross-sectional area and shape.
ROV thrusters must produce enough thrust to overcome the drag produced by the tether and
the vehicle. The drag on the ROV system is a measurable quantity derived by hydrodynamic
factors that include both vehicle and tether drag. The drag produced by the ROV is based upon
the following formula:
𝑉𝑒ℎ𝑖𝑐𝑎𝑙 𝑑𝑟𝑎𝑔 =
1
× 𝜎𝐴𝑉 2 𝐶𝑑
2
𝜎 = 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑠𝑒𝑎 𝑤𝑎𝑡𝑒𝑟
𝐴 = 𝐶𝑜𝑟𝑠𝑠 𝑠𝑒𝑐𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑟𝑒𝑎 𝑖𝑛𝑓𝑟𝑜𝑛𝑡 𝑜𝑓 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 = 380𝑚𝑚 × 160𝑚𝑚
𝑉 = 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦
𝐶𝑑 = 𝑑𝑟𝑎𝑔 𝑐𝑜𝑒𝑓𝑓𝑖𝑐𝑖𝑒𝑛𝑡 (0.8 − 1)
The maximum vehicle drag in 1𝑚𝑠 −1 speed can be found by as follows,
𝑉𝑒ℎ𝑖𝑐𝑎𝑙 𝑑𝑟𝑎𝑔 =
1
× 1030 × 380 × 160 × 10−6 × 1 × 1
2
= 31.312𝑁
17
3.3.3 Tether Effects
This particular vehicle had a tether pull point significantly above the line of thrust (100mm) ,
resulting in a ‘bow up’ turning moment. As the speed ramped up, with little tether in the water,
the vehicle was still able to maintain control about the vertical plane by counteracting the ‘bow
up’ tendency with vertical thrust-down. However, at a constant speed with the tether being
lengthened, the tether drag produced an increasingly higher tether turning moment, eventually
overpowering the vertical thruster and shooting the submersible to the surface in an
uncontrolled
Increase of the tether drag with the depth
Tether of the MAGURA II consist with two CAT 5 cables and one double core power
transmission cable. One CAT 5 cable transmit control signals and other one connected to main
camera of the ROV. Power cable connected to 15v power source in on shore end. It helps to
charge internal battery through a charge control unit.
Length of the tether = 55𝑚
18
3.3.4 Vehicle Control
Vehicle control archive by PS2 bluetooth joystick. Joystick position versus thruster activation
on a four-thruster configuration as follows.
19
3.3.5 Construction of the MAGURA II
This is the brief explanation of important part of the MAGURA II.
No.
Part
Description
1
Main Hull
2
Camera Encloser
Constructed by fiberglass reinforced plastic.
Provide required upthrust for ROV
Hold the camera and water tide it
3
Camera
5.0 MP camera
4
Flash Lights
10W LED chip lights x 2
5
External Weight
6
Main Frame
Made by stainless steel (304). 2.8kg in weight.
Keep the ROV in neural buoyancy position
Hold The ROV
7
Stern Thrusters
Help to move horizontal directions
8
Middle Thrusters
Help to move vertical directions
20
3.3.6 Designing Electrical and Electronic Schematics
Second model of the ROV consist of advanced electrical controlling as well as electronic
system. Basic electrical specification of the ROV can be categorized as follows.
1.
2.
3.
4.
Operating Voltage :- 12VDC
Charging Voltage :- 14.4-14.8VDC
Supply Voltage :- 24VDC
Battery Type :- 12VDC Lead acid battery
Electrical system can be divided system can be divided in to two system.



