記述言語：英語   掲載種別：研究論文（学術雑誌）

Degradation in underwater imaging is as a result of absorption and scattering of light. Propagated
visible light rays through the water column are absorbed at rates that vary depending on the
wavelength of light. Large suspended particles also scatter the propagated light rays, as can be
observed in an underwater environment. Furthermore, color is distorted due to the inverse ratio
of attenuation that is proportional to the wavelength of light through a unit of length through the
water column. These phenomena distort underwater images by making them appear dark and have
low contrast. Conventional underwater image restoration techniques are largely based on the
image formation model (IMF) which restores the image based on estimates from the degraded
images. The results are solutions that are limited to specific underwater conditions. In this paper,
we propose a novel restoration strategy by considering the optical properties in the underwater
environment at the time of image capture, a robust restoration technique can be applied to images
captured in different underwater conditions. In so doing, we design a turbidity meter that capture
wavelength-dependent absorption data which are applied as parameters to restore the distorted
images based on the RGB channels. To validate our proposed technique, we conduct experiments
in a controlled underwater environment while varying the concentration of suspended particles
based on degree of kaolin mixture.

DOI： 10.57417/jrnal.10.2_141

Scopus

CiNii Research

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Acoustics communication and wireless optical communication have limitations of low latency and water conditions effects respectively. Radiofrequency (RF) communication provides a high data rate with free orientation of the transmitter/receiver antennas. However, electromagnetic waves are highly restricted by high attenuation over short distances in the underwater medium. In this study, we investigated the RF communication in a tank full of seawater. A loop antenna and rectangular antenna were used for the base station and AUV respectively. The experiments were conducted to measure the transmission rate with different distances between the base station and the AUV using both User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). Live video streaming with framerate analysis was considered. The results show the effect of the distance between the transmitter and receiver on the transmission rate, in addition, to the antenna's stability has huge effects on the connection stability. We successfully achieved a High-Definition (HD) video streaming with 25fps for over 1 meter.

DOI： 10.57417/jrnal.10.1_84

Scopus

CiNii Research

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan's territorial waters contain vast space and abundant marine resources. In recent years, AUVs have been developed that can conduct resource surveys in various ocean areas. Improving the control performance of AUVs is essential for conducting wide-area and detailed oceanographic surveys. In this paper, designed an algorithm to modify the thrust balance of the thruster and an observer to estimate the tidal current as a disturbance. By considering the thrust balance of the horizontal thrusters, it is possible to estimate the tidal currents on the AUV. In future work, tests will be conducted in sea without cables installed to eliminate estimation errors due to cable tension, and to evaluate the control performance of the control system with the addition of a disturbance observer to estimate the tidal current.

DOI： 10.23919/OCEANS52994.2023.10337342

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Recently, Autonomous Underwater Vehicles: AUVs are utilized as the tools for ocean survey and practical applications such as ocean mineral resources survey and marine biological investigations. We have developed an AUV “Tuna-Sand2” and have succeeded in automatic sampling of shells in sea trials at Suruga Bay in Japan. Tuna-Sand2 is designed for 2000m depth and 8 hours operation with the speed of 1 knot and has several computers for basic motion control with sensor handling, intelligent behaviors based on image processing and data transmission, however, the robot needs efforts in deployment and recovery because of weight and sizes, and must return to the surface in emergency conditions. That is, the system should be stable, reliable and conservative, and not suitable for testing new challenging algorithms and behaviors. We have developed a new AUV KYUBIC which can be operated by a few people as a small testbed of Tuna-Sand2 and have similar shape and thruster arrangement. In this paper, we describe the system architecture of KYUBIC and the experimental results in Underwater Robotics Competition in Okinawa 2020.

DOI： 10.57417/jrnal.10.1_6

Scopus

CiNii Research

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記述言語：英語   掲載種別：研究論文（学術雑誌）

In this work, we have incorporated an electronic travel aid (ETA) as a smartphone application that alerts fall risks to the visually impaired. The application detects negative obstacles, such as platform edges and stairs, and occlusion using a grid map including height information to estimate fall risk based on the distance from an area’s edge to the user, and the area ratio. Here, we describe a grid map correction method based on the surrounding conditions of each cell to avoid area misclassification. The smartphone application incor-porating this correction method was verified in environments similar to station platforms by evaluating its usefulness, robustness against environmental changes, and stability as a smartphone application. The verifi-cation results showed that the correction method is, in fact, useful in actual environments and can be imple-mented as a smartphone application.

DOI： 10.20965/jrm.2023.p0867

Scopus

CiNii Research

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan   Tokyo   2023年03月06日  -  2023年03月09日

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Japan   Tokyo   2023年03月06日  -  2023年03月09日

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Radiofrequency (RF) communication provides a high data rate. However, electromagnetic wave is seriously limited by high attenuation in the water medium. In this study, we investigate Radiofrequency communication in seawater. The experiment results show the effects of the distance between the transmitter and receiver, and the stability of the antennas. We achieved HD video transmission with 25fps.

DOI： 10.5954/icarob.2023.os21-1

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

An International underwater robot competition, "RoboSub" is held in USA to demonstrate robot's autonomy by completing underwater tasks, with a new theme each year. Student project team, "Kyutech Underwater robotics" developed autonomous underwater vehicle (AUV) "KYUBIC" with built-in image processing module for the RoboSub. Sensors on the AUV are connected via ethernet and its automatic navigation program is built using ROS. The AUV moves through gate to the target objects based on self-localization using doppler velocity log and IMU. When approaching the object, the AUV aligns its direction to the object based on the red line detection by image processing as well as the type, position, and altitude of the target objects are detected by deep learning on the image processing module.

DOI： 10.5954/icarob.2023.os20-2

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

A mechanical variable stiffness can adapt to external forces beyond the control cycle, such as overturning of walking robots, which can help solve problems such as actuator and joint destruction. In this research, we will clarify the structure of a two-input, one-output joint mechanism that can realize three functions: normal motion, instantaneous motion, and variable stiffness function. As part of the development of the variable stiffness function, a mathematical model is derived and simulated for the relationship between the joint angle of the output link and the disturbance torque when a disturbance torque is applied to the output link of the proposed mechanism.

DOI： 10.5954/icarob.2023.os21-6

CiNii Research

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Light scattering from suspended particles and attenuation over the water column are constant phenomena that reduce underwater image quality due to low contrast and color distortion. Common image restoration techniques such as the image formation model, assumes a constant attenuation coefficient across color channels. This results in a restoration solution with limited application. We propose a method of image restoration that considers the wavelength-dependent attenuation of underwater images by providing concurrent measurements of the coefficient of attenuation for each color channel. In this paper, a description of the design of a turbidity meter is made. It used to extract absorbance of light in the RGB channel. We conduct experiments to validate the operation of the turbidity meter based on BeerLamberts law.

DOI： 10.5954/icarob.2023.os21-3

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Crops are required to be processed in sanitary manner for lunchbox production in industries. Particularly, foreign object detection is crucial to guarantee consumer's health. Actually, foreign objects are mainly detected by human's eyes. For the automation, image processing is an example, however, is not effective for hidden objects. We propose a method of foreign object detection with ultrasonic reflection analysis. In our experiment, we selected four crops (lettuce, spinach, perilla and komatsuna) for masking material, and a coin for occluded objects. The coin were attached on the backside of the masking material. We recorded reflected wave moving the material linearly. As the result, reflection intensity doubled by the existence of occuluded object.

DOI： 10.5954/icarob.2023.os21-5

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In order to obtain long-term data of marine resources, we proposed an observation system that can navigate the same trajectory repeatedly without highly expensive sensors such as DVL and INS. Our system consists of a station equipped with a reel and a vehicle for observing the sea floor. The vehicle is tethered to the station by a power and communication cable, and the cable winds or unwinds by the vehicle cruising around a reel. In this paper, we describe long-term observation system using a cable-restricted underwater vehicle and its sea trial performed at 3 m depth.

DOI： 10.1109/UT49729.2023.10103413

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

We have developed a fall risk alert system using a smartphone with a LiDAR sensor, Apple’s iPhone 12 Pro, as an electronic travel aid (ETA) for visually impaired to reduce fall risks from the edge of station platform and the stairs. The proposed system generates the height grid map generated from 3D point clouds and posture from the smartphone, and classify the walking area to four areas, walkable, positive obstacle, negative obstacle and occlusion areas. In this paper, we describe the algorithm and the experimental results of the environmental recognition system for the fall risk alert. In the experiments, the accuracy, stability, and time delay are evaluat-ed in approaching a fall risk area, such as stairs. The results show the smartphone has the possibility to be the ETA to support the visually impaired and reduce the fall risks.

DOI： 10.57417/jrnal.9.4_349

Scopus

CiNii Research

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

AUVs are used for marine resource exploration, and although acoustic, laser, etc., are often used for wireless communication for AUVs, wireless communication using RF signals is being studied. By placing the VNA in a waterproof container, we measured the insertion loss between the antennas under seawater and obtained good results with simulation results. Furthermore, using a Wavelet-OFDM module as the communication method, a maximum communication speed of 6.8 Mbps was achieved with the antennas embedded in the AUV immersed in seawater.

DOI： 10.23919/EuCAP57121.2023.10133725

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In this research, authors developed a prototype of an automatic core sampling device for realizing the full autonomous core sampling by AUV (Autonomous Underwater Vehicle). A hovering AUV "TS2"(Tuna-Sand2) was equipped with the ACSS (Autonomous Core Sampling System) developed by authors, and a core sampling test was conducted in an actual sea area. In the core sampling test, Authors succeeded in core sampling with a thickness of 10[cm].

DOI： 10.1109/UT49729.2023.10103418

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Tomato is one of the important fruit vegetables and most tomatoes are produced in the greenhouses, or large-scale farms, where the high temperature and humidity, and long harvest age force the farmer heavy works. To develop the tomato harvesting robot, many research issues exist such as manipulator design, end-effector design, collaborative behavior, artificial intelligence, motor control, image processing, target recognition and so on. With an aim to promote the automation of tomato harvesting, we have organized the tomato harvesting robot competition since 2014, and currently changed the competition field to the greenhouse in 2020. In this paper, we discuss the results of 8th tomato harvesting robot competition in 2021.

Scopus

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>To obtain a long-term data of marine resources which are distributed over a wide area of the deep sea, we have been developed a long-term observation system using cable-restricted underwater vehicle. This paper reports about long-term observation system and its wet test performed at 3 m depth. As an evaluation experiment result, the vehicle tethered by a cable was able to cruise with an error of less than 0.34 m against the planned route. The mosaic image generated based on the captured images was able to measure the width, length, and height of the object with an error of less than 4 cm.</p>

DOI： 10.1299/jsmermd.2023.1p1-c12

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2023/0/2023_1P1-C12/_pdf

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>The oceans occupy about 70% of the Earth ’s surface have vast space and mineral, energy, and biological resources. In recent years, AUV has been developed for resource surveys in various sea areas We are working on developing and implementing a robust control system to improve the AUV autonomy and to navigate safely. This paper reports about observation results by hovelling type AUV ”Tuna-Sand2” on seaweed bed habitat off Iwakuni on January 2023 and estimate currents from the dive data to design the observer to estimate currents and implement for AUV. The dive results show that there were Northwesterly current and AUV position is easily affected by current when change target direction.</p>

DOI： 10.1299/jsmermd.2023.1a2-c09

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2023/0/2023_1A2-C09/_pdf

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Efficient feeding is crucial in cage aquaculture, reducing the cost spent on feeds while minimizing the pollution in water and maintaining optimal fish growth. Working towards digitization of fish feeding knowledge to optimize feeding decisions, we developed a modular sensor network estimating the fish feeding activity by measuring the fish-induced flow and recording underwater videos of the activity. We designed the system to collect data at multiple depths from at least two opposing sides of a fish cage. We also designed an offshore system and automatic data collection mechanism to enable the network to perform long-term observations. Two experiments were performed in cages located at two separate aquaculture farms to demonstrate and evaluate the functionality of the developed. We observed changes of flow during feeding and compared them to the videos of fish activity. Observed differences between the results of the two experiments could be attributed to various factors such as the characteristics of the fish cages as well as the method of feeding. Improvements to the sensor network and further analysis of data are needed to achieve a more effective system for estimating fish feeding activity.

