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)

Contents1. 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. Design4.1 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. Design4.2 Decision Matrix – Hull and Thruster

ConfigurationDifferent design

attributes

Single Hull Dual Hull

Single thruster

Multiple thruster

Azimuthal Thruster Multiple 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. Design4.3 Gripper Design

Dual gripper (DC motor controlled/Pneumatic actuator)

4 bar mechanism Sensors to be attached on the inner side of

the gripper

4. Design4.4 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. Design4.5 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. Design4.6 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. Design4.7 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 &

testingPrototype 2

DesignFabrication & Testing

ROV testing

Arranging sponsorshipOrderin

g Thruste

rs

6. Budget6.1 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 15,000Hull 2 10,000Manufacturing(machining, welding)

15,000

Miscellaneous and Buffer 12,000Total - 2,90,000

6. Budget6.2 Electronics and Vision

Component Quantity

Cost(INR)

Microcontroller – Arduino Mega

2 7,500

Accelerometer 2 2,500IMU Sensor 1 70,000Digital Compass 1 5,000Motor Driver 5 14,000Water Proof Wires 6 6,000Printer Circuit Board 2 5,000Camera 2 15,000Miscellaneous Components

- 5,000

Total - 1,30,000

6. Budget6.3 Overall Budget

Mechanical 2,90,000

Electrical 1,30,000Conferences/ Paper

Presentations 50,000

Overall Buffer 30,000

Total 5,00,000

7. Further Research ProjectThis 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