Milestone #3 Design ReviewGroup 4Victoria Jefferson Reece SpencerAndy Jeanthanor Yanira TorresKevin Miles Tadamitsu Byrne

1

Preliminary Rules released!!!Theme: RoboLoveNew addition

Torpedo LauncherSimilar Tasks

Validation gateOrange PathMarker DropperPVC RecoveryAcoustic Pinger

Same weight and size constraints as previous yearsMust weigh under 110 poundsSix-foot long, by three-foot wide, by three-foot high

2

Conceptual Design

3

4

5

Overview

Motors/Thrusters Cost Thrust Power

ConsumptionDry Weight

Rank

Weighting Factor

0.2 0.2 0.5 0.1 N/A

SeaBotix BTD150

7 6 9 9 8

Crust Crawler 400HFS

6 10 4 10 6

Technadyne 260

5 8 5 8 6.1

6

Motors/ThrustersSeaBotix SBT150:Chosen for functional ability and

water resistance as well it’s built-in motor controller, voltage regulator, and low power consumption

Four thrusters will be placed on the AUV in a configuration that will allow for forward/reverse powertrain, left/right turning and depth control

Similar to BTD150 but includes motor controller

7

Motors/ThrustersMotor Controller:

Built-in voltage regulatorsAutomatic shut-off if it receives

less than 20V DC and more than 30.1 V DC

Wiring configuration calls for 14-gauge power wire as well as Data and Clock inputs that utilize 18-gauge wire

Power Consumption/ Placement:

Max Amp.: 5.8A(30 sec duration)Max Cont. Amp.: 4.25AMax Power: 150W(each motor)Thrusters located on left/right for

turning and bottom/front for balance and weight distribution

8

Risks Associated with…

The Motors/Thrusters•Failure of one or more thrusters•Motorcontroller malfunction•Orientation of thrusters does not provide full range of motion

9

BatteriesThruster Battery OptionsHigh Polymer Lithium Ion Battery:

•Max voltage of 14.8V•Max capacity of 20AH•Max current of 30A•Will allow AUV to run for 1 hour at maximum amp draw

Lithium-Iron Phosphate Battery:

•More expensive than high polymer lithium ion•Slightly heavier than the high polymer lithium ion•No justified gain for the price

Nickel Battery:

•Nickel Metal Hydride batteries could not supply sufficient amp hours•Nickel Metal Cadmium batteries do supply sufficient amp hours or voltage and are very heavy

10

Vehicle Power SystemBatteries Two 14.8 V DC batteries in seriesBuilt-in PCM maintains a voltage

between 20.8 V and 33.6 VPCM prevents a drain of anything

greater than 40ACharge time = 10.1 hours30 min wait time is required after

charge to allow PCB to evenly distribute cells in the battery

11

Batteries Components:

Hercules Switching Regulator Up to 40V input Outputs 5V, 6A Used for “USB” power for

onboard components Switching allows for over %70

efficiencyAll components connected with

inline fuse rated at peak amperage consumption

12

Risks Associated with…

13

The Batteries•Battery over discharging•Battery overcharging•Shorting terminal•Battery failure•Battery not powerful enough to power AUV

HydrophonesSensorTec SQ26-01 hydrophone

Full audio-band signal detection and underwater mobile recording

Operates at required sound level (187 decibels)

Performs in required range of the pinger (20-30 kHz)

Chosen over Reson TC4013 because it is more cost-efficient and provides the functionality we need

14

Hydrophone Configuration 4 hydrophones will be utilized

to determine the location of the pinger

2 hydrophones will be placed horizontally to determine direction

The other two will be vertical in order to determine the depth

15

Risks Associated with…

16

The Hydrophones•Failure of one or more hydrophones

•Damaged•Malfunctioning

•Hydrophones not compatible with microcontroller

Inertial Measurement Unit (IMU)Navigation/Stability ControlPhidgetSpatial 3/3/3-9 Axis IMU

Accelerometer: measure static and dynamic acceleration (5g)

Compass: measures magnetic field (±4 Gauss)

Gyroscope: Measures angular rotation (400°/sec)

Chosen for low cost and because it contained a compass instead of magnetometer unlike other IMUs

17

Risks Associated with…

18

The IMU•Magnetic interference-Compass•“Drift”- Gyroscope•IMU damaged•IMU malfunction

Camera Housing Analysis

19

Stress Tensor (Pa)Total Deflection (in)

•PVC piping•Viewing lens•Aluminum Plate

Risks Associated with…

20

The Camera Housing•Leaks as a result of:

•Fracture•Improper sealing

CamerasCameras chosen:

3 Unibrain Fire I CCD webcamsOriginally chose a Dynex

webcam as wellNeeded for light/color and

shape recognitionCCD camera chosen for ability to

operate in low light conditionsThe cameras chosen for cost

efficiency as well as compatibility with our software

21

Cameras Positioning

Forward facing CCD camera for floating objectsDownward facing CCD camera for objects on the pool floorOverhead camera for shape recognition

Housed in watertight casing to protect from water damage

22

Risks Associated with…

23

The Cameras•Failure of one or more cameras

•Damaged•Malfunctioning

•Camera not compatible with microcontroller•Camera power failure

Software for SensorsHydrophones

In the process of finding a Linux software capable of processing and managing data

