Yellow Submarine - Cam Iseri: Portfoliodesign against the requirements. Customer requirements: The mini-submarine must be able to run for at least 20 minutes non-stop. The batteries

Yellow Submarine

Final Report

EE3730/EGR3810 Engineering Design Spring 2011

Seattle Pacific University Engineering Department

June 6, 2011

Design Team: Electromagnetic Fields Forever Sean Byrnes Jamie Inouye

Cam Iseri Kristin Lorenzen

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ABSTRACT

Completed by all

Our team has designed a Wiimote controlled mini submarine. This design is contained in a

modified water-bottle hull, and uses DC motors, a servo, a microcontroller and batteries stored inside

the hull to power its motion.

The submarine’s movement was considered in three directions: forward, left/right, and

up/down. The right and left turning movement is controlled by the rudder, a vertical platform attached

to the back of the hull controlled by a servo motor. The forward motion is controlled by another motor,

which drives a propeller that extends out of the rear of the hull. The up and down motion (diving and

surfacing) is created with a motorized syringe ballast-mechanism, which draws water into the hull to

sink and expels water back to the exterior to rise. The syringe movement is controlled with a Lego

motor and linear actuator.

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TABLE OF CONTENTS

Abstract ............................................................................................................................................2

Project Plan .......................................................................................................................................4

Executive Summary ..................................................................................................................4

Requirements Specification .....................................................................................................5

Work Breakdown Structure .....................................................................................................6

Contingency and Mitigation Plans ...........................................................................................8

Original Schedule ..............................................................................................................................9

As Completed Schedule ....................................................................................................................10

Functional Description: Electrical......................................................................................................12

Functional Description: Mechanical ..................................................................................................13

Detailed Design: Electrical ................................................................................................................14

Detailed Design: Mechanical.............................................................................................................16

Test Verification ................................................................................................................................22

Account of Resources: Labor Hours ..................................................................................................24

Account of Resources: Costs .............................................................................................................25

Mitigation and Contingency Plan Update .........................................................................................26

Project Outcomes .............................................................................................................................27

Team Dynamics Reflection ................................................................................................................28

Conclusion ........................................................................................................................................29

Signature Page ..................................................................................................................................30

Bibliography ......................................................................................................................................31

Appendix of Reference Material .......................................................................................................32

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PROJECT PLAN – EXECUTIVE SUMMARY

Completed by Sean and Jamie

The purpose of our junior design project is to build a mini yellow submarine that can move

around in fresh water. This project includes a lot of mechanical engineering as well as electrical

engineering.

The mechanical side of our project was done by the mechanical and appropriate and

sustainable engineers Kristin Lorenzen, Cam Iseri and Jamie Inouye. The main mechanical aspects we

needed to focus on were the design of the hull (body) and its movement underwater. The hull itself was

made out of a standard Nalgene water bottle. This hull design needed to be waterproof, contain our

electrical components, and allow water to flow around it. Tin foil, plastics, gasket material and epoxy

made our submarine waterproof.

Our submarine’s movement was considered in three directions: left/right, up/down, and

forward. The right and left movement are simply controlled by a rudder. This is a vertical platform

attached to the back of the submarine controlled by a single servo motor. Forward movement is

controlled by one more DC motor on the back of our submarine. This activates a propeller. The final

movement was slightly more difficult to design. For our sub to float, the mass of the sub and everything

in it needed to be less than the mass of the water displaced by the entire hull. In short, the average

density of the sub needed to be less than that of water. To sink, the average density needed to be

greater than that of water. We did that by having a motorized syringe which could draw and expel

water. The syringe compressed air while it drew water, so when the water was expelled, the air still

took its place. We used a Lego motor geared up to a linear actuator to control this syringe.

All of the work on the electrical side of our project was done by the electrical engineer, Sean

Byrnes. The microcontroller along with a Bluetooth module contained inside the hull are programmed

to take in Wiimote accelerometer data and control the 3 motor systems inside the mini-submarine. This

was done through the use of an ATMEGA168 microcontroller. The microcontroller was programmed

using the Arduino Duemilanove developer board.

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PROJECT PLAN – REQUIREMENTS SPECIFICATION

Completed by Sean

The following specifications are the desired operating parameters for our mini yellow submarine. The customer’s provided specifications are presented here to detail the method of verifying the final design against the requirements.

Customer requirements: The mini-submarine must be able to run for at least 20 minutes non-stop. The batteries will be rechargeable. The submarine must not leak The mini-submarine should move around in the water as directed by the controller. The mini-submarine must be yellow. Customer does not care what the hull looks like (other than it being yellow) or how it is made.

Design specifications based upon the customer requirements:

Specification

Parameter Value Conditions Verification Method

Depth Capacity Will be able to dive and operate normally at a depth of at least

2 feet

Pressure calculations and physical prototype

tests.

Size Length: 6-12” Width: 3-8” Height: 3-6”

N/A Measure our final

prototype

Battery Life Must be able to last at least 20 minutes underwater using all 3

motor functions simultaneously

Power calculations through circuit analysis and physical prototype

testing

Movement Capacity

Able to: turn left and right

sink and float move forward

N/A Prototype mechanical

testing

Waterproof Must remain operable and without significant leakage at a

maximum depth of 2 feet up to 20 minutes

Individual waterproofed parts and final

prototype testing

Controlled Movement Motor functions must be controlled remotely with A Wiimote Wii remote must be within sight of

submarine Final prototype testing

Hull Color Yellow N/A Final prototype hull

color test

Deliverables to the Customer: Requirements Specification Functional specification Detailed design (including schematic and parts list and cost) Final design and verification report.