DOI： 10.1109/UT49729.2023.10103416

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

In food industry, shortage of workers is one of a serious problem. Automation of food handling is a critical nowadays. To alleviate the damage caused by food picking operation by robotic hand, we propose non-contact acoustic impedance estimation with ultrasonic wave, which should be preceded before the picking for optimization of grasp stiffness. We assume the correlation between hardness and acoustic impedance. That is, the harder the medium is, the larger the impedance should be. As cooked food, the unevenness of hardness should be considered. We made samples with media of different acoustic impedances, and experimented with ultrasonic to find the relation between reflection coefficient and hardness. As the result, reflection coefficient increased by 0.03-0.15 at the boundary of two media as the bottom medium is switched from urethane to Aluminum.

DOI： 10.57417/jrnal.9.4_343

Scopus

CiNii Research

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Crops are required to be processed in sanitary manner for lunchbox production in industries. Particularly, foreign object detection is crucial to guarantee consumer’s health. Actually, foreign objects are mainly detected by human’s eyes. For the automation, image processing is an example, however, is not effective for hidden objects. We propose a method of foreign object detection with ultrasonic reflection analysis. In our experiment, we selected four crops (lettuce, spinach, perilla and komatsuna) for masking material, and a coin for occluded objects. The coin were attached on the backside of the masking material. We recorded reflected wave moving the material linearly. As the result, reflection intensity doubled by the existence of occuluded object.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Light scattering from suspended particles and attenuation over the water column are constant phenomena that reduce underwater image quality due to low contrast and color distortion. Common image restoration techniques such as the image formation model, assumes a constant attenuation coefficient across color channels. This results in a restoration solution with limited application. We propose a method of image restoration that considers the wavelength-dependent attenuation of underwater images by providing concurrent measurements of the coefficient of attenuation for each color channel. In this paper, a description of the design of a turbidity meter is made. It used to extract absorbance of light in the RGB channel. We conduct experiments to validate the operation of the turbidity meter based on Beer-Lamberts law.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

A mechanical variable stiffness can adapt to external forces beyond the control cycle, such as overturning of walking robots, which can help solve problems such as actuator and joint destruction. In this research, we will clarify the structure of a two-input, one-output joint mechanism that can realize three functions: normal motion, instantaneous motion, and variable stiffness function. As part of the development of the variable stiffness function, a mathematical model is derived and simulated for the relationship between the joint angle of the output link and the disturbance torque when a disturbance torque is applied to the output link of the proposed mechanism.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Radiofrequency (RF) communication provides a high data rate. However, electromagnetic wave is seriously limited by high attenuation in the water medium. In this study, we investigate Radiofrequency communication in seawater. The experiment results show the effects of the distance between the transmitter and receiver, and the stability of the antennas. We achieved HD video transmission with 25fps.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Image measurement technology for structures on the seafloor and underwater is one of the most important underwater survey methods. The time-synchronized projector-camera (SyncPro-Cam) technology is employed to obtain clear images in turbid water environments in contrast to hazy images caused by light scattering and captured by standard cameras. In this study, we designed and built a SyncProCam prototype and verified its feasibility in acquiring clear images in turbid water environments. In the measurement principle of SyncProCam, the measurement range is determined by the trigger delay signal, camera scanning speed, and baseline length between the camera and the projector. Therefore, the prototype was designed such that these parameters can be controlled by external signals. The imaging experiments were conducted in turbid water environments with two different turbidity levels. Under these, conditions the output images from the prototype underwater SyncProCam system showed a very high signal-to-noise ratio compared to those captured by standard cameras.

DOI： 10.1109/UT49729.2023.10103384

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Improving the efficiency of fish feeding contributes to achieving sustainable expansion of the aquaculture industry. However, expert knowledge on feeding remains reliant on experience. This paper presents a new approach of applying digital transformation (DX) on such knowledge by measuring underwater currents induced by fishes as indicator of their hunger. A prototype sensor suite consisting of current sensors, cameras, and an inertial measurement unit (IMU) was constructed to measure the currents around the fish cage, measure the motion of the suite, and record fish activity, particularly during feeding. An initial experiment was performed in two fish cages during feeding activity. Current measurements were collected and analyzed together with the recorded videos to relate the changes in current to the feeding activities. Results suggest that the currents increase around when feeding was started continuously and decline to zero around when it was stopped. However, more data needs to be collected and analyzed for a better understanding of the relationship between the changes in current and fish activities so it can be used to optimize the feeding decisions of fish farmers.

DOI： 10.57417/jrnal.9.2_143

Scopus

CiNii Research

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Agriculture is one of the most important primary industries, however the agricultural workforce in Japan has been decreasing due to the aging, shortage of successors and their heavy work. Smart agriculture and farms, which aim to automate farm work, have been attracting attention for the future sustainable society. We have been organizing the Tomato-Harvesting-Robot Competitions since 2014 to introduce robotic technology and AI into agriculture and promote agricultural technology. The competition consists of a Junior League for young students and a Senior League for general competitors. In this paper, we report the results of the 6th Tomato-Harvesting-Robot Competition and the regulation changes toward practical applications.

DOI： 10.57417/jrnal.9.1_13

Scopus

CiNii Research

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Autonomous Underwater Vehicle positioning is important for accurate control and high-quality data collection. Conventional positioning systems are expensive. This paper describes the design and performance results of control using equations of motion and an inexpensive acoustic positioning system implemented on a lightweight AUV "KYUBIC" for Underwater Robotic competition in Okinawa 2021. The velocity used to estimate the self-position of the AUV is calculated form the equation of motion without integrating the acceleration. The acoustic positioning method is based on Super-short baseline (SSBL) principle. The system design comprises of self-made hydrophone module using MEMS microphone. The estimated distance and angle are integrated for dynamic control of AUV to locate the position of a Pinger.

DOI： 10.5954/icarob.2022.os28-1

CiNii Article

CiNii Research

その他リンク： https://kyutech.repo.nii.ac.jp/records/7484

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

As crops in greenhouses are widely distributed, IoT devices placed near the crops should be stand-alone and modular, and data from the devices are collected over the networks. Smart agriculture requires knowledge of a wide range of fields including electricity, information, and image processing. We have designed an AI and IoT technology exercise on environmental monitoring and control of a greenhouse where we have been preparing for grow up of tomatoes and other vegetables.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In food industry, shortage of workers is one of a serious problem. Automation of food handling is a critical issue nowadays. To alleviate the damage caused by food picking operation by robotic hand, we propose non-contact acoustic impedance estimation with ultrasonic wave, which should be preceded before the picking for optimization of grasp stiffness. We have the assumption of the correlation between hardness and acoustic impedance. The impedance is calculated by the product of sonic velocity and density of a medium. From the point of view, the harder the medium is, the larger the impedance should be. We built up ultrasonic transmission model considering attenuation by ultrasonic reflection and absorption, then, made an experiment to estimate internal reflection of samples with two overwrapped media of different acoustic impedance.

Scopus

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Fuel consumption of the ship gets worse by barnacles and stains put on its bottom, so that the ship hull should be cleaned regularly. Usual methods such as cleaning by special divers and cleaning after pulling up to the dock are not used frequently due to those high cost and the heavy burden on cleaners. We proposed a cleaning method using underwater vehicle with brushes, however there is a possibility to remove paints on the hull. To improve cleaning performance of the underwater vehicle, the ultrasonic cleaner is developed by using cavitation occurred by sound waves of the acoustic transduces. The cleaner generates sound waves with sound pressure of 0.2MPa or more required to occur cavitation at the point where sound waves from two transducers overlap. In experimental results, the cleaner occurred cavitation enough to make two holes in the aluminum foil located 50mm away from transducers.

Scopus

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Acoustic communication has a lot of influence of noises, and difficulties in sending and receiving data correctly because of the noise from robot’s thrusters and other acoustic devices. To improve the acoustic communication performance, this research developed acoustic communication system against the thruster’s noise. Communication message includes not only data (payloads) but also sync signal and error correction bytes, and the message is converted to acoustic wave by QPSK modulation which four phase data represent two bits.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Autonomous Underwater Vehicle positioning is important for accurate control and high-quality data collection. Conventional positioning systems are expensive. This paper describes the design and performance results of control using equations of motion and an inexpensive acoustic positioning system implemented on a lightweight AUV “KYUBIC” for Underwater Robotic competition in Okinawa 2021. The velocity used to estimate the self-position of the AUV is calculated form the equation of motion without integrating the acceleration. The acoustic positioning method is based on Super-short baseline (SSBL) principle. The system design comprises of self-made hydrophone module using MEMS microphone. The estimated distance and angle are integrated for dynamic control of AUV to locate the position of a Pinger.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Optimization of fish feeding in marine aquaculture has relied on an expert farmer’s decision-making based on subjective experience. This paper presents the development of a network of underwater current, imaging and IMU sensors for estimating fish feeding behavior for digitizing expert feeding decision-making. We constructed the sensor units and deployed them in fish cages and collected measurements during feeding activities. Experiment results indicate that currents were highest at the surface within the duration of the feeding activity.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

The actual situation of marine litter has not been measured accurately; however innumerable floating garbage are drifting in the ocean. Especially, non-perishable waste such as microplastics continues to grow and is damaging marine life, including endangered species, and some are washed ashore and causing pollution damage to coastal areas. Microplastics incorporated into marine organisms, Arctic Sea ice, and deep-sea seafloor sediments have also been detected. The Ellen MacArthur Foundation in the United Kingdom estimates that the total amount of marine debris exceeds 150 million tons, with more than 8 million tons of new inflow each year. We measured and compared the amount of ocean debris in coasts in Hirado and Matsuura cities, Nagasaki with manual count and an aerial drone observation.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

The underwater robot competition in international conference Techno-Ocean 2021 was held to advance underwater technology, in Dec. 2021. The competition consists of five leagues including AUV (Autonomous Underwater Vehicle) league, and Kyushu underwater robotics which is the Underwater Student Project team at our university that joint the AUV league using developed AUV. The wet test of the AUV league includes a Gate Pass mission which requires passing through an underwater green gate, Buoy Touch mission requiring contact with the yellow and red buoys, and Special mission requiring contact with the Pinger which has an unknown location. Our AUV navigates by image processing using underwater camera to achieve the mission. This paper explains the AUV system, the mission strategy and detail of image processing.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

As the fuel cost will rise continuously, the reduction of fuel consumption and CO2 emissions are required more severely in the transportation industry. To achieve more efficient ship transportation, the prevention of marine biofouling is inevitable. Anti-fouling paint is effective to prevent biofouling to the ship hulls like barnacles, however, even the painted hull acquires slime-like biofouling caused by marine alga on its surface easily. In general, the cleaning of the ship hull is carried out during inspection in dockyard once a year or by divers, which are high costs and high risk task. Frequent cleaning during the ship berthing is desirable to keep good fuel efficiency, and if possible, ships can keep good fuel efficiency that contributes the reduction of costs and CO2 production. As a solution for this issue, we have been introducing underwater robots for ship hull cleaning. In this paper, the motion control system of the robot is described.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

