豊田 和弘 (トヨダ カズヒロ)

TOYODA kazuhiro

写真a

職名

准教授

研究室住所

福岡県北九州市戸畑区仙水町1-1

研究分野・キーワード

宇宙機,人工衛星,帯電,放電,プラズマ,太陽電池アレイ

メールアドレス

メールアドレス

研究室電話

093-884-3596

ホームページ

http://laseine.ele.kyutech.ac.jp

取得学位 【 表示 / 非表示

  • 東京大学 -  博士(工学)  2001年03月

学内職務経歴 【 表示 / 非表示

  • 2019年04月
    -
    継続中

    九州工業大学   大学院工学研究院   宇宙システム工学研究系   准教授  

  • 2010年04月
    -
    2019年03月

    九州工業大学   大学院工学研究院   電気電子工学研究系   准教授  

専門分野(科研費分類) 【 表示 / 非表示

  • 航空宇宙工学

  • プラズマ科学

 

論文 【 表示 / 非表示

  • Guest Editorial Spacecraft Charging Technology

    Andersen A., Bodeau M., Cho M., Davis V., Dennison J., Donegan M., Ferguson D., Green N., Inguimbert V., Jun I., Lai S., Likar J., Minow J., Parker L., Roussel J., Toyoda K., Garrett H., Usui H.

    IEEE Transactions on Plasma Science    47 ( 8 ) 3629 - 3630   2019年08月  [査読有り]

     概要を見る

    © 1973-2012 IEEE. This marks the seventh issue of the IEEE Transactions on Plasma Science dedicated to Spacecraft Charging Technology. The theme of this issue is based on the papers presented at the 15th Spacecraft Charging Technology Conference, Kobe, Japan, in 2018. The history of spacecraft charging goes back to the first Spacecraft Charging Technology Conference, sponsored by AFRL and NASA, that was held at the U.S. Air Force Academy, Colorado Springs, CO, USA, in 1978. The 15th Spacecraft Charging Technology Conference was hosted by the Japan Aerospace Exploration Agency (JAXA) and the Graduate School of System Informatics, Kobe University. It continues a tradition of international conferences on a ~2-year cycle. This conference, as well as each previous one in the series, was a great success. The topical discussions have greatly helped in making progress in the fields of spacecraft charging, spacecraft-plasma interactions, and related areas. At the end of the 15th Conference, the assembly agreed to request publication of the proceedings of the conference in the IEEE Transactions on Plasma Science and to encourage the submission of the papers presented at the conference to the Journal.

    DOI Scopus

  • AOBA VELOX-IV: 2U CubeSat for the technological demonstration of lunar horizon glow mission

    Kim S., Orger N., Cordova-Alarcon J., Hernandez-Herrera M., Masui H., Yamauchi T., Toyoda K., Cho M., Duy Vu B., Vinh T., Seng L., Hiang C.

    Acta Astronautica    161   328 - 337   2019年08月  [査読有り]

     概要を見る

    © 2019 IAA AOBA VELOX-IV is a 2U-sized CubeSat that has been developed by the Kyushu Institute of Technology and Nanyang Technological University for the technological demonstration of a future lunar mission. Decades ago, Surveyor and Apollo programs reported light scattering observations on the horizon of the Moon; however, only a limited number of investigations were performed after the Apollo program to observe the lunar horizon glow (LHG). It is still unknown what conditions produce the light glow on the horizon of the Moon. The lunar mission of the AOBA VELOX project is planning to send CubeSats to the Moon and to capture images of the LHG on the lunar orbit while determining the conditions that can support light scattering above the lunar horizon. Before the satellites go into the lunar orbit, the necessary technologies must first be confirmed in Earth orbit. AOBA VELOX-IV was launched to low earth orbit via a JAXA Epsilon rocket in 18th January 2019. This paper explains the LHG mission first, and presents an overview of AOBA VELOX-IV, its payloads, technical issues, and the flight model.

    DOI Scopus

  • Experimental investigation on silica dust lofting due to charging within micro-cavities and surface electric field in the vacuum chamber

    Orger N., Toyoda K., Masui H., Cho M.

    Advances in Space Research    63 ( 10 ) 3270 - 3288   2019年05月  [査読有り]

