My Seminar of Remotely Operated Vehicle ( ROV ) 2017 Port Said University , faculty of Engineering , Naval Architecture and Marine Engineering

2. Remotely Operated Vehicle
ROV
Performed by :
Ahmed Bakr Salem Hassan Mohamed Moursy
Supervised by :-
Prof. Dr./ Heba S. El-kilani

3. Table of contents:-
• Chapter (1) Introduction
History , Classification , Service types , Uses
• Chapter (2) Design of ROV
Stability , Drag , Thrust
• Chapter (3) Modelling of ROV
Example (The Admiral II ROV )
• Chapter (4) Case Study
ROV owned by Suez Canal authority (Seabotix LBV150-4)

5. Underwater
Vehicles
Unmanned
Vehicles
ROVs
(tethered)
AUVs
(non-tethered)
Manned
Vehicles
The underwater vehicles:-
▪ They are the vehicles which designed to operate
underwater.

6. What is the ROV ?
A Remotely Operated Vehicle (ROV) is a system that consists of three primary components:-
1. The Submersible
2. The Tether
3. The Control Console

7. Historical background
• The first credited ROV, named POODLE, was
developed by Dimitri Rebikoff in France in 1953.
• That persuaded the US NAVY to interest in an
ROV and take the first real step toward it because
it’s problem which was the recovery of torpedoes
that were lost on the seafloor.

8. • So US Navy developed the Cable-controlled Underwater
Research Vehicle (CURV) with gripping arm in 1961 to
recovery lost torpedoes.
• Also the US Navy developed a first small-size
observation ROVs called SNOOPY, Which contained
sonars and other sensors to search for shipwrecks.

9. 1953 to 1974 ❑ ROV could not shake the market which lock by the manned submersibles
and saturation divers. In 1974, only 20 vehicles had been constructed. with
17 of those only funded by various governments.
1974 to 1989 ❑ The ROV industry grew rapidly. The first ROV conference in 1983 , was
held with the theme “A Technology Whose Time Has Come!”.
❑ 96% of the 350 vehicles produced were funded, constructed, and/or
bought by private industries.
1990s
❑ This period experienced a very large development in ROVs design and a
great achievements to reach a great depths under the water.

10. • The CURV III, operated by the US Navy , reached a depth of 6128 m.
• The Advanced Tethered Vehicle, developed by the Space and Naval Warfare Systems Center,
broke the previous record with a record dive to 6279 m.
• JAMSTEC’s Kaiko ROV at Japan reached the deepest
point in the Mariana Trench 10,909 m (10 km), a record
that can be tied but never exceeded even today.
• With the beginning of the new century, the ROV industry
has seen improvements and remediation of any previous
problems.

11. Classifications
Depth
Rating
Size versus ability
to carry
sensors/tooling
Total
Size
Observation class
(OCROV)
Mid-sized
(MSROV)
Work class
(WCROV)

12. 1) ROV size classifications:-
• This table depicts representative vehicle configurations and power/telemetry requirements.

13. 2) ROV depth rating classification:-
• Generally man and machine capabilities for working within the marine environment fall within the
depth limitations provided in following table.

14. 3) Size versus ability to carry sensors/tooling:-
• The size of ROV needs to
vary to accommodate the
prime mover (thrusters),
tooling, and sensors while
still powering these items
and thrusting/moving the
package.

15. Types of ROV services:-
• The two types of ROV assignments are broadly defined as “contract” and “call-out” work:
1. Contract work involves long-term (greater than 6 months, duration) assignments that
generally involve (and cost justify) integrating the vehicle into the work platform with the
requisite detailed and complicated mobilization.
2. Call-out work involves short-term (less than 6 months) assignments whereby minimal
integration work is performed into the vessel of opportunity due to its limited duration.

