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中村 啓太; 羽成 敏秀; 松本 拓; 川端 邦明; 八代 大*
Journal of Robotics and Mechatronics, 36(1), p.115 - 124, 2024/02
During the decommissioning activities, a movie was shot inside the reactor building during the investigation of the primary containment vessel by applying photogrammetry, which is one of the methods for three-dimensional (3D) reconstruction from images, to the images from this movie, it is feasible to perform 3D reconstruction of the environment around the primary containment vessel. However, the images from this movie may not be suitable for 3D reconstruction because they were shot remotely by robots owing to limited illumination, high-dose environments, etc. Moreover, photogrammetry has the disadvantage of easily changing 3D reconstruction results by simply changing the shooting conditions. Therefore, this study investigated the accuracy of the 3D reconstruction results obtained by photogrammetry with changes in the camera angle of view under shooting conditions. In particular, we adopted 3D computer graphics software to simulate shooting target objects for 3D reconstruction in a dark environment while illuminating them with light for application in decommissioning activities. The experimental results obtained by applying artificial images generated by simulation to the photogrammetry method showed that more accurate 3D reconstruction results can be obtained when the camera angle of view is neither too wide nor too narrow when the target objects are shot and surrounded. However, the results showed that the accuracy of the obtained results is low during linear trajectory shooting when the camera angle of view is wide.
佐藤 優樹; 寺阪 祐太; 宇津木 弥*; 菊地 弘幸*; 清岡 英男*; 鳥居 建男
Journal of Nuclear Science and Technology, 56(9-10), p.801 - 808, 2019/09
被引用回数：54 パーセンタイル：99.25(Nuclear Science & Technology)The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown in the aftermath of a large tsunami caused by the Great East Japan Earthquake of 11 March 2011. Measurement of radiation distribution inside the FDNPS buildings is indispensable to execute decommissioning tasks in the reactor buildings. We conducted a radiation imaging experiment inside the reactor building of Unit 1 of FDNPS by using a compact Compton camera mounted on a crawler robot and remotely visualized gamma-rays streaming from deep inside the reactor building. Moreover, we drew a radiation image obtained using the Compton camera onto the three-dimensional (3-D) structural model of the experimental environment created using photogrammetry. In addition, the 3-D model of the real working environment, including the radiation image, was imported into the virtual space of the virtual reality system. These visualization techniques help workers recognize radioactive contamination easily and decrease their own exposure to radiation because the contamination cannot be observed with the naked eye.
佐藤 優樹; 小澤 慎吾*; 谷藤 祐太; 鳥居 建男
Journal of Instrumentation (Internet), 13(3), p.P03001_1 - P03001_8, 2018/03
被引用回数：7 パーセンタイル：35.49(Instruments & Instrumentation)The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown after the large tsunami caused by the Great East Japan Earthquake of March 11, 2011. Radiation distribution measurements inside FDNPS buildings are indispensable to execute decommissioning tasks in the reactor buildings. We have developed a method of three-dimensional (3-D) image reconstruction for radioactive substances using a compact Compton camera. We also succeeded in visually recognize the position of the radioactive substances on the real space by integration of the 3D radiation image and the 3D photo-model created by photogrammetry.
佐藤 優樹; 寺阪 祐太; 冠城 雅晃; 谷藤 祐太; 鳥居 建男
no journal, ,
We visualized a hotspot from the sky over the waste storage space inside the Fukushima Daiichi Nuclear Power Station using a remote radiation imaging system consisting of a drone equipped with a Compton camera. By superimposing the images of the hotspots on the 3D building model of the waste storage space created using a photogrammetry, we succeeded in drawing the map that can easily recognize the positions of the hotspots in the actual working environment.
佐藤 優樹; 寺阪 祐太; 宇津木 弥*; 菊地 弘幸*; 高平 史郎*; 鳥居 建男
no journal, ,
The Fukushima-Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown after the occurrence of a large tsunami caused by the Great East Japan Earthquake on March 11, 2011. The radiation distribution measurements inside the site of the FDNPS are indispensable to execute decommissioning tasks. We have developed a three-dimensional (3D) radiation imaging technique for grasping the location of the high-dose rate region (hotspot) using a compact Compton camera and a photogrammetry technique to create 3D optical images. We succeeded in detecting the hotspot in a waste storage space inside the FDNPS using the Compton camera. We also created the 3D structural model of the waste storage space in the virtual space by using the photogrammetry and superimposed the image of the hotspot on the 3D structural model. Furthermore, we are developing a system that imports the 3D structural model including the image of the hotspot into the virtual reality and allows workers to experience the actual working environment. We believe that these visualization techniques help workers to easily recognize the hotspot at the actual working environment and to decrease their own exposure. These visualization techniques are also effective for planning decontamination and eventually accelerating the decommissioning of the FDNPS.
佐藤 優樹
no journal, ,
The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown after the occurrence of a large tsunami caused by the Great East Japan Earthquake of March 11, 2011. The radiation distribution measurements inside the FDNPS are indispensable to execute decommissioning tasks. We have conducted the radiation imaging experiment inside the FDNPS building using the compact Compton camera. The high-dose contamination (up to 3.5 mSv/h) was visualized using the Compton camera in the turbine building of Unit 3 of the FDNPS. We also created a three-dimensional (3D) radiation distribution map inside the turbine building by integrating the radiation image obtained by the Compton camera into the point cloud data of the experimental environment acquired using the scanning laser range finder. In addition, we introduce the photogrammetry technique to create the 3D structural model of the experimental environment. The image of the radioactive hotspot is superimposed on the 3D structural model of inside the reactor building of Unit 1 of the FDNPS created using the photogrammetry. In the presentation, our recent study about the radiation imaging technology for measurements of the distribution of radioactive substances inside the FDNPS is discussed.
中村 啓太*; 馬場 啓多*; 渡部 有隆*; 松本 拓; 羽成 敏秀; 川端 邦明
no journal, ,
本研究では、QRコードを用いた写真測量による立体復元結果の部分間レジストレーションによる統合手法を提案する。写真測量で獲得した復元結果は、復元ごとにスケーリングが異なるため統合が困難である。この問題を解決するために、大きさが既知のQRコードを復元対象環境に配置し、QRコードの大きさに基づいて復元結果をスケーリングし、スケーリングした復元結果をQRコードのマーカに基づいて統合する。本提案手法を検証するため、全画像から復元した結果と複数の復元結果を統合した結果の精度を比較した。検証結果から、精度を維持しつつ写真測量による3Dマッピングに要する時間の短縮に有効であることが示された。
