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application/pdf, 大阪府立大学工業高等専門学校 研究紀要. 2022, 55, P.1-12

The purpose of this study was to clarify the function of torques exerted by the joints of the lower trunk during maximal velocity sprinting. Eight male track and field athletes volunteered, and sprinted 60 m from a standing start position. The ground reaction force of the support leg was determined using a force platform (1000 Hz), which was placed at the 50-m mark from the start position. Simultaneously, 3D coordinates were recorded with a motion analysis system (250 Hz) using 20 cameras (MX-T20). The joint torques were calculated using inverse dynamics. The contribution of joint torques to the right and left hip joint forces, and the torso joint force, was calculated by a method that simultaneously solves equations of motion for each segment and equations of constraint conditions for adjacent segments connected by a joint. The main results were as follows: (1) During the terminal support phase (80-100% normalized time), the angular velocity of anterior rotation of the pelvis decreased and participants in whom this angular velocity decrease was diminished ran faster (p, Keyword: equation of constraint condition for adjacent segments connected by a joint

宇宙空間において、ターゲットを捕獲する場合、初期接触でターゲットを弾き飛ばさないことが必須である。手先インピーダンス制御を用いて手先の見かけの慣性特性をコントロールすることによって接触力を減少させることが可能であるが、実際の宇宙空間では接触時間が非常に短く、また、ロボットの制御時間遅れや敏捷性が影響するために、ターゲットとの接触を維持することは容易ではない。本論文では、フリーフライングロボットにおける手先インピーダンス制御を用いたロボットアームと2次元微小重力環境を模擬できる空気浮上型実験装置を用いて接触力学解析を行う。, This paper presents the analysis on the contact dynamics between a robotic manipulator under impedance control and a floating target in space. After the contact of two free-flying bodies in space, both parties are easily bounced away and start rotating by the contact force. In order to reduce the contact force in satellite capture, the dynamic conditions between the manipulator under impedance control and a free flying target are investigated. As evaluation criteria, the equivalent mass of the tip of the manipulator coming from the impedance control is discussed. The influence of the impedance characteristics and the control time delay upon the equivalent mass are evaluated using experiments and numerical simulations. To replicate microgravity environment, a airfloating testbed on a stone surface plate is used., 資料番号: AA0063718062

宇宙機の精密な3軸姿勢制御を実現する装置として、リアクションホイールが一般的に用いられている。しかし装置が大型になってしまうため小型の宇宙機に搭載するのには適さない。また機械的摺動部を持つために故障を起こす可能性が高い。これらの問題を解決するものとして、3次元リアクションホイールが提案されている。これは、浮上している剛体球に回転磁場を与えることで剛体球内に渦電流を発生させ、それにより得られるローレンツ力を駆動トルクとして剛体球に角運動量を与えるものである。この装置では、機械的摺動部を持たないために耐故障性の向上が見込まれ、また剛体球を3次元的に回転させることで3軸の姿勢制御が可能であり、装置の小型化につながる。本研究では3次元リアクションホイールを用いた姿勢制御システムについて解析的および実験的に検討を行った。その結果から制御特性を見積もり、従来のリアクションホイールに対する有用性を比較、検証する。さらに、実際に宇宙機に搭載する上での問題点の検討も行う。, This paper presents a novel attitude control device which is called Three Dimensional Reaction Wheel (3DRW). 3DRW consists of only one levitated spherical mass which can rotate around arbitrary axes by rotational magnetic field. This leads to the reduction of the weight and volume of the system as compared to existing reaction wheel. Furthermore, this device has no mechanical contact between rotor and stator, so the failure caused by the mechanical contact would be reduced. In this paper, the results of the analysis and experiment on the dynamics and control of 3DRW are shown. To investigate the dynamics of the rotation mass in a magnetic field without mechanical contact with stator, an air levitation system is used. This makes it possible to control the rotation of mass around arbitrary axes. Furthermore, the characteristic of attitude control using 3DRW is also evaluated, and advantage of 3DRW for very small satellites such as micro-class or nano-class satellite is revealed., 資料番号: AA0063718018

小惑星探査機「はやぶさ(MUSES-C: Asteroid Sample-return Spacecraft)」はイトカワの高解像度画像取得をはじめ、様々な観測を行った。イトカワは、がれきの積み重なった小惑星(ラブルパイル小惑星)であり、形状、地表面の土砂の大きさの分布の偏りなど、通常の惑星には見られない特徴が確認された。これらの特徴の主要因として、大きさの異なる粒子を混合した容器に振動を加えるとより体積の大きな粒子が浮かび上がってくる現象であるブラジルナッツ効果と、自転による遠心力の効果の複合的な影響が考えられる。そこで本研究では、多粒子系モデルを用いた数値解析により、宇宙空間においてラブルパイル小惑星を模擬した、異なる大きさの粒子を含む粒子群に振動を加え、どのような挙動を示すか解析し、実際のイトカワと比較し、考察する。, The asteroid exploration spacecraft 'Hayabusa (MUSES-C: Asteroid Sample-return Spacecraft)' took high resolution pictures of asteroid 'ITOKAWA'. ITOKAWA is a rubble-pile asteroid, whose shape and regolith size distribution are unique. These features are caused by composition of the Brazil-Nut effect and centrifugal force by spin. The Brazil-Nut effect is generally known as the phenomenon that causes larger particles to rise to the top of the shaken granular mixtures. In this study, the behaviors of various size particles in the space are analyzed by numerical simulation using Multi-Particle model, which is model of a rubble-pile asteroid. The results are compared with the surface of ITOKAWA, and the inferred internal structure of ITOKAWA is discussed., 資料番号: AA0063718014