16. ROV Uses:-
Fisheries and
AquacultureScience
Inspection
Public
Safety
ConstructionMilitary
Repair and
maintenance
Drill
Support
Seaeye Falcon ROV Inspection for pipeline

17. Advantages Disadvantages
No time constraints Very expensive relative to price of human
divers
Able to cover wide area relative to capacity of
human divers
ROVs are slower to perform tasks comparing
to divers.
More abilities to perform mechanical, inspection
and recording tasks
At water turbidity, ROV thrusters
effectiveness can be limited
Give much information on sea bed topography
and burrow types present
provide limited information on smaller
sediment fauna
mobility allows close-up examination of sea
bed
Often need hard boat to operate

18. Advantages of ROV vs Human Diver:-
❑ ROVs do not get cold, tired, or hungry.
❑ ROVs can spend unlimited time at depth and do not have to deal with decompression.
❑ ROVs can safely perform penetrations and can safely work around HAZMAT (oil,
sewage, etc).
❑ ROVs are not subject to stringent OSHA rules.
❑ Many organizations require the use of two divers. This doubles the cost, makes
scheduling more difficult, and results in a transporting a large amount of equipment.
❑ A ROV can be used in shallow water, contaminated water and any water which affected
by chemical factors hurt the human diver.
❑ While an ROV can be lost or destroyed in extreme situations, loss of life is not a factor.

19. Comparison between ROVs and AUVs:-
Remotely operated vehicle
(ROV)
Autonomous underwater vehicle
(AUV)
Connected to controller console by tether Is programmed and need not tether
Close visual inspection General visual inspection
Accurate inspection Inaccurate inspection
Connected to power source by the tether Limited time due to the power batteries
Can have gripper and various tooling Move at high speed
Open or Closed frame design Closed frame for drag minimization

21. ✓ The body weight would exactly equal that of the
displaced fluid.
✓ Any vehicle has six degrees of freedom
✓ ROVs are not normally equipped to pitch and roll.
Hydrostatic equilibrium
Hydrostatic equilibrium
Vehicle degrees of freedom

22. ✓ The system is constructed with a high center of
buoyancy and a low CG to give the camera platform
maximum stability .
✓ Most ROV systems have fixed ballast with variable
positioning to allow trim.
✓ In the observation class, the lead (or heavy metal)
ballast is located on tracks attached to the bottom
frame to allow movement of ballast along the vehicle
to achieve the desired trim.
✓ Very large vehicles with variable ballast systems that
allow for buoyancy adjustments are an exception.
Vehicle with positive stability
ROV ballast

23. Righting moment
Detail of righting moment Vehicle’s righting moment

24. ✓ The frame of the ROV provides a firm platform for
mounting (or attaching) the mechanical, electrical,
and propulsion components.
✓ ROV frames have been made of materials ranging
from plastic composites to aluminum.
✓ Materials are chosen to give the maximum strength
with the minimum weight.
✓ Weight has to be offset with buoyancy .
Frame& Buoyancy &Types of Foam
Lightweight
foam
polyurethane
or polyvinyl
chloride (PVC)
Syntactic
foam
Frame
Types of Foam

25. Regardless of the material chosen, the following should be taken into consideration
when choosing the type of material:
✓ Specific gravity of the material
✓ Crush point and safety factor
✓ Shrinkage due to pressure, i.e., loss of buoyancy with depth
✓ Abrasion resistance, brittleness
✓ Potential protective coatings
✓ Available shapes and machinability, including hazardous material requirements
✓ Water absorption and thus loss of buoyancy
✓ Placement and stability considerations
✓ Ability to modify in the future

26. Vehicle geometry and stability.Thruster placement and stability.
Vehicle Stability

27. MISSION-RELATED VEHICLE TRIM
Two examples of operational situations where ROV trim to
assist in the completion of the mission :
1. If an ROV pilot requires the vertical viewing of a standpipe
with a camera tilt that will not rotate through 90 Degree ; the
vehicle may be trimmed to counter the lack in camera
mobility.
Vehicle trim with weight forward

28. 2. If the vehicle is trimmed in a bow-low condition
while performing a pipeline survey :
✓ when the thrusters are operated to move forward
✓ the vehicle will tend to drive into the bottom,
requiring vertical thrust (and stirring up silt in the
process).
✓ The vehicle ballast could be moved aft to counter
this condition.
Movement down a pipeline with vehicle out of trim