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PROJECT PLAN – WORK BREAKDOWN STRUCTURE

Completed by all

Task Name Duration Start Finish Predecessors Resource Names

Hour Cost Cost

Mechanical Design 19 days Wed 4/13/11 Mon 5/9/11

Cam, Jamie, Kristin

40 hours each

$95.00

Hull Design 19 days Wed 4/13/11 Mon 5/9/11

Cam, Jamie, Kristin

15 hours each

$50.00

Research 6 days Wed 4/13/11 Wed 4/20/11

Kristin and Cam

Order Parts 1 day Thu 4/21/11 Thu 4/21/11 19 Kristin and Cam

Shape/Solid Works (1)

4 days Thu 4/21/11 Tue 4/26/11 19 Cam

Mass/volume/ calculations

1 day Fri 4/22/11 Fri 4/22/11 20 Jamie

Pressure Resistant

1 day Thu 4/21/11 Thu 4/21/11 19

Water Proof 2 days Thu 4/21/11 Fri 4/22/11 19

Water Proof Testing

2 days Fri 4/22/11 Mon 4/25/11 20


5 days Wed 4/27/11 Tue 5/3/11 21 Kristin and Cam

Movement 19 days Wed 4/13/11 Mon 5/9/11

Cam, Jamie, Kristin

10 hours $30.00


Cam and Jamie

Order Parts 1 day Thu 4/21/11 Thu 4/21/11 28 Cam and Jamie

Motor/propeller 2 days Thu 4/21/11 Fri 4/22/11 28

Propeller Testing

1 day Fri 4/22/11 Fri 4/22/11 29

Motor/Rudder Design

2 days Thu 4/21/11 Fri 4/22/11 28

-Rudder Testing 1 day Fri 4/22/11 Fri 4/22/11 29

Ballast Design 19 days Wed 4/13/11 Mon 5/9/11

15 hours $15.00


Kristin & Jamie

Order Parts 1 day Thu 4/21/11 Thu 4/21/11 35 Kristin &

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Jamie

Ballast calculations

1 day Fri 4/22/11 Fri 4/22/11 36 Jamie

Ballast Testing 3 days Fri 4/22/11 Tue 4/26/11 36

Mechanical Prototyping

11 days Fri 5/6/11 Fri 5/20/11

20 hours

Final Assembly 11 days Fri 5/6/11 Fri 5/20/11

All

Electrical Design 20 days Fri 4/8/11 Thu 5/5/11

Sean 30 hours $10.00


Order Parts 1 day Thu 4/21/11 Thu 4/21/11

Programmed Control

15 days Mon 4/18/11 Fri 5/6/11

20 hours

Research Arduino Code

4 days Mon 4/18/11 Thu 4/21/11

Test code 5 days Fri 4/22/11 Thu 4/28/11

Integrate with hardware

4 days Tue 5/3/11 Fri 5/6/11

Meet with Business Students

27 days Fri 4/15/11 Mon 5/23/11

All 5 hours

Meeting 1 1 day Fri 4/15/11 Fri 4/15/11

2 hours

Meeting 2 1 day Fri 5/20/11 Fri 5/20/11

2 hours

Meeting 3 1 day Mon 5/23/11 Mon 5/23/11

1 hour

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PROJECT PLAN – CONTINGENCY AND MITIGATION PLANS

Completed by Kristin

Contingency Plan

Fri 4/15/11 Thur 6/2/11

All 20 hours

Work weekends

Fri 4/15/11 Thur 6/2/11

10 hours

Work nights

Fri 4/15/11 Thur 6/2/11

10 hours

Mitigation Plan:

If hull is too small – cut hole in back of hull or purchase larger water bottle/hull

If parts weigh too much to account for the volume displaced – purchase larger hull

If parts weight too little to account for the volume displaced – either add mass on the inside or

add pontoons

If the ballast does not work – add floatation devices or tether the submarine

If controlled movement doesn’t work – program specific motions before placed in the water

If water leaks in through the shaft holes – use more tin foil and epoxy or come up with new

design

If water leaks through the end cap – use more gasket material

If there is not enough power to the motors – add more batteries or use different batteries