電波天文観測衛星'ASTRO-G(Radio-Astronomical Satellite)'がVSOP-2(VLBI Space Observatory Program-2)計画のために2012年に打ち上げられる予定である。VLBI(Very Long Baseline Interferometry)観測における大気位相揺らぎ較正のため、ASTRO-Gは搭載アンテナを観測対象の天体とクエーサと呼ばれる較正天体に交互に指向する姿勢制御を行う必要がある。大気位相揺らぎが1分周期で移り変わるため、姿勢変更は1分周期という早い時間で行われる。また、搭載する直径8mの大型アンテナは柔軟構造として扱う必要がある。この様な大型な柔軟構造物はモーダルパラメータの同定が難しいと考えられ、ロバスト制御が必要とされる。この様に、ASTRO-Gの姿勢制御系には、柔軟構造のモデル化誤差に対するロバスト性を持ち、かつ高速な姿勢変更を行うことが要求される。現在、ASTRO-Gに対して、フィードフォワードを主とした制御系が考えられている。この方式では、フィードフォワード指令として、神谷らにより全く振動を励起しないNME(Nil-Mode-Exciting)profilerが提案されており、フィードフォワードのみの制御系でも姿勢変更を行うことが可能である。しかしながら、アクチュエータ、センサなどの特性により、振動が励起されてしまうのではないか、ということが懸念されている。そこで、本稿ではASTRO-Gの姿勢制御系に対し、フィードバック制御系の適用可能性を検討する。設計する姿勢制御系は、H(sub ∞)制御器とNME profilerにより構成される2自由度制御系である。数値シミュレーションにより、設計した2自由度制御系の評価を行い、フィードバック系の適用可能性を検討する。, ASTRO-G (Radio-Astronomical Satellite) will be launched for VSOP (VLBI Space Observatory Program)-2. ASTRO-G has to maneuver the attitude between target celestial-object and quasar alternately and quickly, because VLBI (Very Long Baseline Interferometry) observation requires calibration for phase fluctuations of atmosphere which changes fast. In addition, ASTRO-G will have a huge antenna to compose VLBI, which is a flexible structure and difficult to model. Therefore, in the ASTRO-G mission, attitude control system has to satisfy these challenging requirement: Agile maneuvering and flexible structures. In the current strategy of the attitude control system, feedforward control is mainly applied to ASTRO-G mission. In this strategy, reference called 'NME (Nil-Mode-Exciting) profiler' is proposed by Toshio Kamiya et al. to excite no flexible modes in agile maneuver. Authors, however, are concerned about unexpected disturbance, characteristics of actuators and sensors, noise and so on. On the other hand, feedback control is desirable because it can have robustness against unexpected disturbance. In this paper, we studied whether feedback control is applicable for ASTRO-G mission. Two DOF (Degree Of Freedom) control is applied to ASTRO-G's attitude control system: Robust H(sub infinity) control and NME profiler. The simulation results show the effectiveness of two DOF control system for the agile maneuvering with flexible structures., 資料番号: AA0063718009

近年、フォーメーションフライトの制御に関する研究が盛んになされている。飛行機における編隊飛行、多数機による地球観測ミッション、長焦点距離望遠鏡ミッション、また地上においては自動車の交通量制御など、この考えが用いられている分野は多方面に渡る。群れの制御が用いられる利点は、宇宙機の場合は、機能の分担化による冗長性と多数機であることによる空間的規模の拡大、故障機代替の容易化などが上げられる。また、ITS(Intelligent Transportation System)化における交通量制御では、車列全体の渋滞緩和、エネルギー消費の低減などの利点が考えられる。編隊飛行における相対位置制御では、時間遅れがあることにより、共振、発散といった現象を引き起こす。これは、自動車の交通においては渋滞現象そのものである。本論分ではそのような問題について議論し、特に車列の縦方向に関する隊形制御に焦点を当てて述べる。, In recent years, formation control is studied actively. The area of fields that apply formation control covers, for instance, formation flight of the airplanes, multiple spacecrafts' Earth observation missions or very long focal length telescope concepts, and the traffic control of cars. In the case of spacecrafts, the benefits of applying formation concepts lie in the increasing redundancy by the functional decentralization and the broader spatial coverage by multiple orbiting objects, and so on. On the other hand, in the case of the ground car traffic, ITS (Intelligent Transportation Systems) concepts give a mitigation of traffic congestion and reduction of energy consumption. This paper discusses one of the difficulties in such formation control system, especially focusing on the decentralized formation control., 資料番号: AA0063718029

Patched conics is the standard tool for designing fly-by or gravity assist maneuvers performed by a spacecraft about a planet. In this procedure, the trajectory of the spacecraft about the planet is taken as a perfect hyperbola once the spacecraft is in the sphere of influence of the planet. All other perturbations are neglected. As a consequence the outgoing V infinity is identical to the incoming V infinity. In reality, the spacecraft spends a finite time in the sphere of influence of the planet. A typical time is a week. The small perturbations caused by the Sun will affect the ideal hyperbolic trajectory. When the fly-by planet is the Earth, the Moon and J2 cause also small changes in the hyperbola. The small changes in V infinity are the subject of this paper. The perturbation of the Sun can be modeled as a restricted three body problem or analyzed with the standard averaging technique applied to an hyperbolic orbit. We compare our results to the real data of the fly-by past the Earth on March 4, 2005 by the Rosetta spacecraft on his way to the comet Churymov-Gerasimenko (2014)., 資料番号: AA0063718013

資料番号: AA0063716013

地球へ向けて帰還中の「はやぶさ(MUSES-C: Asteroid Sample-return Spacecraft)」は現在3台中2台のホイールが故障し、いわばバイアスモーメンタム方式で1軸姿勢制御を行っている。この方式ではシンプルな姿勢安定が実現されるはずだが、2007年3月にニューテーションが発散する傾向を示した。本稿では、この現象がホイール回転軸と探査機慣性主軸の不一致によることを解析と数値シミュレーションによって示し、防止策を提案する。, Since Hayabusa (MUSES-C: Asteroid Sample-return Spacecraft) has lost two of three wheels, its attitude is currently stabilized by one-axis bias-momentum wheel. This method should lead to simple attitude keeping, but the motion showed nutation divergence in March 2007. This paper shows that the cause of the instable motion lies in the difference between the axis of wheel and of inertia, and a way to avoid this instability is proposed., 資料番号: AA0063718021

