REMOTE OPERATED VEHICLE (ROV) FOR UNDERWATER
ULTRASONIC NON DESTRUCTIVE TESTING
Dual Degree Project (2013-2014)
Project Guide: Dr. Prabhu Rajagopal
Students:-Tanuj Jhunjhunwala (ME09B097)-Shehzaman Khatib (ME09B130)
Contents
1. Motivation2. Goals3. Proposed Concept4. Design5. Timeline6. Budget7. Further Research Project
1. Motivation
Rover required for inspecting offshore pipes
Currently diver based expensive Deep water capability
Diver taking pipeline CP reading
Source:- www.jcsubsea.com
Underwater ROVSource:- www.bluebird-
electric.net
2. Goals
Capable of navigating underwater Manually (wired) operated Camera vision for live streaming to
operator Gripper to clamp pipes NDT using Ultrasonic sensors on clamps
ROV (wired) is controlled by
operator
ROV navigates underwater to
reach pipe using thrusters
Camera on the ROV provide
visual feedback to
operator
Gripper on rover clamps
the pipe (to be inspected)
Performs Ultrasonic NDT
Send back sensor data to the operator
Analyses and detection of
defects
3. Proposed Concept
Source:- Norsk Elektro Optikk AS (www.neo.in)
4. Design
4.1 Design Considerations Motors for propulsion (no ballast)
Thrust requirement (assuming velocity=0.33m/s) = 1kgf
Hull – Cylindrically Shaped Ellipsoidal Profile of Hull cap (least drag) Dual hull, multiple thrusters design Bottom heavy Elimination of Roll Motion Positively Buoyant Waterproofing
O-ringSealants - Araldite
4. Design
4.2 Decision Matrix – Hull and Thruster Configuration
Different designattributes
Single Hull Dual Hull
Single thruster
Multiple thruster
Azimuthal ThrusterMultiple thruster
Power consumption Less High Medium Medium High
Space available Less Less Less High High
Ease of fabrication Medium Medium Less Less High
Ease of Control Less Medium Medium Medium High
Maneuverability Less High Medium Medium High
Access to inside components
Less High High High Medium
Stability Less Less Medium Medium High
Desired
Moderate
Not desired
4. Design
4.3 Gripper Design Dual gripper (DC motor
controlled/Pneumatic actuator) 4 bar mechanism Sensors to be attached on the inner side of
the gripper
4. Design
4.4 Electronics and Vision Stability – PID based stability control using
multiple sensors and microprocessor(will be internal to the system)
Motor Drivers – Drive all the required thrusters Vision system for manual control – medium
resolution camera with external light source Water proof wires – Cables to be well
insulated Portability – Control the entire ROV with a
single laptop(minimal software) and prevailing UT testing systems
4. Design
4.5 Prototype I [Dual Hull, 4 thrusters]Bilge pump motors for propulsion
PVC Cylindrical Hull
For Surge
For Heave
Neutrally Buoyant
Waterproofing (O-ring; Araldite)
4. Design - 4.5 Prototype I (Video)
4. Design
4.6 Analysis of Prototype I The overall weight without gripper was 12
kgs The major contributor were the thrusters 5.5
kgs The motor response was as expected Sharp maneuvers were possible No leakage problem Balancing it required a “hit and trial”
approach
4. Design
4.7 Thrusters for Prototype 2 Suggestion to buy new thrusters used in AUVs
Only few companies in the world make those Seabotix thruster – BTD 150 is of our
requirement Voltage:- 12 VDC Weight:- 720 gms Thrust: 2.9 kgf (required – 1 kgf) Cost per thruster: $700
5. Timeline of proposed project
Aug Sept Oct Nov Dec Jan Feb Mar
Prototype 1-Design &
fabrication
Gripper design, prototyping &
testing
Prototype 2 Design
Fabrication & Testing
ROV testing
Arranging sponsorship
Ordering
Thrusters
6. Budget
6.1 Mechanical
Note:- If we go through IC&SR customs duty can be avoided
Component Quantity Cost(INR)
Thrusters 5 (1 USD = 62 INR)
2,20,000
Shipping and customs
$200+$100 18,000
Gripper 3 15,000
Hull 2 10,000
Manufacturing(machining, welding)
15,000
Miscellaneous and Buffer 12,000
Total - 2,90,000
6. Budget
6.2 Electronics and VisionComponent Quanti
tyCost(IN
R)
Microcontroller – Arduino Mega
2 7,500
Accelerometer 2 2,500
IMU Sensor 1 70,000
Digital Compass 1 5,000
Motor Driver 5 14,000
Water Proof Wires 6 6,000
Printer Circuit Board 2 5,000
Camera 2 15,000
Miscellaneous Components
- 5,000
Total - 1,30,000
6. Budget
6.3 Overall Budget
Mechanical 2,90,000
Electrical 1,30,000
Conferences/ Paper Presentations
50,000
Overall Buffer 30,000
Total 5,00,000
7. Further Research Project
This will lay down the framework for building underwater NDE machines in IITM and can be developed in later years to: Integrate more NDE techniques - such as
guided waves in underwater pipes
Stimulate research in stability and control techniques for underwater vehicles
Build autonomous NDE machines for underwater pipes
Thank You