29. Drag and Thrust
✓ The vehicle must power itself and overcome the fluid drag
of the vehicle/tether combination to travel to and remain at
the work site.
✓ The overall shape of the vehicle determines the drag it will
experience not counting the effect of the tether.
✓ The smaller the tether cable diameter, the better—in all
respects (except, of course, power delivery).
✓ Stiffer tethers can be difficult to handle, but they typically
provide less drag
✓ Flexible tethers are much nicer for storage and handling
but they provide more drag
Forces on ROV

30. ✓ There is an optimum aspect ratio whereby
the total drag formed from both form drag
and skin friction is minimized
✓ Aspect in the range of a 6:1 aspect ratio
(length-to-diameter ratio)
✓ Assuming a smoothly shaped contour
forming a cylindrical hull
Vehicle drag curves

31. Drag components & Drag Equation
System drag componentsPower = Drag*V/constant
✓ These tether lengths represent theoretical cross-section
drag for a length of tether perfectly perpendicular to the
oncoming water .
✓ Vehicle drag assumes a perfectly closed box frame

32. Tether drag increases to the perpendicular point
Component drag at constant speed
Tether drag at constant speed with varying diameter
✓ Tether Drag Increase As its Length Increases
✓ The more the diameter of Tether the more the tether Drag
the more the Total Drag

33. ✓ Minimal tether diameter
✓ Powered from the surface having unlimited endurance (as opposed to battery
operated with limited power available)
✓ Very small in size (to work around and within structures), yet extremely stable
✓ Have an extremely high data pipeline for sensor throughput
✓ Unfortunately, the perfect ROV is hard to develop, especially when considering
the many tasks
Accordingly, the perfect ROV would have the following
characteristics:

34. Drag curves of systems tested at 0.5 knot.
✓ At a given current velocity (i.e. 0.5 knot), the drag
can be varied (by increasing the tether length)
✓ Until the maximum thrust is equal to the total
system drag , that point is the maximum tether
length for that speed that the vehicle will remain
on station in the current.
✓ Any more tether in the water (i.e., more drag) will
result in the vehicle losing way against the current.
✓ Eventually (when the end of the tether is reached),
the form drag will turn the vehicle around, causing
the submersible to become the high-tech
equivalent of a sea anchor.

35. Thruster and powering
The designer must determine what size thruster is needed for the vehicle ,
The decision process goes something like this:
✓ What is the task that must be done and thus the work system and tools necessary for the ROV?
✓ What size power system is necessary to support the work system and tools ?
✓ What size frame and amount of buoyancy are necessary to support the power and work system?
✓ What are the physical and environmental conditions (current, depth, required operational footprint, etc.)?
✓ What size thrusters are needed to move the vehicle at the necessary speed above the stated environmental
conditions?
✓ What is the total power requirement input to the electric/hydraulic power system?
✓ What is the size of the umbilical/tether to provide the required power?

36. Propulsion systems
✓ ROV propulsion systems come in three different
types
✓ These different types have been developed to suit the
size of vehicle , type of work and the location of the
work task .
✓ For example, if the vehicle is operated in the vicinity
of loosely consolidated debris, which could be pulled
into rotating thrusters, ducted jet thruster systems
could be used .
Electrically
driven
propeller
Hydraulically
driven
propeller
Ducted jet
propulsion
(rarely)

37. Thruster basics
✓ ROV’s propulsion system is made up of two or more thrusters.
✓ Thrusters must be positioned on the vehicle so that the moment arm of their
thrust force, relative to the central mass of the vehicle, allows a proper
amount of maneuverability and controllability.

