1

The SeaWeed Remotely Operated Vehicle

Senior Design Project

Submitted to:

Dr. Stephen Wood, P.E.

Professor of Ocean Engineering Design (OCE 4541)

FLORIDA INSTITUTE OF TECHNOLOGY

Melbourne, FL

Submitted By:

Nick Abruzzini

Janelle Boisvert

Katie Dobek

Anthony Tedeschi

July 25, 2007

2

TRANSMITTAL______________________________________________

Florida Institute of Technology

Department of Marine and Environmental Systems

OCE 4541

TO:

Dr. Stephen Wood, P.E. Dept. of Marine and Environmental Systems Florida Institute of Technology 150 W. University Blvd. Melbourne, FL 32901

FROM:

The SeaWeed ROV Team

Nick Abruzzini, Janelle Boisvert, Katie Dobek, Anthony Tedeschi

Department of Marine and Environmental Systames

Florida Institute of Technology

150 W. University Blvd.

Melbourne, FL 32901

RE: SeaWeed Remotely Operated Vehicle Senior Design Project

DATE SUBMITTED: July 25, 2007

Dr. Stephen Wood, P.E.:

Please review the attached final report for the SeaWeed ROV Senior Design Project. All

research and calculations completed over the course of this project are included. This

report has been prepared independently and to the best of the team’s ability. Please

contact us at SeaWeedROV@gmail.com if you have any further questions. Thank you.

The SeaWeed ROV Team

Nick Abruzzini _____________________

Janelle Boisvert _____________________

Katie Dobek _____________________

Anthony Tedeschi _____________________

3

Final Report

Senior Design Project

Nicholas Abruzzini

Janelle Boisvert

Katherine Dobek

Anthony Tedeschi

4

Executive Summary:

Remotely operated vehicles have become an essential tool in the oceanographic,

offshore and shipping industries. SeaWeed will be an observational ROV designed for

visual inspection, research and minimal data collection. Taking inspiration from several

small-class observational ROVs as well as two previous Florida Tech Senior Design

Projects (Hornet I and Hornet II) we plan to design and build a base ROV that can

operate as is but has much room for improvement and additions that future students can

work towards. SeaWeed will feature an instrument package that includes depth and

temperature sensors and a compass. It will also have a color camera to capture video that

will be displayed on a monitor mounted in the topside control box. We hope that this

ROV will prove that a low-cost ROVs can be as effectively used in the shipping and

offshore industries as its higher-cost competitors.

5

Acknowledgements:

We would like to thank the following people and companies for their help and support of

our Seaweed ROV, without their time and efforts our project would not have been a

success:

Dr. Wood, Florida Institute of Technology

Larry Buist, Florida Institute of Technology

Dr. Swain, Florida Institute of Technology

Maila Sepri, Florida Institute of Technology

Thomas Dobek, Repair Industries of Michigan

Ben Klose, Repair Industries of Michigan

Joe Knoth, Alliance Tool and Machine, Co.

Bill Jorgensen, Bluewater Fabricators

Mainstreet Pub

Jason Sperry, Easylift Gas Springs

1

Table of Contents:

1. Introduction ............................................................................................................... 6

1.1 Overview ............................................................................................................. 6

1.2 Objectives ........................................................................................................... 7

1.3 Organization ........................................................................................................ 7

2. Background ............................................................................................................... 8

2.1 Florida Tech ROV History.................................................................................. 8

2.2 Competitors ......................................................................................................... 9

3. Technology ............................................................................................................... 11

3.1 History............................................................................................................... 11

4. Materials and Parts................................................................................................. 12

4.1 Parts List ........................................................................................................... 12

4.2 Parts and Materials Description ........................................................................ 13

4.2.1 Frame and Housing .................................................................................. 13

4.2.2 Pressure Sensor ........................................................................................ 18

4.2.3 Monitor ..................................................................................................... 18

4.2.4 Light .......................................................................................................... 18

4.2.5 Propulsion ................................................................................................. 19

4.2.6 Kort Nozzle................................................................................................ 21

4.2.7 DC-DC Converter ..................................................................................... 22

4.2.8 AC-DC Front End ..................................................................................... 23

4.2.9 Video Camera MB-1050C model ............................................................ 23

4.2.10 Video Overlay ........................................................................................... 24

4.2.11 Pelican Box ............................................................................................... 24

4.2.12 Tether ........................................................................................................ 25

4.2.13 Joystick ...................................................................................................... 26

5. Procedures ............................................................................................................... 27

5.1 Preliminary Design ........................................................................................... 27

5.1.1 Design Considerations .............................................................................. 27

5.1.2 Final Design Decisions ............................................................................. 29

5.2 Housing Design and Manufacturing ................................................................. 29

5.2.1 Housing Dimensions ................................................................................. 29

5.2.2 Housing Materials .................................................................................... 29

5.2.3 Housing Design ......................................................................................... 30

5.2.3.1 Outer Housing ....................................................................................... 31

5.2.3.2 Internal Systems Mount ........................................................................ 31

5.2.4 Housing Manufacturing ............................................................................ 32

5.3 Frame Design and Manufacturing .................................................................... 32

5.3.1 Frame Dimensions .................................................................................... 32

5.3.2 Frame Materials ....................................................................................... 32

5.3.3 Frame Design............................................................................................ 32

*Note: CAD Drawings can be found in Appendix C .............................................. 32

5.3.3.1 Outer Frame .............................................................................................. 33

5.3.3.2 Motor Mounts ....................................................................................... 33

2

5.3.3.3 Lighting Mount ..................................................................................... 34

5.3.4 Frame Manufacturing ............................................................................... 35

5.4 Internal Systems ................................................................................................ 35

5.4.1 Introduction............................................................................................... 35

5.4.1.1 Compass .................................................................................................... 36

5.4.1.2 Pressure Sensor ........................................................................................ 36

5.4.1.3 Video and Data Transmission ................................................................... 37

5.5 Steering and Propulsion .................................................................................... 37

5.5.1 Power Supply and Transmission ............................................................... 37

5.5.2 Motor Controller Design .......................................................................... 37

5.5.3 Joystick Integration ................................................................................... 37

5.6 Buoyancy and Stability ..................................................................................... 37

5.6.1 Syntactic Foam.......................................................................................... 38

5.6.2 Buoyancy Calculations ............................................................................. 38

5.7 Control Box Design .......................................................................................... 39

5.7.1 Pelican Box Modifications ........................................................................ 39

5.7.1.1 Gas Spring Hinge .................................................................................. 39

5.7.2 Monitor ..................................................................................................... 40

5.7.2.1 Mounting System .................................................................................. 40

5.7.3 Plastic Mold .............................................................................................. 40

5.7.3.1 Design and Manufacturing .................................................................... 40

5.7.3.2 Spring Mechanism ................................................................................ 41

5.7.3.3 Electronics Mounting ............................................................................ 42

5.7.4 Additions ................................................................................................... 42

5.8 Tether Modifications and Tether Management System Design ....................... 43

5.8.1 Basic Hose Reel ........................................................................................ 43

5.8.2 Slip Ring Modification .............................................................................. 43

5.8.3 Slip Ring Cover Modification ................................................................... 43

5.8.4 Basic Tether Properties ............................................................................ 44

5.8.5 Adding Connectors.................................................................................... 44

5.8.6 Splicing Components together .................................................................. 45

6. Results ...................................................................................................................... 46

