HOVs, ROVs and AUVsHOVs, ROVs and AUVs

Marine Instrumentation ClassMarine Instrumentation Class

HOVHOV

• Human Occupied Vehicle– Alvin– Pisces IV and V– Johnson Sea Link

Benfits/LimitationsBenfits/Limitations

• HOVs– You are right there to

see what is going on– Limited by battery and

air supply– Quiet large and

complicated to operate• Usually have a

dedicated support ship

UUVUUV

• Unmanned Underwater Vehicle– AUVs– ROVs

ROVsROVs

• Remotely Operated Vehicle– Connected to ship with a cable

• Cable called either– Tether– Umbilical cable

• Fiber-optic cable with power and strength members– Unlimited capabilities– Wide Varity of sizes

• Micro (less then 3kg) • Trenching more than 200hp

– Two mode of operation• Free Swimming• Garaged

– Large component in the Oil and Gas industry• Pipeline inspection/repair• Cable inspection• Etc.

ROVsROVs

• Scientific research– Can perform tasks

instrumentation is not capable of

• Push cores• Organism collection• Instrument retrieval• Exact location sample

collection

– Cheaper than a HOV

Benefits/LimitationsBenefits/Limitations

• ROV– Complete control over operations

• For deepwater takes place of diver

– Can perform challenging tasks over long periods of time

• Continuously if needed

– Limitations lifting capability– Requires skilled operator

AUVAUV

• Autonomous Underwater Vehicle– Various of sizes

• One-Man portable to couple of tons

– Powered by propeller– Depth Range

• 0-6000m– Dependent on Model

Eagle Ray AUV - NIUSTEagle Ray AUV - NIUST

Benefits/LimitationsBenefits/Limitations

• Battery life– Hours

• Large payload capabilities– Capable of taking instrumentation with high

power requirements• Limits duration

• Most require surface support vessel

GlidersGliders

• Glider through the water using only buoyancy as propulsion– No external moving parts

• Travel Through water in Saw-tooth pattern

• Depth Range– 0-1200m

• Dependent on model

• Multiple types– Spray– SeaGlider– Webb Glider– Wave Glider– ANT

Wave Glider

Underwater Glider OperationUnderwater Glider Operation

Energy only needed attop and bottom of each‘yo’ to change buoyancy

Wings provide forwardmotion during sinkingand floating

No external moving partsneeded to control glider,control managed throughchanges in position of aninternal mass

Slide Taken from ANT Littoral glider presentation

Teledyne Webb Research

Benefits/limitations Benefits/limitations

• Long deployments– Months

• “real-time” data during deployment

• Limited payload

• Most are small easy to recover

• Communication fees are high

PowerPower

• Wave Power• Batteries

– Alkaline, lithium….

• Thermal– Teledyne Webb Glider

• Use Ocean temperature change to alter the state of a wax, creating power

• Solar

Wave Glider Power Concept

Limitations for all typesLimitations for all types

• Density– Limited be displacement motor

• Currents

ChallengesChallenges

• Positioning underwater– AUV/ROV/HOV

• USBL– Tracked by surface ship

• Doppler Velocity Log (DVL)• Bottom Tracking

– Gliders• Dead Reckoning

– Internal Navigation System (INS)

– Acquires new position every time it surfaces to calculated Currents

CommunicationsCommunications

• ROV- Cable• AUV

– Freewave (Radio comms)• Surface

– Iridium (Satellite Comms)• Surface

– Acoustic• Subsurface

• Gliders– Freewave

• Surface

– Iridium • Surface