Here at L2, introduced a satellite formation flying consists of two satellites powered by solar sail, the Mirror SpaceCraft (MSC) and the Detector SpaceCraft (DSC). The two satellites are separated such that the operational detector is at the focus of the mirror. Due to the instability of the collinear Lagrangian points, the desired distance between the two satellites need to be maintained. This paper addresses the control design scheme for formation keeping control. The equation of motion is derived in Hill's frame and inertial frame and then control law formulated mathematically. Halo and Lissajous orbit are considered as options for reference orbit., 資料番号: AA0063718031

本稿では、ダンベル形状の物体まわりの、質量の無視できる質点(以降、第3質点と呼ぶ)の運動の安定性について考察する。ダンベル形状物体は、2つの有限質量質点が剛棒で接合されている物体(以降、2質点と呼ぶ)であると模擬できる。この問題は、制限3体問題の特別な問題であると考えることができる。2つの自由度が存在するため、本稿では、この2つの自由度を無次元角速度、無次元質量で表現した。これによれば、2質点を通る直線上に3つ、またこの2質点の垂直2等分線上に2つで、計5つの平衡点が存在する。また、これらの平衡点のうち、垂直2等分線上の2質点にはさまれた点において安定な領域があることが示される。, This paper describes the stability of the Rotational Dumbbell shaped body. This problem, defined as the Rod-Connected Restricted Three Body Problem, is the special case of the Restricted Three-Body Problem, characterized by three bodies: two primary bodies connected each other by a rigid stick; and a mass-free body. While the Restricted Three-Body problem has only one degree of freedom, there are two degrees of freedom in this problem. By setting properly two parameters, described as the non-dimensional angular velocity and the mass ratio, both positions of equilibriums and stable regions are determined. In this paper, the stability in any type of those non-dimensional values is analyzed. There are five equilibriums and three stable points. Of these equilibriums, three points are along the line passing through two primary bodies, and the other two points are along the perpendicular bisector between two primary bodies. In addition, those stable points are comprised of two points which are along the perpendicular bisector between two primary bodies and a point which is along the line segment between two primary bodies., 資料番号: AA0063718015

本論文は、傾斜磁極磁気軸受ホイールと宇宙機とのダイナミクス干渉解析について論じたものである。磁気軸受ホイールを搭載した宇宙機システムは、磁気軸受制御力およびトルクを介して、磁気軸受ホイール・ロータと宇宙機とが結合したシステムと見なすことができ、このとき磁気軸受制御系が宇宙機姿勢運動を不安定化する可能性がある。本論文では、傾斜磁極磁気軸受ホイール・宇宙機系運動方程式に基づいた姿勢安定性解析により、従来の磁気軸受制御系では、ロータ・ジンバル角度のクロスフィードバック制御と積分器の双方に起因して、宇宙機ニューテーションが不安定化することを示す。次にこのような問題に対して、最小次元オブザーバによる宇宙機角速度の推定と、これをクロスフィードバックする構成を追加した新たな磁気軸受制御系を適用することで、宇宙機ニューテーションを安定化できることを示し、さらに本構成に対して擾乱フィードバック制御系を追加した場合にも、系の安定性が保たれることを確認する。, A Magnetic Bearing Wheel (MBW) with inclined magnetic poles has been developed. This paper deals with the dynamic interactions between a satellite and the MBW. In the MBW-satellite system, the MBW rotor is coupled with the satellite by magnetic bearing forces and torques, and there exists some possibility that the magnetic bearing controller makes the satellite nutation unstable. In this paper, the equations of motion of the MBW-satellite system are formulated by Kane's method. Based on the stability analysis of this system, it is shown that the cross-feedback control of the rotor gimbal angle and integrator in an ordinary magnetic bearing controller are the instability factors responsible for satellite nutation. However, this nutation is stabilized with a cross-feedback control of the satellite angular rate estimated by a minimal-order observer from the magnetic bearing control torques. The effects of the disturbance feedback controller used in our study on the system stability are also considered, and the results show that the system stability is not affected by the disturbance feedback controller., 資料番号: AA0063718019

We investigate spacecraft capture trajectories to the periodic orbits of the L1 and L2 points in the planar restricted Hill three-body problem are studied. The specific focus is on transfer to these vicinities from interplanetary trajectories. This application is motivated by future plan to use the Sun-Earth and Sun-Mars collinear libration points as space hub for Mars Mission. We utilize stable manifolds for capture trajectories to periodic orbits around the libration points. As a result, the cost of capture into a periodic orbit is also reduced relative to direct capture into a parabolic orbit. The way of linking between interplanetary transfer trajectories and the stable manifold is also discussed., 資料番号: AA0063718012

資料番号: AA0063716018

A new approach to statistical mechanic of turbulence based on the cross-independence closure hypothesis is presented and its relationship with Kolmogorov's theory of locally isotropic turbulence is discussed. For homogeneous isotropic turbulence, the one-point velocity distribution is obtained as the inertial normal distribution N1 with the parameter alpha = epsilon/3, epsilon being the energy-dissipation, and no viscosity nu. The energy-dissipation epsilon satisfies the fluctuation-dissipation theorem and causes the inviscid energy catastrophe E greater than 0 in the limit of nu approaches 0. Since no energy supply is assumed for homogeneous turbulence, the energy E decays in time t as E is proportional to t(exp -1) and hence epsilon is proportional to t(exp -2). Two-point velocity distribution is expressed in terms of the velocity-sum distribution and the velocity-difference distribution, and the latter distributions are expressed as another inertial normal distribution N2 with the parameter alpha/2 for r greater than 0, r being the distance of the two points. Although these distributions change discontinuously at r = 0 for satisfying the boundary conditions, they are continuous functions of the local coordinate r* = r/eta. eta = (nu(exp 3)/epsilon)(exp 1/4) being Kolmogorov's length. In the local range, the velocity-sum distribution is expressed as the local normal distribution N3 with the self-energy-dissipation alpha* + (r*) for the velocity-sum as the parameter. The velocity-difference distribution in the local range is axisymmetric with respect to the vector r*, and the lateral component is expressed as the (one-dimensional) local normal distribution N4 with the self-energy-dissipation alpha* - (r*) for the velocity-difference as the parameter. The longitudinal velocity-difference distribution in the local range is obtained as algebraic non-normal distributions A1 and A2 for the inertial and viscous subranges respectively. For inhomogeneous turbulence, the velocity is decomposed into the mean velocity and the fluctuation velocity around it, and the equations for the mean velocity and the distributions of the one-and two-point fluctuation velocities are derived. The general characters of the equations are discussed with systematic application to inhomogeneous turbulence in scope., 資料番号: AA0063908002, レポート番号: JAXA-SP-07-026E

