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The Japan Agency for Marine-Earth Science and Technology (JAMSTEC) developed the full depth ROV (remotely operated vehicle) UROV11K system. UROV system employed a single microfiber optic cable of 1 mm diameter to carry data telemetry and real time video images. The full depth ROV UROV11K system consists of newly developed full depth vehicle and ABISMO launcher. ABISMO launcher employed a primary cable of ROV KAIKO system. Total 20 km optic fiber cable stored by each spooler was mounted on the vehicle and ABISMO launcher. UROV11K system was designed to perform the scientific surveys at the full depth of 11,000 m. UROV11K sea trial was conducted in May 14, 2017 from the R/V Kairei in Mariana Trench, where the vehicle successfully performed scientific observation with real time 4K video camera images at full depth of 10,899 m. This paper describes an overview of the full depth ROV UROV11K system, advanced elements technologies and the sea trial result.

Japan Agency for Marine Earth Science and Technology (JAMSTEC) has started a new project “submarine resource research project” in April 2011. We decided to advance the development of work class ROV “KAIKO Mk-IV” as fourth KAIKO's vehicle applied for submarine resource exploration. “KAIKO Mk-IV” construction started in April 2011 and it completed in March 2013. Then, its sea trials have been carried out in FY2013-FY2015. This paper describes about the development of new ROV (vehicle) “KAIKO Mk-IV” and those equipment using advanced technologies and test results.

Performing oceanographic measurements from the sea surface to the sea bottom is technically challenging under rough or icy sea conditions. In 2011, we tested measures for protecting a buoy under such severe conditions, by incorporating anti-icing and tolerance to high winds and rough seas. Based on the results, we carried out detailed designs of a suitable buoy system. In January 2012, we succeeded in deploying the buoy in the Southern Ocean off the Adelie Coast at 60°S and 140°E. Some of the meteorological and oceanographic data being gathered by the buoy can now be monitored in real time. In this paper, we describe some details concerning the design of the sensor pole and mooring line, in addition to the data already received from the buoy.

Performing oceanographic measurements from the sea surface to the sea bottom is technically challenging under rough or icy sea conditions. As a measure to deal with rough seas, a new dynamic simulation program was developed and its validity was verified by comparison with the results of actual sea tests. This program can therefore be used as a design tool. To develop countermeasures against icing, we carried out basic tests in a large-scale snow and ice laboratory. Some of these countermeasures were then implemented in real sea tests and were found to be effective under icy conditions. These results indicate that deployment of moored surface buoys in regions of rough and icy sea conditions will soon be practical.

11,000m class ROV, KAIKO, was developed in 1995 and dived to the seabed of 11,000m depth at Challenger Deep in Mariana Trench about 20 times (Fig.1). In March, 1996, KAIKO was sampling almost 20ml of sediment at Challenger Deep (10,897m depth). Many microbe in deep sea like extreme environments have been found in it, and their life have been cleared by the little sediment sample. So, it is necessary to collect much sediment sample at Challenger Deep to progress the research. But, the vehicle of KAIKO has been lost in May, 2003, because the secondary cable connecting the launcher and vehicle was snapped. The research of extremophiles in deep sea has been interrupted. Therefore, JAMSTEC has developed 11,000m class free fall mooring system in order to take the image and sediment sampling.

Deep manned submersible ldquoSHINKAI 6500rdquo was built in 1989, and has been operated by Japan Agency for Marine-Earth Science and Technology (JAMSTEC). She has capability to dive down to 6500 m depth. Currently, she made 1097 dives until the end of July 2008. A round hatch on the top of the pressure hull is designed to constitute a part of the spherical pressure hull, and is very important structure to keep atmospheric pressure and waterproof in the hull. Therefore, we handle a hatch carefully in every operation, and moreover, we remove a hatch from the pressure hull at the time of the annual-maintenance and are doing the careful overhaul which involves the measurement and exchange of components. The number of her diving exceeded 1000 times, and she will reach 20 years old shortly. As consideration for that, an operation team, an engineering division and a ship builder implemented investigation for reconfirmation about soundness and safety of the pressure hull including a hatch. In this report, the result of investigation and evaluation about behavior of a hatch including the pressure hull is described.