6.1 Testing Methods................................................................................................ 46

6.1.1 Pool Tests .................................................................................................. 46

6.1.1.1 Test 1: ROV with Dome and Entire Back Plate ................................... 46

6.1.1.2 Test 2: ROV with Dome, Back Plate and Cables and Connectors ....... 46

6.1.1.3 Test 3: Full ROV Test ........................................................................... 51

7. Conclusions and Recommendations ...................................................................... 55

8. Appendices ............................................................................................................... 56

Appendix A: Project Economics ................................................................................ 56

8.1 Team Economics ........................................................................................... 56

8.2 Donated Economics ...................................................................................... 56

8.2.1 Donated Parts ....................................................................................... 56

8.2.2 Donated Monies .................................................................................... 56

8.2.3 Donated Materials and Time ................................................................ 56

8.3 Budget ........................................................................................................... 57

3

8.3.1 Spring Budget........................................................................................ 57

8.3.2 Summer Budget ..................................................................................... 58

8.4 Total Project Economics ............................................................................... 58

Appendix B: Auto-Cad Drawings.............................................................................. 59

Frame Designs .............................................................. Error! Bookmark not defined.

Motor Mount Designs .................................................. Error! Bookmark not defined. Appendix C: Circuit Schematics ............................................................................... 61

Joystick Board ............................................................................................................. 62

Joystick Control Schematic ........................................................................................ 62

Motor Controller Board ............................................................................................. 63

Motor Controller Schematic ...................................................................................... 63

Appendix D: References ............................................................................................. 64

4

List of Figures:

Figure 1: Seabotix, LBV…………………………………………………………………..9

Figure 2: Shark Marine, Stealth 2 ..................................................................................... 10

Figure 3: Video Ray, Scout ............................................................................................... 10

Figure 4: Bottom view of frame........................................................................................ 13

Figure 5: Top view of frame ............................................................................................. 13

Figure 6:Front view of frame ............................................................................................ 14

Figure 7: Side view of frame ............................................................................................ 14

Figure 8: Motor mount on top of frame ............................................................................ 15

Figure 9: Front endcap with dome .................................................................................... 15

Figure 10: Front view with endcap and dome .................................................................. 15

Figure 11: Inside housing from rear.................................................................................. 16

Figure 12: Inside back endcap with connectors ................................................................ 16

Figure 13: Outside back endcap with connectors ............................................................. 16

Figure 14: Front view dome and endcap........................................................................... 17

Figure 15: Spot welding on frame and housing ................................................................ 17

Figure 16: Top front view of housing ............................................................................... 17

Figure 17: Front view of propeller and Kort nozzle ......................................................... 19

Figure 18: Side view of propeller and motor .................................................................... 19

Figure 19: Front view propeller ........................................................................................ 20

Figure 20: Backside of sealed motor ................................................................................ 20

Figure 23: Front view Kort nozzle .................................................................................... 21

Figure 24: Side view Kort nozzle ..................................................................................... 21

Figure 25: Kort nozzle chart ............................................................................................. 21

Figure 26: Kort nozzle drawing ........................................................................................ 22

Figure 28: AC-DC Front End converter schematic .......................................................... 23

Figure 29: Video Camera .................................................................................................. 24

Figure 30: Video Camera Schematic ................................................................................ 24

Figure 31: Pelican Case .................................................................................................... 25

Figure 32: Connector to ROV ........................................................................................... 25

Figure 33: Connector to control box ................................................................................. 26

Figure 34: Spliced section ................................................................................................. 26

Figure 35: 3-axis joystick.................................................................................................. 26

Figure 36: Design 1 front view ......................................................................................... 28

Figure 37: Design 1 bottom view...................................................................................... 28

Figure 38: Design 1 side view .......................................................................................... 28

Figure 39: Design 2 ........................................................................................................... 28

Figure 40: Side view housing ........................................................................................... 30

Figure 41: Internal mount with electronics inside housing ............................................... 31

Figure 42: Vertical motors and motor mount ................................................................... 33

Figure 43: Forward/Aft motor mount ............................................................................... 33

Figure 44: Forward/Aft motor mount with motor and propeller ...................................... 33

Figure 45: Forward view lighting mount .......................................................................... 34

5

Figure 46: Top view lighting mount with light ................................................................. 34

Figure 47: Close up front view lighting mount ................................................................. 34

Figure 48: Side view lighting mount ................................................................................ 34

Figure 49: Internal Systems flow chart ............................................................................. 35

Figure 50: Internal systems sensor board.......................................................................... 36

Figure 51: Pressure sensor attached to back endcap ......................................................... 36

Figure 52: Gas spring on control box ............................................................................... 39

Figure 53: Monitor mounted in control box ..................................................................... 40

Figure 54: View from back of control panel ..................................................................... 40

Figure 55: View from front of control panel .................................................................... 41

Figure 56: Top view control panel .................................................................................... 41

Figure 57: Inside of control box without panel ................................................................. 41

Figure 58: Underside of control panel with mounted electronics ..................................... 42

Figure 59: Tether Management System ............................................................................ 43

Figure 60: Dry-Mateable ROV connector ........................................................................ 44

Figure 61: Dry-Mateable control box connector .............................................................. 44

Figure 62: Spliced section of tether with 3M splice kit .................................................... 45

Figure 63: Front view........................................................................................................ 47

Figure 64: Top view .......................................................................................................... 47

Figure 65: Left front view ................................................................................................. 47

Figure 66: Back view ........................................................................................................ 48

Figure 67: Underwater front view..................................................................................... 48

Figure 68: Underwater front view 2.................................................................................. 48

Figure 69: Underwater side view ...................................................................................... 49

Figure 70: Underwater side view 2 ................................................................................... 49

Figure 71: Underwater deep end ....................................................................................... 49

Figure 72: Underwater traveling to deep end ................................................................... 50

Figure 73: Underwater deep end ....................................................................................... 50

Figure 74: Above surface inspection ................................................................................ 50

Figure 75: Front view with foam ...................................................................................... 51

Figure 76: Working on ROV at pool ................................................................................ 51

Figure 77: Getting ready to test ........................................................................................ 52

Figure 78: Deployment ..................................................................................................... 52

Figure 79: Underwater front view..................................................................................... 53

Figure 80: Adjustments ..................................................................................................... 53

Figure 81: In the water ...................................................................................................... 53

Figure 82: Controlling and Observing .............................................................................. 54

Figure 83: Underwater 2 ................................................................................................... 54