<p>Optimizing fish feeding is needed for a sustainable marine aquaculture production. We approach this problem by estimating the behavior of fishes during feeding by measuring currents they generate around the cage. In this paper, we present our development of an underwater sensor network consisting of current sensors, inertial measurement units, and cameras. This system was deployed in a fish cage and recorded measurements in three fish cages during feeding activities. Results showed that currents generated by fishes were largest at the surface during feeding and decline over time until the feeding ended. Further data analysis is needed for optimizing the farmer’s feeding decisions.</p>

DOI： 10.1299/jsmermd.2022.2a2-a12

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2022/0/2022_2A2-A12/_pdf

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>As crops in greenhouses are widely distributed, IoT devices placed near the crops should be stand-alone and modular, and data from the devices are collected over the networks. Smart agriculture requires knowledge of a wide range of fields including electricity, information, and image processing. We have designed an exercise on environmental monitoring and control of a greenhouse toward smart agriculture. The exercise consists of mechatronics, MATLAB/Simulink and system construction exercises. Students learns technology electrical circuit, embedded programing, network communication, and image processing required for smart agriculture. Almost students who took the exercise acquired technology related to micro-computers, image processing technology and control by MATLAB/Simulink, but a few students couldn’t acquire them. In the next school year, authors plan to teach from a little more basic technology.</p>

DOI： 10.1299/jsmermd.2022.2p2-s12

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2022/0/2022_2P2-S12/_pdf

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Currently, underwater infrastructure facilities in Japan are rapidly aging, but most of them are not inspected by divers because the current inspection by divers is inefficient and potentially dangerous. To realize a system that can inspect underwater infrastructures safely and efficiently, this study develops a motion control system for an underwater robot that is part of the underwater infrastructure inspection system.</p>

DOI： 10.1299/jsmermd.2022.2a2-a11

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2022/0/2022_2A2-A11/_pdf

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>The ocean is one of extreme environments, and underwater robots are expected as the tools for observation of the ocean. Underwater robots require high autonomy and are self-contained to accomplish various deep-ocean observation missions. The next generation AUV is expected to have sampling function of marine benthos with end-effector to catch and bring back marine creatures. However, sampling is not easy task for AUV as the shape, size, motion of targets differs. So that the end-effectors is required to have enough accuracy in control manipulation. One of the key issues is the target recognition from underwater images. In this research, floating objects cancellation method from underwater images using optical flow is discussed.</p>

DOI： 10.1299/jsmermd.2022.2a2-a10

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2022/0/2022_2A2-A10/_pdf

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>In agriculture, the aging and depopulation of farmers cause the shortages of farmers and manpower. Most of commercialized robots are industrial robots for factory automation, and most of robots for the first industry, agriculture, forestry and fisheries are still under developing. The reasons are cost-efficiency of the robotization, safety of the works using robots, difficulty of outdoor operations, and knowledge transfer problem from farmers to computer, etc. As one of solutions for the problems, robot technology into the agriculture is expected to contribute to the laborsaving, improvement of production, production line automation, and also the management toward smart-agriculture. We organize the Tomato-harvesting-robot competition to offer the research field and welcome researchers into agricultural robotics.</p>

DOI： 10.1299/jsmermd.2022.2p2-t08

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2022/0/2022_2P2-T08/_pdf

記述言語：日本語   掲載種別：研究論文（学術雑誌）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In the future estimation of 2050, the food demand increases 70% and the production decreases 15% caused by global warming, and farmer population be 1/5 of current workers. Until 2050, we need an agricultural system of twice production with the same farmland area and 5 times effective operations. To realize the sustainable society, smart agriculture including robot technology, AI, IoT is one of the solutions for food issues. We have been working for a greenhouse project under enPiT-everi for implementation of robotic, AI and IoT technologies to agriculture. In this paper, we introduce the project and robotic applications.

DOI： 10.5954/icarob.2021.os22-5

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In food industry, shortage of workers is a serious problem. Automation of food handling is a critical nowadays. To alleviate the damage during food picking by robotic hand, we propose non-contact acoustic impedance estimation with ultrasonic wave. We have the assumption of the correlation between hardness and acoustic impedance, and, built up ultrasonic transmission model considering attenuation by reflection and absorption, then, made an experiment to estimate the impedance. As the result, we succeeded in detecting acoustic impedance without contact.

DOI： 10.5954/icarob.2021.os23-6

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Ocean is one of big challenging and extreme environments, and hard for human to access directly. As the tool for ocean survey, Autonomous Underwater Vehicles: AUVs are expected and developed from ‘80s. The recent rapid progress of computer and information technologies makes the development of AUVs easier and more practical. We had developed a handy AUV "Kyubic" for the observation of shallow water and artificial structures. In this paper, we describe the system architecture of Kyubic and the experimental results in Underwater Robotics Competition in Okinawa 2020.

DOI： 10.5954/icarob.2021.os22-4

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

For efficiency surveying fishery resource, the authors developed the scanner which measure the target shape at once time. The scanner based on the structured light method irradiated the laser patter coded on De Bruijn for high resolution the measurement under water. The evaluation experiment results showed that the scanner can measure the target shape less than 1.4 % error for the measurement range.

DOI： 10.1109/IEEECONF49454.2021.9382643

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

One of the key issues in improving marine aquaculture is achieving efficient control of feeding, which accounts for large percentages of the production costs in aquaculture operations. To quantify the feeding behavior in seas where the environment conditions are variable, we propose to measure underwater currents generated by fish movement in a feeding activity. We developed a sensor suite consisting of custom-made current sensors and underwater cameras. We deployed this prototype in two sea fish cages and measured the changes of currents during a feeding activity. Results suggest that changes in current may be related to the feeding behavior of the fishes, but more data needs to be collected and analyzed to understand this relationship. To improve on the experiences from the initial experiment, we designed a modular sensor system that will measure currents at more than one side of the fish cage during a feeding activity.

DOI： 10.23919/OCEANS44145.2021.9705858

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In this paper, to realize efficient underwater infrastructure inspection, automatic crack detection by image processing is proposed. In first process of our method generates enhanced image based on the absorbance from the turbidity meter and removes background component, and then detects crack from the enhanced image by using decision tree learning algorithm. This paper explains the algorithm of our method and shows evaluation experiment results.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Improving the efficiency of fish feeding contributes to achieving sustainable expansion of the aquaculture industry. However, expert knowledge on feeding remains reliant on experience. This paper presents a new approach of digitizing such knowledge by measuring underwater currents induced by fishes as indicator of their behavior and appetite. A prototype current sensor suite was constructed to measure the current around the fish cage, especially during feeding.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In order to acquire a time fluctuation data of the resources which needs for a marine resource development, we developed an observation device with low operational risk and a wide observable area. The observation device consists of an underwater station and an underwater vehicle, and underwater vehicle is tethered with a cable. By using the restraint condition of the cable, our device was able to navigate the trajectory planned only by thrust control with an error of up to 0.14m.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In general, farm work is often hard work. In recent years, the number of farm laborers has been decreasing due to the aging of the workforce. Therefore, there is a need to automate agricultural work, and we are organizing a tomato harvesting robot competition to automate tomato harvesting. The competition includes a Junior Division for high school students and a Senior Division for college students. In this paper, we report on the results of 6th tomato harvesting robot competition.

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In agriculture, the aging and depopulation of farmers cause the shortages of farmers and manpower. Most of commercialized robots are industrial robots for factory automation, and most of robots for the first industry, agriculture, forestry and fisheries are still under developing. The reasons are cost-efficiency of the robotization, safety of the works using robots, difficulty of outdoor operations, and knowledge transfer problem from farmers to computer, etc. As one of solutions for the problems, robot technology into the agriculture is expected to contribute to the laborsaving, improvement of production, production line automation, and also the management toward smart-agriculture. We organize the Tomato-harvesting-robot competition to offer the research field and welcome researchers into agricultural robotics.

DOI： 10.5954/ICAROB.2021.PS-1

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

One of the main tasks of AUVs is to capture deep-sea images like fishes, crabs, other living organisms and resources for information leading to research on deep-sea ecosystems. Acoustic transmission are used to establish wireless underwater communications between the AUV and the ship. However, there are some limitations in the communication channels due to limited bandwidth, multi-path, temperature distribution and change in the direction of transmitting source and receiving sensor which results in losses in data being transmitted. Initially, the captured images are enhanced to reduce the effect of light attenuation and then compressed for transmission through acoustic modems. Only an important part of image is being transmitted through set of data packets. The received data packets in the ship will be reconstructed to predict the presence of living organisms. The loss in data during transmission creates a difficulty for the operators to predict the exact information. In this research, to compensate this transmission loss, an efficient compression and reconstruction technique using convolutional autoencoder with minimal distortion is proposed. Finally, for evaluation of the proposed image compression technique, the quality of reconstruction of images with and without data loss will be compared using the quality metrics signal to noise ratio (PSNR), structural similarity index(SSIM) and perceptual quality of image.

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2020, Marine Technology Society Inc. All rights reserved. Simultaneous operation of multiple autonomous underwater vehicles (AUVs) can increase seafloor mapping efficiency. However, AUVs typically rely on support vessels with an operations crew for transport to sites of interest and supervision during their dives. This is costly and limits the scalability of AUV-based seafloor mapping. This paper describes a robotic system that can transport AUVs from shore and deploy them in a survey area located offshore, without the need for a crewed support vessel. We clarify the functional requirements for ship-free AUV operations and propose a concept that allows a single autonomous surface vehicle (ASV) to transport, release, and monitor multiple large and heterogeneous AUVs. The proposed system uses towing modules that can be connected in parallel and can accommodate a variety of pre-existing ASVs and AUVs. A full-scale system was developed and tested during sea trials in the Mediterranean Sea off Greece, to verify basic functionality and gather data on the impact of towing multiple AUVs on ASV endurance and range. Results of these trials and lessons learned are discussed.

DOI： 10.4031/MTSJ.54.5.10

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 1976-2012 IEEE. Manganese crusts (Mn-crusts) are a type of mineral deposit that exists on the surface of seamounts and guyots at depths of >800 m. We have developed a method to efficiently map their distribution using data collected by autonomous underwater vehicles and remotely operated vehicles. Volumetric measurements of Mn-crusts are made using a high-frequency subsurface sonar and a 3-D visual mapping instrument mounted on these vehicles. We developed an algorithm to estimate Mn-crust distribution by combining continuous subsurface thickness measurements with the exposed surface area identified in 3-D maps. This is applied to data collected from three expeditions at Takuyo Daigo seamount at depths of ∼1400 m. The transects add to ∼11 km in length with 12 510 m2 mapped. The results show that 52% of the surveyed area is covered by Mn-crusts with a mean thickness of 69.6 mm. The mean Mn-crust occurrence is 69.6 kg/m2 with a maximum of 204 kg/m2 in the mapped region. The results are consistent with estimates made from samples retrieved from the area, showing more detailed distribution patterns and having significantly lower uncertainty bounds for regional-scale Mn-crust inventory estimation.

DOI： 10.1109/JOE.2020.2978967

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In the future estimation of 2050, the food demand increases 70% and the production decreases 15% caused by global warming, and farmer population be 1/5 of current workers. Until 2050, we need an agricultural system of twice production with the same farmland area and 5 times effective operations. To realize the sustainable society, smart agriculture including robot technology, AI, IoT is one of the solutions for food issues. We have been working for a greenhouse project under enPiT-everi for implementation of robotic, AI and IoT technologies to agriculture. In this paper, we introduce the project and robotic applications.