38. There are numerous placement options for thrusters to
allow varying degrees of maneuverability
✓ The three-thruster horizontal arrangement allows only
fore/aft/yaw,
✓ The fourth thruster also allows lateral translation.
✓ The five-thruster variation allows all four horizontal
thrusters to thrust in any horizontal direction
simultaneously
✓ Multiple vertical thrusters further allow for pitch and
roll functions via asymmetrical thrusting.
Thruster arrangement
Thruster arrangement

39. ✓ Placing the thruster off alignment from the
longitudinal axis of the vehicle will allow a better
turning moment, providing the vehicle with strong
longitudinal stability.
✓ One problem with multiple horizontal thrusters
along the same axis, without counter-rotating
propellers, is the “torque steer” issue .With two or
more thrusters operating on the same plane of
motion, a counter-reaction to this turning moment
will result.
Thruster aligned off the longitudinal axis
Thruster rotational effect on vehicle

40. Thruster design
Underwater electrical thrusters are composed of the following major components:
✓ Power source
✓ Electric motor
✓ Motor controller (this may be part of the internal thruster electronics or may be part of a driver
board in a separate pressure housing)
✓ Thruster housing and attachment to vehicle frame
✓ Gearing mechanism (if thruster is geared)
✓ Drive shafts, seals, and couplings
✓ Propeller
✓ Kort nozzle and stators

41. Sub-Atlantic Model SA300 hydraulic thruster
D=300 mm
Sub-Atlantic Model SPE-
250 electric thruster (D=
246 mm )
Tecnadyne Model
8020 electric
thruster
D= 305 mm
✓ The electric examples all use brushless DC motors.

42. ✓ As the speed of the vehicle ramps up, the low
speed stability is overtaken by the placement of
the thrusters with regard to the center of total
drag.
✓ For slow-speed vehicles the designer can get
away with improper placement of thrusters.
✓ For higher speed systems, thruster placement
becomes a more important consideration in
vehicle control
Bow turning moment due to asymmetrical
drag as speed ramps up.
Thrusters and speed

43. ✓ The shafts, seals, and couplings for an
ROV thruster are much like those for a
motorboat.
✓ The shaft is designed to provide torque to
the propeller
✓ Seal maintains a watertight barrier that
prevents water ingress into the motor
mechanism .
Fluid sealing of direct drive thruster
coupling
Drive shafts, seals, and couplings

45. The Admiral II ROV of AQUAPHOTON co. at Alexandria, Egypt.
Specifications
ROV Name: THE ADMIRAL II
ROV cost: 3.076 $ / 52.252 LE (Dollar = 17 LE)
Dimensions: 70cm X 50cm X 40cm
Max Depth: 9 meters
MAX. current consumption: 30 Ampere
Production year: 2014
Total Weight: 48 kg
Period Construction: about two months
Primary Materials: Nylon Sheet, Stainless steel

46. Design rationale:-
Frame
• Admiral II frame design based on resisting mechanical stresses.
• And easy assembly different ROV systems.

47. Available materials and manufacturing techniques:-
Aluminum-Fiber Composite Polyurethane
• low cost, but the machining process is manual
and not accurate.
• Very good as the material provides a high
mechanical strength. But the high manufacturing
cost as it needed to get the required shape.

48. Nylon sheets - TECAMID PA6 GF30 polyamide (The chosen material)
• Used for good impact strength, high degree of toughness,
and good wear-resistance.
• The machining process is CNC router which provides a
very precise fabrication.
Density = 1350 Kg/m³
Modulus of Elasticity= 8500/6000 Mpa
Ultimate Strength = 140/110 MPa (brittle)
Elongation at break = 2.5% / 5%
Hardness (ball indentation) = 147 MPa
Water absorption at saturation = 6.6%
Material properties in dry/wet conditions:-

49. Advantages of the frame shape:-
1. Designed to allow putting the ROV on 5 of its 6 faces to provide an easy access to all ROV
mechanical parts and thus providing easy maintenance.
2. Easy handling of the ROV.
3. Ease of assembly: Due to all fixation bolts are of the same size.
4. It gives an elegant shape because of the appearance of the material, and the stainless steel fixation
bolts to avoid rust.
Using this data, stress analysis on the frame was done to see points of maximum stress and ensure safe design.
Stress plot for the bottom
plates of the frame
Displacement plot for the bottom
plates of the frame

