Autonomous Underwater Vehicle:

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Autonomous Underwater Vehicle

• Milestone 3 Design Review
• Group 4
• Victoria Jefferson Reece Spencer
• Andy Jeanthanor Yanira Torres
• Kevin Miles Tadamitsu Byrne

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Preliminary Rules released!!!

• Theme RoboLove
• New addition
• Torpedo Launcher
• Similar Tasks
• Validation gate
• Orange Path
• Marker Dropper
• PVC Recovery
• Acoustic Pinger
• Same weight and size constraints as previous
  years
• Must weigh under 110 pounds
• Six-foot long, by three-foot wide, by three-foot
  high

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Conceptual Design
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Major Components of the System
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Overview
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Motors/Thrusters
Cost Thrust Power Consumption Dry 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
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Motors/Thrusters

• SeaBotix SBT150
• Chosen for functional ability and water
  resistance as well its 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

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Motors/Thrusters

• Motor Controller
• Built-in voltage regulators
• Automatic 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. 4.25A
• Max Power 150W(each motor)
• Thrusters located on left/right for turning and
  bottom/front for balance and weight distribution

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Risks Associated with
The Motors/Thrusters
Failure of one or more thrusters Motorcontroller malfunction Orientation of thrusters does not provide full range of motion
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Batteries
Thruster Battery Options Thruster Battery Options Thruster Battery Options
High 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
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Vehicle Power System

• Batteries
• Two 14.8 V DC batteries in series
• Built-in PCM maintains a voltage between 20.8 V
  and 33.6 V
• PCM prevents a drain of anything greater than 40A
• Charge time 10.1 hours
• 30 min wait time is required after charge to
  allow PCB to evenly distribute cells in the
  battery

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Batteries

• Components
• Hercules Switching Regulator
• Up to 40V input
• Outputs 5V, 6A
• Used for USB power for onboard components
• Switching allows for over 70 efficiency
• All components connected with inline fuse rated
  at peak amperage consumption

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Risks Associated with
The Batteries
Battery over discharging Battery overcharging Shorting terminal Battery failure Battery not powerful enough to power AUV
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Hydrophones

• SensorTec 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

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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

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Risks Associated with
The Hydrophones
Failure of one or more hydrophones Damaged Malfunctioning Hydrophones not compatible with microcontroller
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Inertial Measurement Unit (IMU)

• Navigation/Stability Control
• PhidgetSpatial 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

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Risks Associated with
The IMU
Magnetic interference-Compass Drift- Gyroscope IMU damaged IMU malfunction
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Camera Housing Analysis
Stress Tensor (Pa)
Total Deflection (in)

• PVC piping
• Viewing lens
• Aluminum Plate

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Risks Associated with
The Camera Housing
Leaks as a result of Fracture Improper sealing
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Cameras

• Cameras chosen
• 3 Unibrain Fire I CCD webcams
• Originally chose a Dynex webcam as well
• Needed for light/color and shape recognition
• CCD camera chosen for ability to operate in low
  light conditions
• The cameras chosen for cost efficiency as well as
  compatibility with our software

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Cameras

• Positioning
• Forward facing CCD camera for floating objects
• Downward facing CCD camera for objects on the
  pool floor
• Overhead camera for shape recognition
• Housed in watertight casing to protect from water
  damage

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Risks Associated with
The Cameras
Failure of one or more cameras Damaged Malfunctioning Camera not compatible with microcontroller Camera power failure
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Software for Sensors

• Hydrophones
• In the process of finding a Linux software
  capable of processing and managing data
• IMU
• RS-232 interface
• Visualization and Configuration Software
  SmartIMU Sensor Evaluation Software
• Linux C Source Code
• Cameras
• Digital Image Processing using MatLab

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Microcontroller

• The BeagleBoard
• Main Computer
• OMAP 3530 Platform
• USB/DC Powered
• 2GB NAND Memory
• 1GB MDDR SDRAM
• Additional memory can be added (if necessary)
• A 6 in 1 SD/MMC connector is provided as a means
  for expansion
• UART

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Microcontroller

• Software
• Operating system will be a Linux distribution
• Ubuntu, Angstrom and Debian-GNU are the current
  choices
• Mission code will be written in a combination of
  C/C
• Program will receive data from sensors as input
• Output will be sent via PWMs to the motor
  controllers to drive the motors
• Program will be decision based using mostly
  if-else statements and loops

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Risks Associated with
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
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Mechanical Grabber

• Used to complete the final task of the mission
• Grasp 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

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Risks Associated with
The Mechanical Grabber
Mechanical grabber malfunction Mechanical grabber damage
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Marker Dropper

• Use to complete tasks in which a marker must be
  dropped
• Will be machined out of aluminum
• Utilize waterproof servomotor that will rotate
  marker dropper mechanism to release markers
• Traxxas servomotors will be used
• This method was chosen because it was the most
  cost efficient

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Risks Associated with
The Marker Dropper
Marker dropper malfunction Marker dropper damage Marker dropper power failure
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Frame Overview

• Simplistic Design constructed of 80/20 Aluminum
• Allows for easy adjustability
• 80/20 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

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Hull Overview

• Hull consists of a watertight Pelican Box
• Purchasing 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

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Risks Associated with
The Frame and Hull
Pelican Box leak Frame is too heavy SubConn connectors leak
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Schedule
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Fall Semester Goals/Accomplishments

• Select 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 Hull
• Design and build mounting brackets

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Spring Goals

• Write the programs for all subsystems
• Test and debug
• Color/shape recognition, sound detection,
  mechanical grabber and marker dropper, depth
  control
• Integrate all subsystems into AUV
• Full scale testing

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Risks Associated with
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
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Budget
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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
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Item Price
Transportation 6,000.00
Hotel Accommodations 4,000.00
Miscellaneous Expenses 2,000.00
Total Expenses 12,000.00
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Risks Associated with
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
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Summary of Major RisksTechnical, 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
Schedule/Budget Risks Probability/Consequence
Behind Schedule High/Severe
Insufficient Funds (including travel) Moderate/Catastrophic
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References

• Official Rules for 2010 competition
• "Official Rules and Mission AUVSI ONR's 13th
  Annual International Autonomous Underwater
  Vehicle Competition." AUVSI Foundation. Web.
  Sept.-Oct. 2010. lthttp//www.auvsifoundation.org/A
  UVSI/FOUNDATION/UploadedImages/AUV_Mission_Final_2
  010.pdfgt.
• Barngrover, Chris. "Design of the 2010 Stingray
  Autonomous Underwater Vehicle." AUVSI Foundation.
  Office of Naval Research, 13 July 2010. Web. 09
  Nov. 2010. lthttp//www.auvsifoundation.org/AUVSI/F
  OUNDATION/UploadedImages/SanDiegoiBotics.2010Journ
  alPaper.pdf