1CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

A LONG-RANGE ACOUSTIC GLIDERA LONG-RANGE ACOUSTIC GLIDER

January, 2010January, 2010PresentationPresentation

2CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

SEAEXPLORER

• Main characteristics:– No wings

– Long, low-drag antenna

– Internal actuators

– Li-Ion rechargeable batteries

– Integrated acoustic positioning

and communications

– High tolerance, self-adjusting trim

– Optional hybrid propeller

• Specifications:– Depth rating: 700 m

– Speed (max): 1 kt

– Weight: 59 kg

– Length: 2.2 m

+Antenna: 0.8 m

– Diameter (max): 240 mm

GPS FIXRADIO/SAT COMM.

BALLAST INFLATION

BALLAST DEFLATION

ACOUSTIC FIX

HYBRID THURSTER MODE

GIBTM FIX and COMM.

3CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

GENERAL DESIGN

Acoustique transducer (Positioning and communications)

4 sensor ports (openings)

Li-Ion battery (2.5kWh)

Roll actuator

Pitch actuator

Control hardware

Static fins

GPS/Iridium/Radio (foldable)

Ballast Unit

Air bladder

Oil bladder

User P

ayload-dedica

ted secti

ons:

Flooded and Wet

Connectors: 10MBitEthernet; Recharge and external power; External sensors

Water-compressibility matching hulls

4CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

ACOUSTIC INTEGRATION

• Main glider weekness:– Poor location estimation by Dead reckoning using low-performance

compass and no speed sensor (DVL…)

– Sensors georeferencing: Why using very high accuracy science

sensors is the vehicle position is poorly known ?

– Required numerous surfacings:• High Risk of collition in coastal areas

• Loss of energy

• Solution:Acoustic Integration allowing:

– Realtime Tracking by four buoys (GIBTM) or one buoy (Synthetic Long-

baseline)

– Autonomous positioning by inverse Synthetic Long-baseline• Only one beacon at fixed location is used as underwater lighthouse

• Several beacons can be layed underice along the vehicle track for arctic missions

– Basic communications using double-pulse techniques:• Critical commands: target tepth, heading and mode

• Feedback on vehicle status

– Advantages:• Metric localisation in a 10km range to beacons/buoys

• No surfacings required

Fix Zone

10km radius

Fix Zone

10km radius

5CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

ACOUSTIC MODES AVAILABLE

• Tracking:– GIBTM :

• Generation of broadband periodic pulses by the glider at precise timing (low-drift clock), tele-transmission of depth by

double-ping

• Time stamping of signals by surface buoys (TOAs)

• Realtime calculation of vehicle position by centralized radio-receiver

– Synthetic long baseline• Generation of broadband periodic pulses by the glider at precise timing (low-drift clock); tele-transmition of depth and

heading by triple-ping

• Time stamping of signals by unique receiver (TOAs)

• Calculation of vehicle position by processing n previous TOAs

• Self positioning:– Inverse Synthetic long baseline

• Generation of broadband periodic pulses by a buoy at precise timing (GPS); tele-transmission of data by time spectral

spread codes (TSSC)

• Precise Time stamping of signals by the vehicle (TOAs)

• Calculation of the vehicle dead-reckoning drift by processing the "n" previous TOAs

6CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

INTER-OPERABILITY

• Positioning: – WGS84

• Clock : – GPS Time

• Acoustics– Rx : 0 to 70 kHz

– Tx : 8 to 17 kHz

– Transducer Aquatec compatible

• RF– RF European frequencies (868MHz)

– Iridium

• Data– Export of logfiles in NetCDF Format

• SAR– To be defined

7CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

SEA EXPLORERDispositif de réglage de pesée

Deux composantes:

Réglage de la pesée suivant les conditions opérationnelles et réalisation

des phases « descente-remontée » par ballast réversible à huile (Poids

constant et volume variable)

Flottabilité complémentaire en surface pour faciliter la transmission des

données par ballast air

8CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

SEA EXPLORERDispositif de réglage de pesée

BALLAST HUILE:

Volume total transférable: 1,3 litres

Volume transféré pour descente/remontée: 0,2 litre

Réservoir externe : vessie souple

Réservoir interne : soufflet déformable

Mesure de volume par potentiomètre linéaire

Débit de remplissage du soufflet interne réglable en fonction

de l’immersion

9CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./DSEA EXPLORERDispositif de réglage de pesée

10CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./DSEA EXPLORERDispositif de réglage de pesée

11CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

SEA EXPLORERDispositif de réglage de pesée

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 50 100 150

nElec

nHPI

nTotal

nLED

nBIE

nMAR

nPAR

• Rendement global du groupe motopompe n= 0,62 à 70 bars

12CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

SEA EXPLORERDispositif de réglage de pesée

•Performances mesurées en caisson hyperbare à 70 bars pour tranférer 0,2 litre:

débit: 0,735 l/min

durée: 16,4 secondes

tension: 24,44 V

Intensité: 5,96 A

énergie consommée: 2324 J; 0,645 Wh

13CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./DSEA EXPLORERDimensionnement de la coque

•Volume de la déformation: 100 cm3 à 700 mètres

Alourdissement compensé par l’augmentation de la densité

14CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

To VasquesTo Vasques

January, 2010January, 2010PresentationPresentation

15CONFIDENTIEL INDUSTRIE - © ACSA 2010 © IFREMER,

V.Rigaud SM./D

GENERAL DESIGN

Acoustique transducer (Positioning and communications)

4 sensor ports (openings)

Li-Ion battery (2.5kWh)

Roll actuator

Pitch actuator

Control hardware

Static fins

GPS/Iridium/Radio (foldable)

Ballast Unit

Air bladder

Oil bladder

User P

ayload-dedica

ted secti

ons:

Flooded and Wet

Connectors: 10MBitEthernet; Recharge and external power; External sensors

Water-compressibility matching hulls