6

1. Introduction

Overview

Remotely operated vehicles are tethered, human operated, underwater robots used in the

marine industry for scientific and engineering purposes. The tether is both the best

and worst feature of an ROV. It can send unlimited power, video and other data signals

from the surface vessel to the ROV and send collected data back to the surface; however,

the drag the tether creates on the vehicle is immense, having very negative effects on

the efficiency and maneuverability of the vehicle. In order to minimize these effects most

ROV tethers, including the one used on SeaWeed, are neutrally buoyant and of small

diameter. (2)

The most basic ROV is a small observational vehicle equipped only with a light and

camera. The scientific and technological community however, tends to use ROV's of

much more complexity. Several features and additional equipment are incorporated into

the design to make the ROV more applicable. The most complex vehicles include

several subsystems that widen the range of use. ROV's began as engineering tools to

inspect pipelines and underwater structures utilizing manipulator arms and

magnetometers but have now crossed into the scientific realm by incorporating

oceanographic instruments such as CTD, water and sediment samplers, water quality

measurements, and even biological sampling. (3)

The U.S. Navy headed the increase in ROV development beginning in the 1960s. Since

then ROVs have been developed for several situations. For example, rescue ROVs

are designed to recover other vehicles and objects from the ocean floor; others are used in

the offshore oil and gas industry assisting the development of resource fields by

inspecting pipelines or making pipeline repairs; still others are used in ship hull

inspections and shipwreck exploration.

7

Objectives

The objective of the SeaWeed ROV team is to design, build and test a working

investigative ROV, specifically designed for research and inspection. After reviewing

several previous Florida Tech ROV projects, including both the Hornet I and Hornet II,

we have decided to use their working parts and redesign and reconstruct a working ROV.

The size and weight of the SeaWeed will be similar to that of the Hornet II. Instruments

included in our design are a color camera, light, pressure sensor, temperature sensor,

and compass. We are planning for the ROV housing to be depth rated to 300 feet. Its

main uses will be ship hull inspections, shipwreck surveys and any other investigative

situations it is suited for.

Organization

To stay organized throughout the course of the project several procedures were used.

The biggest concern was time; therefore, we constructed a Gantt chart, which outlined

each procedure, its estimated duration and deadline providing the team with guidelines

and deadlines to ensure the project moved at an acceptable pace. In addition, a design

notebook was kept with all manuals, purchases and design ideas to document our

progress.

8

2. Background

Florida Tech ROV History

SeaWeed is the third small observational ROV built at Florida Tech and will be a hybrid

of parts from the two previous ROVs, the Hornet I and Hornet II. We will also integrate

several new parts into our new research and recovery ROV. The Hornet I was a very

basic ROV that ran into several problems. Its most prominent problem was the weight

and length of its tether, which made the thrust less effective. The ROV could only work

near the surface because its tether was only 100 feet long. The simple control box,

featuring three dials only had control over the three motors and had a power switch. The

motors were not efficient because there were no nozzles over the propellers. The Hornet

I’s maximum speed was one knot.

The Hornet II attempted and succeeded to solve all of the issues presented in the Hornet

I, however, the second generation ROV had its own problems. The second ROV added

nozzles over the propellers that made it move faster and more efficient while the tether

was 300 feet long. All of the Hornet II’s subsystems worked independently however

when the subsystems were integrated into one system the ceased to work. When the

motors were turned on the video feed was lost. The PVC frame of the Hornet I was

lightweight, strong, cost-effective and easy to machine, and therefore carried over to the

Hornet II.

Our SeaWeed Team is going to take the recommendations of both previous ROV’s and

design a fully functional observational ROV. We are going to build an aluminum frame

to make the ROV look and hold up better. We are changing the tether from a regular

extension cord to a real umbilical cord, which will help everything run smoother and

together. Our tether is in three sixty foot sections and has been put together to make just

under 180 feet.

The Hornet I, Hornet II and SeaWeed are not the only ROV’s in their class. There is a

good market for small observational ROV’s. A few of the main companies that build

9

these include Video Ray, Shark marine, and Seabotix. Video Ray makes a Scout ROV

that includes a five-inch monitor, 131ft of tether, color camera and two lights. This Scout

model can cost up to 7,000 dollars. The ROVs designed and built by Florida Tech

undergraduates have all been under 2,500 including all donations.

Competitors

There are plenty of companies that build ROV for commercial use. The ROVs similar to

the same size as our ROV can cost as much as $30,000.

Seabotix has a ROV called LBV150BE2

that is also very similar to our version. It has a

100-meter long tether that has low drag otherwise; it has about the same features as our

ROV. (7)

Figure 1: Seabotix, LBV

10

The Stealth 2 ROV is slightly smaller than the SeaWeed. It is mostly made from plastics

rather than metals. It has all the features of our ROV with a few extras, such as a built in

DVD recorder which we considered but did not have enough funds for. (5)

Figure 2: Shark Marine, Stealth 2

The VideoRay Scout system only includes 131 feet of tether, but like the SeaWeed, all its

controlling components are together in a watertight Pelican box. It includes a very small

5-inch color monitor, but also has a recording device. (6)

Figure 3: Video Ray, Scout

11

3. Technology

History

In the 1960’s the first ROVs were being designed; however, the scientists preferred the

manned vehicles. The Navy took interested into the technology behind ROV’s and

provided funding for them. This new technology allows the Navy to recover objects from

the seafloor. When the 1980’s rolled around the scientists needed to go deeper and stay

down longer than they were doing before and turned to the ROV’s technology to help

them out.

Today ROV’s are completely different to the earlier versions. The technology being

developed today has changed every aspect of the ROV from the tether to its flotation as

well as its functionality. Japan created the kaiko, which was used to reach and survey the

world’s deepest trench to help explain earthquakes. This ROV cost Japan 50 million

dollars back in 1995.

The technology advances in the ROV's tether has significantly increased the potential

use of them. A tether can now either be positively buoyant, negatively buoyant, or

neutrally buoyant for any application. Fiber optic wire can now be used allowing the

tether to be thinner; therefore, causing less drag. In addition, the fiber optic cable, which

is 0.9mm in diameter, allows more data to be transferred between the ROV and

the control box than a 12 mm coaxial wire. (design aspects of underwater intervention

systems 6-16)

12

4. Materials and Parts

Parts List

o Compass, Vector Electronics

o XBOB Video Overlay, Decade Engineering

o Pressure Transducer, Measurement Specialties, Inc.

o Flat Panel LCD TV, Polaroid

o Slimline HID MR11 (Dive Light), Dive Rite

o ROV Tether, Video Ray

o Acrylic Dome, Video Ray

o Slip Ring, MOOG Components Group

o Triple Axis Joystick, P3 America

o Tether Management System (Hose Reel)

o Control Box Connector, SealCon

o Connector, Seaconn

o Pelican Case

o Gas Spring and Brackets, Easylift Gas Springs of North America

o AC-DC Front End Converter, RO Associates, Inc.

o Microverter, RO Associates, Inc.

o Miscellaneous Electronics for Motor Controllers (see Purchase Orders)

o Motors, Servo Magnetics, Inc.

o Color Digital Camera, Polaris Industries

13

Parts and Materials Description

Frame and Housing

Our frame is made out of pipe aluminum and is 16" X 18" X 24". There is a pressure

housing mounted to the bottom of the frame that is 5.5" in diameter and has two

welded on flanges at either end. The front end has a plate with an acrylic dome that

seals with an O-ring and acts as a viewport for the camera. The back end just has a

flat plate with tapped holes for the wire connectors and is also sealed with an O-ring.