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ORIGINAL SCHEDULE

Completed by all

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AS COMPLETED SCHEDULE


Task Name Duration Start Finish Predecessors Resource Names Hours

Mechanical Design 36 days Wed 4/13/11 Wed 6/1/11

Cam, Jamie, Kristin

72 hours each

Hull Design 34 days Wed 4/13/11 Wed 6/1/11

Cam, Jamie, Kristin

24 hours each


Kristin and Cam

Order Parts 1 day Thu 4/21/11 Thu 4/21/11 19 All


4 days Thu 4/21/11 Tue 4/26/11 19 Cam

Mass/volume/ calculations

7 days Fri 5/6/11 Mon 5/16/11 20 Kristin and Cam

Pressure Resistant 1 day Mon 5/16/11 Mon 5/16/11 19 Kristin

Waterproofing 18 days Thu 4/21/11 Mon 5/16/11 19 Cam, Jamie, Kristin

Waterproof Testing

11 days Mon 5/16/11 Mon 5/30/11 20 Cam, Jamie, Kristin


3 days Mon 5/30/11 Wed 6/1/11 21 Cam

Movement 35 days Wed 4/13/11 Tue 5/31/11

Cam, Jamie, Kristin

24 hours each


Cam & Jamie

Order Parts 12 days Thu 4/21/11 Fri 5/6/11 28 All

Motor/propeller 13 days Mon 5/2/11 Wed 5/18/11 28 Cam, Jamie, Kristin

Propeller Testing 5 days Wed 5/18/11 Tue 5/24/11 30 Cam, Jamie, Kristin

Motor/Rudder Design

13 days Mon 5/2/11 Wed 5/18/11 28 Cam, Jamie, Kristin

Rudder Testing 17 days Fri 5/13/11 Tue 5/31/11 32 Cam, Jamie, Kristin

Ballast Design 23 days Wed 4/13/11 Tue 5/31/11

Cam, Jamie, Kristin

24 hours each


Kristin & Jamie

Order Parts 1 day Thu 4/21/11 Thu 4/21/11 35 Kristin & Jamie

Ballast Assembly 16 days Mon 5/2/11 Mon 5/23/11 36 Cam, Jamie, Kristin

Ballast Testing 10 days Wed 5/18/11 Tue 5/31/11 36 Cam, Jamie, Kristin

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Electrical Design 38 days Fri 4/8/11 Tue 5/31/11

Sean 100 hours


Order Parts 1 day Thu 4/21/11 Thu 4/21/11

Controlling motion 32 days Mon 4/18/11 Tue 5/31/11

Research Arduino Code

4 days Mon 4/18/11 Thu 4/21/11

Test Code 19 days Fri 4/22/11 Wed 5/18/11

Integrate with Hardware

10 days Wed 5/18/11 Tue 5/31/11

Mechanical Prototyping

19 days Fri 5/6/11 Wed 6/1/11

Cam, Jamie, Kristin

24 hours each

Final Assembly 6 days Wed 5/25/11 Wed 6/1/11

All

Business Students 5 days Tue 5/10/11 Mon 5/16/11

All 6 hours

each

Meeting 1 1 day Tue 5/10/11 Tue 5/10/11

Cam, Jamie, Kristin

Meeting 2 1 day Thu 5/19/11 Thu 5/19/11

Kristin and Sean

Preparation 1 day Fri 5/20/11 Fri 5/20/11

Kristin and Sean

Presentation 1 day Mon 5/23/11 Mon 5/23/11

Kristin and Sean

As a whole, we deviated a lot from our original plan. Most of the differences were found in the

mechanical side of things. There are additions and changes made in the people who completed the

tasks. The timeline also changed quite a bit. We rearranged schedules in order to fit things in. And

since oftentimes things didn’t work out like we planned, we spent more time (contingency time) on

certain tasks in order to finish them. Overall, more specific dates are included and hourly totals are

included for the main tasks.

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FUNCTIONAL DESCRIPTION: ELECTRICAL

Completed by Sean

Block Diagram

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Wiimote Communication: Wiimote Accelerometer data is sent to a computer

wirelessly via a Bluetooth connection between the computer and Wiimote. The connection is made with using the Windows 7 OS’s built in Bluetooth device detection

Transmit Wiimote Data: A custom made program on the computer then grabs the data being sent from the Wiimote, stores it into a small byte array, then transmits that array out through a particular serial port in the computer. An XBee Bluetooth module (XBee #1) is connected to this serial port so it grabs that data and then transmits it wirelessly again via Bluetooth

Acquire Wiimote Data: Our yellow submarine has a matching Bluetooth module (XBee #2) set up to receive the transmitted Wiimote data. XBee #2 is wired up to our Arduino Microcontroller and developer board. As data is received it is stored into the Arduino’s memory.

Motor Function Control: Once the data is received and stored the microcontroller is programmed to respond by turning on or off one of the 3 motors inside the Yellow Submarine. Each motor controls a specific motor function The ballast controls the sinking and floating function. The propeller controls the forward and backward movement. The rudder controls the turning of the submarine.

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Top side of the Removaboard

Bottom side of the Removaboard

FUNCTIONAL DESCRIPTION: MECHANICAL

Completed by Cam

Final SolidWorks Models:

Hull (water bottle)

Rudder

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End Cap

Battery

Arduino Developer Board

Propeller

Batteries

Propeller motor Rudder (servo) motor Batteries

Half syringe

ballast Lego motor

Lego actuator

Battery

End cap

Battery

Hull (water bottle): Used to contain and protect all of our components from water

Rudder: Controls the left and right movement of the submarine

Removaboard: The board inside the hull that all of our parts are attached to

Bottom view of the

removaboard, removed

from the hull

Top view of the

removaboard, removed

from the hull:

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Ballast: Made up of the half syringe, Lego motor and Lego actuator. Enables us to change the

overall density of the submarine, therefore moving it up and down

End cap: Seals the large hole at the back of the hull, what the removaboard attaches to

