Underwater Technologies

1. UnderwaterTechnologies 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 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. CurrentDesigns • 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 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. 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. 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……………………………………………….……..2116 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?