The frame was welded by Blue Water Fabricators.

Figure 4: Bottom view of frame

Figure 5: Top view of frame

14

Figure 6: Front view of frame

Figure 7: Side view of frame

15

Figure 8: Motor mount on top of frame

Figure 9: Front end cap with dome

Figure 10: Front view with end cap and dome

16

Figure 11: Inside housing from rear

Figure 12: Inside back end cap with connectors

Figure 13: Outside back end cap with connectors

17

Figure 14: Front view dome and end cap

Figure 15: Spot welding on frame and housing

Figure 16: Top front view of housing

18

Pressure Sensor

The pressure sensor we are using was given to us by Dr. Wood. It can operate for -40

to 257 degrees Fahrenheit and it has a pressure range of 0-010 Bar. To accommodate

the pressure sensor in our ROV there is a tapped hole through the backside of the

pressure housing so the probed end can be in the water.

Monitor

We purchased a 15 inch Polaroid LCD monitor. It is mounted on the top half of our

pelican box and weighs approximately 5.8kg. A video cable will run from the back

of the monitor into the bottom of the pelican box, which is housing all of our

electronic components. This screen will show video feedback from the ROV as well

as an overlay of the date/time, depth, and compass reading.

Figure 17. Monitor mounted in control box

Light

We have one dive light on our ROV, model MR11 Sunspot. It is a 10 watt bulb and

will last for over 1,000 hours. It is connected through our pressure housing through a

tapped hole in the back of the pressure housing. The light is attached to the ROV by

a clamp so it can be removed or if it needs to be adjusted.

19

Figure 18. Side view of light Figure 19. Front view of light

Propulsion

Seaweed uses the four motors that the Hornet II used. They are Molded Brushless

DC motors from Servo Magnetics. The Hornet II group incased the electronics in

epoxy. The wire comes in through a watertight connector. The motors last for over

25,000 hours and can take up to 160 V. They have a max speed of 20,000 RPM and

each one weighs 13 ounces. We implemented the same plastic mounts on our ROV

as the Hornet II did on theirs.

Figure 17: Front view of propeller and Kort nozzle

Figure 18: Side view of propeller and motor

20

Figure 19: Front view propeller

Figure 20: Backside of sealed motor

Figure 21: Motor Schematic and Drawing

Figure 22: Motor performance curve

21

Kort Nozzle

We are using the same type 37 Kort Nozzles as the Hornet II. They chose these

nozzles because of its performance. They are made from plastic and have three

stainless steel screws holding them in place.

Figure 23: Front view Kort nozzle

Figure 24: Side view Kort nozzle

Figure 25: Kort nozzle chart

22

Figure 26: Kort nozzle drawing

DC-DC Converter

This DC-DC converter converts the 300VDC to 12VDC with very little current input

but high output current. The 12VDC is used by all the electronics in the ROV.

Figure 27: DC converter schematic

23

4.2.8 AC-DC Front End

This FE-300 model takes the normal 110 or 220 AC power and converts is to the 300

DC. This is used to send 300 volts DC down through the tether to our ROV. . The

reason we are using 300VDC is to minimize the power loss down the cable. Since

power loss is proportional to current draw, sending a high voltage down the cable and

converting it, with low current draw, to the voltage needed below is much more

efficient

Figure 28: AC-DC Front End converter schematic

4.2.9 Video Camera MB-1050C model

This is a high resolution color video camera. It is not waterproof so we placed it

inside our pressure housing facing a clear dome to see in front of the ROV. The

camera auto adapts to different brightnesses ranging from sunlight to fluorescent

light.

24

Figure 29: Video Camera

Figure 30: Video Camera Schematic

4.2.10 Video Overlay

The video overlay that was used creates an output on the monitor to show the data

collected from the sensors on our ROV. This way we can tell the time, pressure, and

the direction the ROV is facing.

4.2.11 Pelican Box

The pelican box has our Monitor mounted to the top and a gas spring (100 N of

force) helping the box to be stable. The bottom of the pelican box has all the controls

and electronics for our ROV. To house these electronics, Plastic Design

Manufacturing created a custom mount for the electronics. The electronics are

mounted on the bottom of the plastic insert; while, the joystick and on/off switches

are mounted on the topside. To make the joystick easily usable we created a spring

25

system that allows us raise the plastic insert while the ROV is in use then lower it

back down to close the box.

Figure 31: Pelican Case

4.2.12 Tether

The tether carries down power to the ROV and relays the Data collected by the ROV

allows for communications to and from the ROV, and provides a line for real time

video feed back up to our pelican box. The tether we purchased has 10 conductors

and came in three 60 foot parts and is neutrally buoyant. We cut off an eight foot

section to connect our control box to our tether reel. There is a slip ring to prevent

the wire to twist or kink through the reel. We stripped the tether wiring and soldered

them together, and then we took a 3M scotchcast splicing kit (R) and covered the

exposed wiring to be waterproof. We attached the other end of the tether to a

connector, which is also being attached through a hole in the pressure housing.

Figure 32: Connector to ROV

26

Figure 33: Connector to control box

Figure 34: Spliced section

4.2.13 Joystick

The joystick is the main human interface into the ROV. This allows the user to

control the movement of the vehicle with pinpoint precision. The control is a three

axis joystick that provides command of both horizontal and vertical movement. It has

three potentiometers that feed into a board created by Larry Buist, which transmits the

RS-485 signal down to the ROV. This is then inputted into the Motor Controllers,

also built by Larry Buist, which sends out the power to the Motors.

Figure 35: 3-axis joystick

27

5. Procedures

Preliminary Design

The main design criteria taken into consideration for SeaWeed were that it was to be

a small, observational ROV most comparable to the Hornet I and Hornet II as well as

the Video Ray, Shark Marine and other competitive ROVs on the market. We hoped

to produce an ROV up to the caliber of ROVs being sold today; however, we wanted

to produce a lost-cost version allowing availability to many more consumers.

Design Considerations

The instruments we planned to feature when we began designing SeaWeed included a

camera, lights, pressure sensor, temperature sensor, compass, recovery arm and other

oceanographic instruments. We also planned to implement a suction-cup like track to

help the ROV “walk” along boat hulls during ship hull inspections. The pressure

housing was going to be depth rated to 300 feet, and therefore we planned to have a

tether of at least 600 feet, in order to provide us with a 2:1 ratio length to depth. We

planned on four motors, two forward and aft on vertical and one horizontal placed

perpendicular to the back plate of the housing. The frame was to be made out of

aluminum extrusion and we were going to order an acrylic dome to add to the

housing as a viewfinder.