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

For efficiently observing the marine resources, we developed an observation device with low operational risk and a wide observable area. The observation device consists of a seafloor station and an underwater vehicle tethered by a cable. As experimental validation result, we found that the vehicle tethered by a cable was able to navigate with an error of less than 0. 071m compared with the planned trajectory. The vehicle is controlled using the cable restraint condition and the forces exerted by the thrusters while considering the effect of the cable slack, without the need of any feedback signal.

DOI： 10.23919/OCEANS44145.2021.9705674

Scopus

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p></p>

DOI： 10.7210/jrsj.39.926

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130008130006

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Most of the conventional hydrophones (underwater microphones) use PZT ceramic as the material, and there are problems such as variation in sensitivity, the necessity of high-magnitude amplification and high cost.</p><p>We developed and evaluated a low-cost, easy-to-use MEMS hydrophone that is waterproof and pressure-resistant while maintaining the bandwidth of a commercially available MEMS microphone.</p>

DOI： 10.1299/jsmermd.2021.1A1-B03

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130008134877

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Marine resource survey by an underwater vehicle is expected. To realize cheap self-positioning for the underwater vehicle, we have been developing on the acoustic positioning system which is low cost and easy to maintain. The acoustic positioning system has four hydrophones which consists of molding commercially available MEMS micro phones with pressure-resistant resin, an audio device, and a micro controller. To evaluate the system, positioning experiments was performed in the small tank. In the experiments, the system detected delay time among four hydrophones, however its positioning was not good accuracy. In the future, we will improve the accuracy of positioning by interpolating data and considering the effect of baseline.</p>

DOI： 10.1299/jsmermd.2021.1A1-B01

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130008134856

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（その他学術会議資料等）

<p>Predicting fish feeding behavior is crucial in improving marine aquaculture production. We are addressing this problem using a novel approach – measuring underwater currents generated by fish, especially at feeding times. In this paper, we present our development of a suite of sensors that will collect these measurements, as we investigate their relationship with fish behavior during feeding. We added we have further developed our sensor suite by adding another current sensor for calibrating the previously developed propeller sensors and tested them along a narrow river to examine the relationship of their measurements. While a strong linear relationship was observed between the measurements, it is difficult for the propeller sensors to measure currents accurately at slower currents. Experiment at the fish farm is still needed to determine if this constraint is acceptable in our application.</p>

DOI： 10.1299/jsmermd.2021.1P1-B17

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130008134963

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

その他リンク： https://alife-robotics.com/Volume1/Issue1/03.ICAROB2020(OS22-5)_Yuya%20Nishida(revised%20by%202020,%2008,%2004).pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 1976-2012 IEEE. The exploration of oceans using autonomous underwater vehicles (AUVs) is necessary for activities, such as the sustainable management of fishery resources, extraction of seafloor minerals and energy resources, and inspection of underwater infrastructure. As the next step in ocean exploration, AUVs are expected to employ end-effectors to make physical contact with seafloor creatures and materials. We propose a scenario for realizing a sampling mission using an AUV that is equipped to sample marine life. In this scenario, the sampling AUV observes the seafloor while concurrently transmitting the observed images to a surface vessel for inspection by the AUV operators. If the received images show an object of interest, the object is selected as a candidate of sampling target by the operators, who send a sampling command to the AUV. After receiving the command, the AUV returns to the target area and attempts to sample it. In this paper, we propose a system for transmitting images of the seafloor as part of the sampling-mission scenario. The proposed image transmission system includes a process for enhancing images of the deep seafloor, a process for selecting interesting images, and processes for compressing and reconstructing images. The image enhancement process resolves imaging problems resulting from light attenuation, such as color attenuation and uneven illumination. The process for selecting interesting images selects those that contain interesting objects, such as marine life. The selection process prevents the transmission of meaningless images that contain only flat sand on the seafloor. The proposed image compression method, which is based on color depth compression, reduces the amount of data. The combined process of selecting an interesting image and compressing it reduces various problems in acoustic communication, such as low information density and data loss. Instead of an overall image, part of an overall image is transmitted by a set of data packet, and each received data packet is reconstructed onboard the vessel. Because of image compression, the colors of a reconstructed image differ from those of an enhanced image. However, the reconstructed image contains similar colors, and the structural similarity index was found to be 91.4% by evaluating images that were subjected to a 4-b color compression. The proposed image transmission system was tested in the Sea of Okhotsk, and these tests were performed four times in different sea areas (minimum depth 380 m, maximum depth 590 m). The results show that the size of the data for a single image was reduced by a factor of 18 using the proposed image compression process, with each image taking 3.7 s to be transmitted via an acoustic modem (20 kb/s). Of the automatically selected images, 63% contained marine life, and the total transmission success rate was 22%.

DOI： 10.1109/JOE.2018.2872500

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Animals can achieve agile behaviors such as jumping and throwing in addition to flexible behaviors with the same musculoskeletal systems, and those movements can extend the range of their activities. We have been working on actuators capable of rapid and flexible motions learning the musculoskeletal systems. In this paper, we propose a new rotary actuator using a pair of motors, springs, and cams to perform three functions, namely, normal motion, rapid or instantaneous motion, and rigidity control using an antagonistic cam mechanism, and describe the operating principle of the proposed mechanism, the mathematical model of the mechanism during rapid motion, and the design principle of the cam, which is a key mechanical element in this mechanism. Finally, we present an analysis of the error between the theoretical the measurement results during rapid motion.

DOI： 10.57417/jaalr.1.3_144

CiNii Article

CiNii Research

その他リンク： http://hdl.handle.net/10228/00008167

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Acquiring flexible and agile behaviors as seen in biological systems, the robot can achieve acrobatic movements such as jumping and throwing. These acrobatic movements are expected to extend the range of robot activity. In this research, we propose a special mechanism using a pair of motors, springs and cams, which has three functions: normal operation, instantaneous operation and variable rigidity. Then, we derived a mathematical model of the mechanism and discussed the input-output characteristics of the mechanism by changing the design parameters, and analyzed the difference between the theoretical and measured results.

DOI： 10.5954/ICAROB.2020.OS24-6

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In order to improve the efficiency of the seafloor survey, it is necessary for AUV to report the state of the seafloor to the operators on board reasonably. We have been developing seafloor image selection and image compression technology for the seafloor image transmission using the underwater acoustic communication device. In this paper, we report the results of underwater image selection and transmission in biological sampling experiments conducted in November 2019 off the coast of Suruga-bay, Shizuoka, Japan.

DOI： 10.5954/ICAROB.2020.OS23-2

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

For enhancement of oceanic engineering technology and researchers, underwater robot competition has been held since 2016. Seventh competition in this year consists AUV league that university’s vehicles automatically cruise at field and junior league that underwater craft is made. The paper reports competition regulations of AUV and junior league and results of the competition held in October 2019.

DOI： 10.5954/ICAROB.2020.OS22-5

Scopus

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

For enhancement of oceanic engineering technology and researchers, underwater robot competition has been held since 2016. Seventh competition in this year consists AUV league that university’s vehicles automatically cruise at field and junior league that underwater craft is made. The paper reports competition regulations of AUV and junior league and results of the competition held in October 2019.

DOI： 10.5954/ICAROB.2020.OS23-1

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85108784286&origin=inward

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>Autonomous underwater vehicles (AUVs) observe a wide area by using mounted camera and LED lights and is used for bio-resource survey. However, AUVs is difficult to capture the sample useful for scientists. Previous AUVs can capture only specific benthos that its developer decided the target before resource survey, but scientists for fisheries resource can't chose sampling target during observation by AUVs. To realize an efficient bio-resources survey, the authors developed AUV that can capture the target instructed by the operator during observation. Because the slurp gun installed on the AUV has no canister, the AUV catches only one sample in one dive. This paper explains developed AUV and slurp gun with the canisters, and reports on sea trials using them.</p>

DOI： 10.1299/jsmermd.2020.1P1-C13

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007943437

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>There are many marine resources including mineral and energy resources in Japanese EEZ and those have been surveyed by Underwater vehicles. It is expected that time-varying data will be continuously obtained with low risk in environmental surveys of the seabed. Therefore, we proposed the long-term observation method using Cable-restricted Underwater vehicles.</p>

DOI： 10.1299/jsmermd.2020.1P1-C07

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007943421

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>In food industry, autonomous food arrangement is expected. For the achievement of safety food arrangement by robots, in order to prevent from damaging food, rigidity of the hands is hopeful to be adjusted according to the food stiffness. Measurement of the food stiffness should be estimated before handling. In this research, we propose non-contact stiffness measurement with ultrasound to enable variable rigidity of hands while food handling is ongoing.</p><p>We measured power spectrum of ultrasound reflected on food. As the result of the experiment, the spectrum varied according to the stiffness.</p>

DOI： 10.1299/jsmermd.2020.1A1-K06

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007943408

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2019 IEEE. This research focuses on two self-localization methods for observation of the sea floor and sampling. One is a method of estimate the self-localization using Kalman filter from the acceleration data calculated from equation of motion and the velocity data considering the effect of underwater vehicle's oscillation. The other is visual odometry using a stereo camera. The AUV was deployed in a sea area 40m depth to evaluate the performance of self-localization estimated by two methods. Self-localization estimation using Kalman filter was less accurate than visual odometry, but it was confirmed that the variance of the estimated velocity was smaller than before estimation. In the visual odometry using stereo camera, it was confirmed that the estimation error depends on the travel direction of AUV and the moving direction of a stereo camera.

DOI： 10.1109/ICIIS47346.2019.9063345

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85084155438&origin=inward

記述言語：英語   掲載種別：研究論文（学術雑誌）

A method for estimating the volumetric distribution of Cobalt-rich Manganese Crusts (Mn-crusts) by combining multi modal sensor data collected using an Autonomous Underwater Vehicle (AUV) is described. The AUV calculates the thickness of Mn-crusts using a sub-bottom sonar and generates a 3D colour reconstruction of the seafloor using a light sectioning mapping system. The 3D map is classified into one of the 3 types of seafloor - crusts, sediments and nodules, using a machine learning classifier. The thickness measurements are made along a seafloor transect whereas the 3D maps have a width of ~1.5 m, depending on the AUV altitude. The thickness measurement is then extrapolated to areas not scanned by the sonar, by defining an area of influence which is the area over which the thickness of the Mn-crust is not expected to change significantly. Estimates for percentage coverage of the Mn-crust and mass of Mn-crust per unit area are determined along the AUV transect based on the extrapolated thickness. This method provides a novel approach to estimate the distribution of Mn-crusts over large areas.

DOI： 10.1109/OCEANSE.2019.8867481

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85103860769&origin=inward

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2019 IEEE. This research has developed AUV Tuna-Sand2 for wide area survey and benthos sampling to understand biological diversity for sustainable use of living marine resources. For evaluating sampling system of the AUV, the AUV was deployed at 100 m depth in Sagami bay of Japanese. The AUV which received image number of sampling target, returned to its photographing point, and started to search the target by the image processing. After finding the target, the AUV shifted to sampling altitude and succeeded in suction the shell using suctioning of mounted manipulator.

DOI： 10.1109/UT.2019.8734330

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2019 IEEE. This study focuses on the two vision-based control technologies for sampling-AUV(S-AUV) to observe and sample objects on the seabed. One is the visual interface between shipboard researchers and the S-AUV via an acoustic modem for obtaining the seabed information. We are able to select the sampling target object in-situ using this visual interface and instruct it to the S-AUV. The other is the visual tracking technique for sampling target objects in the underwater environment. We succeeded three times in a row in sampling experiments at a depth of 80m-120m in Suruga Bay in March 2018.