Arduino Developer Board: What controls all of the motors in the submarine

Propeller: Attaches to the propeller motor, makes the submarine move forward

Rudder Motor: Attaches to the rudder

Batteries: Give power to the individual motors

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float roll = (float)(Math.Atan2(ws.AccelState.Values.Z, ws.AccelState.Values.X) * 180.0/ Math.PI) / 360 * 255; float pitch = (float)(Math.Atan2(ws.AccelState.Values.Z, ws.AccelState.Values.Y) * 180.0 / Math.PI) / 360 * 255;

if (count == 25) { if (SerialPort.IsOpen) { comm[0] = Convert.ToByte(check_limits((int)roll));// Rudder Control Data comm[1] = Convert.ToByte(check_limits((int)pitch));// Ballast Control Data if (ws.ButtonState.A) // Propeller Control Data { comm[2] = 56; } if (ws.ButtonState.B) { comm[2] = 57; } SerialPort.Write(comm, 0, 1); // Write rudder control data to s-port SerialPort.Write(comm, 1, 1); // Write ballast control data to s-port SerialPort.Write(comm, 2, 1); // Write propeller control data to s-port } count = 0; } }

DETAILED DESIGN: ELECTRICAL

Completed by Sean

Wiimote Communication:

The Wiimote is connected to a laptop running Windows 7 using its own built in Bluetooth device adapter.

Once the laptop recognizes the Wiimote the data from the Wiimote needs to be gathered. To do this we

employ a premade Wiimote data collection library (Wiimote.lib) and a modified C# program (see

Wii_RC_CSExpress.cs). The main function I’ve changed in this C# code is the UpdateWiimoteState

function. I’ve included 2 new lines of code which take the X-Y position accelerometer data and converts

it into pitch and roll data:

As we can see the roll and pitch are stored as floating point values. These values are computed from the

arctangent of the X and Y accelerometer data compared to the Z accelerometer data gathered from the

Wiimote. These values are then converted into degrees and then changed into a value between 0 and

255, the max value of a byte. It must be converted to a byte value as that is the type of data that will be

sent out to the yellow submarine from the computer.

The next modification comes from including an ‘if’ statement that waits until the computers serial port is

open. The serial port is where we’ll actually be sending all of our data. It then converts the pitch and roll

floating point values into bytes and then places them in their own index on a 3 byte array named

“comm”. The 3rd byte comes from the next two ‘if’ statements which check if either button ‘A’ or

button ‘B’ on the Wiimote has been pressed. If either is pressed an integer value between 0 and 255 will

be stored into the last spot in the “comm” array. Each byte in the array is then respectively written out

into the serial port on the computer. This is then repeated every 25 cycles.

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Transmitting Wiimote Data:

More specifically, the serial port in which the data is being written to is connected via a FTDI usb/serial

cable to our XBee 802.15.4 Bluetooth module. Once the data has been written to the serial port by the

Wii_RC_CSExpress program it is recieved by the XBee Bluetooth module. The XBee is set up with the

following configuration:

PAN ID: 3137

This is set up as a specific and unique value to be used only by the two BT modules in our product. This prevents cross talk with any other BT devices nearby.

Baud Rate: 19200

This data transfer rate seemed to give a smoother and faster transfer of the Wiimote control data. This value was used instead of the standard value 9600

Parity: None

A parity bit check is not needed to check the successful transfer of our data.

Stop Bit: 1 This ensures that data is not being overwritten to quickly to the receiving Bluetooth module.

The XBee transmits the byte array that is being sent to it via a Bluetooth signal to the XBee module

receiver incased in the Yellow Submarine’s hull.

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Acquire Wiimote Data:

Inside the hull of the Yellow Submarine is a second XBee Bluetooth module to receive data. This module

is set up to match the data transfer rate and PAN ID of the transmitter XBee module. This Xbee module

is connected to our Arduino microcontroller.

The XBee Bluetooth module and motor functions of the mini-sub are controlled by an ATMEGA168 microcontroller connected to the Arduino Duemilanov microcontroller developer board.

The Arduino Duemilanove is a microcontroller board based on the ATmega168. It has 14 digital

input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz crystal oscillator,

a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to

support the microcontroller.

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The XBee’s Rx and Tx pins are connected as a digital input and output respectively to the Arduino. The

Arduino is programmed as seen below: (from Yellow_Sub_wiiMoteControl)

void loop() { while (XBeeSerial.available() < 3) //wait till it has 3 bytes available { } int wiiRoll = XBeeSerial.read(); // set roll data as wiiRoll int wiiPitch = XBeeSerial.read(); // set pitch data as wiiPitch int wiiButton = XBeeSerial.read(); // set button press as wiiButton …

The arduino waits does nothing until it has received 3 bytes from the XBee. These 3 bytes come from the

3 byte array sent out by the C# program. Once it has received these bytes it places them respectively

into memory as integer values.

Wiring: XBee Rx (receive) wire is connected to digital I/O pin #2. XBee Tx (transmit) wire is connected to digital I/O pin #5

XBee Receiving Module

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Motor Function Control:

More specifically the motors that drive our 3 movement mechanisms (propeller, ballast, rudder) are

controlled with the help of a detachable Motorshield for the Arduino board. (picture of shield and board

shown below).