The remotely operated vehicle (ROV) Kaiko, built in 1995, is able to dive at ocean depths of 11,000 m. On May 29, 2003. the Kaiko's secondary cable snapped, and the Kaiko's vehicle has been missing. JAMSTEC (Japan Agency for Marine-Earth Science and Technology) was decided to remodel the 7,000 m class ROV UROV7K instead of the lost vehicle in order to continue the scientific activities. This system was called "KAIKO7000" system, and remodeling was finished in March 2004. After success of the sea trials, actual science activities that were interrupted by the Kaiko's vehicle lost was resumed in May 2005. JAMSTEC planed that over 10,000 m deep segment sampling in the Challenger Deep at the Mariana Trench by using the launcher system of "Kaiko". On December 10, 2006, we are carried out the sea trial for the segment sampling in the Challenger Deep at the Mariana Trench by using the launcher system of Kaiko. The launcher reached the depth of 10,131 m of the sea bottom at the Challenger Deep, and the core sampler "Asyura" succeeded in segment sampling. This paper describes about the method of deep-sea sediment sampling and the sea trial in the Challenger Deep at the Mariana Trench by using the launcher system of Kaiko.

On May 29th, 2003, 10000 m class ROV KAIKO cruised for research mission in Nankai Trough at the southeast of 130km off Cape Muroto in Kochi prefecture. After completing the research mission at a depth of 4675 m, the vehicle of KAIKO has been missing because the secondary cable connecting the launcher and vehicle was snapped. Immediately, the vehicle has been searched from surface and air but it could not find. JAMSTEC has planned to remodel the 7000m class thin cable system ROV UROV7K as a replacement of the KAIKO vehicle, though operation depth and kinematical performance of it are lower than KAIKO vehicle. And JAMSTEC would use it temporarily for deep sea research, until new KAIKO system would be built. The system with KAIKO launcher and remodeled UROV7K is called KAIKO7000. UROV7K had the battery for power source and it was linked with the support vessel using a fiber optic cable of 1mm in diameter. It was developed for the missions of monitoring deep sea mooring systems and to survey deep seafloor. Some parts of UROV7K have been remodeled for replacement of the KAIKO vehicle. Main remodeling points were power supply system, increasing thrust and communication line. Furthermore, the safety measures pointed out by the Committee for the Investigation of Accident, have been included, too. KAIKO7000 has been finished remodeling in March, 2004, and the sea trials have been started in April, 2004. This paper describes about remodeling of KAIKO7000.

A deep and long cruising range AUV (autonomous underwater vehicle) named "URASHIMA" (AUV-EXI; development code name), has been developed by JANISTEC since 1998. URASHIMA can cruise long distance in the sea and collect sea data and water samples automatically for offshore exploration. The dimensions and weight of URASHIMA are 10m (L), 1.3m (W), 1.5m (H), and about 7.5 tons in the air. There are two very important key technologies for a long cruising range autonomous underwater vehicle. One technology is the power source. URASHIMA has two types of power sources. One is a high capacity lithium-ion rechargeable battery. The other one is solid polymer electrolyte fuel cell. With these power sources the vehicle capable of performing long ranges missions. The estimated cruising ranges are about 100 km by using battery and about 300 km by using fuel cell each other at three knots. The other technology is the navigation system. The AUV cruises independently without any communications between the mother ship and vehicle. It is very important to know its present position and forward environment. URASHIMA has highly accurate navigation sensors, such that the inertial navigation system (INS) consists of three sets of ring laser gyro and accelerometers, obstacle avoidance sonar (OAS), Doppler velocity log (DVL) and acoustic homing sonar. The AUV enables long distance cruising independently with these navigation sensors. The sea-going tests started in June 2000. The equipment, hardware, software, and autonomous functions, will be improved gradually. In these sea trials, URASHIMA achieved a dive to3518 m and cruised 132.5 km in autonomous navigation mode.

An AUV goes along a pre-programmed route depending on the INS position; it is useful to watch the vehicle status and give commands correcting position error or alternating control mode by the existing state from a surface vessel in test phases. The AUV system has a digital acoustic communication system, capable of 4100 m maximum range in duplex. The communication range is shorter because the acoustic signal to noise ratio decreases at the AUV when a vertical thruster is operated. Noise is caused by reduction gear in the thruster unit. The reduction gear is improved to decrease the noise. The communication range is enhanced 2.5 times compared to previously, even if the thruster is operated in the sea. This article describes an investigation of low noise reduction gear for the acoustic down-link and test results.

