Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Marine Technology Department
the AUV cruising over long distances. For the power
source the AUV will use a Polymer Electrode Fuel
Cell (PEFC) backed up by a lithium-ion secondary battery,
and for the navigation system, we have combined
optical ring laser gyros and doppler speed meters to
minimize errors that occur in inertial navigation. The
AUV equips side scan sonar and digital camera for
seafloor imaging, and conductivity-temperature-dissolved
oxygen sensor for oceanic measurements. In
fiscal , AUV conducted a total of five diving tests
in actual sea conditions. In a long-distance autonomous
cruise trial planned so that it was cruised at maximum
power efficiency based on the results of past trials, as
shown in Figure , it completed a continuous
autonomous cruise of km, which exceeded the target
distance (km) with lithium-ion batteries. The roughly
-hour cruise confirmed that AUV could be accurately
guided with the inertial navigation system,
Doppler speed indicator, and sonar for positioning error
correction in INS. In October we replaced AUV's lithium-ion
batteries with a fuel cell system. The fuel cell
system uses hydrogen gas and oxygen gas. To increase
the safety of the hydrogen, it is stored in solid metal
138˚00'E
138˚30'E
139˚00'E
35˚00'N
35˚00'N
34˚30'N
34˚30'N
34˚00'N
34˚00'N
138˚00'E 138˚30'E 139˚00'E
Fig. 5 Deep sea cruising AUV URASHIMA
Fig. 6 Autonomous cruising route
Fig. 7 General layout of URASHIMA (after modification)
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