     概要を見る

    © 2019 COSPAR The charged dust particles can be mobilized electrostatically by the repulsion between the adjacent grains and the surface electric field due to the incoming electron current and the charge accumulation within the micro-cavities. In this study, the experimental results of the initial vertical launching velocities and the maximum dust heights are compared with the estimated values for the lofted spherical dust grains by the patch surface charging equations. Silica particles with the sizes between <6 and 45 µm in radius are loaded on a graphite plate, and they are exposed to the electron beam with 450 eV energy under 4 × 10 −3 Pa vacuum chamber pressure. During the first set of the experiments, the dust samples are tested without an initial compression process and an additional horizontal electric field. Second, the dust samples are compressed by two different weights in order to increase the packing density under approximately 780.7 Pa and 3780 Pa. Finally, the dust grains are placed between the two parallel aluminum plates to apply approximately 2000 V/m and 4800 V/m horizontal electric field. A high-speed camera is used to record the transportation of the dust grains together with a microscopic telescope, and the results point out that the patch surface dust-charging model estimations are in agreement with the first experiments. On the other hand, the dust particles from the compressed samples are lofted with higher velocities than the estimations, and the number of the dust lofting observations decreases significantly, which demonstrates the importance of the micro-cavities and the increased charging requirement to overcome the contact forces. When the horizontal electric field is present, the initial vertical launching velocities are measured to be lower than the other experiments, which can be attributed to the decreased charging requirement for the dust lofting as a result of inter-particle collisions and rolling motion. According to the experimental results, the electrostatic dust transportation can be controlled not only by the ambient plasma and the solar irradiation on the airless planetary bodies, but also by the surface properties such as the contact surfaces between the dust grains, the number of the micro-cavities related to the packing density, and the presence of the horizontal electric field contributing to the external forces by other particle motions.

    DOI Scopus

  • Electrostatic Discharge Threshold on Coverglass Used to Protect Solar Cells in the Low Earth Orbit

    Khan A., Minh N., Toyoda K., Cho M.

    IEEE Transactions on Plasma Science    47 ( 2 ) 1445 - 1452   2019年02月  [査読有り]

     概要を見る

    © 1973-2012 IEEE. Coverglass has been widely used to cover the solar cells of solar arrays for space power generation. Coverglass with high antireflection is widely used to protect the solar arrays from performance deterioration due to irradiation of space ultraviolet, protons, electrons, atomic oxygen (AO), and so on. Along with these, thermal cycles and/or shock may accelerate the decay synergistically affecting the threshold voltage of electrostatic discharge (ESD) on the coverglass. In order to reveal the effect of aging due to AO interaction on the ESD threshold, several coverglass samples have been exposed to low earth orbit grade AO generated by the CO 2 laser on the ground. Later, both pristine and AO-exposed coverglasses have been irradiated by energetic electrons to generate artificial arcing (ESD) under high vacuum system. Statistical analysis and Weibull distribution confirm that the threshold voltage of ESD is lower on the aged coverglass than virgin.

    DOI Scopus

  • Evaluation of Electron-emitting Film for Spacecraft Charging Mitigation (ELFs Charm)

    TANAKA Atomu, MATEO VELEZ Jean-Charles, DADOUCH Sarah, OKUMURA Teppei, SAKAMOTO Kenji, IWATA Minoru, TOYODA Kazuhiro, CHO Mengu

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN    17 ( 1 ) 1 - 6   2019年01月  [査読有り]

     概要を見る

    <p>To protect a satellite from accidents due to spacecraft charging, Kyushu Institute of Technology (Kyutech) is developing a device called ELFs-Charm, which stands for ELectron-emitting Film for Spacecraft CHARging Mitigation. Electron emission from ELFs-Charm was already confirmed in Polar Earth Orbit in 2012 via flight experiment onboard HORYU-II. As a next step, we are considering the practical operation for spacecraft charging mitigation. The present emission level is not enough to increase the satellite potential. We focus our efforts on improving two properties, charging property and the emission threshold. The charging property is measured by how well the differential voltage between the ELFs-charm insulator surface and the satellite chassis increases. The emission threshold is measured by the differential voltage when the electron emission starts. This paper reports the laboratory experimental results to measure the two properties of various samples. The sample made of fluorin resin coating had a good combination of the charging property and the emission threshold that makes it possible to emit electron under realistic ambient electron current density in orbit.</p>

    DOI CiNii

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口頭発表・ポスター発表等 【 表示 / 非表示

  • Deorbit system based on vacuum ARC thruster for microsatellite

    Aheieva K., Toyoda K., Cho M.

    Proceedings of the International Astronautical Congress, IAC  2015年01月  -  2015年01月   

     概要を見る

    In this article presented Vacuum Arc Thruster (VAT), which was designed and manufactured in Kyushu Institute of Technology. Presented principle of work and design. Thruster, firstly, will be operating onboard satellite Horyu-4, which will be launch in 2015 and demonstrate work with direct power source-High Voltage Solar Array (300 V). For VAT presented main discharge and power characteristics measured in experiments. Was calculated thrust (56 nN) and efficiency (2.5 %). Specific impulse is 1200 sec, impulse bit 2 uNs. The total weight of the system including circuit and mounts to satellite is 32 grams. Presented results for efficiency improving methods, such as new type of propellant use in the thruster and magnet system. Calculated deorbit time dependence to satellite mass and power consumption for Vacuum Arc Thruster.

  • Development of mission payloads for arc event generator and investigation satellite HORYU-IV

    Fukuda H., Shimizu T., Toyoda K., Cho M.