IMURS-232 interfaceVisualization and Configuration Software: SmartIMU Sensor

Evaluation SoftwareLinux C Source Code

CamerasDigital Image Processing using MatLab

24

MicrocontrollerThe BeagleBoard:Main ComputerOMAP 3530 PlatformUSB/DC Powered2GB NAND Memory1GB MDDR SDRAM Additional memory can be

added (if necessary)A 6 in 1 SD/MMC connector is

provided as a means for expansion

UART

25

MicrocontrollerSoftware:Operating system will be a Linux distributionUbuntu, Angstrom and Debian-GNU are the current choicesMission code will be written in a combination of C/C++Program will receive data from sensors as inputOutput will be sent via PWMs to the motor controllers to drive

the motorsProgram will be decision based using mostly if-else statements

and loops

26

Risks Associated with…

27

The Microcontroller and Software•Microcontroller power failure•Error in sensor-microcontroller communication•Purchased sensors not compatible with microcontroller•Microcontroller does not have all the necessary inputs/outputs to communicate with the sensors•Software not executing tasks properly •Errors in program

Mechanical GrabberUsed to complete the final

task of the missionGrasp and release mechanism

located at the bottom of the AUV

Our design will depend on the size and orientation of the rescue object

The current design is to have a mechanical claw attached to a solenoid that will attach to an object in the water

28

Risks Associated with…

29

The Mechanical Grabber•Mechanical grabber malfunction•Mechanical grabber damage

Marker DropperUse to complete tasks in which a

marker must be droppedWill be machined out of

aluminumUtilize waterproof servomotor

that will rotate marker dropper mechanism to release markers

Traxxas servomotors will be usedThis method was chosen because

it was the most cost efficient

30

Risks Associated with…

31

The Marker Dropper•Marker dropper malfunction•Marker dropper damage•Marker dropper power failure

Frame OverviewSimplistic Design constructed

of 80/20 AluminumAllows for easy adjustability80/20 is structurally sound

and can support all components of the AUV

The design mitigates vibration and will reduce hydrophone interference

Hull will be placed within the frame

32

Hull OverviewHull consists of a watertight

Pelican BoxPurchasing Pelican Box is simpler

than designing watertight housing and is also inexpensive

Hull will house all onboard electronics

Reduces the risk of water damage to electronics

Exterior components will be connected via Fischer connectors

33

Risks Associated with…

34

The Frame and Hull•Pelican Box leak•Frame is too heavy•SubConn connectors leak

35

36

Fall Semester Goals/AccomplishmentsSelect and design major components

Thrusters, battery, camera, electronics, connectors, motors, hull, frame, programming language, pseudo-code and software (mission tasks and sensors)

Still need to finish design of marker dropper and mechanical grabber, pseudo-code (sensors), and write software (mission tasks), verify that software is compatible with each other

Design and build AUV HullDesign and build mounting brackets

37

Spring GoalsWrite the programs for all subsystemsTest and debug

Color/shape recognition, sound detection, mechanical grabber and marker dropper, depth control

Integrate all subsystems into AUVFull scale testing

38

Risks Associated with…

39

The Schedule•Temporary loss of team member•Permanent loss of member•Drastic change in competition rules•Robosub damaged on way to competition•Malfunctioning parts•Parts are not compatible with each other•Team is critically behind schedule

40

41

Item Quantity Price

Main Battery 2 $800.00

Battery Charger 1 $80.00

Motors/Thrusters 4 $3,000.00

Hydrophones 4 $960.00

Microcontroller** 1 Free

CCD Camera 3 $390.00

Pelican Case 1 $150.00

Wires/Electronic Kits/Cables & Connectors

N/A $1,200.00

8020 Frame N/A $220.00

Aluminum Plate 14 in x 12 in x ¼ in 1 $70.00

Inertial Measurement Unit 1 $170.00

Total Expenses N/A $7,500.00

42

Item Price

Transportation $6,000.00

Hotel Accommodations $4,000.00

Miscellaneous Expenses $2,000.00

Total Expenses $12,000.00

Risks Associated with…

43

The Budget•Drastic change in competition rules•Robosub damaged on way to competition•Malfunctioning parts•Parts are not compatible with each other•Insufficient equipment funds•Insufficient travel funds

Summary of Major Risks:Technical, Schedule, Budget

Technical Risks Probability/Consequence

Motor/Thruster Failure Low/Serious

Battery Failure/damaged Low/Catastrophic

Microcontroller-Sensor Communication Error

Moderate/Serious

Software not executing tasks High/Catastrophic

Leaks of any kind Moderate/Catastrophic

44

Schedule/Budget Risks Probability/Consequence

Behind Schedule High/Severe

Insufficient Funds (including travel)

Moderate/Catastrophic

ReferencesOfficial Rules for 2010 competition: "Official Rules and Mission AUVSI & ONR's 13th Annual International

Autonomous Underwater Vehicle Competition." AUVSI Foundation. Web. Sept.-Oct. 2010. <http://www.auvsifoundation.org/AUVSI/FOUNDATION/UploadedImages/AUV_Mission_Final_2010.pdf>.

Barngrover, Chris. "Design of the 2010 Stingray Autonomous Underwater Vehicle." AUVSI Foundation. Office of Naval Research, 13 July 2010. Web. 09 Nov. 2010. <http://www.auvsifoundation.org/AUVSI/FOUNDATION/UploadedImages/SanDiegoiBotics.2010JournalPaper.pdf

45