A method is presented for the optimum aeroelastic design of a flapping wing employing lifting-surface theory as an aerodynamic tool and the complex method as the optimization algorithm. The method is applied to the optimum design of a flapping wing of a Kite Hawk (Milvus migrans) UAV (Unmanned Aerial Vehicle) and the optimum thickness distribution of the main-spar is determined. As the result of the optimization, a high propulsive efficiency of 75 percent is attained considering only dihedral flapping of the main spar. By evaluating the viscous effect for this optimum design using a three-dimensional Navier-Stokes code, the effectiveness of the design is confirmed., 資料番号: AA0063824003, レポート番号: JAXA-SP-07-008E

資料番号: AA0063351005

モーメンタムホイールを搭載した本体とマニピュレータから構成される宇宙ロボットにおいてエンドエフェクタを制御する場合、角運動量ベクトルとマニピュレータ形状の関係によって本体のニューテーション運動が安定化もしくは不安定化する現象がみられる。本研究では固有値解析によって、ニューテーション運動の安定性がマニピュレータ形状によって変化することを示し、冗長マニピュレータを用いて安定な運動をあたえる運動計画をおこなう。, The problem of controlling the end effector of a space robot that consists of a main body equipped with a momentum wheel and a manipulator is difficult, because nutation of the body may become stable or unstable depending on the geometric relationship between the angular momentum vector of the wheel and the shape of the manipulator. In this paper, we show the change in the stability of nutation according to the geometric relationship by eigenvalue analysis and propose a method of planning a motion that makes the nutation stable for a space robot with a redundant manipulator., 資料番号: AA0063481048

テザー型太陽発電衛星(SSPS: Space Solar Power Systems)など、テザーを伴う大型柔軟構造物において、テザーを制御アクチュエータとして用いる案が検討されているが、テザーの非線形性が柔軟構造物に影響を与え複雑な挙動になることが予想される。本研究では、柔軟梁および柔軟パネルと、テザー要素からなるシステムを取り扱い、その動特性、制御特性を数値的、実験的に解析している。梁、パネルの柔軟性は偏微分方程式により記述し、ミッションファンクション制御を応用したテザーの制御入力によりパネル、梁の振動抑制を行う。, This paper is devoted to study a control method of the vibration of the large flexible solar panel of the Space Solar Power Systems (SSPS) numerically. The tether tension is employed as the actuator of the control and the Mission-Function control is used as the control algorithm. In the numerical analysis, the partial differential equation of motion for the flexible solar panel is transformed to the difference equation and then, the vibration is analyzed resulting in a much sophisticated numerical simulator. Mission Function control method is employed to suppress the structural vibration caused by external disturbances. A beam-tether system and a panel-tether system are employed to analyze fundamental characteristics of the tethered SSPS., 資料番号: AA0063481052

小惑星サンプリングの1つの手法として、テザーを用いたサンプリング方法が検討されている。この方法を用いると小惑星表面の層構造を保持したままサンプル回収ができると期待されている。本発表では、サンプル回収時に着目し、テザーやサンプルを保持しているコアラーの運動について考察を行う。, In this paper, dynamics behavior of tether ejecting and tether retrieving with a reel mechanism in a tethered sampling method is discussed. The tethered sampling method has been proposed by the authors as a candidate soil sample collection method of minorbody. The method consists of three phases: (1) shooting a corer together with a tether, (2) inserting the corer into a surface and collecting soil in the corer, (3) pulling back and retrieving the corer with the tether. This paper mainly deals with dynamics of the tether and corer in the ejecting and the recovery phases, and numerical simulations and fundamental experiments of the tether dynamics are conducted using a tether control mechanism. The tether mechanism can control the tether tension and measure the tether length and velocity. The results show the feasibility of the proposed tethered sampling method., 資料番号: AA0063481058

JAXA宇宙科学研究本部が2010年代の実現を目指して検討中の地球磁気圏観測衛星「SCOPE(cross-Scale COupling in Plasma universE)」は、5機の衛星が編隊飛行をしながら電磁場の同時観測を行うミッションである。このSCOPEで想定されている軌道は近地点距離+3,000km、遠地点距離30程度の長楕円軌道である。一般に地球周回軌道での編隊飛行では月の影響はほとんど考慮しないが、SCOPEで想定されているような長楕円軌道になってくるとその摂動効果が無視できないものとなってくる。本稿では月摂動を考慮した編隊飛行の運動方程式を導出し、その周期性を利用した半解析的手法を用いて月摂動の影響を調べる。さらに数値シミュレーションを行い、用いた解析法の妥当性を検証する。, Japan Aerospace Exploration Agency (JAXA) is currently planning the next generation magnetosphere observation mission called 'SCOPE' (cross-Scale COupling in Plasma universE). SCOPE consists of five satellites, one mother satellite and four daughters. The planned orbit of the SCOPE mission is a highly elliptic orbit with Re+3,000 km perigee and 30 Re apogee. In general, the effect of the lunar perturbation on the relative dynamics of formation flying spacecrafts is negligible in low earth orbit. However in highly elliptic orbit, the effect becomes large and needs to be considered. This paper investigates the effect of the lunar perturbation on the formation flight dynamics in a half analytical way, and compares it with the result of numerical simulation to evaluate the validity of the analysis., 資料番号: AA0063481001