DOI： 10.1109/UT.2019.8734462

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068449860&origin=inward

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2019 IEEE. There are many marine resources in Japanese ocean, those have been surveyed by a underwater robot. The accuracy of the resources survey results using the vehicle depends on the accuracy of its self-localization. Thus, we propose a self-localization method by Kalman filter consdering the effect of vehicle's oscillation and the effect of the current. It is possible to reduce the positioning accuracy by 0.2 m by considering the effect of the vehicle's oscillation. In future work, we will develop an algorithm considering delay time for sensor fusion with acoustic positioning device.

DOI： 10.1109/UT.2019.8734461

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85068478136&origin=inward

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2019 IEEE. As the future seafloor survey system without a support vessel, combinations of autonomous underwater vehicles (AUVs) and autonomous surface vehicles (ASVs) are expected. To realize ship-less operations, we have designed unmanned survey systems which consists of multiple AUVs, AUV towing frames, and an ASV. The ASV of the proposed system works as two roles: transporting AUVs between a shore base and a survey site, and relaying the communication between AUVs and a ground-based mission control. We have developed and tested the two sets of the proposed survey system. The first one is the survey system for 2,000m depth consists of three AUVs supervised by an ASV and the second one was for 4,000m depth consists of two AUVs supervised by the ASV. In this paper, we respectively introduce the two sets of the system design and also report the implementation and results of recent sea-trials in Suruga Bay.

DOI： 10.1109/UT.2019.8734296

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

We developed an AUV's sampling device control system. It is employed the any toolboxes provided in MATLAB/Simulink by Mathworks. The toolboxes are powerful, useful, and functional. "Robotics System Toolbox" in theirs supports the ROS middle ware. It provides the cloud data communication. "Parallel Computing Toolbox" can struct a multi process and parallel computing on script base and Simulink model base program. "Stateflow" is a powerful tool for design of state transition control method. The toolboxes are employed in the sampling device control system of the AUV. This method with using the toolboxes of MATLAB/Simulink realize the rapid prototyping of the system designs, developments and system test. The developed system mounted on an AUV was powered in several real sea areas. Report on the results and problems when operating in real environments.

DOI： 10.5954/icarob.2019.os21-1

CiNii Research

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Inspection of underwater infrastructure of bridge pier is important for bridge maintenance, however, the underwater environment is dangerous and their observation is one of difficult problems. We have been developing the underwater inspection system which consists of an unmanned surface vehicle (USV) and a remotely operated vehicle (ROV). The concepts of the system are (1) Operation is executable with a small number of persons, (2) USV and ROV are controllable from land or bridge, (3) Build 3D model and images for crack detection. The ROV observes the status of whole infrastructure using cameras and control its posture using a depth sensor and IMU sensor. The USV vertically lifts up and down ROV by winch and carries ROV to the infrastructure. USV has GPS, LRF and IMU for horizontal positioning and pan-tilt control of the camera. In this paper, we discuss the results of the inspection operation test by the robot.

DOI： 10.5954/icarob.2019.os21-2

CiNii Research

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

DOI： 10.5954/ICAROB.2019.OS21-3

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>In this paper, we propose a new formula to accurately estimate the output value on the real machine of the proposed mechanism as a part of the development concerning the high power joint mechanism. The previously proposed formula did not consider the energy loss when the slider translated. Considering the mass of the slider, we derived an expression that can estimate the angular velocity of the output link from the energy conservation law and the geometrical relationship. As a result of comparing the theoretical value and measured value, the performance of real machine could be more accurately estimated by using the proposed mathematical formula.</p>

DOI： 10.1299/jsmermd.2019.1P2-K09

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007774443

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2018 IEEE. The observation of marine life by autonomous underwater vehicle and the marine life counting and measurement system are highly required for the fisheries resources management. In this research, we propose an automatic flounder, which is valuable as a food resource, length measurement system. The proposed system consists of the image enhancement process, selection region of candidate process, recognition process and measurement process. In the image enhancement process, the Retinex theory is employed to improve visibility of seafloor image, and the enhanced image used to select candidate region in the selection region of candidate process. Then, AlexNet, which is object recognition algorithm based on convolutional neural networks, employed for the flounder recognition, and the length of recognized flounder is estimated by measurement process. Flounders are inhabited on seafloor and the shape does not change significantly, by these properties, the length of flounders is estimated using a straight line from head to tail in the measurement process. For evaluation, 10 seafloor images, which are obtained by AUV, are used. The result of evaluation, the region selection error was 31%, recognition accuracy was 85% and the average of error of estimated flounder’s length was 6 pixels.

DOI： 10.1109/OCEANSKOBE.2018.8559296

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2018 IEEE. We developed operation system for a multiple AUV operation using a ASV. The operation system has functions that the operator at remote location monitors the AUVs during cruising and it safety navigates according to instructs from the operator. In sea trials using the operation system, the two AUV succeed navigating about 4.7 km in parallel, and measured the seafloor using equipped. the operator on the barge constantly monitored navigation data of the AUVs through the ASV.

DOI： 10.1109/OCEANSKOBE.2018.8559319

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2018 IEEE Autonomous underwater vehicle (AUV) operations require manned support vessel for communication, navigation, deployment, and recovery. Because the number of the support vessel is limited, the strong tie between AUV and support vessel prevents to operate many AUVs simultaneously. Since this problem has been shared in oceanic markets, we propose a compact and mobile package of multi-robot system to realize fast and ultra-wide area bathymetric survey without support vessel. The proposed system consists of several numbers of AUVs, single autonomous surface vehicle (ASV), and ground mission control. The proposed system includes an unmanned deploy and recovery system, which enables towing, deploying and recovering multiple AUVs by an ASV without manned support vessel. The three AUVs can equip different payloads and basically follow the order of forming a convoy from the ASV which is also supervised by operators at a remote ground base station. Satellites communications are used between the ground base station and the ASV, and acoustic communications are used between the ASV and the ASVs. The proposed system has been developed and implemented. Several sea-trials had been conducted to confirm the validity of the proposed system. In this paper, we introduce the overall design concept of the proposed system and the recent activities.

DOI： 10.1109/OCEANSKOBE.2018.8559056

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2018, Fuji Technology Press. All rights reserved. We developed a vision system for an autonomous underwater robot with a benthos sampling function, specifically sampling-autonomous underwater vehicle (AUV). The sampling-AUV includes the following five modes: preparation mode (PM), observation mode (OM), return mode (RM), tracking mode (TM), and sampling mode (SM). To accomplish the mission objective, the proposed vision system comprises software modules for image acquisition, image enhancement, object detection, image selection, and object tracking. The camera in the proposed system acquires images in intervals of five seconds during OM and RM, and in intervals of one second during TM. The system completes all processing stages in the time required for image acquisition by employing high-speed algorithms. We verified the effective operation of the proposed system in a pool.

DOI： 10.20965/jrm.2018.p0248

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2018, Fuji Technology Press. All rights reserved. A hovering-type autonomous underwater vehicle (AUV) capable of cruising at low altitudes and observing the seafloor using only mounted sensors and payloads was developed for sea-creature survey. The AUV has a local area network (LAN) interface for an additional payload that can acquire navigation data from the AUV and transmit the target value to the AUV. In the handling process of the state flow of an AUV, additional payloads can control the AUV position using the transmitted target value without checking the AUV condition. In the handling process of the state flow of an AUV, additional payloads can control the AUV position using the transmitted target value without checking the AUV condition. In this research, water tank tests and sea trials were performed using an AUV equipped with a visual tracking system developed in other laboratories. The experimental results proved that additional payload can control the AUV position with a standard deviation of 0.1 m.

DOI： 10.20965/jrm.2018.p0238

Scopus

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Underwater imaging is an important part to seafloor observation by underwater robot. Underwater robots provide many images, which contain seafloor environment, and theses images contribute to various fields such as marine biology, marine geology and fishery science. However, underwater images has different properties, such as uneven illumination and light attenuation, compared to images which taken in air, and these properties impede image checking by researchers. In this paper we propose an image enhancement based on scale-gain Retinex, and the proposed method is experimented on the Suruga-bay in Japan.

DOI： 10.5954/icarob.2018.os20-2

CiNii Research

記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p>A variety of robots has been studied and developed for undersea exploration. One of the applications for undersea exploration is mining of undersea resources such as methane hydrate and rare metal by Autonomous Underwater Vehicle (AUV). To extend active duration time of the robot in the sea, a system through which the AUVs recharge autonomously batteries is a key technology. Our reseach group has confirmed in a pool environment the dual-eye visual servoing system made a pole attached to the vehicle dock into a hole. This experiment simulates situation where the vehicle approaches recharging station under deep sea. But previous studies were conducted with ROV (Remotely Operated Vehicle) that is controlled by remote computer instead of human operator. In those experiments, power cables affected performance of control accuracy. Therefore the performance of visual feedback with AUV named Tuna-Sand2 that is compeletely indepent from cables or wires and has a general structure of modernized AUV system, has been verified to confirm the practicability of dual-eye dockig system.</p>

DOI： 10.1299/transjsme.17-00242

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130006401787

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Rich undersea mineral resources are confirmed around Japan and the research about undersea mineral resources and deep sea creatures has been conducted actively. Since three-dimensional data could not be get by human, three-dimensional measurement technology is important in the deep sea survey. Therefore we designed a measuring device suitable for underwater environment. </p>

DOI： 10.1299/jsmermd.2018.2P2-C07

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/130007551964

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

DOI： 10.5954/ICAROB.2018.OS20-3

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

DOI： 10.5954/ICAROB.2018.OS20-4

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2017 IEEE. Autonomous Underwater Vehicle (AUV) has become one of the promising tool for ocean exploration during the last few decades, and, in particular, is the solution for the spatial-temporal investigations in wide areas for a long period. One of the next mission expected from AUV is deep sea specimen sampling, which is currently performed by Remotely Operated Vehicle (ROV) or Human Occupied Vehicle (HOV) where the sampling targets are selected by scientists on-line. In order to establish the similar on-line investigation with AUV system, the sea-floor images have to be transmitted to the scientists on the support vessel by acoustic communication. However, the speed of the acoustic communication is low compared with that of radio communication, and the data can be lost because of the directionality of acoustic modem, the positional relationship between the AUV and the support vessel, attenuation and so on. The robust image transmission system is necessary with acoustic communication for in-situ decision making for sampling by AUV with many tasks. In this paper, we propose a sea-floor image transmission system with image compression, and evaluated by sea trials in Suruga-bay. The image compression method is based on a set of color palettes, where the colors of a color palette are assigned as a set of main colors obtained from the minimum variance quantization, to represents a typical sea-floor image. The colors of the obtained images are replaced by the most similar colors in the color palette. The images compressed by a 16-colors color palette are evaluated by Structural SIMilarity (SSIM) method, and these compressed images have shown the SSIM index of 88.5%. The duration of one image transmission is about 40 seconds in the sea trials and the transmission success rate is 75%.

DOI： 10.1109/OCEANSE.2017.8084926

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2017 IEEE. This paper presents docking experiments for AUV using stereo vision for sea bottom battery recharging application. Real-time 3D pose tracking system was installed in AUV 'Tuna-Sand 2'. Underwater battery recharging unit with unidirectional docking function was simulated in a pool. 1\ma-Sand 2 approached to the docking station using other sensors and docking operation was performed by visual servoing when a 3D marker was detected. Experimental results showed the performance of the proposed system with accurate docking accuracy in a short time.

