Autonomous Underwater Vehicles

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Autonomous Underwater Vehicles
Autonomous Underwater Lagrangian Platforms and
Sensors Workshop
Christopher von Alt Woods Hole Oceanographic
Institution Woods Hole, MA 02536 March 24, 2003
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Outline

• Background
• History
• Current Status
• The Future

WHOI Fast Fish (A. Bradley)
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Autonomous Under Vehicles

• Driven by a propulsion system
• Controlled and piloted by an onboard computer
• Maneuverable in three dimensions
• Support spatial and time series measurements
• Normally provide superior quality data
• Support multiple vehicle operations
• Can insure adequate spatial and temporal sampling
  
• Support investigations of spatial and temporal
  coherence

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Comparison with other Lagrangian Platforms

• Benefits
• Control of survey
• Adequate power for most sensors
• Adequate power to continuously sample
• Drawbacks
• Limited endurance 8 - 50 hours
• Higher platform costs
• Lower number of platforms less access

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Benefits of AUVsWater column measurements

• Stop and float requires ballast control
• Actively loiter
• Constant altitude above the bottom
• Constant pressure or layer of interest
• Sea saw or saw tooth sample pattern
• Seafloor surveys acoustic or optical

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Time series measurements
Over 500 km mapped in 100 hours.
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San Luis Bay Spatial Time Series
REMUS transect
M. Moline California Polytechnic State University
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Bioluminescence Sensor
Developed by Mark Moline at Cal Poly, Cyril
Johnson, Jim Case at UCSB
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San Luis Bay Weekly Deployments
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M. Moline California Polytechnic State University
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Monterey Bay Spatial Time Series
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M. Moline California Polytechnic State University
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August 20, 2002
M. Moline California Polytechnic State University
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CC Technologies Hugin Vehicle380 sq-km region
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Temperature and Sound Speed Data
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HISTORY
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Odyssey MIT Sea Grant

• Developed in the early 90s
• Operational 94
• Six vehicles developed
• Characteristics
• Displacement 160 kg
• Survey speed 1.5 m/s
• Max depth 6 km
• Endurance 6 hours
• Notable missions
• AOSN missions docking
• Mission depth 1.4 km
• Mission duration 3 hours

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ABE - Autonomous Benthic Explorer

• Developed in the early 90s
• Operational 94
• Completed 80 science dives
• Characteristics
• Displacement 680 kg
• Survey speed 0.75 m/s
• Max depth 5 km
• Endurance 34 hours
• Notable mission 1996
• Mission depth 2.2 km
• Mission duration 30 hours

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International Submarine Ltd

• Thesues
• Developed early 90s
• Operational 94
• Characteristics
• Displacement 8,600 kg
• Survey speed 2 m/s
• Max depth 1 km
• Endurance 100 hours
• Most notable mission 1996
• Deployed 190 km of fiber optic cable on the
  seafloor (500 m) under ice
• Mission distance 365 km
• Mission duration 50 hours

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Naval Oceanographic Office UUV Program

• Draper UUVs
• WHOI Tracking System
• Penn State- Seahorse
• Semi-Autonomous Mapping System
• UUV Fest

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Southampton Oceanographic Center Autosub

• Developed early 90s
• Operational 98
• Characteristics
• Displacement 1,700 kg
• Survey speed 1.5 m/s
• Max depth 1.6 km
• Endurance 144 hours
• Notable information
• 271missions/750 hours/3596 km
• Deepest mission 1 km
• Longest mission 50 hours

Offered 2.6 m pounds in 1998
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Commercial Services CC Technologies, Inc.

• Developed late 90s
• Operational 00
• Characteristics
• Displacement 8,600 kg
• Survey speed 2 m/s
• Max depth 3 km
• Endurance 40 hours
• Most notable missions
• System mapped 17,702 km
• Mission depth 3 km

Kongsberg Simrad HUGIN Vehicle - Norway
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Status 2003
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Adaptive SamplingAdaptive Mission Planner (AMP)

• The AMP is a separate brain installed on the
  vehicle
• AMP has the ability to take control of the
  vehicle and provide it with external navigation
  and control commands
• Vehicle takes over if AMP tells it to do
  something dangerous
• During normal operations, the vehicle
• Executes a pre-programmed mission
• Navigates from waypoint to waypoint
• AMP
• On board algorithm adaptively modifies plan based
  on inputs received during the mission from its
  sensors

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Conventional Appraoch
Conc --gt
0 min Time ( as the UUV conducts its mission)
---gt 24 min
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Adaptive Plume Following
Spatial Map
Plume Tracing
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Automated Target DetectionHuman in the loop
4. Acoustic modem on vehicle transfers data to
HSV-1 via an RF link
3. Vehicle CPU Assembles message with target
snippet
1. Vehicle surveys area with sidescan sonar
Modem Buoy With RF Link
2. On Board CAD/CAC autonomously scans sonar
files and identifies targets
HSV 1
5. Target data is analyzed on laptop
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Redirection of Reacquisition Vehicle
Image snippets sent back, displayed
Reacquisition vehicle is directed to survey
targets with high scores from CAD/CAC
The survey mission is sent to the vehicle via the
acoustic modem and RF link - the vehicle
interprets this message and performs the mission.
Operator creates redirection survey on REMUS VIP
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Human in the loop Redirection Mission with two
vehicles in the water

1. SCM vehicle performs survey
2. Reacquire vehicle loiters
3. CAD/CAC system passes targets to HSV
4. Reacquire vehicle receives new mission and exits
   loiter location
5. SCM vehicle continues the survey seeking another
   target

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REMUS 6000

• Stand-alone 6 km rated self contained system
• Transportable - one ISO container
• Productive 3 10 times current survey rates
• Affordable - 1 M/vehicle
• Multiple vehicle operations (Two vehicles may be
  stored in one container.)

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2,500 m Test Area
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Mission 13 12nm Redirect
Rim - 2,250 m Base - 3,875 m Depth 1,625
m Transect 20,000 m Slope 4.6 deg
Vehicle Transect
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Descent Down the North Kaibab Trail
Rim 2,512 m Colorado River 739 m Depth
1,773 m Trail Length 22,000 m Slope 4.6 deg.
Bright angel point
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Future
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Benefits of AUVsShip based deep water operations

• Increase survey speeds
• Precise feature following
• Acoustic communication
• Uplink sensor data
• Redirect mission or reconfigure sensors
• Superior data quality
• Portability
• Cost effective 40 to 60 savings

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CC Technologies, Inc.

• Yearly support costs 14 million
• Ship, software engineers, consumables, parts and
  depreciation.
• Adequate utilization main problem not enough
  business to support the capabilities of the
  system.
• Offering 50 days of AUV time per year for 60k/day

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Cross Shelf and Shelf Break System