This Motorshield offers bundled circuitry specified to handle the type of motors we have inside the Yellow Submarine.

5V servo connection: Our rudder is moved using a 5V micro servo. The servo connection is linked directly to the Arduino's high-resolution dedicated timer allowing accurate control of the servo position without a lot of jitter. Control for up to 4 bi-directional DC motors: In our design we only use 2 DC. Each DC motor has individual 8-bit speed selection (so, about 0.5% resolution) using the Arduino’s PWM. 4 H-Bridges: L293D chipset H-Bridges provides 0.6A per bridge (1.2A peak) with thermal shutdown protection, 4.5V to 36V. This works well for our design as none of the motors draw more than 0.6A Pull down resistors that keep motors disabled during power-up

Power Supply:

Our power supply for our submarine consists of 6 NiMH rechargeable batteries. Each battery delivers a

1.2V supply. This gives us a combined total of a 7.2V. The batteries combined are rated to have a

capacity of 3000mAH.

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Ballast Control:

Our Ballast is controlled by a 6V Lego Mindstorm DC motor. To control the motor we have programmed

Arduino accordingly.

As we can see depending on the pitch degree of the Wiimote the ballast motor is either turned on

forward, backward or off.

… //Ballast if (wiiPitch = 170) // if pitched down { motor2.run(BACKWARD); // turn motor on to sink submarine } if (wiiPitch = 86) // if centered { motor2.run(RELEASE); // turn off motor } if (wiiPitch = 1) // if pitched up { motor2.run(FORWARD); // turn motor on to raise submarine } …

Ballast DC Motor

Wiring:

The ballast motor is

connected to the

motorshields M2

positive and negative

pinouts.

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Rudder Control:

Our Rudder is controlled by a 5V micro servo with 1.6kg-cm of torque. Depending on the roll degree of

the Wiimote, the Arduino increments the servo either left or right by 5 degrees.

… //Rudder if (wiiRoll = 170) // if rotate wiimote left { if (pos >= 5)

{ pos-=5; //increment servo by ‘-5’ degrees } } if (wiiRoll = 86) //do nothing if wiimote is generally centered { } if (wiiRoll = 1) // if rotate wiimote right { if (pos

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Propeller Control:

The Propeller is controlled by a 6V DC motor. The Arduino consistently checks whether the Wiimote’s ‘A’

or ‘B’ button has been pressed then turns the motor on forward or reverse. If nothing is pressed the

motor is turned off.

… motor.run(RELEASE); //Propeller if (wiiButton == 56) // if ‘A’ is pressed { motor.run(FORWARD); delay(50); } if (wiiButton == 57) // if ‘B’ is pressed { motor.run(BACKWARD); delay(50); }

…

Wiring: The propeller motor is connected to the Motorshields M1 positive and negative pinouts.

Propeller Motor

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Power Consumption:

Running idle (without motors) the Arduino draws approximately 175mA. The XBee module is drawing a

large amount of that current running at approximately 68mA. The rest is consumed by idle currents in

the motors and powering the Arduino developer board. The Ballast motor, once turned on, draws

approximately 434mA. The propeller motor draws on average 502mA. The rudder servo draws

approximately 212mA while incrementally turning. All these measurements were taken with only one

motor turned on. Also these measurements were taken while out of the water. So the motors will be

slightly more loaded when in water. With all motors turned on at the same time outside of water the

current draw is approximately 1.06A. while in water I will estimate the current draw to be closer to 1.5A

Our battery pack has a supply of 3000mAH. Therefore, if the users were to use all the motor functions

constantly and simultaneously the Yellow submarine should remain powered for an estimated maximum

time of:

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DETAILED DESIGN: MECHANICAL

Completed by Cam and Kristin

Component Image Mass (g)

Length (Diam)

Height (cm)

Width (cm)

Arduino Developer Board

61.83 7.0 2.7 5.5

Rudder

11.88 11.9 0.3 3.4

RemovaBoard

35.51 16.1 0.3 7.3

End Cap

14.36 7.6 1.3 -

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Tubing

2.79 0.5 18.7 -

Small Metal Clamp (x3)

9.57 5.8 2.3 1.9

Large Metal Clamp

15.67 7.4 2.6 2.2

Servo Motor

9.45 2.2 3.1 1.2

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Cylindrical Motor

50.94 2.8 3.5 -

Lego Motor

32.32 2.4 4.8 -

Lego Linear Actuator

16.21 1.5 9.5 -

Half Syringe

10.66 2.8 6.2 -

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Nail (x2)

7.01 .30 9.1 -

90 Degree Piece

28.01 3.8 3.2 3.2

Plumber’s Tape

6.23 7.1 2.1 -

NiMH Rechargeable Battery (x6)

45.63 2.1 4.2 -

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Short Shaft (x2)

3.2 0.25 5.9 -

Small Grey Gear

3.53 3.7 0.7 -

Small White Gear (cut in half)

0.755 2.9 0.1 -

Alligator Clip (x2)

2.54 - 4.5 -

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Gasket Material

- - - -

Miscellaneous Wires

- - - -

PVC Pipe

21.76 8.7 2.0 -

Assorted Weights

10-100 3.0 .2-1.6

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Hull (Nalgene Water Bottle)

175.59 9.3 21.0 -

Water bottle (hull)

Max depth: 2 feet

Water Pressure = 0.433 psi/ft

Max Pressure = 0.866 psi at 2 feet

Volume inside: 1176 milliliters

Total volume displaced: 1310 milliliters

Approximate mass to make the sub sink: 1310 grams

Total mass (without adding weight): 830 grams

Density (without adding any weight):

Therefore the sub floats without any weight. The density needs to be greater than 1 in order for

it to sink. When the ballast has no water in it, the density should be a little bit under 1, so that

when the ballast takes in water the sub will sink, and when the ballast expels that water it

should float.