DOI： 10.1109/OCEANSE.2017.8084659

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2016 IEEE. Autonomouse underwater vehicles(AUVs) are vital tools for detailed ocean survey in recent years. Amongst them, hovering-type AUVs are specialized in optical observation using cameras and travel near the seafloor avoiding obstacles. Therefore, it is important to maintain proper distance between AUV and objects which should be approached to take pictures.

DOI： 10.1109/Techno-Ocean.2016.7890645

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2016 IEEE. The noise evaluation of the platform is necessary to use passive acoustic monitoring. In this study, we measured background noise of underwater platforms such as AUVs and deep sea landers. AUV that has thrusters was higher background noise level, when control own position and speed. However, background noise level was deduced, when stopped thrusters. The background noise of AUV of the type of control buoyance of own and of the deep sea lander was low. The background noise of AUVs on low frequency range was higher than high frequency range. A biological sound was observed using AUV. Even if AUV was to depth of the water 900m, the sound of the creature was measured. Therefore, the biological sound could be observed using AUVs or the deep sea lander, and the possibility that the biological sound could be observed automatically and extensively was indicated.

DOI： 10.1109/Techno-Ocean.2016.7890669

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

Underwater robot is one of the important research tools to explore deep-sea. Especially, Autonomous Underwater Vehicles (AUVs) attract attentions as new tools because they are un-tethered and suitable for wide area observation. As the next generation AUV, we have been developing a Sampling-AUV that can dive into deep-sea and bring back marine creatures using a mounted manipulator. In the mission, the AUV transmits the deep-sea floor images to the support ship using acoustic communication, and the operator selects the marine creatures to sample and bring back them. In this talk, we introduce the new AUV, the underwater manipulator and image processing techniques for sampling.

DOI： 10.5954/icarob.2017.ps1

CiNii Research

記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>We developed an image sensing system for an autonomous underwater robot with a benthos sampling function, namely sampling-AUV. The mission of a sampling-AUV consist of following four phases: observation phase (OP), return phase (RP), tracking phase (TP) and sampling phase (SP). For an achievement of the above mission, proposed image sensing system comprises software modules of image acquisition, image enhancement, object detection and image selection, and object tracking. The camera in proposed system acquires an image by intervals of five seconds during OP and RP and of a second during TP. The system completes all processing within image acquisition times by employing high-speed algorithms. We checked operations of proposed system in a pool.</p>

DOI： 10.1299/jsmermd.2017.2a2-g09

CiNii Article

CiNii Research

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Many mechanisms with Impulse Force Generator is generally operated at high speed and strong force. We have been working on high power joint mechanism imitating locust hind-leg in order to realize a mechanism capable of not only rapid motion but also normal motion. However, they have some problems as following. In rapid motion, The developed mechanism has energy loss due to the viscous resistance of the reduction gear of the actuator. And the direction of rotation during rapid motion is restricted. In this paper, we propose a high power joint mechanism with higher performance which solves this problem. The mechanism proposed by us can perform rapid motion and normal motion at clockwise and counterclockwise. And the mechanism can change of the articular compliance. The mechanism consist two motors with cams, two wires, one spring and some links. Our verification experiment of rapid motion showed that the proposed mechanism can realize rapid motion without viscous drag.</p>

DOI： 10.1299/jsmermd.2017.2a1-a06

CiNii Article

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2017/0/2017_2A1-A06/_pdf

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>A rich undersea mineral resource is confirmed in the basin of Japan. Three-dimensional measurement technology is indispensable for developing undersea resources. By applying structural light to the underwater environment, it is possible to measure not only the three-dimensional topography but also the seabed creature. Therefore, we aim to develop an underwater three-dimensional measuring device using structured light and light cutting method. In order to develop a new three-dimensional measuring instrument, basic measurement theory was verified.</p>

DOI： 10.1299/jsmermd.2017.2a2-o07

CiNii Article

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2017/0/2017_2A2-O07/_pdf

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

This paper describes a method to optimize the spatial resolution of image surveys based on the spatial scale of features on the seafloor that are not known prior to observation. The method makes use of the density of visual features as a measure of the complexity of a seafloor image. In order to achieve this, two approaches to assess scene complexity we investigated. The performance of the method was verified using seafloor imagery obtained in the Iheya North field in the Okinawa Trough. The results demonstrate that it is effective for a large range of feature sizes.

DOI： 10.1109/AUV.2016.7778692

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2016 IEEE. This paper describes the design of a newly-developed Autonomous Underwater Vehicle 'HOBALIN' by National Maritime Research Institute, Japan. The major mission of the AUV is to explore hydrothermal vents by taking photographs hovering over the seafloor at an altitude of 2-5 meters, up to 2,000 meters depth. 'HOBALIN' was developed as a practical AUV based on the design of the AUV 'TUNA-SAND'. Therefore, rapid construction and deployment was achieved. Moreover, as the AUV is a small-sized system, it is easy to handle on any type of support ship which doesn't have any specialized facility for AUVs. Several trial dives were conducted to confirm the validity of the system in Suruga Bay. 'HOBALIN' dived and traveled along the predefined survey lines and took seafloor pictures.

DOI： 10.1109/OCEANS.2016.7761452

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2016 IEEE. AUV Tuna-Sand 2 developed in February 2016 can take photograph of the seafloor with high resolution using a camera and two LED strobe every five second and detect sea creature from it based on color information. If sea creature is detected from taken photograph, the AUV transmit its compressed image to the ship using acoustic modem for image transmission. Operator on the ship can select photographing position that the AUV return it, from received photograph. After instruction by operator using acoustic modem for command, the AUV can return to photographing position in the range of ± 0.3 m. In future work, we will develop visual feedback method and manipulation method for sea creature sampling.

DOI： 10.1109/OCEANS.2016.7761471

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2016 IEEE. One of the important missions of AUVs is to take deep-sea images and make maps of sea floor to contribute the understanding of deep-sea biology and geology. The sea floor images include lots of information such as distributions of creatures, minerals and so on. The next mission expected for AUVs is to bring the samples back concurrently with taking interesting photos, autonomously. However, this mission is difficult to perform fully-autonomous without the knowledge of biologists or geologists, as the AUVs don't know which objects are interesting or important for them and it takes long time to teach AUVs all features of target samples. It is necessary for AUVs to work semi-autonomously by collaborating with scientists on the ship and getting commands to indicate the important samples. In this research, we proposed an image enhancement and compression method for acoustic transmission with limited communication density. The proposed method enhances the effect of light attenuation in the deep-sea floor image and reduces the image depth from 24-bit of original images to 4-bit. The method is evaluated by transmission experiment using a new AUV "TUNA-SAND 2".

DOI： 10.1109/OCEANSAP.2016.7485453

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

We developed a virtual mooring buoy, called an autonomous buoy “ABA” for AUV, which navigates the sea using thrusters in 2014. Its purpose was to deploy autonomous underwater vehicles (AUVs) effectively in seafloor exploration. The ABA tracks and positions AUVs operating underwater using onboard acoustic positioning. We have deployed the ABA with two type AUVs in seafloor exploration. That conducted in February 2015 used the ABA with one AUV to survey and inventorymineral deposits, demonstrating the ABA’s capability of positioning an AUV navigating at 1, 370–1,550m depths at a standard deviation of 100 m or less and tracking it while maintaining a horizontal distance of 50 m or less. The ABA navigated the AUV within a position error of about 10 m.

DOI： 10.20965/jrm.2016.p0086

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担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

In order to effectively investigate the distribution and amount of cobalt-rich manganese crust (CRC), an autonomous underwater vehicle BOSS-A equipped with visual and acoustic instruments were developed. BOSS-A observes the seafloor along preset waypoints at a constant speed and altitude. Detailed 3D seafloor images can be obtained from the visual instrument, which employs a sheet laser and a camera. In addition, an acoustic instrument measures the CRC thickness beneath BOSS-A. The CRC at Katayama seamount was surveyed in February. The results visually presented the state and distribution of the CRC in this site and clarified the amount of the CRC. In the future, the authors will develop amore reliable thickness measurement method.

DOI： 10.20965/jrm.2016.p0091

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2015 MTS. AUV BOSS-A with visual and acoustic instrument device has been developed to survey manganese crusts located at the depth of 1,000 to 2,400 m. The AUV navigates at constant speed and altitude along waypoints with primary set, and automatically observes the seafloor by developed instruments. Visual instrument device mounted on the AUV creates 3D color reconstruction which shows the condition and the distribution of manganese crusts. Mounted acoustic instrument device is able to measure manganese crusts thickness. This paper describes the system and survey method of the AUV BOSS-A and survey results of sea trial for the demonstration of the manganese crust survey using the AUV. Survey results shows that manganese crusts with thickness of 15 to 45 mm are distributed at Katamaya sea mount. coustic instrument devices.

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記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>The autonomous Underwater Vehicles (AUVs) are developed to contribute various science filed such as oceans biology, geology by deep-sea observation. The deep-sea observation by AUV provides various information such as lifestyle of deep-sea creature, volcano of deep-sea bottom, etc. by photographing image. Next mission using AUVs is required to sample targets such as creature, mud or stone in deep-sea floor. For success of this mission, AUV needs supports by researcher in support ship. However, underwater communication based on acoustic has less density compared to electronic. In this research, we proposed a method of image compression and reconstruction for acoustic communication. And we evaluated reconstruction image by Structural similarity.</p>

DOI： 10.1299/jsmermd.2016.1a1-16b7

CiNii Article

CiNii Research

その他リンク： https://www.jstage.jst.go.jp/article/jsmermd/2016/0/2016_1A1-16b7/_pdf

担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>In order to effectively investigate the distribution and amount of CRC (Cobalt-Rich manganese Crust) an AUV BOSS-A equipped with visual and acoustic instruments were developed. The AUV observes CRC on the seafloor along preset waypoints at a constant speed and altitude. Detailed 3D seafloor image is created based on navigation data from the AUV and images from visual instrument. In addition, an acoustic instrument measures the CRC thickness. We surveyed the CRC at Katayama seamount in February 2015. The results visually presented distribution of the CRC in this site. In the future, we will develop a reliable, accurate measurement method for CRC thickness by combining visual and acoustic instruments.</p>

DOI： 10.1299/jsmermd.2016.1a2-17b2

CiNii Article

CiNii Research

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記述言語：日本語   掲載種別：研究論文（その他学術会議資料等）

<p>Underwater robots are employed to marine organisms' research in ultimate environments. In this study, we aim to do automation of marine organisms sampling by autonomous underwater vehicle with a manipulator. We developed a manipulator to pick up deep-sea benthic organisms. The developed manipulator is driven by a master-slave cylinder type hydraulic driven system. Moreover, the manipulator's joints are actuated by hydraulic cylinder, and linear motion of the cylinder is converted to rotational motion by a motion conversion cam-mechanism. This control system was integrated by MATLAB/Simulink. So we adopted Stateflow (this is a toolbox for Simulink) in the high level control layer.</p>

DOI： 10.1299/jsmermd.2016.1a1-17a3

CiNii Article

CiNii Research

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2015 IEEE. In this paper, we introduce a newly developed autonomous buoy system that enables remote monitoring of an AUV. The buoy system has a dynamic positioning function and can track the target AUV. Using an acoustic data link and a radio data link, the buoy can relay the messages between the AUV and the surface monitoring system of the AUV. The first sea trial was successfully performed in October 2014.