現在、JAXAの提供するS-520型ロケットを使用した観測ロケットプロジェクトに、テープテザーを使用する実験を提案中である。提案している実験は、1つの工学的実験と2つの理学的実験である。工学的実験は、幅30[mm]のテープテザーを1[km]展開するというものである。高速でテープテザーを展開するため、これまでのテザーの展開方法とは異なる、折りたたみ展開方式という新しい方法でテープテザーの展開を検討している。本研究では、プロジェクトをモデル化した数値シミュレーションと、折りたたみ展開方式での各実験について説明する。実験は、主に繰り出し抵抗測定実験と高速展開実験の2つである。また、現在取り組んでいるシステム全体の設計についても述べる。, A sounding rocket project is proposed to exploit the utility of bare electro-dynamic tape tether in space. The project consists of one technological experiment and two scientific experiments. The technological experiment is the swift deployment of tape tether of 1,000 [m] in length, 30 [mm] in width and 0.05 [mm] in thickness. We have devised the foldaway deployment method in order to deploy tape tether at high speed with sufficient reliability. The characteristics of the foldaway deployment method and each experiment to confirm the performance of the deployment method is described. Experiments include mainly two procedures which are the experiment on measurement of deployment drag employed with the Tower Type Deployment Simulator and the High Speed Deployment Experiment employed with Water Rocket Model. The time history of the deployment velocity at the actual payload separation is designed with using the numerical simulation. The whole system in the project is also under synthesized and some experimental verification is addressed including the ejection system and braking scheme for the tape tether deployment., 資料番号: AA0063481050

太陽-地球系L2点に深宇宙港を設置することを想定し、その脱出方法について検討を行った。前年の発表で、L2点から惑星間へは容易に脱出させることができるが、ポテンシャルの観点から脱出方向は、太陽から地球に向かう線上、すなわち半径方向におおよそ限定されることを述べた。これは、逆の言い方をすれば、半径方向に脱出させることが、加える増速量と獲得できる脱出速度の比の効率の観点で有利であることを示している。この結果をもとに、複数インパルスでの脱出軌道について考察し、また、低推力推進を使用した脱出軌道を求め評価する。, Recently, various kinds of planetary explorations have become more feasible, taking the advantage of low thrust propulsion means such as ion engines that have come into practical use. The field of space activity has now been expanded even to the rim of the outer solar system. In this context, the Japan Aerospace Exploration Agency (JAXA) has started investigating a Deep Space Port built at the L2 Lagrange point in the Sun-Earth system. For the purpose of making the deep space port practically useful, there is a need to establish a method to making spaceship depart and return from/to the port. This paper first discusses the escape maneuvers originating from the L2 point under the restricted three-body problem. Impulsive maneuvers from the L2 point are extensively studied here, and using the results, optimal low-thrust escape strategies are synthesized. Furthermore, this paper proposes the optimal escape and acceleration maneuvers schemes using Electric Delta-V Earth Gravity Assist (EDVEGA) technique., 資料番号: AA0063481009

自動車などの車列を、各車が車間を計測して分散的に制御をする際には、車間が粗密波のような振る舞いをし、それが後方に伝播される現象が起こる。本研究では、Z変換を用いて車列を表現し、粗密波の拡大が起こらず車列が一様収束するような制御則を考える。得られた制御則は、測距装置のような複雑な機器を必要とせず、実際の自動車の車列制御に適応が可能である。, When the car platoon is controlled by the decentralized control law which uses the distance between the members, the vibration of relative distance between the members is propagated backward. This propagation system sometimes induces the resonance phenomenon in which magnitude of vibration grows according to following cars, and traffic jam can also happen at the end. In this paper, the mechanism of this propagation phenomenon is dealt via z-transformation method and the control strategy aimed for a uniformly convergence which solves or relaxes the propagation system is shown. This control strategy is easily applicable to the actual traffic control system because the complicated devices such as ranging system are unnecessary. So, this paper also presents the system for demonstration and the result of it., 資料番号: AA0063481012

本稿では楕円軌道における宇宙機の編隊飛行制御について検討する。相対的なフォーメーション軌道において、楕円軌道と同じ対称性を仮定することによってフォーメーションの初期条件を導く。この初期条件から従宇宙機が主宇宙機の周りを少ない距離変動で周回するような軌道や、従宇宙機が局所水平面内で周回する軌道など、いくつかの特徴的な軌道を求めることができる。, Formation flight of spacecraft in eccentric orbits is considered in this paper. Symmetry of the eccentric orbits is assumed in a relative formation trajectory, and under this assumption, relations of initial conditions in formation flight are derived. Some characteristic trajectories are obtained from these relations, such as a trajectory where a deputy spacecraft rotates around a chief spacecraft with relatively small variation in the distance between the two spacecraft, or a trajectory where the deputy spacecraft moves on a local horizontal plane on which the chief spacecraft exists. Formation flight by plural spacecraft is possible by combining these relative trajectories., 資料番号: AA0063481004

地球・月系におけるラグランジュ点の中で、L2点は地球から見て月の裏側に位置する。このL2点の周辺において、地球から可視となる軌道上に配置した衛星を経由すると、月の裏側と地球の通信が可能となる。本研究では、この地球・月系のL2点周りにHalo軌道を設計する。さらに月の離心率も考慮した制限3体問題において、軌道保持のための制御法を検証する。, In Earth-Moon system, L2 point lies behind the Moon as seen from the Earth. By using a satellite around this point, it is possible to communicate with the far side of the Moon. In this study, we show a control method to keep Halo orbit around the L2 point. Then, to evaluate the Moon eccentricity effect, we applied the restricted three body problem and examine the possibility of keeping the orbit., 資料番号: AA0063481015

