Nereid UI:
Under Ice Light-Tethered ROV
Andrew D. Bowen
Deep Submergence Lab
Woods Hole Oceanographic Institution
Oceanology 2014
Photo courtesy S. McPhail, NOC1
Development of a Light-Tethered Undersea Robotic Vehicle for
Seafloor Intervention in Ice-Covered Environments
and Ship of Opportunity Deployment
An Instrument Development Project Funded by the
2011 NSF Major Research Instrumentation Program
Andrew Bowen1, Dana R. Yoerger1, Christopher German2,
James C. Kinsey1, Louis L. Whitcomb1, 3, Larry Mayer1,4
1Department
of Applied Ocean Physics and Engineering
of Geology and Geophysics
Woods Hole Oceanographic Institution
2Department
3Laboratory
for Computational Sensing and Robotics
Johns Hopkins University
4Center
for Coastal and Ocean Mapping
University of New Hampshire
Photo courtesy S. McPhail, NOC
Polar ROV: Nereid UI
Routine, efficient Deep Sea-Floor interventions
under ice are not presently possible
Need:
• No suitable ROV-like system
exists that is capable of
performing exploration of the
under-ice of glacial ice tongues
• Polar Observing systems will
benefit from robotic
interventions in the same
manner required for Coastal,
Regional and Global ocean
exploration and observing
Conventionally Tethered ROV Operations
from Icebreaker in Permanent Moving Ice
Challenge:
Present vehicles ROVs are
constrained by their tethers during
ice-bound operations
Icebreaker Constrained to
Move with Moving Ice Pack
• Tethers vulnerable to ice damage
• Vehicle systems not resistant to
tether connection damage or loss
(e.g. no “come home” function)
• Surface ships cannot hold
position thus limiting ability to
work predictably in specific seafloor locations with vehicles
Steel Armored Cable
• Through-ice deployment
concepts immature
Depressor/Garage
Conventional ROV
ROV Footprint of Operations: Small
(~500 m) Under Ship, Moving with Ice
Light-Tethered Nereid UI Operations from
Icebreaker In Permanent Moving Ice
Solution:
• Recent advances in ROV
tethering technologies now
enable real-time control
over extended distances
thus freeing the vehicle
from restrictions imposed
by surface ice cover
Steel Armored Cable
Depressor/Garage
Light Fiber-Optic Tether
Nereid UI Footprint of
Operations: Large (~20 km) and
Decoupled From Ship
Nereid UI
Conventional ROVs
SIR*
SCINI
Capability
Nereid UI
Manipulation
MSLED*
Multi-Node
AUV
Systems*
Inspection
Autosub
Mapping/Survey
100 m
1 km
10 km
100 km
Horizontal Range from Launch Point
Gliders
Hybrid Remotely Operated Vehicle Nereus
AUV Configuration
ROV Configuration
• Nereus is reconfigurable as an autonomous or light fibre optic tethered vehicle
• AUV for mapping
• ROV for close inspection, sampling and manipulation
• HROV class of vehicle intended to offer a cost effective solution for survey, sampling, and
direct human directed interaction with extreme environments to 11,000 meters (36,000 feet)
depth.
New WHOI Technologies:
Enabling New Vehicle Concepts
Acoustic and Optical
Communications
Micro-Fiber Tether
System
Low Power
High Quality Imaging/Lighting
Low Power
Capable Manipulators
Automation Hierarchy Paradigm
Thruster Control
➘Auto heading, depth
➘Station keeping, waypoints,
track-following
➘Mission Planning/
Sequencing
Energy
Storage
HROV Fiber Optic Tether
250 m Polymer Buffer
125 m Optical Fiber
20 km fiber spool
Nereid UI Concept
Mission:
• Penetrate under fixed ice up to 20 km as a
tethered vehicle while supporting sensing and
sampling in close proximity to the under-ice
surface
• Return safely to the ship
Notional Concept of
Operations:
• Install acoustic Nav/Comms as
required near ice-edge
20 km
• Deploy from vessel at ice edge as
tethered system
• Transit to ice-edge and begin
survey activities under-ice to the
maximum range of the tether.
• Complete mission and return to the
vessel as an AUV and recover
onboard in open water
Use Case 1:
Near-Ice Inspection and Mapping
Instrumentation
Multibeam
Stereo Camera Pair
HD Video
(Water and Suction Samplers)
Use Case 2:
Boundary Layer Investigations
Instrumentation
Sonde:
- Fast Response CTD
- ADV
- Shear Probes?
Vehicle:
- ADCP
- CTD
Use Case 3:
Grounding Line Inspection
Instrumentation
HD Video
Manipulator*, coring tools*
Use Case 4:
Sediment Sampling
Instrumentation
Siting:
- Video
- multibeam
Coring tools
- multicorer
- push cores (w/ manip.)
Use Case 5:
Ice Shelf Cavity Physical Oceanographic
Mapping
Instrumentation
Multibeam
ADCP
CTD
OBS, Fluorometers, etc.