Electrical transmission system
Electrical distribution system.
Charging system.
Electrical transmission system consist with two core 1.75mm electrical cable witch will
transmit the power current from the surface to the ROV. Since the main power is drawn from
a battery it will help to reduce the cable diameter witch help to reduce the drag force due to the
thither. Since cable length is 50m voltage drop is significant issue. To eliminate this voltage
drop supply voltage kept to 24V.Seprate buck converter then used to convert the voltage to
charging voltage.
Electrical distribution system is responsible for powering the axillary parts of the electronics.
Voltage ratings of the auxiliary parts are as follows.
1.
2.
3.
4.
Brushless motor ESC :- 12VDC
Observation camera :- 12VDC
Vision system :- 12VDC
Tilting servo motor :- 7VDC
Distribution system capable of delivering smooth voltage flow during the operation.
Distribution system is equipped with numbers of LM 2596 adjustable voltage regulators to
regulate the voltage according to the required voltage. LM 2596 has the wide range of 1.23V to 30V
voltage resolution witch is within the operating voltage.
Charging system is used to provide smooth charging, during the discharging of the battery .LM
317 adjustable voltage regulator used to control the charging voltage. This circuit will
automatically charge the battery until the battery voltage reaches to 14.8V.
Electronics of the ROV has built to modular type to increase the overall efficiency & easy
maintains. Electronics can be categorized as following.
1. Mother Board
2. Power Electronics
3. Electronics Speed Controller
21
Mother board consists of four AT Mega 328PU micro controllers to provide more
flexible control to the operation. Each microcontroller is defied according the
function.




Sub 1 - Control the four thrusters of the ROV
Sub 2 – Read the pressure transmitter & transmit the value to the surface
Sub 3 – Control the front flash light intensity
Sub 4 – Control the tilting & panting servo motors.
22
3.4 Material Selection
3.4.1 Initial Material Selection
When selecting material for this project certain points were prioritized
1. Materials which are resistant to rusting
Materials which are resistant to rusting Special priority was given when selecting metallic
material. Mainly because of the frequent contact with water this was considered seriously. So
as solutions materials like brass, 304 stainless steel and aluminum were chosen for this
project
Thus, for nonmetallic elements this doesn’t need a direct consideration. As nonmetallic
materials fiberglass, reinforced plastic was mostly used. Apart of that acrylic and poly
propylene material were also used.
2. Materials which are resistant to water pressure
There are two main parts in this design which needs to be designed to bear the water resistance.
Which is the camera enclose and the intermediate enclose of the hull. The strength of these two
decides the maximum depth the ROV can reach
Maximum surface stress camera encloser can bear Maximum surface stress intermediate encloser of the hull can bear 3. Materials which are cheap and easy to find/obtain
This point was also considered a lot when choosing materials. Mainly due to our main goal of
creating a highly capable underwater vehicle with the minimum amount of project cost it is
compulsory to take the cost of materials as a highly-prioritized consideration.
3.4.2 Finding Suitable Suppliers
Suppliers selected carefully selected after doing deep technical evaluation. All the high end engineering
material suppliers was contacted via internet & Local material suppliers was contacted via email.
3.4.3 Purchasing
For the purchase that is above Rs 5000 three quotation was taken & for the other purchase only
one quotation was taken.
23
3.5 Hull Construction
3.5.1 Manufacturing Process
The hull of the ROV is made with fiberglass (reinforced plastic). The hull consists of two parts.
Which is an outer structure and an intermediate encloser.
The intermediate encloser contains the Central control unit and the battery backup which results
in need of proofing from water getting inside. So the intermediate enclosers walls are made
with a higher thickness level (5mm). This helps it to bear the hydrostatic pressure. These walls
can sustain a maximum pressure of 5.047 bar. Also the total up thrust which the ROV need is
provided by this part. The outer structure is mainly used to hold the equipment and to keep up
with the dynamic balance.
24
3.6 Manufacturing Mechanical accessories
Mechanical accessories are the mounting brackets and assembling supports . All of
mechanical accessories and there manufacturing operations can be listed as bellow.
Item
Raw material
Vertical movement thruster
mounting bracket
Horizontal movement thruster
mounting bracket
Main stand supporters
Head light mounting bracket
Head light housing
Camera encloser mountings 1
2mm Stainless steel (304) sheet
Camera encloser mountings 2
Wire penetrators
5mm Acrylic sheet
Stainless steel (304)
2mm Stainless steel (304) sheet
∅10mm stainless steel rod
Stainless steel (304)
Aluminium
2mm Stainless steel (304) sheet
Manufacturing process
Plasma cutting and TIG
welding
Plasma cutting and TIG
welding
Lath operations
Lath operations
Lath operations
Plasma cutting and TIG
welding
Laser cutting
Lath and arc welding
operations
For every area, which gets contacted with water we have used nut and bolts made of stainless
steel (304) material
3.7 Final assembling
For the final assembling part the main tools we used was the hand drill and the hand grinder.
Here separately crafted parts were assembled. When assembling the main stand and the hull
we had special precautions regarding the alignments. Here to do the assembly the mounting
halls were done using the hand drill.
When finalizing the assembly of wire penetrators and the main hull epoxy glue was added in
between the wire penetrators and main hull. This was done to prevent any leakages. The same
was done between wire and wire penetrators expecting the same results.
25
3.8 Discussion results and observations
Test 1
10th May 2016
The first test run of MAGURA II was done inside an abandoned well which was about 8 meters
deep and had a diameter of 3 meters. Here we prioritized to check the static balance of the
design. From this test we discovered that,