50. Thrusters
Admiral II have 6 thrusters (2 vertical - 4 horizontal) which fully designed by solidworks
software and manufactured by AQUAPHOTON co.
• The used material in manufacturing is same material used in a frame manufacturing
and Machined by Centre lathe machine.
• This design has many advantages of low drag force, small size, ease of maintenance.
Horizontal thrusters’ specification Vertical thrusters’ specification
Type: Canon brushed DC motor Type: Ampflow brushed DC motor
Voltage Rating: 24 V Voltage Rating: 36 V
Load current: 3A Load current: 8A
Full load current: 8A Full load current: 22A
Power : 72 Watt Power : 150 Watt
RPM : 1350 rpm RPM : 3500 rpm

51. Electric cylinder
• To make a totally secure for electric boards and prevent any leakage.
• The used material is stainless steel due to its ability to withstand impact loads and
high pressures.
• Cylinder shape not box shape because it produces a low drag resistance to water,
and it is easier in machining compared to the box shape.
Sealing
• To best seal and prevent any leakage, AQUAPHOTON CO. divided it into 3
individual branches.
1- Static Sealing
• Made between two stable and immovable components such as electric cylinder,
lights and camera casings.

52. 2- Wire sealing
• Nozzles and hoses system used in gaseous application, used for
sealing the wires of the whole ROV.
• The nozzles is installed in each component in the ROV, then all components
are connected to the junction boxes via the hoses, then all the wires are
collected in two big hoses and connected to the electric canister.
• To insure the zero leakage approach, a jubilee clips used on each nozzle.
3- Dynamic sealing
• A seal required to prevent leakage past parts which are in relative motion
such as thrusters.

53. Buoyancy
• To make the ROV to be easier in flying and maneuvering.
• Done by calculating the O.A weight of the ROV, including the weight
of the foam in order to calculate the amount of foam needed to reach
the design goal.
ROV total weight = 48 kg
Foam Volume needed = 0.021m³
• The material used is extruded polystyrene foam with density of 35 Kg/m³
and a compressive strength of 300 Kpa and cutting process made by CNC
laser.

54. Balance boxes
• To easily shift the Cg (Center of gravity) point to the required
place between the two vertical thrusters.
• A 2 balance boxes are fitted on the 2 sides of ROV along its
length to shift the Cg forward and backward,
• And 1 balance box fitted along the width of ROV to shift the Cg
left and right for any asymmetry.

55. Gripper
• The Admiral II has one gripper with one DOF (degrees of freedom), used
for gripping.
• The gripper material and gripper motor casing are made of nylon sheets
TECAMID polyamide.
• It is made of 6mm thickness sheet and assembled with set screw.
• The gripper mechanism consists of a worm and 2 worm gears to transfer
the motion from the rotating shaft to the two end effectors.
Gripper Motor Specification
Motor type: brushed DC motor
Rated Voltage: 12 Volt
Speed: 200 RPM
Load current: 0.4 ampere
Full Load Current: 1 ampere

56. TETHER
• Admiral II uses a 25 terminals tether with totally diameter
38mm. It was made of heavy copper.
• Admiral II has 2 tethers. The first one consists of 2 terminals
of 4 mm thickness used for power transmission to the ROV.
• The second tether consists of 12 terminals of 0.5mm thickness;
6 of them are used for the vision system while the other 6
terminals are used for the communication between the surface
control and the ROV.

57. Vision system
• Admiral II has 3 cameras for a complete view of the environment and the manipulator.
• The first camera is installed on a tilting mechanism to enable a wide range of vision for the
pilot.
• The second camera is used to show the platform under the ROV to help the pilot interact with
the gripper easily.
• The third camera is installed for the rear view of the ROV as part of the mission may require
backward motion.

58. • The USB DVR is used to allow to monitor the 3 cameras simultaneously on a laptop screen with
a live view and to record a live video or take snapshots.
• Admiral II have two powerful light spots installed on the tilting mechanism for a better vision
underwater.