Use Case 6:
Instrument Emplacement
Instrumentation
HD Video
Manipulator
Nereid UI
Exploration
•
•
•
•
Maneuverability
•
•
•
Real time visualization
Immediate Re-tasking
20 km standoff
1.8 m
•
Close inspection, HD
Intervention
Reconfigurable nose section for
specialized sensing or manipulation needs
(90 kg, ~1 kW)
Air Weight: 1800 kg
Endurance: 60 km
Speed: 1 m/s transit
Design Parameters
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Bathymetry -> Depth rating
Ice Draft -> Maneuverability/Sensing
Water column structure -> Need for, and capacity of VBS
Circulation and Tides -> Minimum speed
Sea-Ice and Sea State -> LaRS complexity
Phenomena -> Special design considerations
State of Knowledge -> Conservatism in design
Logistics -> Special design considerations, field-planning
Regions Studied:
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Antarctic Ice Shelves
Greenland Glaciers
Assumptions:
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Ship-based, open-water launch/recovery, sub-type for through-ice deployment
Design Constraints: Antarctica
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Bathymetry -> Depth rating: 1500 m
Maneuverability/Sensing: highly maneuverable/situational
awareness (e.g. Not an AUV)
Water column structure -> Need for, and capacity of VBS: missiondriven, potential for creative solutions
Circulation and Tides -> Minimum speed: 0.5 m/s
Sea-Ice and Sea State -> LaRS complexity: simple, AUV-like
Phenomena -> Special design considerations: minimize entrained
volume, thermally couple as much as possible, detect ?, pre-launch
washdown?
State of Knowledge -> Conservatism in design: reliability-driven
Logistics -> Special design considerations: Much can be learned
from small, proxy vehicles and limited previous work
Specifications
Navigation
Range
Air Weight
Depth Rating
Battery
Inertial
Acoustic
Communication
Tether
Acoustic
Imaging
Acoustic
Optical
Chemical/Physical
Sensors
Biological Sensors
Auxiliary payload allowance
40 km @ 1 m/sec.
1800 kg
2000 m
20 kWhr lithium-ion
IXSea Phins INS
LF 1000 m range up/down
altimetry; up/down ADCP/DVL;
LF (3.5 kHz) homing; imaging
sonar for obstacle avoidance
Fiber-optic Gb Ethernet, 20 km
LF (3 kHz) 20-300 bps for ship to
vehicle; HF (10-30 kHz) 300 bps
for vehicle to sensor; vehicle to
vehicle
Reson 725 multibeam or Mesotech
675 profiling (upward-looking)
Real-time color HD video; high
resolution digital camera; LED
lighting
Seabird CTD; pH; micro-structure
probes on deployable sonde
Optical backscatter;
Photosynthetically Active
Radiation (PAR); Chlorophyll;
Turbidity; Dissolved Oxygen
20 kg; 500 Wh
21
Equipment Overview: Over-the-side
nUI
Tow-Body
• 1800 kg
• 1.8 m x 1.8 m x 3 m
• Soft-line recovery
Transponders (2)
Benthos XT 6001
• Deployed fore and aft
• Battery powered
Depressor
(prototype)
• 35 kg
• 1 m long
• Mated to depressor
for launch
• ≥ 5 m umbilical to nUI
Acoustics
Package
• ~100 kg
• 2 m tall
• 1000 m max depth
• 2 m tall
• ~40 kg
Software Systems:
Integrated with DSLCore project.
Architecture nearing
completion with
networking and
middlerware components
in prototype phase.
Under-ice concept of
operations complete.
Acoustic
Telemetry:
WHOI
Micromodem
Flotation:
CMT 2500 meter
Doppler Velocity
Logs Two TRDI
300 kHz
Thrusters:
WHOI design
1200 Watts x 8
Navigation
Housing:
Acomms
LBL
LF command
Science Housing:
Multiple interfaces
for flexibility
Modular Payload
Section:
Science payload and
future manipulator
Telemetry
Housing:
40 km GigE
Main J-Box:
Pressure tolerant
components selected
(high-power
switching, fuses).
Vehicle Frame:
Welded Aluminum
Phins 6k
Battery module
(1/3):
SWE modules in
WHOI enclosure
DSL-Core Housing:
In house design
Science Sensing:
Kongsberg PTZ with
DSPL aux. DSPL
lighting. Sonars:
Blueview, Reson.
Chemical sensing suite
notional.
Nereid UI Program Notes
 Total Project was de-scoped from $5.6M to $3.3M
 Cost share provided by WHOI as required by NSF is $1M
 Partnering with:
 Johns Hopkins
 Defense Research and Development Center (DRDC) –
Atlantic – Canada
 Informal Polar Risk workshops with NOC, MARUM,
IFREMER
 NOAA/ONR and NSF funding for initial trials on
icebreaker Polarstern, summer 2014
 Commercial partnering?
New Technologies from the Nereus HROV
Enabling New Vehicle Concepts
Existing and maturing technologies:
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Energy storage
Autonomous vehicle control
High and low bandwidth acoustic communication
Optical communications
Small diameter tethers as pioneered by HROV Nereus
Ceramic pressure housings
LED lighting and integrated imaging sensors
Low power manipulators
Leads to new class of UUV capable delivering both autonomous and
tethered vehicle capabilities for both survey and intervention missions
Ice-bounds applications drive the technology solution with additional applications
"Cutting the cord” for undersea operations:
•
Demonstrate tetherless vehicle operation
at sea 2013
• Perform highly interactive ROV-like
tasks in water depths of several
thousand meters
• System Design tolerant of a broad range
of communications bandwidth,
intermittency, and latency
Through-water
optical
communications
at ranges up to
100+ meters for
complete
freedom from a
tether
Nereid HT Operating Modes
Light-Fiber Tether
Free-Space Optical
Practically unlimited
bandwidth with 20 km
horizontal standoff.
Expendable cost ~$20k
Through-water optical
communications at
ranges up to 100+
meters for complete
freedom from a tether
Small Footprint Tether
Light conventional
tether (CTD wire)
capable of tricklecharging with minimal
on-board infrastructure
Tetherless ROV Operations
Thank you for your attention