Nowadays, the flight distance of champion team of the birdman rally contest was over 400 m. In order to break the record, we have to consider the weather conditions, flight conditions and design optimization of the glider. For this purpose, we developed the three-dimensional flight simulator and the optimization program based on genetic algorithm. The simulation result of the three-dimensional flight simulator was reasonably agreement with the real flight. GA (Genetic Algorithm) optimization was carried out with two hundreds samples and fifty generations. The dominant genes of airplane for the contest were obtained with GA. The performance map showed the optimal airplanes such as the champion team were sensitive and not easy-handle. The simulator was suggested another optimized model with flexible wing that was not sensitive to flight conditions. The proposed model got the fourth prize and the referee's award of the birdman rally contest 2005., 資料番号: AA0063156013, レポート番号: JAXA-SP-06-013

Inhomogeneous turbulence is studied statistically using the cross-independence closure hypothesis for the equations of multi-point velocity distributions. First, the turbulent velocity field is decomposed into the mean flow and turbulent fluctuation around the mean. The equations for the mean velocity and the distributions of turbulent velocity are derived. These equations are closed by applying the cross-independence closure hypothesis which has been successfully used for homogeneous turbulence (Tatsumi & Yoshimura, 2004, 2006). The closed equations are obtained for the mean velocity and the one- and two-point velocity distributions. At large Reynolds numbers, these equations are shown to give the inertial normal velocity distributions in the outer range and the non-normal velocity distributions in the local range respectively., 資料番号: AA0063156015, レポート番号: JAXA-SP-06-013

宇宙空間でフリーフライングロボットが回転している未知パラメータのターゲットを捕獲する際に、接触後においてチェイサーのベース姿勢を安定に保つための、ターゲットを含めた系全体の角運動量を再分配する手法について考察する。ターゲットとの接触後にアームを積極的に制御する手法と、その時に懸念されるアームとチェイサー自身との接触の危険性を回避するためのリアクションホイールを活用する手法についてそれぞれ述べる。さらにこれらの角運動量再分配に関する手法が、単腕ロボットの場合だけでなく、双腕ロボットにおいても有効である事を示す。, A manipulator control strategy to be utilized during the post-impact phase of a satellite capturing operation is introduced. It is based on redistribution of the angular momentum in the system consisted of chaser and target satellites, in a way that keeps the chaser's base attitude stationary. The general case when the target undergoes rotational motion and its mass and inertia properties are unknown is considered. A method for accommodation of the unknown amount of angular momentum from the target satellite in a system of reaction wheels is discussed. Furthermore the application of the proposed post-impact control to a dual-arm space robot is examined., 資料番号: AA0063480051

本発表では、次期小惑星探査ミッションの検討の中で進めている軌道計画の検討状況を報告する。昨年度のシンポジウムでは、対象天体と探査シーケンスを絞り込むための予備検討として、弾道飛行とスウィングバイを組み合わせた探査シーケンスの検討結果を報告した。今回は、その結果を元に選定したミッション候補に対し、電気推進を主推進として地球スウィングバイを組み合わせたE-ΔVEGAの使用を想定した軌道計画を検討したので、その結果を報告する。, Reported in this paper is the status of the trajectory analysis of the asteroid explorer mission now under study in JAXA/ISAS. In the previous symposium, we have reported the results of the preliminary analysis to select the candidates of the target asteroids and the exploration sequence. The global search of the targets and sequences in the space of the combinations of the ballistic trajectories and planetary swing-bys successfully made clear the mission candidates suited our objective. Following the preliminary analysis, more detailed trajectory analysis is performed assuming the usage of the electric propulsion, and the results of which are reported in this paper., 資料番号: AA0063480022

再突入飛行時に非常に大きな迎角で飛行する有翼式再突入機は、横方向の安定性と制御性に関する困難な問題に直面する。本論文は、我が国の宇宙往還技術試験機HOPE-X(H-2 Orbiting Plane-Exprimental)の開発で得られた知見に基づき、有翼式再突入機の厳しい飛行ダイナミックスについて解析的な理解を示すことを意図している。極超音速飛行マッハ数領域においては、横滑りのエルロンへの補償を伴うバンク角のヨーRCS(Reaction Control System)へのフィードバックが、緩やかな制御ゲインの観点から最も適切な制御方式であることが分かり、HOPE-Xの非常に長い開発を通して得られた最も重要な成果の1つとなった。, Winged reentry vehicles flying at an extremely high angle of attack during their reentry flight encounter difficulties with lateral and directional stability and controllability. This paper aims at a theoretical understanding of the critical flight dynamics of winged reentry vehicles based on the lessons learned from the development of the Japanese experimental space transportation system HOPE-X (H-2 Orbiting Plane-Exprimental). The most important conclusion from what has been gained through the very long development of HOPE-X is that the bank angle feedback to yaw RCS (Reaction Control System) associated with sideslip augmentation by aileron is the most appropriate control law for the hypersonic flight Mach numbers in view of moderate feedback gain., 資料番号: AA0063480062

太陽-月・地球系におけるラグランジュ点の中で、L2点は太陽と地球との距離がほぼ一定で、太陽、地球との幾何学的関係が保たれ、またダウンリンク通信が太陽の影響を受けない点でL1点よりも有利である。そのためL2点周辺の軌道は、赤外線天文衛星や外惑星探査のための起・終点としての宇宙港の軌道として利用が考えられている。本論文では、新しい制御法によりL2点回りに小さな円形のHalo軌道が作れることを示す。まず初めに、円制限3体問題における線形化された方程式から理論的に制御則を導く。その後、実軌道要素を用いて軌道制御方法を検証する。軌道制御に必要な推力は十分小さく大変実用的な制御方法である。, A Lagrange point of Sun-Earth system, L1 or L2 is conceived one of the best point for astronomy and connection ports for outer planets. This paper describes a new useful control method for realizing and keeping small circular Halo orbits around the L2 point. First, a control law is mathematically derived from the restricted three body problem formulation and the associated properties are discussed. And next, some useful cases for the space mission are verified numerically using real ephemeris. The resulted Halo orbit is compact and circular realized with satisfactorily small thrust. The paper concludes the strategy is applied to many kinds of missions., 資料番号: AA0063480003