The Hull had been trimmed to a stern side in a certain amount?
Also confirmed that the thrust provided by the side thrusters is not enough for the
vehicle to go into the water.
Facts such as Intensity of the front light in water environment, Horizontal propulsion
thrust and rotational ability are in a good condition.
Test 2
1st June 2016
The second test of MAGURA II was done in a 10m x 6m swimming pool with around 3m of
depth. Here we were able to reduce the hull trim by bringing the total center of gravity by
10mm backwards. We also tried to reduce the up thrust given by the hull by simply adding a
8kg external balance weight on the vertical mid plane of the vehicle.
From the second test we observed that the upward thrust force was a higher amount which
meant that the externally added weight was not enough to withstand or reduce it. We had to
find another solution for that, but it was confirmed out that the vehicle can be easily controlled
with the remote controller
Test 03
3rd October 2016
The third test of the MAGURA II was done in a 15m x 7m swimming pool which had around
5m of depth. The whole hull apartment which was previously made totally sealed had to be
flooded to prevent the total up thrust which is given by it. Apart of that with the help of an
additional weight of 2.8kg we were able to get the vehicle to a state of neutral buoyancy.
After the 3rd test





Vehicle was in neutral buoyancy state successfully
Vehicle trim was in minimum value
Dynamic balancing of the ROV was excellent
Control data communication and sensor feedback was highly successful
Maneuvering of ROV by a remote joystick was successful
26
3.9 Other considerable facts
Objectives achieved to date
Construct the ROV prototype according the initial design
without exceeding the budget.
Output arising from the project
Underwater inspection.
Deviations to the work plan when
compared to the original proposal
None
Whether the work was on schedule
No. had some issues with finishing the project according
to the expected date.
Problems encountered during the
implementation of the project
Finding suitable suppliers, testing.
Proposed follow up action regarding
output
Prototype was accepted by lanka shipping pvt.ltd to
inspect there ship.
Was able to create a introduction video clip that can be
showed to those who are interested in the prototype.
27
4 Comments Regarding Project Implementation
Three key points has been identified as primary modifications that need to be implemented
during the next model.



Robot arm capable of grabbing object that lies in the sea bed.
Fix a container that can collect water samples
Implement high definition video camera
Robot arm is a part that can add a high value to the ROV. During a mission user can use this
arm to gather live samples (rocks, biological objects...Etc.). Materials and the controlling’s will
be need to select and tested carefully to operate this arm in higher depths.
Gathering live sample includes not only the solid objects but also the liquid samples. It is very
important to gather water samples in different depths for further analysis of the water quality.
Vacuumed container with a fixed volume will be used for this to store the liquid.
HD camera is a critical part since it is acting as the eye of the ROV. HD camera with high level
control interface (serial interface) will be implement during the next prototype.
5 Comments of the Head of the Department/ Institution
regarding progress
6 Recommendation of the Dean of the Faculty and Vice
Chancellor or Head of the Institution
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