28

Some of the first designs:

Figure 36: Design 1 front view

Figure 37: Design 1 bottom view

Figure 38: Design 1 side view

Figure 39: Design 2

29

Final Design Decisions

After several considerations, the final design decisions were made. Our frame is

made out of aluminum pipe with aluminum bar supports. The housing is also

aluminum and an end cap holds the acrylic dome in place at the front of the housing.

The motor mounts from the Hornet II project were incorporated into our design so

that new ones would not have to be machined and an adjustable light mount is located

at the front lower left hand side. The final instrument package includes a pressure

sensor and compass, as well as a color camera. The tether is 170 feet in length and

neutrally buoyant. It is stored on a tether management and deployment system. The

control box is a modified Pelican Box that now houses the monitor, joystick and all

topside electronics. The design of each component of the system will be detailed in

the following pages.

Housing Design and Manufacturing

Housing Dimensions

The housing is cylindrical in shape and its dimensions are as follows:

Inner Diameter: 5.000”

Outer Diameter: 5.125”

Flange Outer Diameter: 7.592”

Length: 6.125”

Housing Materials

The housing is roll formed 1/8” aluminum.

30

Housing Design

SeaWeed’s housing design was setup to be compact, lightweight, and extremely

adaptable, as well as being secure to protect the instruments. This was accomplished

by using lightweight aluminum. The pressure housing is made up of three pieces: the

main body, forward end cap, and aft end cap. The pressure housing was placed in

the center on the bottom section of the frame to allow for balance and to allow the

vertical thrusters to be mounted directly above which in turn made SeaWeed a more

compact unit. It also leaves room for attachments to be added to the left and right of

the pressure housing. Looking at SeaWeed from the front on the right lower side is a

light mount in which the angle can be adjusted. This allows the light to be position

correctly as to not white out the ROV’s video feed. To the left side of the ROV there

is still room to mount a manipulator arm or some other kind of attachment. The

overall length of the pressure housing is shorter then the frame length which allows

the frame to protect the dome in the front of the ROV as well as the connectors if the

aft of the ROV.

*Note: See Appendix B for CAD drawings

Figure 40: Side view housing

31

Outer Housing

The housing is 1/8” roll formed aluminum with two flanges welded on either end to

support the end caps. The forward flange has a raised circular center in which the

acrylic dome sits over. The forward end cap is a ¼” piece of circular aluminum that

has a hole in the center to allow the dome to slide through. It also has holes drilled

around the outer edge to match those of the forward flange to slide bolts through to

tighten the end cap down allowing it to become watertight. The aft end cap is a solid

piece of aluminum but has six holes drilled in the center area with through hole

connects. These connectors are for the four motors, one light, one pressure sensor

and one for the tether. There is also holes drill around the perimeter, which match the

holes on the aft flange to allow fasteners to slide through to enable the end cap to

tighten down and become watertight.

Internal Systems Mount

The internal systems mount is made out of two pieces of sturdy plastic, two long

threaded posts and a piece of sheet aluminum. All of the internal electronics that will

be in the housing itself are mounted to this piece and then snugly slid into the

housing. This keeps the electronics safe from bouncing around or touching each

other and being damaged. It also provides an easy way to insert and remove all the

electronics.

Figure 41: Internal mount with electronics inside housing

32

Housing Manufacturing

We collaborated with Alliance Tool and Machine, Co. to have the housing and end

caps manufactured. After some discussion, we realized a few modifications were

needed. Ed Robbins, from Robbins welding continued working on the housing and

welded an end cap for us. He also drilled the holes needed for all the connectors into

the back end cap. The front cap has a radial O-ring seal against the dome and an end

cap to apply pressure. The back end cap has an O-ring face seal and pressure is

applied with six bolts.

Frame Design and Manufacturing

Frame Dimensions

The frame dimensions are as follows:

Length: 24 inches

Height: 16 inches

Width: 20 inches

Frame Materials

The frame was made out of 1-inch outer diameter, 1/8 inch wall thickness aluminum

tubing. There are also pieces of 1/8 inch aluminum bar for supports and mounts. We

chose aluminum because it is lightweight, durable and easy to access.

Frame Design

Our main design criteria were dimensions, weight and feasibility. We wanted to the

frame to be lightweight and durable, so we chose marine grade aluminum as the

material. Several designs were created, however the basic shape and size have been

consistent throughout the entire design process. We kept a lot of room for extra

flotation and other instruments by mounting the housing at the bottom of the frame.

This will also keep the vehicle more stable.

*Note: CAD Drawings can be found in Appendix C

33

Outer Frame

Made of lightweight marine grade aluminum tubing, the outer frame protects the

housing and motors, and provides a basis for flotation and instruments to be mounted

in the future. The tubing has drain holes in order to flood the frame brining it closer

to neutral buoyancy. The reinforcing aluminum bar in the center of the frame

lengthwise runs vertically on each side of the frame. There are also tubing supports

along the bottom, both sides, and the top.

Motor Mounts

We integrated the plastic motor mounts from the Hornet II into our design. They are

mounted to the frame by screws and supports.

*Note: CAD Drawings can be found in Appendix C

Figure 42: Vertical motors and motor mount

Figure 43: Forward/Aft motor mount

Figure 44: Forward/Aft motor mount with motor and propeller

34

Lighting Mount

The light mount is made out of 1/8 inch aluminum plate and consists of a clamp and

rotating support. This rotational support allows the light to be angled 20 degrees up

or down, letting the light be directed in a specific area. For example, if SeaWeed is

performing a hull inspection, the light would be angled downward to shine onto the

hull.

Figure 45: Forward view lighting mount

Figure 46: Top view lighting mount with light

Figure 47: Close up front view lighting mount

Figure 48: Side view lighting mount

35

Frame Manufacturing

The frame was a team effort between the SeaWeed ROV team, contact Tom Dobek

with Repair Industries of Michigan and their sub-contractor Blue Water Fabricators.

We had several design meetings with both companies to decide on a final design.

They provided all the materials and manufacturing for the frame.

Internal Systems

Introduction

The internal systems on the ROV include a pressure sensor, compass and video feed.

Bottomside we also have a power converter. The topside internal systems are slightly

more complex, including video overlay as well as PIC controllers to decode the data

sent up the tether. We also have power supply and topside converters.

Figure 49: Internal Systems flow chart

36

Figure 50: Internal systems sensor board

Compass

The compass we integrated into the internal systems mounts onto the sensor board

and has a signal that is decoded by a PIC 18 controller. The data is then fed into the

video overlay and displayed on the monitor.

Pressure Sensor

The pressure sensor is mounted onto the back plate of the ROV with all the

connectors, so that it can read the pressure outside the vessel. Its data is also sent up

to the control box.

Figure 51: Pressure sensor attached to back end cap

37

Video and Data Transmission

Video signal is converted into a differential signal that allows it to be transmitted over

1000 feet of twisted pair. The compass and pressure sensor data is sent up the tether

again is RS-485 format, into the control box. The top side controller decodes the

video back into a RCA connector and is run through a store bought video overlay

board that displays the data over the video screen.