今日の電気推進機関の技術進歩により、高比推力の推進機関が実用化されるようになり、さまざまな惑星探査が可能となった。そして今後も、火星や木星をはじめとする、深宇宙の惑星を探査する機会が増えていくと考えられている。宇宙航空研究開発機構・宇宙科学研究本部では、地球近傍ではなく地球引力圏界に、中継拠点として深宇宙港を建設しようという検討を行っている。本研究では、太陽-地球系L2点に深宇宙港を設置することを想定し、低推力推進機関を搭載した宇宙機によるL2点を発着地とした深宇宙往還システムを考え、その脱出軌道を論じる。, Recently, various kinds of planetary explorations have become more feasible, taking the advantage of low thrust propulsion means such as ion engines that have come into practical use. The field of space activity has now been expanded even to the rim of the outer solar system. In this context, the Japan Aerospace Exploration Agency (JAXA) has started investigating a Deep Space Port built at the L2 Lagrange point in the Sun-Earth system. For the purpose of making the deep space port practically useful, there is a need to establish a method to making spaceship depart and return from/to the port. This paper first discusses the escape maneuvers originating from the L2 point under the restricted three-body problem. Impulsive maneuvers from the L2 point are extensively studied here, and using the results, optimal low-thrust escape strategies are synthesized. The paper presents, as the major results, the optimal escape and acceleration maneuvers schemes using Electric Delta-V Earth Gravity Assist (EDVEGA) technique, in which the comprehensive delta-V evaluation method is presented. The results obtained are highly useful, ushering the future solar system exploration era., 資料番号: AA0063480007

本論文は、テザーシステムに付加されたクローラーシステムの力学に関する研究である。テザーシステムには、軽量、大型構造、自立構造が可能といった多くの利点がある。また、テザーシステムは破断などの可能性があっても建設が可能である。クローラーシステムは、テザーシステムの保守・点検などの重要な役割を果たすこと考えられている。クローラーを付加したテザーシステムの運動方程式を拘束条件を含んだケーンの方法を用いて導き、またテザーシステムの性能を数値解析から求めた。, This paper studies the dynamics of a crawler system equipped on a space tether system. The tether system has such many advantages characteristics as the light weight, very long structure, and autonomous construction. The tether system is able to be constructed advantageously if any such failure as severance can be avoided. The crawler system is expected to play an important role in the course of the maintenance of the tether system. The equations of motion are formulated for the tether system equipped with the crawler by using the Kane's method and the method to include the constraints. Results of numerical analysis show an efficient performance through the employment on the tether system., 資料番号: AA0063480039

本研究では、電流の切り替えによるエレクトロダイナミックテザーシステム(EDT: ElectroDynamic Tethered)の姿勢制御について、これまでに提案されている手法と比較して安全かつ高効率な運用を実現するための制御手法を示す。EDTのテザー内部の電流は、周辺のプラズマ環境や熱環境によって変動すると考えられている。電流の切り替えによる姿勢制御は、これら予測できない電流の変動の影響を避けることの出来る制御手法である。本研究では、軌道面内・面外を同時に姿勢制御する手法を提案し、新たに軌道パラメータの変化を考慮した安定性評価関数を導入した。数通りの数値計算により、まず本研究で提案する制御手法の有効性を実証し、さらに実際のシステムに適用するための方法を検討した。また特に楕円軌道において、従来の手法と比べてより安全かつ効率的な軌道降下が可能となることを示した。, A libration control strategy through electric current switching for an ElectroDynamic Tethered system (EDT) is presented. It is expected that the electric current in the tether experiences some unexpected change due to its plasma environment, thermal condition, etc. Libration control through current switching can avoid such changes and unexpected instability. A simple control law to determine current switching to stabilize both in-plane and out-of-plane libration is presented. A new stability function is also presented to facilitate the evaluation of the stability of a tethered system on an elliptic orbit. Through several numerical simulations, the effectiveness of the libration control strategy and the stability function is demonstrated. It is clearly shown that the stability function and a switching control toward a periodic solution facilitate a more appropriate stability evaluation and an efficient libration control. The control strategy is considered to be easily materialized in actual EDTs, and enables a more rapid and secure de-orbit., 資料番号: AA0063480042

タンブリング状態にある故障衛星に外力を加えることでその角運動量を減衰させる問題において、特に繰り返しインパルスを入力とする場合の制御上の特徴について検討する。, We discuss an angular momentum control of a tumbling spacecraft. The proposed control method is to apply an impulse by a space robot arm to measure and control the relative position and attitude between the target spacecraft, and then to apply another impulse until the rotational motion of the target spacecraft is well damped. A discrete controller is designed using the simplified equations of rotational motion through appropriate coordinate transformation. The stationary response under contact model uncertainty is investigated and stability condition is analytically derived. Numerical simulations are given to validate the proposed approach., 資料番号: AA0063480050

The orbital dynamics of solar photon thrusters is investigated considering the limit of reflective sail temperature. Although reflective sails can normally be articulated so as to provide transverse and radial thrust, a sun-facing attitude may be preferred for very large or gossamer sails. The stability of the heliocentric circular orbit under such radial thrust is investigated with respect to solar photon thrusters under a temperature constraint. Stability conditions are obtained as functions of radius of circular orbits and the solar sail lightness number assuming optical/thermal properties., 資料番号: AA0063480005

Future exploration and exploitation of Jovian system is expected. Establishment of an outpost in Jovian system will ensure maximum benefit of the exploration with capability for extending the exploration to outer solar system and beyond. Outpost base around Callisto is tentatively selected to avoid the Jupiter's main radiation belt. Since multiple missions are required for the outpost establishment, the establishment trajectories must be optimized. Multiple gravity assists or low thrust propulsion is expected to be employed for the Jupiter en route trajectory. Braking using a Galilean moon prior to Jupiter insertion, followed by multiple Galilean moons resonance hopping for step by step apojove reduction are assumed to be taken as Callisto en route trajectory. This approach already save much Delta V compare to a direct trajectory scenario, but still leave a quite big Delta V for final orbit insertion. Final approach to Callisto along a trajectory on the weak stability boundary of Callisto with respect to Jupiter is examined. Numerical study of Callisto ballistic capture linked to an arriving joviocentric trajectory, with and without other Galilean moons effect, is performed for construction of an optimum final insertion maneuver., 資料番号: AA0063480013