The hull has a three inch diameter hole drilled into the bottom of the water bottle. Attached to this

open end with marine epoxy is the piece of PVC pipe. This is so the hole is an even, smooth radius all

the way around. Attached to the inside of the pipe are two thin layers of gasket material, which aids in

the sealing and waterproofing of the end cap. A thicker layer of the gasket material is attached directly

to the end cap in a circular manner. This is the final and most reliable step in waterproofing the large

opening in the hull.

Directly attached to the end cap on the inside of the hull is the 90 degree piece. This piece

connects the removaboard to the end cap. Attached to the removaboard are all the pieces inside the

hull.

Propeller

Propeller motor rotates at about 6000RPM unloaded

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Propeller motor is estimated to rotate at about 4500RPM in water at a depth of 1ft

The propeller shaft is attached to the motor through a small hole in the end cap. It is sealed using

tin foil and epoxy. We decided on this option because it allowed the shafts to rotate freely but also

prevented water from entering the inside of the hull. The tin foil was wrapped tightly around the shaft

and then the shaft was removed. This created a hollow shell of tin foil, which was held together using

epoxy. This tin foil shell was then inserted into the drilled hole in the end cap. Epoxy was applied

liberally around the outside of the tin foil shell on both sides of the end cap to prevent leaks and

translational movement of the shaft.

The propeller itself is wedged in between two batteries on the underneath side of the

removaboard. It is held in place with a zip tie.

Ballast

Pulls in and expels 25 milliliters of water

The ballast is comprised of the half syringe, Lego motor and Lego actuator. These parts are attached

to the board using three small metal clamps and one large metal clamp. It is positioned on the top side

of the removaboard. The ballast opens directly to the outside water using a small portion of tubing. The

tubing exits the hull through a hole drilled in the end cap. The tubing is secured to the end cap using

epoxy.

Rudder

Rotates a total of 90 degrees

Rudder motor rotates at about 5 degrees per second

The rudder motor (servo motor) is wedged directly in between the propeller motor and two batteries. It

is secured using a zip tie. To connect to our rudder shaft extending outside the hull we’ve attached a

small gear directly to the servo and another small gear directly to the rudder shaft. When the servo

turns it then turns the gear attached to it which in turn rotates the rudder shaft gear.

Other Electronics

The Arduino developer board is attached to the board using small screws. There are a total of

six batteries that are placed within the hull in order to power the components. Four of them are on the

underside of the board, one is on the top and the last one is in the very back of the hull.

P a g e | 34

TEST PLAN

Completed by all

Depth Capacity:

1. Put hull underwater at a depth of two feet for at least one hour (since the sub is only required to

be underwater for 20 minutes, this time should be sufficient to verify the long term depth

capacity).

2. Take out hull and open it, examine hull itself.

3. If there are no cracks in hull, the depth capacity is verified.

Size:

1. Measure the length, width and height of the hull.

2. If it is within specifications, the size is verified.

Battery Life:

1. Turn on both DC motors and the rudder servo simultaneously.

2. Measure the current draw from the batteries to the Arduino’s power terminal.

3. Divide the rated battery capacity of 3000mAH by the measured current.

4. If the calculated value is greater than .2 hours (20 minutes) then the battery life is within

specification.

Movement Capacity:

Rudder:

1. Turn the rudder servo on to rotate left and right.

2. If the rudder rotates left and right accordingly, then the rudder out of water is verified.

3. Repeat step 1 when the rudder is submerged.

4. If the rudder rotates left and right accordingly, then the rudder in water is verified.

Propeller:

5. Turn the propeller motor on.

6. If the propeller rotates, then the propeller out of water is verified.

7. Repeat step 1 when the propeller is submerged.

8. If the propeller rotates, then the propeller in water is verified.

Ballast tank:

1. Put the open end of the ballast tank underwater.

2. Program the ballast tank motor to take in water.

3. Run program with ballast tank connected.

4. Do steps 1, 2 and 3 for excreting water.

5. If the ballast tank takes on and excretes water as expected, without any leaks, then the ballast is

verified.

P a g e | 35

Waterproof:

Waterproof hull:

1. Put hull underwater at a depth of two feet for at least one hour (since the sub is only required to

be underwater for 20 minutes, this time should be sufficient to verify the waterproofing.

2. Take hull out of water and open it.

3. If it’s dry on the inside, then the waterproofing is verified.

Waterproof shafts:

1. Place and seal shaft to an empty container.

2. Submerge the shaft and container in water.

3. Rotate the shaft at least 100 times (this should be sufficient to mimic the actual running

scenario.