Steering and Propulsion

Power Supply and Transmission

Power to the ROV is converted through an AC-DC Front End converter from the

usual 110 V AC to 300 V DC. This 300 V is sent down the tether into a bottomside

DC converter that converts it to 5 V and 12 V DC to power the ROV and its

subsystems.

Motor Controller Design

Larry Buist, the electronics technician for Florida Tech, designed a very efficient set

of motor controllers for our project. We have one board that controls the forward and

aft thrusters and one board that controls the vertical thrusters.

Joystick Integration

Larry Buist also built a joystick integration board for us. Our three axis joystick was

integrated into the system so that the forward and aft thrusters would be controlled by

any horizontal movement of the joystick, and the z-axis or the spin on the joystick

would control the two vertical thrusters.

Buoyancy and Stability

The buoyancy and stability of the vehicle are very important properties to consider in

one’s design. The tendency is to make an ROV slightly buoyant and the tether

neutrally buoyant. Usually an ROV is operated while it is positively buoyant for two

reasons: so it can operate at any depth in the water column, and as a safety

mechanism so the vehicle will float to the surface in case the tether is disconnected or

38

power is lost. As a rule of thumb, smaller vehicles like the SeaWeed require

approximately 5 pounds of buoyancy. (4)

Syntactic Foam

We plan to use donated syntactic foam for our floatation on the vehicle.

Syntactic foams are composites made by filling metal, ceramic or polymer matrix

with hollow microballoons, usually glass.

Buoyancy Calculations

Overall, through the following calculations it was found that SeaWeed needed

approximately 184 cubic inches of syntactic foam to be neutrally buoyant. However,

because we want the vehicle to be positively buoyant we plan to implement

approximately 250 cubic inches

V

m

)1( 2

object

OH

b mm

32 1025m

kgOH

301824.0 mV kgw 39.8

3635.460

08214.0

39.8

m

kgobject

kgmb 27775.10)635.460

10251(39.8

305.8281.9)018214.0(635.460 VgFb

3

3

61.183

00301.0

81.9)(635.4606.13

inV

mV

V

39

Control Box Design

The goal of SeaWeed’s Control box was to have a single unit that was very

streamline and compact. The whole control system is boxed inside a watertight

Pelican box, which allows for stowage outside on a ships deck when not in use In the

middle of the control panel it sinks in to allow for the holding cables as well as

manuals for the ROV itself. When the ROV is not in use the Pelican box lid can be

shut and latched, allowing the internal parts of the Control Box to be seal from the

elements.

Pelican Box Modifications

Gas Spring Hinge

. The weight of the lid is supported by a lifting spring mounted inside the box on the

left hand side. The gas spring was donated by Easy Lift of North America and has 12

pounds of pressure.

Figure 52: Gas spring on control box

40

Monitor

. Inside the lid of the control box is a 17” color monitor to watch the video feed

coming from the ROV.

Figure 53: Monitor mounted in control box

Mounting System

The monitor is mounted in the pelican box by an aluminum metal piece that we had

machined at the shop on campus.

*Note: CAD Drawings for the mount can be found in Appendix B.

Plastic Mold

The plastic control panel acts as an interface between the ROV and the human

operator. Everything that controls the ROV is mounted on the plastic control panel.

Design and Manufacturing

The panel was manufactured by Plastic Design. It is made out of thin, lightweight,

black plastic.

*Note: CAD Drawing for the panel can be found in Appendix B.

Figure 54: View from back of control panel

41

Figure 55: View from front of control panel

Figure 56: Top view control panel

Spring Mechanism

On the bottom section of the Pelican box are four bars attached to the box standing

vertically. This allows the plastic control board to slide down the four posts and be

secure. Springs on these posts will allow the panel to “pop” out making the joystick

and controls easily accessible.

Figure 57: Inside of control box without panel

42

Electronics Mounting

. On the under side of the plastic control board are the topside electronics, which

allow SeaWeed to send and receive information back and fourth. On the topside of

the plastic control panel there is a joystick to control the ROV. As well as two

switches: one to turn the light on and off, and the other to power the surface controls

and the ROV itself. There is also the connector to allow the tether to connect to the

control system in which the data/power is sent back and forth through

Figure 58: Underside of control panel with mounted electronics

Additions

The control box was designed to add a few more features added to it. The first is an

LCD screen, which can be mounted next to the joystick so the pilot of the ROV can

monitor the thrusters speed, electronic temperature, and thrusters directions. There is

also room to add switches for more attachments such as a manipulator arm or a

crawler type attachment. Finally a LED system still has to be mounted to show when

the unit is powered, another to give a warning and finally an error indicator.

43

Tether Modifications and Tether Management System Design

Basic Hose Reel

The tether management system is a simple hose reel purchased from a hardware store.

We modified it to accommodate the tether. Although we initially thought the reel

was small and it would be a tight fit for our 180 feet of tether it turns out we have

enough room on the reel to add at least one more 60 foot section.

Figure 59: Tether Management System

Slip Ring Modification

We installed a slip ring on the side of the hose reel that allows the tether to pay out

while attached to the control box. The slip ring itself is a mechanical device that

allows 12 conductors to pass through it while it spins, without allowing the wires to

become twisted. We had to splice our tether onto both sides of the slip ring and then

secure the tether to the TMS.

Slip Ring Cover Modification

The slip ring is a very delicate device so we cut a piece of elbowed plastic and

attached it to the hose reel to act as a guard for the slip ring in case the TMS was

bumped the wrong way.

44

Basic Tether Properties

We purchased 3 60 foot sections of neutrally buoyant tether from Video Ray LLC at

an educational discount. It is a very small diameter tether to reduce drag underwater

and is the tether that all Video Ray products use.

Adding Connectors

We recycled the connector that attaches to the ROV from a previous project, and had

to splice that together with the tether. It had 12 conductors in it, but we only needed

10. It is a dry-mateable connector, meaning it should only be connected when the

connector is dry.

Figure 60: Dry-Mateable ROV connector

The other connector we used is a metal connector with a mounting piece. It is for the

tether to connect into the control box.

Figure 61: Dry-Mateable control box connector

45

Splicing Components together

Because the tether came in 60 foot sections we had to splice it together, we also had

to splice on the connectors. Splicing is a fairly simple, yet tedious procedure. You

first remove the outer jacket and the wire insulation, then twist and solder the specific

wires together. Shrink wrap is used to keep the wires from touching each other and to

keep everything organized, however, shrink wrap is not waterproof. Therefore, for

the sections of tether that we spliced that were going to be underwater we used a 3M

splicing kit.

Figure 62: Spliced section of tether with 3M splice kit

46

6. Results

Testing Methods

Pool Tests

Test 1: ROV with Dome and Entire Back Plate

The first test was to see if the O-ring seals were water tight. For this, we took the two

end caps and tightened them together with the appropriate nuts and bolts. We placed

them into south gate pool and watched for bubbles. When we saw that there were no

bubbles we moved it into the deep end and left it there for an hour. After we resurfaced

it, we checked for water inside the dome. This test was very successful and there was no

water inside the dome. From this we believed there were no leaks in the O-ring seals.

