研究者業績
基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 教授
- 学位
- 工学博士(1991年3月 東京大学)
- J-GLOBAL ID
- 201801002275500853
- researchmap会員ID
- B000340311
研究分野
1論文
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SMART MATERIALS AND STRUCTURES 33(8) 2024年8月1日
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Smart Materials and Structures 30(6) 065014-065014 2021年6月1日Abstract We propose and demonstrate a novel method to enhance vibration harvesting based on surge-induced synchronized switch harvesting on inductor (S3HI). S3HI allows harvesting of a large amount of energy even from low-amplitude vibrations by inducing a surge voltage during the voltage inversion of a synchronized switch harvesting on inductor (SSHI). The surge voltage and the voltage amplification from the conventional voltage inversion improve energy harvesting. S3HI modifies SSHI by both rewiring the circuit without adding components and using a novel switching pattern for voltage inversion, thus maintaining the simplicity of SSHI. We propose a novel switching strategy and circuit topology and analyze six methods that constitute the S3HI family, which includes traditional S3HI and high-frequency S3HI. We demonstrate that the six methods suitably harvest energy even from low-amplitude vibrations. Nevertheless, the harvestable energy per vibration cycle depends on the switching pattern and storage-capacitor voltage. The use of the proposed switching strategy, which allows energy harvesting before energy-dissipative voltage inversion, substantially increases the harvestable energy per vibration cycle. In the typical case considered in this study, the said increase is on the order of 11%–31% and 15%–450% compared to the traditional and existing high-frequency S3HI methods, respectively, depending on the storage-capacitor voltage. Additionally, the proposed circuit can be used as a traditional circuit. It could be considered a promising alternative to S3HI methods owing to its potential auto-reboot capability, which is not found in traditional S3HI circuit.
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 16(2) 181-187 2018年<p>An Extensible Optical Bench (EOB) for a X-ray satellite (ASTRO-H) had a length of 6.4m in extended configuration. Although the same type of extensible mast was used in Space Radio Telescope (Halca) in 1997, the tip mass was quite different in the case of ASTRO-H. Due to the tip mass of 150 kg, the natural frequency of EOB was less than 1Hz in the extended configuration. ASTRO-H was launched on Feb. 17, 2016, and the EOB was extended on Feb. 28, 2016, successfully. However, because the vibration of EOB occurred during the extension, the extension operation was carried out over four passes intermittently. When the amplitude of induced vibration excessed the predefined threshold, we stopped the extension, then stayed until the vibration was damped. In this paper, the induced vibration during extension and its mechanism are reported. Through simulations, it is confirmed that one of the major causes of the vibration is a periodic change of gap between mast and canister at the root of EOB.</p>
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Journal of Astronomical Telescopes, Instruments, and Systems 4(1) 2018年1月1日 査読有り
MISC
93-
SPACE TELESCOPES AND INSTRUMENTATION 2024: ULTRAVIOLET TO GAMMA RAY, PT 1 13093 2024年
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SPACE TELESCOPES AND INSTRUMENTATION 2024: ULTRAVIOLET TO GAMMA RAY, PT 1 13093 2024年
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2021年3月第3回観測ロケットシンポジウム(2021年3月24-25日. オンライン開催)著者人数: 14名資料番号: SA6000162017レポート番号: Ⅴ-3
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56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference 2015年1月1日
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日本航空宇宙学会誌 60(1) 8-14 2012年イプシロンロケットは,段階的な開発を実施する計画であり,第1ステップではM-VロケットおよびH-IIAロケットで培った技術を最大限に活用し,平成25年度に打ち上げる.この方針に従い,構造系開発も第1ステップでは短期間で確実な開発(効率的開発)のため,多くの既開発コンポーネントを流用または改修流用する.本稿では,まず第1ステップ構造系全体の概要を述べ,次に新規開発コンポーネントである第2,3段固体モータケース(軽量・低コスト化),衛星分離部(衛星振動環境緩和),第3段機器搭載構造,フェアリング(水没機能付加)について説明する.衛星機械環境としては,乗り心地向上のため音響環境を世界標準レベル(OASPL 140dB程度)まで緩和することを目的とした射座煙道の設計解析と地上燃焼試験の概要を示す.最後に,第2ステップに向けた構造系抜本的低コスト化研究の概要について述べる.
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日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences 59(686) 55-60 2011年3月5日Passive damping augmentation is one of attractive methods for vibration suppression to various kinds of structures because it is definitely stable and generally simple. Using viscous adhesive indicated a remarkable effect to the vibration suppression in the practical application to a satellite. In this paper, mathematical model of thin viscous adhesive layer using non-linear elements has been proposed. In this model, the characteristics of elements are correlated with non-linear internal phenomena of polymer. The simulation results using this proposal model are good agreement with experimental ones.
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スペース・エンジニアリング・コンファレンス講演論文集 2010 _J4-1_-_J4-4_ 2011年To meet advanced science missions, large and precise support structures such as truss structures are needed. In this paper, pointing control of a truss structure is discussed. To control the truss structure, thermal expansion of truss members is utilized instead of mechanical actuators. Heaters are equipped to truss members so that the thermal expansion of the members is controlled by heaters. PI control is applied to an experimental model which is box truss with 1.9m height. Through experiments, it is shown that the truss structure can be controlled with good accuracy, for example, within 3 arcsec error.
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Proceedings of SPIE - The International Society for Optical Engineering 7732 2010年
講演・口頭発表等
13-
33rd International Symposium on Space Technology and Science 2022年3月1日
担当経験のある科目(授業)
2-
2024年10月 - 2025年1月飛翔体構造工学概論 (東京大学大学院工学系研究科航空宇宙工学専攻)
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2024年9月 - 2024年9月衛星システム設計学特論 (公立大学法人大阪)
共同研究・競争的資金等の研究課題
12-
日本学術振興会 科学研究費助成事業 2023年4月 - 2027年3月
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日本学術振興会 科学研究費助成事業 基盤研究(C) 2020年4月 - 2023年3月
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日本学術振興会 科学研究費助成事業 基盤研究(C) 2014年4月 - 2018年3月
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日本学術振興会 科学研究費助成事業 基盤研究(B) 2008年 - 2010年
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日本学術振興会 科学研究費助成事業 基盤研究(B) 2007年 - 2008年