4. Take shaft and container out of the water.

5. If the inside of the container is dry, then waterproofing the shaft is verified.

Controlled Movement:

1. Connect Wiimote to computer via Windows 7 OS device registration

2. Open C# code to connect Wiimote data to serial port.

3. Turn on Yellow Submarine and put in water.

4. Using Wiimote turn all 3 motors on and verify it is accurately controlling each motor function

Hull Color:

1. Check to see that the hull is yellow.

2. If it is yellow, then the color is verified.

P a g e | 36

TEST VERIFICATION

Completed by all

Depth Capacity:

The submarine can easily achieve the specified depth of 2ft without any sign of cracks or breaks in the

hull. However controlling it wirelessly via Bluetooth becomes an issue the deeper it goes. At the 2ft the

submarine can still be wirelessly controlled however transmitting Bluetooth module must be close to

the water’s surface above the submarine.

Size:

The entire submarine is measured to have a length of 28cm a width of 14cm and a height of 14cm

converting this to inches we have a hull size of 11.02”x5.51”x5.51”

Battery Life:

We’ve estimated our average current draw from all 3 motors to be approximately 1500mA therefore

our estimated battery life is

Movement Capacity:

Rudder: The servo and rudder shaft gears are not aligned accurately mainly because there is little room

in the hull. The servo moves the rudder but only slightly and unreliably.

Propeller: The propeller rotates at a high RPM. The submarine is able to move forward at a somewhat

high velocity.

Ballast tank: The ballast syringe takes in and expels water perfectly and does not leak. The submarine is

able to sink, float and obtain neutral buoyancy.

Waterproof:

Waterproof hull: The hull does not leak when underwater

Waterproof shafts: the propeller shaft leaks only about a small drop every 3 minutes. While the rudder

shaft leaks about a drop a minute. This is a tolerable amount.

Controlled Movement:

The Yellow submarine has been programmed successfully to receive Wiimote data wirelessly and

control its 3 motor functions accordingly.

Hull Color: The hull was created out of a yellow Nalgene water bottle

P a g e | 37

SATISFACTION OF SPECIFICATION REQUIREMENTS

-Depth Capacity: Satisfied -Size: Satisfied -Battery Life: Satisfied -Movement Capacity: Not satisfied

Rudder: Not satisfied Propeller: Satisfied Ballast Tank: Satisfied

-Waterproof: Satisfied Waterproof Hull: Satisfied Waterproof Shafts: Satisfied

-Controlled Movement: Satisfied -Hull Color: Satisfied

P a g e | 38

ACCOUNT OF RESOURCES – LABOR HOURS

Completed by all

All of the mechanical tasks were separated

evenly between Jamie Inouye, Cam Iseri and

Kristin Lorenzen. Sean also helped in some

of the building process for the Ballast

mechanism. Most of the time we were

working collaboratively, and the other times,

approximately an even amount of time was

spent working on the project individually.

Sean Byrnes completed all of the electrical

tasks of the project.

Task Name Hour Cost

Mechanical Design 72 hours

each

Hull Design 24 hours each

Research 4 hours

Order Parts 1 hour

Shape/Solid Works (1) 3 hours

Mass/volume/ calculations 1 hours

Pressure Resistant 1 hour

Water Proof 4 hours

Water Proof Testing 6 hours

Shape/Solid Works (2) 4 hours

Movement 24 hours each

Research 3 hours

Order Parts 1 hour

Motor/propeller 6 hours

Propeller Testing 4 hours

Motor/Rudder Design 6 hours

Rudder Testing 4 hours

Ballast Design 24 hours each

Research 3 hours

Order Parts 3 hours

Ballast calculations 2 hours

Ballast Testing 16 hours

Mechanical Prototyping 19 days 24 hours each

Final Assembly 6 days 20 hours each

Task Name 10 days Hour Cost

Electrical Design 38 days 100 hours

Research 6 days 15 hours

Order Parts 1 day 5 hours

Control (programmed) 32 days

Research Arduino Code 4 days 10 hours

Rework and Retest 19 days 3 hours

Integrate with hardware 10 days 4 hours

P a g e | 39

ACCOUNT OF RESOURCES: COSTS

Completed by Sean

Part

Cost $

RC Model Boat Ship 38mm Plastic Propeller Props

7.37

Marine Grease (5 oz.)

9.44

O-Ring Assortment

5.50

Disposable Syringe 60cc

3.50

Ballast Motor (6V 60RPM High Torque Electric Gear Box Motor)

15.00

Propeller and Rudder Motor (6V high RPM) (each)

10.00

Ni-MH 7.2V/2800mAh rechargeable battery pack and charger

45.00

Random Gears and parts

10.00

Water Bottle (ship hull)

1.00

Arduino Deucimilanov + MotorShield

45.00

Other miscellaneous tools and supplies

20.00

Total

$171.80

P a g e | 40

MITIGATION AND CONTIGENCY PLAN


Contingency Plan

Fri 4/15/11 Thur 6/2/11

All 20 hours

Work weekends

Fri 4/15/11 Thur 6/2/11

10 hours

Work nights

Fri 4/15/11 Thur 6/2/11

10 hours

We definitely utilized our contingency plan, especially towards the end of the quarter. Although we

were a little behind in the project plan outline, we were able to complete the tasks by coming in and

working long hours on the weekends and evenings.

