1. Underwater Technologies
P08454 – Thruster for a Remotely Operated Vehicle
Anthony Squaire – Industrial and Systems Engineer – Team Lead
Alan Mattice – Mechanical Engineer – Lead Engineer
Brian Bullen – Mechanical Engineer
Charles Trumble – Mechanical Engineer
Cody Ture – Mechanical Engineer
Aron Khan – Electrical Engineer
Jeff Cowan – Electrical Engineer
Andre McRucker – Computer Engineer
Multidisciplinary Engineering Design Program

2. Project Scope Mission: Customers: P06606 – An Underwater ROV
Derived from one of the most successful projects in RIT’s history
Mission:
To create a thruster for an underwater remotely operated vehicle (ROV) that is integrated with an ROV light design. This design shall be accessible to any person or persons who wish to use and/or modify it in the future.
Customers:
Dresser-Rand has graciously donated the majority of the funds for this project. Hydroacoustics Inc. has supplied many resources to the project. Dr. Hensel and the Mechanical Engineering Department have supplied leadership and guidance through the design process.

3. Current Designs Tecnadyne Model 260: $4,000.00
High Power Consumption (80W)
Very in-efficient in reverse
Only 1/3 of forward thrust
Seabotix Model 150:
$1,000.00
Inefficient Thrust
No possible design variances
Competitor company for Hydroacoustics Inc.
Top Right: Seabotix Model 150
Left: Tecnadyne Model 260

4. Customer Requirements
Need more efficient thrust, ie. better thrust with lower power consumption
Must be easily mountable to the Hydroacoustics Inc. ROV
Needs to be operational up to 400ft (121.92m) of water, roughly 173psi (1192.8kPa) of pressure
Needs to work in a large range of temperatures
Modular, open source design so that any person or persons can use and/or modify the design
Needs to comply with all federal, state, and local laws, including the policies and procedures of RIT

5. Design Process Decisions, Decisions, Decisions:
Shaft Seal – Decide between magnetic coupling or dynamic seal
Answer: The magnetic coupling was chosen because allows for a much simpler seal, gives protection to the motor and impeller, and is frictionless
Motor – Brushed or Brushless?
Answer: Brushless was chosen because of there being reduced losses and the use of Hall Sensors for feedback
Impeller – Design or use pre-existent designs?
Answer: Decision was to use pre-existent impeller designs. Computer muffin fans have perfect sized impellers for the projects application.

6. Design Process Nozzle – Rice or Kort Nozzle?
Answer: The Rice nozzle was chosen based on it’s reduced drag through the fluid and a better geometry to promote increased thrust
Communication – Use single microcontroller for all thrusters or single for each?
Answer: Decision was to use a single microcontroller in each separate thruster or light. Allows the ROV to “limp” on

7. Nozzle Comparison Kort Nozzle Rice Nozzle Relatively Simple Geometry
High Circulation off Leading Edge
Rice Nozzle
Lower Drag Coefficient
Improved Flow Geometry

8. System Architecture

9. Final Design Special Mechanical Features:
Magnetic Coupling – No dynamic Seals
Aluminum Housing – Lightweight and strong
Rice Nozzle – Low drag and increased thrust
Polymer Membrane – High strength PEEK (Polyetheretherkeytone) material
Modular Housing – Used for both thruster and light

10. Left: Microcontroller
Final Design
Special Electrical/ Software Features:
Feedback via Hall Sensors – Monitors position, speed and direction of the rotor, allows for synchronous control and fine tuning
Motor driver – 5.6A peak with over-current protection, enable, forward/reverse, variable speed using pulse width modulation
ATmega168 Microcontroller – Efficiently uses power, and has numerous PWM channels
Topside GUI – Made using GTK to control thrusters and lights
Board Layouts
Left: Microcontroller
Right: Motor Driver

11. ST Microelectronics Driver

12. ATmega168 Microcontroller

13. Engineering Specifications
Must have a continual forward thrust of at least 4.8 lbf (2.18kg)
Must have a reverse thrust at least ¾ the value of the forward thrust
Power consumption must be limited to under 80W
Impeller shaft must be balanced to within 0.001in (0.0254mm)
Must withstand pressures up to 173psi (1192.8kPa)
Should be of comparable weight and volume to both the Tecnadyne Model 260 and the Seabotix Model 150
Needs to operate at ambient temperatures ranging from 38 to 75oF (3.3 to 23.9oC)
Should be able to run for 168 hours without failures

14. Design Verification

15. Projected Cost per Thruster: $668.00
Project Costs
Mechanical………………………………………………………….$1,623.74
Electrical………………………………………………………………$484.64
Machining (Production)……………...………………………………$2,150.00
Research and Development…………………………………………...$563.55
Total Project Cost: $2,671.93
Projected Cost per Thruster: $668.00
Man Hours……………………………………………….…… Hours

16. For The Future…
Place thrusters on the Hydroacoustics Inc. ROV named Proteus to test design characteristics
Maximize the thrust to weight ratio by reducing the wall thickness of the light housing
Maximize the thrust to power consumption ratio by reducing friction losses in places such as the gearbox
Use a new motor supplier
A future RIT MSD project could be an open source ROV design and these thrusters can be integrated into the design
Look at modularity in the software and electronics
Possible uses for land-based and hybrid (land and sea) vehicles

17. Questions?