Milestone #3 Design Review Group 4 Victoria Jefferson Reece Spencer Andy Jeanthanor Yanira Torres...
Transcript of Milestone #3 Design Review Group 4 Victoria Jefferson Reece Spencer Andy Jeanthanor Yanira Torres...
Milestone #3 Design ReviewGroup 4Victoria Jefferson Reece SpencerAndy Jeanthanor Yanira TorresKevin Miles Tadamitsu Byrne
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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
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Conceptual Design
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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
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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
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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
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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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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
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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
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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
efficiencyAll components connected with
inline fuse rated at peak amperage consumption
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Risks Associated with…
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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
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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…
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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
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Risks Associated with…
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The IMU•Magnetic interference-Compass•“Drift”- Gyroscope•IMU damaged•IMU malfunction
Camera Housing Analysis
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Stress Tensor (Pa)Total Deflection (in)
•PVC piping•Viewing lens•Aluminum Plate
Risks Associated with…
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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
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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
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Risks Associated with…
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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
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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
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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
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Risks Associated with…
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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
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Risks Associated with…
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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
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Risks Associated with…
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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
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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
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Risks Associated with…
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The Frame and Hull•Pelican Box leak•Frame is too heavy•SubConn connectors leak
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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
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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
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Risks Associated with…
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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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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
Risks Associated with…
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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
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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
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