Mitigation Plan:

If hull is too small – cut hole in back of hull or purchase larger water bottle/hull

o Completed: We first bought a new water bottle and when it was still too small, we cut a

hole in the back of the hull

If parts weigh too much to account for the volume displaced – purchase larger hull

o Not completed

If parts weight too little to account for the volume displaced – either add mass on the inside or

add pontoons

o Completed: We added various small weights to the inside of the hull in order to increase

the weight of the sub

If the ballast does not work – add floatation devices or tether the submarine

o Not completed

If controlled movement doesn’t work – program specific motions before placed in the water

o Not completed

If water leaks in through the shaft holes – use more tin foil and epoxy or come up with new

design

o Not completed

If water leaks through the end cap – use more gasket material

o Completed: There were significant leaks in the end cap, so we purchased a thicker foam

gasket material and sealed the end cap with that. This was very successful at keeping

the water out

If there is not enough power to the motors – add more batteries or use different batteries

o Not completed

P a g e | 41

PROJECT OUTCOMES AND CONCLUSION

Completed by all

Our project came out very close to working exactly as specified in the end. The entire submarine is

controlled wirelessly via a Wiimote. The hull and motor shafts are tolerably waterproof.

The Wiimote control took a long time to get working. Mainly the program I had used to grab the

Wiimote data had to be configured to do fewer checks for the integrity of the Wiimote computer

connection.

There were a lot of issues waterproofing the rudder and propeller shafts in the hull. Wrapping tin foil

around the propeller shaft actually worked out surprisingly well. Only a small amount of water was able

to get in when the propeller ran in the forward direction. Reverse direction was another story. When in

reverse water was more likely to be pushed in and it leaked an intolerable amount.

The only thing that did not work as specified was our rudder mechanism. This was partly due to the fact

that we had to change the rudder design unexpectedly. The first propeller motor we had designed our

project with ended up not working as we had hoped and eventually broke down on us. So we had to

change the motor to a longer one. This forced us to use a gear system to move our rudder.

All in all however things worked out for the most part in the end. We have a mostly working prototype

and it was a very fun project.

P a g e | 42

TEAM DYNAMICS REFLECTION

Completed by all

Team organization

Our team organization improved a lot as the quarter went on. At the beginning it was quite difficult to

coordinate schedules and find times to meet as a group. Many times, the whole team wasn’t on the

same page, which caused some frustration. By week seven, we got a routine down. Most of the time

we would meet around the same time each day, so that helped coordinate us. Also, if one or two

people worked on the project alone, we emailed each other with status updates to keep each other in

the loop.

Team chemistry

We had great team chemistry, especially by the end of the project. We even had fun hanging out

outside of working on the project.

Things that worked well

The things that worked well were brainstorming sessions with all four of us present. Having both the

mechanical and electrical people together was really productive for us. We also designated extra time

to making specific weekly schedules, which kept us on track and focused our attention on getting

specific tasks done.

Things that did not work well

The lack of communication at the beginning of the project was a big challenge. It was unclear what

people had completed or hadn’t completed. People just weren’t on the same page. Also, the lack of

clarity on individual tasks was a problem. We should have designated specific tasks for each team

member earlier and better.

Adjustments based on what happened

We started making specific weekly schedules which specified both when we were meeting and what

tasks we would complete that day. This was extremely helpful to our productivity. We also coordinated

our efforts between the mechanical and electrical sides of the project. At first there was quite a gap

between the two, but when we started communicating better through emails and texts things improved.

Lessons learned through this experience that can be applied to Senior Design next year

Through this experience, we learned how important it is to communicate with each other. Especially

with our unique situation between electrical and mechanical engineers, communication is crucial. Also

starting to be productive early is important. We spent a lot of time working later in the quarter, but if

we would have spaced out our time better, it could have gone more smoothly at the end.

P a g e | 43

SIGNATURE PAGE

Completed by all

Sean Byrnes, Electrical Engineer

Jamie Inouye, Appropriate and Sustainable Engineer

Cam Iseri, Mechanical Engineer

Kristin Lorenzen, Mechanical Engineer

P a g e | 44

BIBLIOGRAPHY


"Actuators - How to Waterproof a Servo." How to Build a Robot Tutorial. Society of Robots,

2010. Web. 11 Apr. 2011.

Brain, Marshall, and Craig Freudenrich. "How Submarines Work." Howstuffworks. Discovery.

Web. 11 Apr. 2011.

"Calculating Underwater Pressure." Ask the Van. University of Illinois at Urbana-Champaign, 12

Nov. 2007. Web. 2 May 2011.

Heiszwolf, Johan J. "Submarine Dive Technology." Submarine Technology. 2001. Web. 11 Apr.

2011.

"Mini RC Submarine Ballast Tank Test 1." Youtube.com. 21 Apr. 2009. Web. 11 Apr. 2011.

"Monthly FAQ." NALGENE Labware. Thermo Fisher Scientific Inc., 2011. Web. 2 May 2011.

Documents

Yellow Submarine - Cam Iseri: Portfoliodesign against the requirements. Customer requirements: The mini-submarine must be able to run for at least 20 minutes non-stop. The batteries