59. Surface control
• It consists of 3 main components. The first component is the control box
(made by AQUAPHOTON CO. engineers) which contains a monitor, 32
ampere main feeder circuit breaker, a 25 ampere fuse and LCD for sensor
reading.
• The main advantage of it is the fast connecting system for the tether and
power source input.
• The admiral II is controlled via a PS2 joystick. The third component is the
co-pilot’s external laptop to collect any data required for the mission.

60. Safety features:-
Safety Signs Shrouded propeller Main Fuse
No sharp edges Tether well attached to ROV
Special Features:-
Smooth propulsion
systems
Camera tilting mechanism Powerful vertical
thruster
Lighting spots Multiple function manipulators Fast connection
system
Proposed Uses in Egypt:-
Detector Oil wells Tourism Drainage
Detector Mines Discover Ships problems at Suez Canal

62. SeaBotix LBV150-4 MiniROV
Owned by Suez Canal Authority since 2009

63. System components:-

64. Technical specifications:-
General
Depth Rating 150 m
Length 530 mm
Width 245 mm
Height 254 mm
Weight in Air 11 kg

65. Thrusters | Performance
Configuration 2 forward, 1 vertical, 1 lateral
Motor Type Brushless DC direct drive
Speed at
Surface
3 knots
Bollard
Thrust
-Forward - 7 kgf
-Lateral - 3 kgf
-Vertical - 3 kgf

66. Cameras | lighting
Camera 680 line high resolution color
Camera Tilt 180 degrees
Focus Manual (90 mm to infinity)
Format NTSC or PAL
Lighting Internal 700 Lumen LED array,
tracks color camera

67. Tether
Diameter 8.9 mm
Length 150 m standard
Working
Load
100 kgf
Breaking
Strength
700 kgf
Buoyancy Neutral in fresh water, slightly
positive in seawater
Reel Heavy duty w/slip ring

68. Control System
Configuration Single rugged case with monitor, OCU & power supply
Monitor 38 cm (15 in) LCD
Power Requirement 1,200 Watts, 100-130/200-260 VAC
Safety Isolated input, circuit breaker, LIM, leak monitor
Auto Functions Depth, heading, trim
Video Overlay Depth, heading, lights, thruster gain, turns counter, camera
angle, time, date & user programmable characters

69. Options
Grabber Three jaw, interlocking small, interlocking
large, parallel and cutter
Lights 2 HD LED (1080 lumen per head)
Reel Tether reel (heavy duty with slip ring)
Other HD zoom camera and laser scaling

70. Applications In Egypt by Suez-Canal Authority
✓ Used as a video camera for inspection, either for SCA tasks or for tasks
assigned via other companies.

71. Product features
1. Suitable For Narrow Places.
2. 4-Axis Maneuverability..
3. Small Diameter Low Drag Tether.
4. Integrated Control console (ICC).
5. Powerful Brushless DC Thrusters.
6. High Resolution Color Video.
7. High Intensity LED For Camera.

72. • The ROV manual - A user guide for remotely operated vehicles 2nd edition
• Alexandria_university_aquaphoton_technical_report
• Seabotix_lbv150-4_data_sheet_2015-080615
• Http://www.Teledynemarine.Com
• Http://www.Rov.Org
• Http://www.Rovegypt.Org
• Https://www.Marinetech.Org/rov-competition
References

73. PREPARED BY
• ENG : HASSAN MOURSY
• +20 01157409977
• HASSANMOURSY50@GMAIL.COM
• ENG : AHMED BAKR
• +20 01022536169
• AHMEDBAKR321@GMAIL.COM
• SUPERVISED BY : PROF.DR./ HEBA ELKILANY
• VERY SPECIAL THANKS TO PROFESSOR HEBA S. EL-KILANI AS SHE SPARES NO EFFORT TO HELP US IN THIS
SEMINAR AND WE ALL WISH A GREAT LIFE TO HER.
• PORTSAID UNIVERSITY , FACULTY OF ENGINNERING
• DEPARTMENT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING (2018 SEMINR )