著者

巻 俊宏 近藤 逸人 浦 環 坂巻 隆 水島 隼人 柳澤 政生

出版者

海洋調査技術学会

雑誌

海洋調査技術 (ISSN:09152997)

巻号頁・発行日

vol.21, no.1, pp.1_13-1_25, 2009 (Released:2010-10-18)

参考文献数

14

被引用文献数

2

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The authors have proposed an innovative method to navigate an autonomous underwater vehicle (AUV) for visual mapping of seafloor with high positioning accuracy without using any vision-based matching. The proposed method was implemented in the AUV Tri-Dog 1 and sea experiments were carried out at Tagiri vent field, Kagoshima bay in Japan (Maki et al., 2008). Based on the success of the experiments, a series of dives was carried out at the same place. The AUV Tri-Dog 1 succeeded in 12 fully autonomous dives with a total duration of 29 hours. The vehicle took 9,288 pictures of the seafloor, keeping the altitude of 1.2 m with a surge speed of 0.08 m/s. A photomosaic of the seafloor was created by mapping 7,289 pictures based on the real-time estimates of the AUV state, without any pictorial correlation. The distributions of detailed features such as tube-worm colonies and bacteria mats are clearly shown. The photomosaic covers around 3,000 square meters. To the knowledge of the authors, this is one of the largest underwater photomosaic ever reported. The mapping accuracy was estimated to be 0.3 to 0.8 m based on the comparison of the photomosaic between dives.

著者

巻 俊宏 近藤 逸人 浦 環 坂巻 隆 水島 隼人 柳澤 政生

出版者

海洋調査技術学会

雑誌

海洋調査技術 (ISSN:09152997)

巻号頁・発行日

vol.20, no.1, pp.1_1-1_16, 2008

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Although underwater visual observation is an ideal method for detailed survey of seafloors, it is currently a costly process that requires the use of Remotely Operated Vehicles (ROVs) or Human Occupied Vehicles (HOVs), and can cover only a limited area. This paper proposes an innovative method to navigate an autonomous underwater vehicle (AUV) to create both 2D and 3D photo mosaics of seafloors with high positioning accuracy without using any vision-based matching.<br>The vehicle finds vertical pole-like acoustic reflectors to use as positioning landmarks using a profiling sonar based on a SLAM (Simultaneous Localization And Mapping) technique. These reflectors can be either artificial or natural objects, and so the method can be applied to shallow vent fields where conventional acoustic positioning is difficult, since bubble plumes can also be used as landmarks as well as artificial reflectors. Path-planning is performed in real-time based on the positions and types of landmarks so as to navigate safely and stably using landmarks of different types (artificial reflector or bubble plume) found at arbitrary times and locations. Terrain tracker switches control reference between depth and altitude from the seafloor based on a local map of hazardous area created in real-time using onboard perceptual sensors, in order to follow rugged terrains at an altitude of 1 to 2 meters, as this range is ideal for visual observation.<br>The method was implemented in the AUV Tri-Dog 1 and experiments were carried out at Tagiri vent field, Kagoshima Bay in Japan. The AUV succeeded in fully autonomous observation for more than 160 minutes to create a photo mosaic with an area larger than 600 square meters, which revealed the spatial distribution of detailed features such as tube-worm colonies, bubble plumes and bacteria mats. A fine bathymetry of the same area was also created using a light-section ranging system mounted on the vehicle. Finally a 3 D representation of the environment was created by merging the visual and bathymetry data.

著者

巻 俊宏 近藤 逸人 浦 環 坂巻 隆 水島 隼人 柳澤 政生

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集

巻号頁・発行日

vol.2008, pp._2A1-A11_1-_2A1-A11_4, 2008

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This paper proposes an innovative method to navigate an autonomous underwater vehicle (AUV) for detailed visual seafloor mapping with high positioning accuracy without using any vision-based matching. The method consists of three parts, SLAM (Simultaneous Localization And Mapping), path-planning and terrain tracking. The method was implemented in the AUV Tri-Dog 1 and a series of experiments were carried out at Tagiri vent field, Kagoshima bay in Japan. The AUV succeeded in observation of interesting features of the field including bubble plumes, bacteria mats and tube-worm colonies through 12 fully autonomous dives, totaling 29 hours duration. Finally a photomosaic covering about 3,000 square meters was created.