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 教授東京大学 大学院工学系研究科 航空宇宙工学専攻 准教授
- 学位
- 博士（工学）(2007年3月 東京大学)
- 研究者番号
- 70509819
- J-GLOBAL ID
- 200901051354637504
- researchmap会員ID
- 5000090886
研究キーワード
11研究分野
1受賞
4論文
115-
Journal of Guidance, Control, and Dynamics 47(9) 1905-1919 2024年9月In autonomous space systems, the reliability of navigation systems is essential. Observability in autonomous orbit determination techniques depends on the spacecraft’s orbital motion, making the design of autonomous navigation systems and orbital maneuvers a coupled process. This study develops a stable and efficient algorithm based on differential dynamic programming to design maneuver sequences that improve navigation performance. Our approach incorporates the Fisher information matrix into a cost function to quantify state observability and facilitates its convergence using a semi-analytic gradient and Hessian derived under impulsive maneuvers. Two numerical examples show the validity and effectiveness of our algorithm. The results indicate the stability and efficiency in determining maneuver sequences and the improvement of state estimation accuracy along an optimized trajectory. It is also applicable to other observability-aware optimal control problems because the algorithm is independent of specific systems.
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Space Science Reviews 220(1) 2024年1月24日Abstract Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum $\varDelta $V capability of $600\text{ ms}^{-1}$. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 67(5) 274-284 2024年
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Journal of Astronomical Telescopes, Instruments, and Systems 9(03) 2023年9月12日
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Journal of Evolving Space Activities 1 n/a 2023年The low reliability of nano-satellites has become a problem, with the cause often being defects in the design and manufacturing process. It is required to take sufficient measures to account for those defects through ground tests to reduce on-orbit failures. The model-based fault diagnosis method can prevent oversight of fault candidates and compensate for a lack of knowledge in human-based diagnosis. Since the developing time of nano-satellites is limited, fault diagnosis needs to be carried out efficiently also while being careful not to cause secondary faults. This paper presents a novel method that can find the appropriate command to verify candidates of fault location in a satellite. The proposed method can consider the side effect of a command and the efficiency of narrowing them down by using the information transmission path model. In the case study, the proposed method is applied to an earth-orbiting 6U CubeSat, and this case study reveals that 33% of the failures that occur in ground tests can apply to the proposed method. In addition, the proposed method can identify the fault location of some of these failures, although there are several limitations to implementing the proposed method in the actual satellite development.
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2022 IEEE Aerospace Conference (AERO) 152 1-11 2022年3月5日
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The Journal of the Astronautical Sciences 2022年2月4日
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SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY 12181 2022年
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JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 69(5) 179-186 2021年
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Journal of Guidance, Control, and Dynamics 43(4) 645-655 2020年3月 査読有り最終著者
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Acta Astronautica 171 208-214 2020年2月 査読有り
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Proceedings of the International Astronautical Congress, IAC 2020- 2020年
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Proceedings of the International Astronautical Congress, IAC 2020-October 2020年
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Flight Model Development and Ground Demonstration of Water Resistojet Propulsion System for CubeSatsTRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES 63(4) 141-150 2020年
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日本航空宇宙学会論文集 68(2) 89-95 2020年 査読有り最終著者<p>A Fault Detection, Isolation, and Recovery (FDIR) algorithm for attitude control systems is a key technology to increasing the reliability and survivability of spacecraft. Micro/nano interplanetary spacecraft, which are rapidly evolving in recent years, also require robust FDIR algorithms. However, the implementation of FDIR algorithms to these micro/nano spacecraft is difficult because of the limitations of their resources (power, mass, cost, and so on). This paper shows a strategy of how to construct a FDIR algorithm in the limited resources, taking examples from micro deep space probe PROCYON. The strategy focuses on function redundancies and multi-layer FDIR. These ideas are integrated to suit the situation of micro/nano interplanetary spacecraft and demonstrated in orbit by the PROCYON mission. The in-orbit results are discussed in detail to emphasize the effectiveness of the FDIR algorithm. </p>
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JOURNAL OF SPACECRAFT AND ROCKETS 56(5) 1400-1408 2019年9月 査読有り
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Advances in the Astronautical Sciences 168 281-300 2019年
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Advances in the Astronautical Sciences 168 4015-4026 2019年
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Advances in the Astronautical Sciences 168 301-318 2019年
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Advances in the Astronautical Sciences 168 3511-3526 2019年
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Aerospace Technology Japan 17(1) 43-50 2019年1月 査読有り
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Aerospace Technology Japan 17(3) 315-320 2019年1月 査読有り
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Advances in the Astronautical Sciences 168 1331-1343 2019年 最終著者
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Acta Astronautica 152 299-309 2018年11月 査読有り
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JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS 4(4) 2018年10月 査読有り
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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 41(2) 377-387 2018年2月 査読有り
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Flight Model Development and Ground Demonstration of Water Resistojet Propulsion System for CubeSatsTransactions of the Japan Society for Aeronautical and Space Sciences 16(5) 427-431 2018年 査読有り
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10th Symposium on Space Resource Utilization, 2017 2017年
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SICE Journal of Control, Measurement, and System Integration 10(3) 192-197 2017年 査読有り
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日本航空宇宙学会論文集 65(6) 219-226 2017年 査読有りEarth observation satellites can improve the flexibility of observation sites by having “maneuverability,” and low-thrust obtained by ion thruster will be a promising method for orbital change for micro-satellites. Designing low-thrust trajectories for these satellites is a multi-revolution and multi-objective (time/fuel-optimal) optimization problem, which usually requires high computational cost to solve numerically. This paper derives an analytical and approximate optimal orbit change strategy between two circular orbits with the same semi-major axis and different local time of ascending node, and proposes a graph-based method to optimize the multi-objective criteria. The optimal control problem results in a problem to search a switching point on the proposed graph, and mission designers can design an approximate switching point on this graph, by using two heuristic and reasonable assumptions that 1) the optimal thrust direction should be tangential to orbit and 2) the optimal thrust magnitude should be bang-bang control with an intermediate coast. Finally, numerical simulation with feedback control algorithm taking thrust margin demonstrates that the proposed method can be applicable in the presence of deterministic and stochastic fluctuation of aerodynamic disturbances.