DOI： 10.1109/OCEANS-Genova.2015.7271614

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2014 IEEE. This paper proposed a novel approach to the kichiji rockfish recognition method for investigation of the fish biomass. This method does not depend on the size, position and attitude of the fish, because SIFT feature with rotation invariant is used and is represented by vector quantization histogram. The experiment results showed that our method detected 94 % of object which is the fish from 37 photographs and recognized 57 % of the fish from detected image. And our method was able to recognize kichiji rockfish from SIFT features of the fish head. However, if more than one object is piled up, our method is a possibility of mistaken recognition because features of object other than target are used for recognition

DOI： 10.1109/OCEANS.2014.7003268

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2014, Nishida et al.; licensee Springer. Expensive kichiji rockfish is important catch for fishers and decreas significantly by over fishing. Common investigation method by the trawl for the fish is difficult to survey on rough terrain and need for big support of the ship. This paper proposes resource investigation method for kichiji rockfish using autonomous underwater vehicle (AUV) Tuna-Sand, and image processing method for precise measurement of the fish length. The AUV Tuna-Sand was developed for survey of material and energy resources in deep-sea such, and can observe natural seafloor automatically using only mounted sensors and devices. Our image processing makes a photograph possible to measure accurately the fish length by color correction for removing the unevenness of the brightness and distortion correction. The AUV Tuna-Sand surveyed for 24 hours in Kitami-Yamato Bank off Northern Japan. The vehicle took about 5,300 pictures of the seafloor during five dives in the bank. 37 kichiji rockfish of about 90 to 340 mm long were in all photographs. The survey results showed the fish of 150 to 200 mm long was most often found in all dives although the number of the othSer long was not many. Six mosaic images made by our method showed that all kichiji rockfish stay on the seafloor by oneself without swam and the shortest distance between kichiji rockfish was 4.0 m.

DOI： 10.1186/s40648-014-0002-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）

An autonomous underwater vehicle Tuna-Sand operating at a depth of 1,500 m to investigate benthic organisms was developed to observe detailed images of the seafloor. Once submerged, vehicle Tuna-Sand navigates several meters altitude above the seafloor with complex terrain using only onboard sensors and taking 2,000 high-resolution images of the seafloor before returning to the surface. Since its launch in March 2007, vehicle Tuna-Sand has performed underwater research 81 times in Japan's exclusive economic zone, e.g., Kagoshima Bay, the Myojinsho caldera, and the Kuroshima knoll as of March 2014. Survey on the Joetsu knoll in the waters off of Niigata in July 2010 clarified the presence of live red snow crabs - a confirmation highly appreciated by fisheries researchers. An image-based photomosaic showed that 3,341 red snow crabs lived on the Joetsu knoll within an area of 800 m2. The authors are planning to survey the biomass of Kichiji rockfish in the Kitami-Yamato sea bank.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

© 2014 IEEE. We surveyed the biomass of valuable kichiji rockfish using hovering type AUV Tuna-Sand which developed for observation of the seafloor, in Kitami-Yamato bank in northern ocean of Japan at June 2013. The AUV took about 5,300 photography of the seafloor for over 24 hours. The photograph had 37 kichiji rockfishes 90 mm to 340 mm long. Kichiji rockfishes which were taken several times by the AUV stayed on the seafloor at same attitude. TS-076 dive point of 652 m depth had most number of kichiji rockfish and many brittle stars. TS-077 dive point of 305 m depth had two fishes although the AUV observed the broadest range in all dive points. In TS-079 dive, the AUV observed ten fishes although observation area was the smallest, and fish density (= number per 1 ha) was over 220 /ha. Made photomosaic shows that a kichiji rockfish stayed in oneself without troop and shortest distance between two fishes was about 4.0 m.

DOI： 10.1109/OCEANS-TAIPEI.2014.6964503

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

During the operation of and AUV in the ocean, it is necessary to monitor the vehicles position and the status in real time to prevent accidents that may occur abrupt changes in oceanic condition. Therefore a support ship should follow and monitor the AUV during survey. The ship operation costs are high and it is inefficient use if only one AUV dives during a survey. We developed a new survey method for multiple AUVs to make effective use of ship time. In our survey method, two cruising AUVs (AE2000a and AE2000f) pass through approximately the same route and observe the seafloor at a high altitude. One hovering type AUV (Tuna-Sand) navigates and takes pictures of seafloor at a low altitude. The ship follows the two cruising AUVs and sends the command by acoustic communication as necessary. Then an SSBL device on a moored buoy localizes Tuna-Sand and sends vehicle's position and status to the ship by satellite communications. To avoid sound wave interference, sufficient time gap is added between signal transmissions and the GPS time is used for synchronization. The Tuna-Sand AUV observed on Smith caldera in Izu-Ogasawara ocean area in two dives using our survey method. In first dive, the vehicle surveyed for about 2 hours and took 170 pictures of the seafloor. In second dive, we succeeded that AE2000a, AE2000f and Tuna-Sand dived and surveyed on the caldera at same time. The results obtained during the survey are described in detail in this paper. © 2013 MTS.

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Many insects can jump several times their own body length. Locusts with their powerful hind legs can for example jump up to five times as high - 250 mm. We propose a high-power joint mechanism mimicking the locust leg structure in walking and jumping. The mechanism can produce power higher than motors mounted in the joint mechanism and separate walking and jumping using two motors. We also report the joint mechanism design principles.

DOI： 10.20965/jrm.2011.p0225

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

We have been working on high power joint mechanism which is expected to improve robot functionality and the activities in various working environment. In general, the performance of joint mechanisms depends on actuators performance, and the power mass ratio of actuators is almost constant in the same type motors. Locusts whose length is about 50mm have powerful hind-leg to jump five times high (about 250mm) at the peak. The aim in this research is to develop high power joint mechanism by mimicking leg mechanism of locusts. Proposed high power joint mechanism consists of a closed link structure with 4 links, a spring and 2 linear slide actuators. This paper descries how to generate high power in the joint mechanism, and shows the characteristic of the joint mechanism by the analysis. © 2010 TSI Press.

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記述言語：英語   掲載種別：研究論文（学術雑誌）

The size and weight of an actuator tend to increase with actuator power because the actuator power-to-mass ratio is near constant for a given type of motor. Rapid motion such as jumping or running is difficult to realize by using simple actuator power. The aim of this research is to develop a high power joint mechanism that mimics the leg mechanism of a locust. The characteristics of the joint mechanism are evaluated using vector and dynamic analysis.The proposed high power joint mechanism consists of a closed link structure comprising four links and a spring. Linear actuators are attached to the top and bottom links, and the joint angle changes by controlling the lengths of the top and bottom links. A spring is located between two of the links, and is contracted using two linear actuators to provide stored force, which can be released instantaneously to produce a higher power response than that available directly from both actuators.The analysis demonstrates how the joint mechanism produces an output with a higher power than the rated input actuator power. The output characteristics of the joint mechanism depend on link length and link conditions. © 2010 Jilin University.

DOI： 10.1016/S1672-6529(09)60238-9

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

In our previous research, we developed a jumping legged robot aiming at expansion of mobile robot's activities. In jumping motion, the velocity and mass of robot have large effect on jumping height and motion. In order to analyze the jumping motion, one-mass or two-mass models are proposed. At the moment of jumping, the velocity of the robot in two-mass model changes rapidly because the top mass of robot lifts up the foot mass together. The balance of two masses, upper and lower bodies, is one of the important parameters to have enough jumping height. For designing a real robot, we must estimate/design the robot function, total weight, actuator type, motor power, etc, however, it is difficult to find optimal design under ill-defined constraints. It is known that relative proportion of the body and length in animals follows the elastic similarity law. One reason for the relationship is supposed that animals keep safety and robustness in the strength of body. In this paper, we propose index parameters for jumping robot by taking into account the elastic similarity law in animals, and the mass of the robot and necessary actuator power are estimated. ©2009 IEEE.

DOI： 10.1109/ICSMC.2009.5346136

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=74849084660&origin=inward

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）

The attitude control of a horizontal underactuated Manipulator (UAM) is a difficult control problem because of its second-order nonholonomic constraints. This paper proposes a new method for the trajectory planning of the UAM. In the proposed method, the trajectory planning is transformed to a constraint satisfaction problem, and the constraint satisfaction problem is solved by using a sequence of multi-layer perceptrons which are trained to be a forward model of the UAM. We show the effectiveness of our method by several experimental results. © 2009 Springer Berlin Heidelberg.

DOI： 10.1007/978-3-642-02490-0_96

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=70349113487&origin=inward

記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

Today, we tend to waste considerable amount of things and energy and produce a large amount of garbage in our daily lives. We are now forced to use a lot of expenditures and time to dispose of a lot of waste materials. Under such circumstances, reusable bottles, one of familiar waste materials, are recycled more frequently than before. In addition, the washing process of collected bottles has been automated. However, caps of collected reusable bottles are sometimes replaced although there are some regional differences about the treatment of caps. One possible problem is that such caps have to be detached by hand. Therefore, with the commercialization of product in mind, this research made an attempt to develop a machine that automatically unscrews caps. As a result of this research, a decapping machine was successfully developed. Caps of reusable bottles are automatically unscrewed with a minimum failing rate.

CiNii Article

その他リンク： https://ci.nii.ac.jp/naid/110006392542

開催期間： 2020年05月27日 - 2020年05月30日   記述言語：日本語   開催地：金沢（オンライン）  

CiNii Article

開催期間： 2020年05月27日 - 2020年05月30日   記述言語：日本語   開催地：金沢（オンライン）  

CiNii Article

開催期間： 2020年05月27日 - 2020年05月30日   記述言語：日本語   開催地：金沢（オンライン）  

CiNii Article

開催期間： 2017年01月   記述言語：日本語  

<p>Many mechanisms with Impulse Force Generator is generally operated at high speed and strong force. We have been working on high power joint mechanism imitating locust hind-leg in order to realize a mechanism capable of not only rapid motion but also normal motion. However, they have some problems as following. In rapid motion, The developed mechanism has energy loss due to the viscous resistance of the reduction gear of the actuator. And the direction of rotation during rapid motion is restricted. In this paper, we propose a high power joint mechanism with higher performance which solves this problem. The mechanism proposed by us can perform rapid motion and normal motion at clockwise and counterclockwise. And the mechanism can change of the articular compliance. The mechanism consist two motors with cams, two wires, one spring and some links. Our verification experiment of rapid motion showed that the proposed mechanism can realize rapid motion without viscous drag.</p>

CiNii Article

開催期間： 2017年01月   記述言語：英語  

<p>We developed an image sensing system for an autonomous underwater robot with a benthos sampling function, namely sampling-AUV. The mission of a sampling-AUV consist of following four phases: observation phase (OP), return phase (RP), tracking phase (TP) and sampling phase (SP). For an achievement of the above mission, proposed image sensing system comprises software modules of image acquisition, image enhancement, object detection and image selection, and object tracking. The camera in proposed system acquires an image by intervals of five seconds during OP and RP and of a second during TP. The system completes all processing within image acquisition times by employing high-speed algorithms. We checked operations of proposed system in a pool.</p>

CiNii Article

開催期間： 2017年01月   記述言語：日本語  

<p>A rich undersea mineral resource is confirmed in the basin of Japan. Three-dimensional measurement technology is indispensable for developing undersea resources. By applying structural light to the underwater environment, it is possible to measure not only the three-dimensional topography but also the seabed creature. Therefore, we aim to develop an underwater three-dimensional measuring device using structured light and light cutting method. In order to develop a new three-dimensional measuring instrument, basic measurement theory was verified.</p>

CiNii Article

開催期間： 2016年01月   記述言語：日本語  

<p>Underwater robots are employed to marine organisms' research in ultimate environments. In this study, we aim to do automation of marine organisms sampling by autonomous underwater vehicle with a manipulator. We developed a manipulator to pick up deep-sea benthic organisms. The developed manipulator is driven by a master-slave cylinder type hydraulic driven system. Moreover, the manipulator's joints are actuated by hydraulic cylinder, and linear motion of the cylinder is converted to rotational motion by a motion conversion cam-mechanism. This control system was integrated by MATLAB/Simulink. So we adopted Stateflow (this is a toolbox for Simulink) in the high level control layer.</p>