Since 2000, JAMSTEC has been developing an AUV (length: 2.5 m, weight in the air: 800 kg), MR-X1, with a shape like the head of a fish. The maximum depth of the AUV is 4,200 m and its operating time is approximately 15 hours with a Li-ion battery unit. Five thrusters are equipped for high maneuverability. A TV camera, a side scan sonar, and a manipulator are equipped for various scientific works. MR-X1 has three operation modes: an autonomous mode, an UROV mode, and a wireless (acoustic/radio) control mode. The development goal of the MR-X1 is achievement of the working robot with high intelligence for detailed ocean investigation, installation of observation equipment on the sea floor and so on.

Japan Marine Science and Technology Center (JAMSTEC) has advanced the development of an ocean going autonomous underwater vehicle (AUV). Technical problem on an AUV is to develop instruments for digital telemetry, highly accurate positioning in the sea and an efficient power source. The AUV in JAMSTEC has digital telemetry, accurate positioning system and high energy density battery. Sea test started in 2000, results were fed back to instruments to improve AUV performances. The quality of the communication has improved by the noise reduction. The positional error of the AUV was evaluated with a track given by an acoustic positioning system and DGPS on board a support vessel. The examination was planned and expanded based on previous results step by step. As the result, the AUV cruised more than 130km along the preprogrammed route while having submerged. This paper summarized the result of the sea area examination executed from 2000 to 2002.

The ROVs with thin cable system have been developed in JAMSTEC. The thin cable system is very convenient for AUVs, therefore it has been applied for the AUVs that have been developed in JAMSTEC. Conventional ROV systems need the thick cable to supply electric power from mother ship to under-sea vehicle. In the thin cable system, a thick cable is not necessary because a power source like a battery is installed in the vehicle. The communication between the vehicle and mother ship just needs to include observation data from vehicle and control data from mother ship. The data are communicated through only one optical fiber cable that is about 1 mm in diameter. The thin cable system is called "UROV system" in JAMSTEC. UROV system has some merits because of thin cable. First, since the optical fiber cable with the length of 10 km is installed in the small cylindrical case called "spooler", the onboard system is very compact against conventional ROVs. Second, if a tether cable gets entangled in something like under-sea structure, it is considered that a vehicle can not be recovered in worst case. In the case of UROV system, the vehicle can be recovered because it has safety sequence that will release the ballast for surfacing. UROV system has other merits. For example, there is no cable drag. UROV system is available not only ROV but also AUV. URASHIMA developed by JAMSTEC has 3 operation modes. UROV mode is one of these operation modes. This mode is mainly useful for debugging in early stage of developing. When troubles happen, it is difficult for normal AUV that has no cable to know the detailed state on real-time. In that case, in URASHIMA, UROV mode is very convenient debugging of software and hardware. Furthermore, URASHIMA can survey like ROV by optical communication for UROV mode, for example, to watch the TV image on real-time. This paper describes UROV system for 7,000 m class UROV, UROV7K, and AUV, URASHIMA.

Japan Marine Science and Technology Center has been developing a long-range autonomous underwater vehicle (AUV) since 1998. This vehicle was named "AUV-EX1" and it is designed to have a capability of cruising up to 300 kilometers along a pre-programmed route. The body is a streamlined shape with a total length of 10 meters and its weight of 7.5 tons. For long range cruising, key technologies are energy source and navigation. Electric-energy is supplied from lithium ion rechargeable battery and it can be combined with a fuel cell. The navigation system is based on a high accuracy inertial navigation system. The vehicle is designed to gather scientific data by an on-board water sampler, side scan sonar and CTDO. This paper presents the overview of the AUV-EX1 and test plan in the future.

JAMSTEC started on the development project of AUV in 1998 fiscal year, and the first test machine AUV-EX1 which renamed Urashima has been developed in March 2000. Urashima has many excellent features. The cruising range is relatively long and working depth is very deep. It has a new inertia navigation system with ring laser gyros. The fuel cell system will be selected for its power device. From this June, the first test in the sea of Urashima and the fuel cell test on ground have started. This paper introduces the feature of Urashima, and shows an outline of these tests.