Autonomous underwater vehicles (AUVs) allow us to survey and explore globally and freely in vast deep sea. We aim to develop long cruising range AUVs (LCAUVs) for researches of the global change, ocean-trench earthquake, and biodiversity and for exploring ocean resources. We have developed the first prototype of LCAUV, Urashima since 1998. The vehicle powered by a PEFC system marked the world record of cruising distance of 317 kilometers in 2005. The vehicle, 10 m long and 10 tons in weight, has the specifications: maximum depth ratings; 3500 m, maximum cruising speed; 3.2 knots, and endurance; 60 hours. This large vehicle has large user payload of a few hundreds kilograms. In 2007, research and development of the elemental technologies which will be utilizes for development of the second generation LCAUV started to expand cruising range to 3000 kilometers. For long range cruising, technology improvement of power sources, navigations, communications, and vehicle controlling are mainly important. Since endurance of the LCAUV becomes over 600 hours, during this cruising period the vehicle controller must autonomously deal with problems which may occur in any devices. If the vehicle controller does not recover a fatal problem, the controller appropriately leads status of the vehicle to quit an executing mission and ascend itself. We have improved the vehicle controller and plan sea-trials using the controller in January 2009. On the other hand, The AUV, MR-X1, 2.4 m long and 800 kg in weight, has been developed for scientific research and the test bed of the LCAUVs since 2000. This working AUV is also needed for installing or recovering observation equipment, tracking and sampling benthos or planktons, and doing simple repetitive works. The first sea-trial of MR-X1 was carried out in 2003. After that, the MR-X1 system is only used as a test bed of the developed devices in the LCAUV project. In this year, we have developed new items, a device installer on the sea-floor and mud core sampler for the MR-X1. In the technical report, a redundant controlling system for the LCAUV installed on the MR-X1 is described. And new items and their test results will be reported.

This content is only available via PDF.
You do not currently have access to this content.