Monterey Bay Aquarium Research Institute
AUVs
Mapping vehicle specifications
Interior of the mapping AUV, with components called out.
© MBARI 2006
Computer-Aided-Design drawing of the interior of an AUV
Computer-Aided-Design (CAD) drawing of the batteries, sensors, and computers assembled in the interior (top), surrounded with syntactic foam for flotation (middle), and encased in the plastic outer fairings (bottom).
© MBARI 2006

General Specifications

  • Dorado- class autonomous underwater vehicle (AUV)
  • Named the D. Allan B.
  • Size: 0.53 meters (1.7 feet) in diameter; 5.3 meters (17.3 feet) long,
  • Three modular sections
  • Hull: ABS plastic (acoustically transparent at the relevant frequencies and provides structural strength)
  • Syntactic foam between housings provides buoyancy
  • Weight: 680 kilograms in air
  • Endurance: 17.5 hours
  • Speed: 1.5 meters per second and 5.4 kilometers (3 knots) per hour.
  • Depth rating: 6,000 meters.
  • The AUV is shaped similar to a torpedo.
  • The average speed of the AUV is three knots per hour.
  • Altitude: 50 to 100 meters above the seafloor
  • Inertial Navigation System (INS) and Doppler Velocity Log (DVL) navigation: rated to 6000 meters 1
  • Range: 55-85 kilometers depending on sonar load
  • Turning diameter: less than 20 meters
  • Maximum climb/dive rate: more than 30 meters/minute
  • Operable: From MBARI R/V Zephyr and R/V Western Flyer, and from blue water UNOLS vessels.

Instrumentation

  • Nose Section:
    • Conductivity, temperature, and depth (CTD) sensor (SeaBird SBE-49 fastCat)
    • Lithium-ion batteries
    • Fluorometer
    • 200 kHz forward looking sonar
  • Mid-body module:
    • Reson 200 kHz Multibeam Sonar
      • Flat receive array (model 7125)
      • 0.94 degree by 0.94 degree beams
      • 256 beams across a 150 degree swath
    • Edgetech FS-AU Sonar Package
      • 110 kHz chirp sidescan
      • 410 kHz chirp sidescan
      • 2-16 kHz chirp subbottom profiler
      • More about sonars
  • Tail section:
    • Kearfott inertial navigation system with Doppler velocity log
    • Paroscientific pressure sensors
    • Main vehicle computer
    • Ultra-short baseline, and acoustic modem for communications
    • Articulated propeller inside a circular duct for propulsion
receive ring
Multibeam receive ring, viewed from aft.
© MBARI 2005

Power Options

  • 5 kilowatt-hour Eagle-Pitcher secondary cells in a 1 atmosphere glass housing
  • 3 x 2 kilowatt-hour lithium-polymer pressure-tolerant batteries

Propulsion

  • MBARI-patented propulsion system
    • Brushless DC motor and gear box
    • Double-gimballed ring-wing duct moves vertically for elevator, and horizontally for rudder
    • Propeller moves with the duct
    • 52 Newtons (12 lbf) of thrust at 300 rpm
tailcone
Tailcone of the AUV © MBARI 2005

Surface Communications

  • Freewave RF modem, 57.6 kilobits per second.
  • Iridium phone
  • Radio Direction finder (RDF)

Submerged communications

  • Sonardyne Fusion Ultra-short baseline (USBL) MF, 19 kilohertz (kHz) down, 27 kilohertz (kHz) up

Safety

  • Slight positive buoyancy (~8 pounds buoyant)
  • Emergency 10 kilogram drop weight with internal and remote acoustic trigger
  • Homerpro acoustic beacon, Radio Direction Finder, strobe light
  • When on the surface, Iridium calls home to give a position

References:

1 Paduan, J.B., Caress, D.W., Clague, D.A., Paull, C.K., Thomas, H., “High-Resolution mapping of mass wasting, tectonic, and volcanic hazards using the MBARI Mapping AUV”, International conference on seafloor mapping for geohazard assessment, Forio d’Ischia, Italy, May 11-13, 2009.

Last updated: May. 13, 2011