Test 2: ROV with Dome, Back Plate and Cables and Connectors

Test two was to see if the pressure housing had any leaks with all the tapped holes in the

back-end for all the connectors and in the welds. We placed the whole ROV into the pool

without the electronics, but all the wires were in the connectors. We started again in the

shallow end and worked our way into the deep end looking for bubbles the whole time.

We did not see any bubbles; however, we did notice three drops of water inside the

pressure housing when we brought up our ROV. Because we noticed these drops we

took an air compressor and filled the pressure housing up to 50psi. We put liquid soap

around all the welds and o-ring seals and saw three locations where bubbles occurred.

There were two pin holes in the welding and the back O-ring seal was not sealing

correctly. We discussed the cause of the back O-ring seal and concluded that it’s because

the pressure was pushing out of the pressure housing moving the O-ring out of the groove

instead of the pressure coming from the outside sealing up the O-ring. We brought the

ROV over to the schools machine shop to fix the pin holes.

47

Figure 63: Front view

Figure 64: Top view

Figure 65: Left front view

48

Figure 66: Back view

Figure 67: Underwater front view

Figure 68: Underwater front view 2

49

Figure 69: Underwater side view

Figure 70: Underwater side view 2

Figure 71: Underwater deep end

50

Figure 72: Underwater traveling to deep end

Figure 73: Underwater deep end

Figure 74: Above surface inspection

51

Test 3: Full ROV Test

Our third and final test for the summer was the whole ROV, electronics and all, with two

cut pieces of foam for floatation. We tested out the motors and only two of them worked.

We placed these two motors so the ROV can move horizontally but not vertically. We

put the ROV in the pool again and started up the motors. The ROV did not move much

at all, mostly due to the fact that the motors were going in opposite directions

counteracting each other. In addition, we realized that these small motors with small

props were probably not powerful enough to move our ROV at a decent speed.

Figure 75: Front view with foam

Figure 76: Working on ROV at pool

52

Figure 77: Getting ready to test

Figure 78: Deployment

53

Figure 79: Underwater front view

Figure 80: Adjustments

Figure 81: In the water

54

Figure 82: Controlling and Observing

Figure 83: Underwater 2

55

7. Conclusions and Recommendations

From the three tests that we have done we have figured out that much work needs to be

continued on this ROV. During the next two semesters we would like to get our ROV

fully operational and get it ready for the ROV competition for the next summer. To do

this we need to fix the electronics and pot four new motors so they are water proof. In

addition, we need to cut and attach the syntactic foam that we will be using. If we stick

to the motors we are currently using we will have four lateral motors to insure that the

ROV has some momentum to it, otherwise we will put four new motors that have larger

propellers.

There are a few recommendations that the next ROV group should consider. The biggest

recommendation is get the electronics started right away, it takes the longest to do and it

is the hardest part. We also waited too long to get the frame built so by the time we got it

we had to work from 8am to 10pm. Before the frame got here we had to put a lot of

things off until the frame arrived. Another good recommendation would be to try and get

as many sponsors as you can, especially during the spring semester so you have it for the

summer. The two largest factors in this project are time and money. As long as the next

team keeps both of these factors in mind, they should be on the right track.

56

8. Appendices

Appendix A: Project Economics

Team Economics

Team Member Hours Worked

Estimated Employment Cost

Total Hypothetical Pay

Nick Abruzzini 461.5 $30.00/Hour 13845.00

Janelle Boisvert 428.0 $30.00/Hour 12840.00

Katie Dobek 434.0 $30.00/Hour 13020.00

Anthony Tedeschi 440.5 $30.00/Hour 13215.00

Total Team Hours 1764 Total Team Pay Costs 52920.00

Donated Economics

Donated Parts

Donator Item Cost

Easy Lift Gas Spring 45

Donated Monies

Donator Amount

Mainstreet Pub 50

Donated Materials and Time

Donator Service Cost of Material Time

Pay Rate per Hour

Total Donation

Repair Industries Design 5 55 275

Repair Industries Consulting 10 150 1500

Larry Buist Consulting 140 40 5600

Blue Water Fabricators Manufacturing 72 28 41 1220 Alliance Tool and Machine Manufacturing 198 29.5 60 1968 Precision Tech Machining Manufacturing 2 60 120

Maila Sepri Consulting 240 30 7200

57

Budget

Spring Budget

DMES Money

Total Starting Budget $1,250.00

Total Spent 1251.63

Items Cost Shipping

Dive Light 125 14.75

Transistors 40

Pelican Box 112.19

Monitor 149.99

Tether 180 15 Pressure Housing Connectors

SealCon Connectors 58.02

Joystick 101 8

Gas Spring 9.86

Electronics Mouser 96.06

Electronics DigiKey 134.99

Brackets 3.5

Hose Reel 19.99

Slip Ring 153

Acrylic Dome 10

Miscellaneous

Bookstore 17.93

Copy Center 2.35

58

Summer Budget

Item Cost Quantity Shipping Total

Max 627 4.90 5 16 40.50

Control Panel 53.94 1 0 53.94 Miscellaneous Electronics 5.0 2 0 10.00

Marine Tex 9.99 1 0 9.99

Shrink Wrap 2.99 2 0 5.98 Electronics (Larry Buist) 38.25 2 9.70 86.20 Electronics (Larry Buist) 29.16 1 13.74 42.90 Electronics (Larry Buist) 59.00 1 0 59.00 Micsellaneous Fasteners 24.87 1 0 28.65

Tap 7.53 1 0 7.53

Anti-seize 2.94 1 0 2.94

Spade term 0.97 2 0 1.94 Miscellaneous Hardware 42.02 1 0 42.02

InsDisc Contact 0.99 2 0 1.98

Ceramic Fuse 2.99 1 0 2.99 Electronics (Maila Sepri) 94.95 1 0 94.95

Shipping 0 1 222.2 222.20

Hex Nut 2.56 1 0 2.56

Wire 6.99 1 0 6.99

Splice Kit 27.72 3 0 83.16

Total Spent 806.42

Amount Left -

306.42

Total Project Economics

Spring Budget 1251.63

Summer Budget 806.42

Donations 3678

Team Pay 52920

Consulting Pay 14300

Total Project Cost 72956.05

59

Appendix B: Auto-Cad Drawings

Preliminary Control Panel Design

60

Pressure Housing Design

61

Appendix C: Circuit Schematics

Sensor Package Board

Sensor Package Board

62

Joystick Board

Joystick Control Schematic

NC

LED - Red- "Reverse"

LED - Grn- "Forward"

LED - Yel- "Brake"

NC

5K

.1

Gen LED represents Forward

Red LED represents Reverse

Yel LED represents Brake On

Grd

8

5

RO1

DI4

RE2

DE3

A6

B7

MAX485

DB6

DB5

DB7

20 X 4 line

NC

LM 044LLCD

RA4....

