Makoto Sugesawa

An autonomous underwater vehicle with a canard rudder for underwater minerals exploration

Exploration and mining of natural resources in the region of seabed are needed for lasting economic growth, because an abundance of natural resources, including rare metal, is in Japans exclusive economic zone (EEZ). The cost down of exploration and mining is an important issue for industrialization. It is well known that unmanned and/or autonomous platforms for exploration are effective to reduce operation cost. JAMSTEC has developed a cruising type autonomous underwater vehicle (AUV) to perform exploration in hydrothermal activity areas up to depth of 3,000 meters since 2011. This specified purpose AUV (5 m long, 2.7 tons in weight) has capability of high maneuverability for eliciting high performance of sonars and is equipped with three sonars: a synthetic aperture sonar (SAS), an interferometry sonar (IFS) and a sub-bottom profiler (SBP). The cruising AUV, named Yumeiruka, is thus has a canard rudder to maintain a fixed posture in horizontal and vertical plane. In March 2013 the 15-days sea trial of the vehicle was carried out in the Sagami Bay and we achieved constant pitch control by using the canard rudder during an altitude change.

A concept design of underwater docking robot and development of its fundamental technologies

This paper discusses the concept design of a long term underwater observation system utilizing an AUV and described two key technologies to develop a practical system.

The development of an autonomous underwater vehicle “Otohime” with the multiple operation

Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been developing three autonomous underwater vehicles (AUVs). And one of them is “Otohime”. The aim of this vehicle is the underwater environment research and the seabed mineral resources exploration. One of main missions is to get the detailed seafloor map. So some new technologies were applied to this vehicle in order to achieve such missions. And moreover, the non-conventional operation system was also applied. Although “Otohime” is still in a developmental stage, it is soundly near completion because various tests are repeatedly conducted. In this paper, the outline of “Otohime” including her operation style is explained.

Development of AUV for scientific observation

JAMSTEC has tried a feasibility study of carbon dioxide capture and storage (CCS) using geobiological processes in the deep subsurface. We expect a biological CO2 turnover. Japan Society for the Promotion of Science (JSPS) funded this project. We found that a hydrocarbon system associated with lignite-coalbed is buried more than 2,000 meters below the seafloor off the Shimokita Peninsula in 2006. In this project, they need to perform pre-survey and post-survey of CO2 distribution around the target seafloor. And they also carry out detail survey of the bathymetry in this area. To perform above things, two AUVs were required. One is cruising AUV, the other is working AUV to approach sea floor. In the paper, I introduce specification and some results of sea trials cruising AUV.l results.

Working-AUV "Otohime" and its sea trials at Sagami Bay

Since October 2010, JAMSTEC has developed two autonomous uderwater vehicles (AUVs); a cruising-AUV “Jinbei” and a working-AUV “Otohime” (Fig.1). Their major purposes are to observe underwater CO2 distribution around carbon dioxide capture and storage field, and to explore seabed mineral resources in Japans EEZ. The cruising-AUV performs wide area survey with sonars and chemical sensors. According to the survey results, the working-AUV “Otohime” accesses feature points and observes seafloor in detail, with its chemical sensors, cameras, and a manipulator. In this paper, we introduce the newly developed AUV “Otohime” and its sea trials at Sagami Bay. Through two dives at the depth of 80-120m for total 3 hours operation, we verified the performance of the overall hardware/software systems.

Seabed resource exploration performed by AUV “Yumeiruka”

JAMSTEC has been developed underwater vehicles and observation equipments required for a variety of study about oceanography. Among the many research fields about deep-sea, in Japan there has been a growing interest in seabed resources from a few years ago. Then we had developed an AUV “Yumeiruka” to perform seabed resource survey. As one of the most significant feature of the shape of “Yumeiruka”, its equipped with two sets of X-rudders. Therefore, “Yumeiruka” can trace such an irregular sea bottom surface with controlled attitude. After sea trials, its conducted that observation cruise of “Yumeiruka” with equipped 3-axis fluxgate magnetometer. This cruise was conducted to study about origin of marine resources and the area of confirmed of exists of hydrothermal deposit. In this cruise we confirmed availability of attitude control for seabed resource survey. This paper shows a result of seabed resource exploration performed by “Yumeiruka”.

An ocean experiment of inverse SSBL acoustic positioning using underwater vehicle OTOHIME

An acoustic positioning method to measure position of an underwater vehicle by inverse super short baseline (ISSBL) and acoustic data transmission is introduced in this paper. In this method a receiver array is equipped on the vehicle and direction of arrival (DOA) of acoustic signal from a surface station, such as research vessel and autonomous surface vehicle (ASV), is measured. Additionally information of position of the surface station is included in the acoustic signal. Then position of the vehicle is calculated in the vehicle itself using measured DOA, depth obtained equipped sensor, and information of position of surface station. An ocean experiment using underwater vehicle “OTOHIME” was carried out in Sagami Bay in Japan. Receiver array and experimental device was equipped on the vehicle. Depth of experimental site was 300 to 800 meters. As result, those are found that this method is feasible for actual deep-sea underwater observation, that filtering of high-rate positioning output is effective to reduce random error even if the positioning target is cruising, and that reduction of random error is limited to 1 to 2 meters due to error of estimation of the position of the transmitter equipped on the bottom of the surface station.

An AUV Yumeiruka for Seabed Topography Survey

Japan Agency for Marine – Earth Science and Technology (JAMSTEC) has been recently advanced the development of several underwater vehicles for the survey of mineral resources buried under Japan’s territorial sea. One of them is Yumeiruka. It has characteristic canard wings and rudders which are attached on its fore and rear parts. Since they cause good maneuverability, good survey results using acoustic observation devices can be obtained. And it has a high performance compact inertial navigation system which was developed as Japan’s first INS for an underwater vehicle by the cooperation between JAMSTEC and a Japanese manufacture. Yumeiruka has now conducted sea trials in order to improve its performance and functionality.Copyright

Multi-mission underwater vehicle “OTOHIME” and its control system

JAMSTEC developed some new underwater vehicles. One of them is “OTOHIME”. Because it was designed as a multi-mission type, it has not only the cruising ability but also the working ability through its skid is exchanged or desorbed. In order it to perform various missions, its control system was newly developed as a multi-CPU control unit. The control system is mainly composed of seven CPUs and they are connected to each other with an Ether-network. And each CPU executes some different processes and controls some different devices which are installed into it, respectively. Thus the control system can realize the load distribution of a CPU, the trouble detection of the system, the function compensation and the self-restoration owing to the information sharing applying the Ether-network. Now, sea trials were carried out in order to verify the performance of some new technologies which have been already applied into it. And then the utility of the control system was also confirmed.