January 2012 Issue
JAMSTEC Assists Research by Developing, Operating Vessels and Robotic Vehicles
By Kazunori Midorikawa Sub Leader, Planning and Coordination Group
Dr. Eng. Yukihisa Washio
Marine Technology and Engineering Center
Japan Agency for Marine-Earth Science and Technology
The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) conducts research and development relating to the ocean. In the past year, JAMSTEC has developed a variety of equipment and systems to be used in AUVs, ROVs and research vessels that will be introduced in the near future.
Developments in Advanced Marine Technology
Next-Generation AUV Technology. JAMSTEC is researching and developing technology for a next-generation AUV that would be able to cruise autonomously over a distance of up to 1,000 kilometers. It will be utilized for resource exploration, such as examining hydrothermal deposits using resource-mapping equipment.
In August 2010, JAMSTEC used the Marine Robot Experimental-1, a small AUV the agency developed for light work such as collecting deep-sea instruments, as a platform for conducting at-sea tests on equipment that could be used on future AUVs. These tests proved the effectiveness of: a lithium-ion battery as a power source that has 1.7 times the capacity of a conventional product; a high-precision inertial navigation system that is half the size of a conventional systems; a space-distributed CPU system designed to increase system performance by reducing CPU load; and a high-performance imaging system that enables measurements in 3D stereo views.
For AUV communication systems, JAMSTEC performed a long-range underwater transmission test at sea over a horizontal distance of 1,000 meters using time-reversal underwater acoustic communication. JAMSTEC also conducted short-range transmission tests, with a horizontal distance of 800 meters at a speed of 80 kilobits per second and 600 meters at 120 kilobits per second. The tests confirmed the basic performance of these communication systems, however, the practical application of time-reversal acoustic communication systems to AUVs will take several years or more.
AUV for Surveying Sea-Bottom Resources. By applying these developed underlying technologies, JAMSTEC is now building new types of AUVs that can position themselves close to the ocean floor to conduct detailed surveys on sea-bottom resources. The agency plans to assemble these AUVs by 2012 and 2013.
High-Performance ROV. JAMSTEC is also researching and developing technology for its high-performance ROV, which will perform high-precision heavy work such as seabed investigation at water depths of 7,000 meters or more.
In October 2010, JAMSTEC began at-sea tests on a high-strength, lightweight cable that connects the vehicle to its support vessel; a rotary joint for fiber-optic communication that will be used for rotating a cable drum in the water; and a flipper-thruster type of crawler system for propulsion that enables an ROV to move around even when the ocean floor has complex terrain. The effectiveness of these systems was confirmed by these tests, which ended last March.
A new mechanical hand was designed to serve as a work manipulator. JAMSTEC also constructed a prototype model of a wide-angle imaging system that can supply a 360° view using just two cameras mounted on the front and rear of the ROV.
JAMSTEC is applying these developed technologies to build a new type of ROV that can perform column sampling of sea-bottom resources and can be fitted with different types of equipment depending on the work objective. The agency plans to assemble this ROV by 2013.
Deep-Sea Image Transmission Technology. JAMSTEC conducted at-sea transmission tests in August to send high-definition video taken in the deep sea to the Japan Aerospace Exploration Agency Tsukuba Space Center via the Kizuna satellite in real time. Designs have been made for new structural materials, such as carbon fiber-metal composites or ceramics, for observation equipment to be used below 7,000 meters’ depth or in cold conditions. Development has also been done for a system to take measurements and make on-the-spot decisions independently.
Research Vessels and a Deep-Sea Investigation System
JAMSTEC supports research activities through preparing opportunities for research vessels, a research submersible and other vehicles to be used.
Research Vessels. In March, the research ship Kairei investigated the submarine topography near the hypocenter region of the 2011 Tohoku earthquake off the Pacific coast of northern Japan. JAMSTEC confirmed movement of the region by the earthquake. Furthermore, research ships have been conducting oceanographic observations accompanied by seawater sampling. JAMSTEC confirmed movement of the region by the earthquake; it had shifted 50 meters to the southeast or east-southeast and 7 to 10 meters upward.
In June, researchers on the research vessel Hakuho-Maru collected about 150 Japanese eel egg samples along the southern end of the West Mariana Ridge Seamount chain. The team had collected the first-ever samples of freshwater eel eggs in 2009 around the same area. The eel is a traditional Japanese food, but its egg-laying habitat had long been a mystery. It is expected that this result will open the possibility of complete eel aquaculture.
Furthermore, it was reported that the white scaly-foot gastropod, known to be armored with black iron-mineral scales, had been found during the navigation of research vessels Yokosuka and manned research submersible Shinkai 6500.
Research Submersible and Other Vehicles. The ROV Hyper-Dolphin was operated at Kumano-nada, off the Kii Peninsula, for the wiring work of DONET, a submarine-cabled real-time seafloor observatory network for precise earthquake and tsunami monitoring. Improvements were also made to the Shinkai 6500, such as exchanging propulsion system equipment and the equipment inside the pressure-resistant shell.
A buoy system for the Southern Ocean near Antarctica has been developed, and a test mooring was successfully conducted offshore of Muroto-Misaki in Hokkaido from November 2010 to February 2011. JAMSTEC plans to deploy the buoy system in January 2012.