Molex pins & Header

R/W

EN

RS

161

DB6

NC

RA5....

Forward/Reverse

SPEED

Joystick POT

NC

NC

6.8uf

.1

LM78L05

-

+

7 to 12 Volts

Optionable LCD Display

5K

+5 Volts

198

Joy3

AN0....

PIC Assignments:

AN1....

Up/Down

Joystick POT

AN2....

Joy2

Joy1

AN3....

Right/Left Steer

MCLR/VPP/THV1

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA3/AN3/VREF+5

RA4/T0CKI6

RA5/AN4/SS7

OSC1/CLKIN9

OSC2/CLKOUT10

RC0/T1OSO/T1CKI11RC1/T1OSI/CCP212RC2/CCP113RC3/SCK/SCL14RC4/SDI/SDA15RC5/SDO16

RC6/TX/CK17RC7/RX/DT18

VD

D20

RB0/INT21RB122RB223RB3/PGM24RB425RB526RB6/PGC27RB7/PGD28

U9

PIC16F876

.1

FWD/REV-Speed

20pf 20pf

4MHZ

Steer Joystick POT

6.8K

1.2K

5K

RB2....

RB3....

RB4....

RB5....

RB6....

RB7....

LCD EN

LCD DB4

LCD DB5

LCD DB6

LCD DB7

LCD RS

VIN VOUT

RB1....

RB0....PC Serial out

NC

2N3904

RC7....

.1

.1

RC6....

RC5....

Comm to PC Serial Port

Comm to Submersable

RC4....

300

300

Grn

Red

RC3....

RC2....

Yel

300

.1

120

RC1....

RC0....

SUB TX/RX control

SUB Serial Out

SUB Serial In

63

Motor Controller Board

Motor Controller Schematic

Brake

MCLR/VPP/THV1

RA0/AN02

RA1/AN13

RA2/AN2/VREF-4

RA3/AN3/VREF+5

RA4/T0CKI6

RA5/AN4/SS7

OSC1/CLKIN9

OSC2/CLKOUT10

RC0/T1OSO/T1CKI11RC1/T1OSI/CCP212RC2/CCP113RC3/SCK/SCL14RC4/SDI/SDA15RC5/SDO16

RC6/TX/CK17RC7/RX/DT18

VD

D20

RB0/INT21RB122RB223RB3/PGM24RB425RB526RB6/PGC27RB7/PGD28

U8

PIC16F876

OUTA2

OUTB20

DB014

DB113

DB212

DB311

DB410

DB59

DB68

DB77

VD

D17

REFA4

REFB18

DACA/DACB6

WR16

CS15

RFBA3

RFBB19

U7

TLC7528

"B" FWD/REV

8

5

RO1

DI4

RE2

DE3

A6

B7

MAX485

.1

.1

LM7805 or 4805

Grd

8

Temperature Sensor

for board assembly

Temp

Sensor

LM34D

VINVOUT

A

C

B

.1

120

8

* NOTE:

Q2,Q4,Q6 = IRLI3705 N-Channel

Molex Connector

Brushless

DC Motor

A

MOTOR B

C

B

Serial Communications

Molex Connector

Brushless

DC Motor

"A" FWD/REV

+12v

Fwd/Rev A

A

DAC Buss

RA5.....

RA3.....

RA2.....

RA1.....

RA0.....

4.3K

4.7uf

4.3K

4.3K

.1

4.7uf

Red

Blk

Wht

Yel

Brn

Org

Gry

Blu

.1

Color code for SeaWeed motors

.1

D

D

D

D

D

D

S

S

S

S

S

G

G

S

G

G

G

G

MC33055

Temperature

"B" Speed

"A" Speed

N

U2

Battery

P

ERA+11

ERA-12

ISENSE-15

OE7

OSC10

60/12022

AB21

BB20

CB19

AT2

BT1

CT24

FAULT14

REF8

ER/PWM13

VC

18

VC

C17

ISENSE+9

BRAKE23

FWD/RV3

SA4

SB5

SC6

Grd

16

P

N

3

412

14

U4BTC4469

1

213

U4ATC4469

5

611

7

U4CTC4469

8

910

U4DTC4469

3

412

14

U3BTC4469

1

213

U3ATC4469

5

611

7

U3CTC4469

8

910

U3DTC4469

Q11

Q10

Q9

Q7

Q12

Q8

Q1,Q3,Q5 = IRF5305 P-Channel

Fwd/Rev B

5

P

N

C

PIC Analog Assigments

270

270

270

270

270

270

B

6

MOTOR A

7

1

2

3

Current Sense

Resistor

4

Q8,Q10,Q12

(Temp sensor)

____

PIC I/O Assigments

Serial RX/TX

A

4.3K

4.3K

10uf

10uf

4.3K

.1

.1

.1

D

D

D

D

D

D

S

S

S

S

S

G

GS

G

G

G

MC33055

G

N

U1

P

ERA+11

ERA-12

ISENSE-15

OE7

OSC10

60/12022

AB21

BB20

CB19

AT2

BT1

CT24

FAULT14

REF8

ER/PWM13

VC

18

VC

C17

ISENSE+9

BRAKE23

FWD/RV3

SA4

SB5

SC6

Grd

16

N

P3

412

14

U6BTC4469

1

213

U6ATC4469

5

611

7

U6CTC4469

8

910

U6DTC4469

3

412

14

U5BTC4469

1

213

U5ATC4469

5

611

7

U5CTC4469

8

910

U5DTC4469

Q5

Q1

Q2

Q4

Q3

Q6

U9

5

RC4....

RC5....

RC6....

RC7....

RB0 TO RB7....

N

P

C

270

270

270

270

DAC Write

DACA/DACB

B

270

270

"B" Speed

"A" Speed

Q7,Q9,Q11

Brake

6

Ground

High Current

Ground

+5v

+5v

+5v

7

+12 Volts

6.8uf

RC3....

+5v

+12v

+12v

51

1

(Blu/Gry swapped on prototype)

+5v

RC2....

.005 ohm = 20amp

.005 ohm = 20amp

5.1K

.22

.22

.1

10uf

5.1K

RC1....

2

10K

20K

20pf 20pf

4MHZ

68

68

10uf

10uf

10K

3

B

A

RA4.....

RC0....

100

.1

.1

100

4

NC

Current Sense

Resistor

Spare Analog

Input

Fault Ind.

Serial Out

Serial In

64

Appendix D: References

1. Hornet II report

2. www.isope.org/publications/journals/ijope-11-4/ijope-11-4-p282-abst-WK-56-

Buckham-2.pdf

3. http://oceanexplorer.noaa.gov/technology/subs/rov/rov.html

4. http://www.rov.org/educational/pages/Ballast.html

5. http://www.sharkmarine.com/Stealth2Article.htm

6. http://www.videoray.com/Products/scout.php

7. http://www.seabotix.com/