CiNii Article

開催期間： 2016年01月   記述言語：日本語  

<p>In order to effectively investigate the distribution and amount of CRC (Cobalt-Rich manganese Crust) an AUV BOSS-A equipped with visual and acoustic instruments were developed. The AUV observes CRC on the seafloor along preset waypoints at a constant speed and altitude. Detailed 3D seafloor image is created based on navigation data from the AUV and images from visual instrument. In addition, an acoustic instrument measures the CRC thickness. We surveyed the CRC at Katayama seamount in February 2015. The results visually presented distribution of the CRC in this site. In the future, we will develop a reliable, accurate measurement method for CRC thickness by combining visual and acoustic instruments.</p>

CiNii Article

開催期間： 2016年01月   記述言語：日本語  

<p>The autonomous Underwater Vehicles (AUVs) are developed to contribute various science filed such as oceans biology, geology by deep-sea observation. The deep-sea observation by AUV provides various information such as lifestyle of deep-sea creature, volcano of deep-sea bottom, etc. by photographing image. Next mission using AUVs is required to sample targets such as creature, mud or stone in deep-sea floor. For success of this mission, AUV needs supports by researcher in support ship. However, underwater communication based on acoustic has less density compared to electronic. In this research, we proposed a method of image compression and reconstruction for acoustic communication. And we evaluated reconstruction image by Structural similarity.</p>

CiNii Article

開催期間： 2015年01月   記述言語：日本語  

This paper proposed a novel approach to the kichiji rockfish recognition method for investigation of the fish biomass. This method does not depend on the size, position and attitude of the fish, because SIFT feature with rotation invariant is used and is represented by vector quantization histogram. The experiment results showed that our method detected 94 % of object which is the fish from 37 photographs and recognized 57 % of the fish from detected image. And our method was able to recognize kichiji rockfish from SIFT features of the fish head. However, if more than one object is piled up, our method is a possibility of mistaken recognition because features of object other than target are used for recognition

CiNii Article

開催期間： 2014年01月   記述言語：英語  

Underwater is extreme environment. So, underwater robots are employed to some tasks for human's safe. However, high-speed motion in underwater condition is occurred drag forces. In this paper, we propose a sampling device for underwater robots. It was designed as a high-speed mechanism. Because, a mechanism which it has performances higher than human make new applications. The high-speed motion is needed an energy and an efficient transmission system. We explain a design of the mechanism.

CiNii Article

開催期間： 2014年01月   記述言語：日本語  

Many insects can jump several times their own body length. Locusts with their powerful hind-leg can for example jump up to five times as high 250mm. We have been working on high power joint mechanism imitating locust hind-leg. The mechanism can produce a several times as much power as mounted actuator and separates normal and rapid motion by controlling the actuator force. This paper proposes fin actuator with the high power joint mechanism which can realize rapid motion of two directions. The fin actuator consist two motors with cams, two wires, one spring and L-shape link. Our analysis of output characteristics showed that the proposed fin actuator develops higher output power than mounted actuator.

CiNii Article

開催期間： 2013年01月   記述言語：日本語  

We have been working on survey system by AUV troop to extend survey efficiency during one cruise. This paper reports about dive survey system for AUV troop and observation results by hovelling type AUV "Tuna-Sand" in KY12-13 research cruise that Izu-Ogasawara ocean area was observed on October 2012. "Tuna-Sand" dived three times and total diving time is over six hours in the cruise. "Tuna-Sand" took over 170 pictures of Smith caldron see floor in first dive. "Tuna-Sand" navigated along serpentine course during observation, because periodic current in sea floor is strong for "Tuna-Sand". Diver survey by 3 AUVs include "Tuna-Sand" was success in second, but "Tuna-Sand" had CPU problems and emergency surfaced. In third, "Tuna-Sand" could not observe for lack of time.

CiNii Article

開催期間： 2013年01月   記述言語：日本語  

The underwater condition is extreme environment for us. Almost tasks under water such as capturing water creatures are difficult. So, underwater robots are wanted to those tasks. In this paper, we propose a sampling device for underwater robots. It was designed as a high-speed mechanism. Because, a mechanism which it has performances higher than human make new applications. The high-speed mechanism uses a cam transmission system. We explain a concept and the structure of the mechanism.

CiNii Article

開催期間： 2012年01月   記述言語：日本語  

In this paper, we propose a wheel which can move steps using grousers mounted in the wheel without using electric controls. We assumed that the proposed wheels are used for mobile robots, for example rescue robots. In our laboratory, we develop a mobile robot having the four wheels. Carrying out the performance test of the proposed wheels, the robot can move steps of 91% of diameter of the developed wheel.

CiNii Article

開催期間： 2012年01月   記述言語：日本語  

CiNii Article

開催期間： 2012年01月   記述言語：日本語  

Deep vein thrombosis (DVT) is a disease suffer a blood clot in the vein of lower limb deep place mainly. In order to prevent DVT, we have been developing a prototype of the lower limbs movement assistant robot which forcibly moves a foot so as to improve blood circulation. We found that this robot is effective in preventing deep vein thrombosis. However, our prototype is still large, and also very heavy (10 [kg] weight), thus there is a problem in production. We have developed a improved one. In this paper, we describe a rehabilitation robot of version 2 with a new user interface that can be operated in a compact, lightweight and low cost.

CiNii Article

開催期間： 2012年01月   記述言語：日本語  

We have been working on high power joint mechanism by mimicking locusts leg structure. The proposed joint mechanism, which consists of two motors, three pulleys, two wires, one spring, and one link, controls the output link using the tension provided from the motors to wires connected to the link. Operation of either of the two motors enables flexional and extensional motion. With the joint mechanism put into flexion, simultaneous operation of two motors accumulates power in the spring. Shutting down one motor releases power accumulated in the spring to realize rapid motion. Power produced during rapid motion decreases by viscosity resistance from passive motor. Therefore, links length where viscosity resistance of passive motor is the minimum is found to gain high output power. In this paper, viscosity resistance of the joint mechanism was analyzed. The result of analysis, it was shown that viscosity resistance during rapid motion is possible to decrease by shorten output link.

CiNii Article

開催期間： 2011年10月12日   記述言語：日本語  

バックやコオロギはなどのバッタ目に属する昆虫は力強い後脚を保有しており,瞬発運動や歩行運動を実現している.本研究では,歩行,瞬発運動か可能な小型で高出力関節機構の実現を目的とし,バックの後脚を模倣した高出力関節機構を開発した.バックの脚構造を模倣することで特殊な機構を有することなく,バネにエネルギを蓄積し,瞬間的に解放することが可能である.実験の結果,本関節機構は瞬発動作開始80[ms]後に最大の角速度9.23[rad/s]を得ることが分かった.

CiNii Article

開催期間： 2011年01月   記述言語：日本語  

When the human keep the same postures for a long time, e.g., after operation, sit on bed with same posture, there is a possibility to cause deep-vein thrombosis (DVT) of which the most serious complication is that the clot could dislodge and travel to the lungs and death. In order to prevent DVT, we have been developing a prototype of the lower limbs movement assistant robot which forcibly moves a foot so as to improve blood circulation. We compared the bloodstream using the developed robot by changing the trajectories of foot movement patterns. In this paper, we verify trajectory pattern to promote the bloodstream.

CiNii Article

開催期間： 2011年01月   記述言語：英語  

There are many insects which can jump several times its body length. It is reported that desert locusts can jump five times high (about 250 mm) at the peak using its powerful hind-legs. This high level of mechanical performance comes from a special mechanism formed in the cuticle of the hind-legs of the locusts which has the similar function with the spring. In previous our researches, we proposed the model of high power joint mechanism by mimicking locusts leg structure witch two actuators, the spring and link. And, the model was analyzed using Jacobian Matrix derived from cross product. The result of analysis, it was shown that the model produce power more than 10 times as mounted actuators. In this research, high power joint was developed based on knowledge of previous researches and experimented. The result of experiment, it was shown that the joint mechanism can realize walking and jumping.

CiNii Article

開催期間： 2010年01月   記述言語：日本語  

Locusts and grasshoppers have powerful hind-legs which are adapted to produce jumps and kicks. It is reported that the desert locust (Schistocerca gregaria) which is about 50mm long can jump to the height of about 250mm at the peak. Hind-legs of locusts have special cuticle called "semi-lunar process" same as the spring. Locusts charge jumping force in semi-lunar process using own muscle before jumping. And, they can jump by instantaneously releasing the force. So, locusts obtain high jumping performance which is impossible by only own muscle, using semi-lunar process. The aim in this research is to develop high power joint mechanism by mimic jumping system of locusts. This paper reports how to produce high power in the mechanism.

CiNii Article

開催期間： 2010年01月   記述言語：日本語  

In adaptable compliant mechanisms, employing nonlinear elasticity materials is common. However, they have some problems as following. The analyzing of materials for the non-linear element is complex, downsizing is difficult. And the response time isn't speedy because the material for the non-linear element must be charged when changing of the articular compliance. So we propose a mechanism using kinematic transmission mechanism (KTM) which is the solution of above problems. This mechanism is composed by links and cams. Using cams, we are able to design freely about input-output of the antagonistically driven joint.

CiNii Article

開催期間： 2009年01月   記述言語：日本語  

Behavior of A Robot which was two point-mass system is changed in the vicinity of jumping. Thus, the analysis of two point mass system is known to be difficult. And design principle of the system is reported. On the other hand, it is known that variety of body size follow law of elasticity similarity between different animals. Mass of animals changes significantly depend on changing of animal's size, because animals need to compensate own robustness and safety. Thus, shape and mass of body can be estimated in object which is followed law of elasticity similarity. In this research, two point-mass system is also followed law of elasticity similarity. Design principle of two point-mass system is shown.

CiNii Article

開催期間： 2009年01月   記述言語：日本語  

In antagonized wire-driven mechanisms that are observed at a point of realizing joint mechanisms with flexibility, employing nonlinear elasticity materials is standard. However, they have some problems as following. The analysis of the materials is complex. And the response time isn't speedy when changing compliance of theirs. So we propose a way which is the solution of above problems by using nonlinear kinematic transmission mechanism.

CiNii Article

出願番号：PCT/JP2019/010609  出願日：2019年03月14日

出願番号：特願2018-052108  出願日：2018年03月20日

出願番号：特願2010-170680  出願日：2010年07月29日

発表言語：日本語   講演種別：その他   開催地：明専会東京支部  

発表言語：日本語   講演種別：招待講演   開催地：東京大学生産技術研究所 (online)  

発表言語：日本語   講演種別：特別講演  

講演種別：特別講演  

講演種別：招待講演  

講演種別：招待講演  

講演種別：特別講演  

講演種別：招待講演  

講演種別：招待講演  

講演種別：特別講演  

受賞国：日本国

受賞国：日本国

受賞国：日本国

受賞国：日本国

研究区分：共同研究

指定されたエリアの海底浚渫工事を行う際には、バケットの正確な着底位置情報を把握して作業する必要があるが、潮流などの影響を受けてバケットの着底位置を特定することは困難である。

本研究は、バケット着底場所を正確に把握することを目的とし、バケットの着底の際に生じる音を複数の音響センサーを用いて計測することで着底位置を計測するものである

研究区分：共同研究

研究区分：受託研究

研究区分：受託研究

研究区分：その他共同研究等

研究区分：その他共同研究等

研究区分：その他共同研究等