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Transactions of the Japan Society for Aeronautical and Space Sciences 60(3) 181-191 2017年 査読有り最終著者
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Geophysical Research Letters 44(23) 192-197 2017年 査読有り
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Advances in Space Research 58(4) 528-540 2016年8月 査読有り
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Initial Flight Operations of the Miniature Propulsion System Installed on Small Space Probe: PROCYONAerospace Technology Japan 14(ists30) Pb_13-Pb_22 2016年7月 査読有り
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AIAA/AAS Astrodynamics Specialist Conference, 2016 2016年
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AIAA/AAS Astrodynamics Specialist Conference, 2016 2016年
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Advances in the Astronautical Sciences 158 239-258 2016年
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Advances in the Astronautical Sciences 158 933-951 2016年
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Advances in the Astronautical Sciences 158 3053-3068 2016年
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Advances in the Astronautical Sciences 156 1617-1630 2016年
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Proceedings of the International Astronautical Congress, IAC 2016年
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日本航空宇宙学会論文集 64(2) 131-138 2016年 査読有りWe propose thrust vector management by correctly positioning the thruster on a spacecraft by thrust vector measurement to decrease unwanted torque of thrust vector misalignment. A ground test was performed to measure 2-dimensional ion current distribution of 10W-class miniature ion thruster by electrostatic probe. The thrust vector measurement test showed that the thrust vector inclining angle was 1.4º from the geometrically symmetric axis of the thruster. The thruster was positioned on the first interplanetary micro-spacecraft: PROCYON after redesigning thruster bracket. Thrust vector estimation in the initial on-orbit operation of 6.5 hours showed that thrust vector passes through within 5mm of the PROCYON's center of gravity.
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Proceedings of the International Astronautical Congress, IAC 7 5231-5239 2015年
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Aerospace Technology Japan 12(ists29) Tr_1-Tr_5 2014年11月 査読有り
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Aerospace Technology Japan 12(ists29) Pk_43-Pk_50 2014年11月 査読有り
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Aerospace Technology Japan 12(ists29) Pd_85-Pd_90 2014年11月 査読有り筆頭著者
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Aerospace Technology Japan 12(ists29) Tk_19-Tk_24 2014年8月 査読有り
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Aerospace Technology Japan 12(ists29) Tk_7-Tk_11 2014年7月 査読有り
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TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN 12(ists29) Pb_33-Pb_38 2014年5月 査読有りSolar sail is a spacecraft that has a large-scale membrane to utilize the solar radiation pressure for its thrust. Hence, maintaining the membrane structure during space flight is a critical issue to keep thrust performance of the spacecraft. In this paper, we focused on the electrostatic force due to spacecraft charging on the membrane as one of the possible factor to cause the deformation of the membrane structure. We had estimated the electrostatic force via charging simulation for the IKAROS spacecraft in solar wind plasma at 1.0 AU. We had also made a structural analysis for the deployed membrane of IKAROS with the electrostatic force. The structural analysis showed that the electrostatic force could hardly affect the membrane structure in this case.
MISC
279所属学協会
1共同研究・競争的資金等の研究課題
5-
日本学術振興会 科学研究費助成事業 基盤研究(S) 2016年5月 - 2021年3月
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日本学術振興会 科学研究費助成事業 若手研究(B) 2013年4月 - 2017年3月
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日本学術振興会 科学研究費助成事業 若手研究(B) 2011年 - 2012年
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日本学術振興会 科学研究費助成事業 若手研究(スタートアップ) 2008年 - 2009年
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日本学術振興会 科学研究費助成事業 特別研究員奨励費 2004年 - 2006年