    Proceedings of the International Astronautical Congress, IAC  2015年01月  -  2015年01月   

     概要を見る

    Copyright © 2015 by the International Astronautical Federation. A nano-satellite "HORYU-4" is under development in Kyushu Institute of Technology (Kyutech) and is planed to be launched in FY 2015. The main mission of HORYU-4 is measurement of discharge phenomenon (e.g. discharge current, discharge point) on orbit. The one of the submission of this satellite is demonstrate of discharge mitigation method. The discharge experiment system is needed for this mission. This paper introduces the over view of HORYU-4, and discusses following contents: 1, Development of EM of the discharge experiment system. 2, Ground-based discharge tests at Kyutech. This mission will be first measurement of arcing current in space orbit. It will be able to evaluate the validity of ground-based test systems by comparing the result of ground-based tests with experiments conducted in space.

  • Role of aging on the threshold of electrostatic discharge on solar array coverglass

    Khan A., Hughes R., Chen Y., Toyoda K., Cho M., Gray A.

    Proceedings of the International Astronautical Congress, IAC  2014年01月  -  2014年01月   

     概要を見る

    Copyright © 2014 by the International Astronautical Federation. All rights reserved. Coverglass has been widely used to cover the solar cells of satellite solar arrays. This acts to protect the arrays from damage due to irradiation by UV, protons, electrons, etc. However, charge accumulation due to high-energy proton/electron irradiation or ageing due to thermal cycling may degrade the quality and affect the threshold for electrostatic discharge (ESD) from the coverglass. In order to reveal the effect of aging on the threshold for ESD in an inverted potential gradient (IPG) condition, several coverglass samples (CMG100-AR) produced by Qioptiq Ltd. have been aged by thermal cycling (-160 to +110 C) and high-energy (500 keV) electron beam irradiation. A ground experiment was conducted by placing virgin and exposed (aged) samples in vacuum, irradiating the samples with a beam of energetic electrons to generate an artificial ESD, and measuring the sample's surface potential by a non-contact method before and after the discharge occurred. Statistical analysis and Weibull distribution confirms that the ESD threshold for aged coverglass is higher than that of virgin.

  • Total electron emission yield measurement of insulating materials due to different temperatures

    Miyahara A., Wu J., Khan A., Toyoda K., Cho M.

    Proceedings of the International Astronautical Congress, IAC  2014年01月  -  2014年01月   

     概要を見る

    Copyright © 2014 by KYUSHU INSTITUTE OF TECHNOLOGY. Electron induced secondary electron emission from space insulator is a very important factor in understanding spacecraft charging behaviour. Due to the injection of primary electrons and the emission of secondary electrons in the surface layer of insulator, the target surface will be negatively or positively charged. Additionally, the electron emission yield of the spacecraft surface materials is highly dependent on space environments, such as the temperature variation. In our tests, we chose the polyimide film (Kapton 100H) as the research object, and used a single short, low-density pulsed beam, and also developed a scanning method for the total electron emission yield (TEEY) measurement, which can avoid surface potential influence for insulating materials. Moreover for the TEEY system, we installed a heater for high temperature (around 100°C) and the shroud by using liquid nitrogen for low temperature (around -50°C). Under this experimental situation, TEEY of polyimide films of room, high and low temperature was tested respectively. The conductivity variation of the polyimide film due to the different temperatures was considered to influence TEEY.

  • Performance of electroconductive bonded lubricant films in space environment for electrodynamic tether of debris removal system

    Matsumoto K., Takahashi A., Shiomi H., Kawamoto S., Ohkawa Y., Kawamura M., Toyoda K.

    European Space Agency, (Special Publication) ESA SP  2013年12月  -  2013年12月   

     概要を見る

    Several types of electroconductive solid lubricant films, developed as bonded films for the electrodynamic tether (EDT) of an active space debris removal system, were evaluated. These films used molybdenum disulfide or graphite as lubricants, and additives to obtain conductivity. Examination of tribological properties using a pin-on-disk tribometer in vacuum conditions showed that the tested bonded films had low friction and slight wear, but differences in tribological properties were observed especially for different counterpart materials. Details of the evaluation results of the electroconductive solid lubricant films, including tribological behaviors, the effects of atomic oxygen and performance of electron collection from space plasma are reported. Copyright © 2013 European Space Agency.

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工業所有権 【 表示 / 非表示

  • 真空アーク推進機

    特開 特開2017-002851  日本国

    豊田和弘

科研費獲得実績 【 表示 / 非表示

  • 超小型衛星搭載用300V発電直接駆動真空アーク推進機の開発

    挑戦的萌芽研究

    研究期間:  2012年04月  -  2014年03月

    研究課題番号:  24656521

  • 宇宙プラズマを利用したデブリ除去方法の開発

    挑戦的萌芽研究

    研究期間:  2010年04月  -  2012年03月

    研究課題番号:  22656195

 

担当授業科目 【 表示 / 非表示

  • 2018年度  エネルギー工学特論

  • 2018年度  数値計算法

  • 2018年度  宇宙環境技術特論

  • 2018年度  電子回路Ⅰ

  • 2017年度  エネルギー工学特論

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