将来型宇宙輸送機が大気中を上昇飛行する際の誘導法についてわずか4つのパラメータを用いて表現できる手法を提案する。空気吸い込み式推進機関には最大作動動圧が存在するため、上昇径路には動圧拘束が存在するが、提案する誘導法を区間に分けて適用することで、準最適な飛行経路を飛翔することができることを示し、また前進積分による単純なパラメータ更新法により、リアルタイムでの誘導計算が可能であることを示す。, This paper shows the new guidance method on the aerodynamic ascent path. This method can be described by using only four parameters. In the case that the path constraints like maximum dynamic pressure are considered, we can apply this method by dividing the flight path into several phases. And guidance parameters are easily determined by simple forward integration of equation of motion., 資料番号: AA0063480063

小型のスピン型宇宙機のスピン軸制御系は、重量リソースなどの問題から軽量かつ単純な装置が求められる。ラムライン制御は、簡単なスピン型の太陽センサとリアクション制御スラスタのみで構成できるため、最も広く使われている姿勢変更方法の1つである。このラムライン制御とニューテーションを抑える制御を組み合わせれば、任意の方向にスピン軸を向ける制御が可能となる。本報告では、ラムライン制御とアクティブニューテーション制御を実装した制御系の作成を行い、ISASのモーションテーブルを用いたハードウェアシミュレーションの結果を示す。, The instruments and actuators of the attitude controller of small spacecrafts are restricted in weight and space and they should be reduced in weight and size. The rhumb line control strategy is one of the most popular schemes in reorientation of spin stabilized spacecrafts, since it requires only spin sun sensor as well as single axis reaction control system. By combined with the active nutation control, the rhumb line control can reorient the spin axis of the spacecraft to any directions. To verify the control strategy, we manufactured the controller and a demonstration experiment was conducted via motion table in ISAS. This paper reviews the configuration of the controller and the outline of the experiment, and evaluates the control performance., 資料番号: AA0063480031

近年スペースデブリの増加が問題となっており、その対策の1つとしてJAXA総合技術研究本部宇宙先進技術研究グループでは、スペースデブリ除去システムについて研究を行ってきた。軌道移行をするには大きな速度増分が必要であり、従来型の推進系では実現が不可能となってしまうため、地磁気との干渉を利用することによりほとんど燃料を必要としない導電性テザー(ElectroDynamic Tether, EDT)の適用について検討している。本論文では、テザーのダイナミクスや軌道変換能力の評価のための詳細数値シミュレーションについて報告する。テザーは柔軟性や質量を考慮するため多数質点モデルでモデル化し、テザーの温度変化によるテザー長や導電率の変動なども考慮した。プラズマ密度や地磁場などの変動はそれらの環境モデルを用いて考慮した。テザーのパラメータには、試作・試験を行っているベアテザーの値を用いた。, As a countermeasure for suppressing space debris growth, the Institute of Space Technology and Aeronautics, Japan Aerospace Exploration Agency (JAXA), is investigating an active space debris removal system that employs highly-efficient ElectroDynamic Tether (EDT) technology as its orbital transfer system. A small, expendable EDT package is under development that consists of a bare conductive tether and Field Emitter Cathodes (FECs) that utilize carbon nanotubes. In this paper, precise numerical simulations are performed for some aspects of mission analysis, such as available electric currents, orbital changes, tether stability, and deployment dynamics. A tether is modeled as a lumped mass to take into account tether flexibility, and environment models (changes in the plasma density and geomagnetic field, and so on) are also considered. Test manufacture of the tether is conducted, and measured parameters of the manufactured tether are reflected in the numerical simulations., 資料番号: AA0063480041

複数の人工衛星が地球周回軌道の1部を囲む有界領域を航行させるためのニアミス回避・燃費低減・自動制御を満たす軌道誘導則は線形力学であるにもかかわらず未だ構成されていない。導出の指針を得るために、より単純化されたモデルである自由空間の1次元航行をする複数宇宙機において3条件を満たす協調制御を解析した。宇宙機が2機あるいは3機の場合に、2機のニアミスを消費燃料最小の自動制御で回避する誘導則を導いた。しかし、3機によるニアミス回避を低燃費で行なうことが証明されなかったため、大域的な探索をするために区分2次となるペナルティ関数による最適化を試みる指針を与える。, Fuel-minimum optimization of one-dimensional traffic by multiple-spacecraft in the free space is analyzed as a bridge work between the potential-function guidance which enables automatic near-miss avoidance and the penalty-function guidance which performs fuel-minimum near-miss avoidance. In order to preserve the essence of cluster formation around the earth orbit, both proximity-synchronization avoidance during the control duration and the terminal synchronization are imposed on such a simple linear model. The former corresponds to near-miss avoidance and the latter is imitation of synchronized cluster formation. For two-spacecraft traffic, full avoidance with fuel minimization is expressed by the closed form, which means attainment of all the three requirement: near-miss avoidance, fuel minimization, and automatic control. For three-spacecraft traffic, automatic proximity avoidance by two spacecraft is achieved as the same way. Fuel-minimum avoidance of three-spacecraft proximity is, however, still unsolved. Then, simplified penalty-function guidance is formulated by the piecewise quadratic form., 資料番号: AA0063480010

本研究では3体問題における回転座標系において、低推力加速度を用いて任意の点(停留点)で宇宙機を周期的に周回させる事を考える。周期軌道を解析的に求めるために運動方程式を停留点で線形化する。停留点に固有の周回周期に着目し、面内と面外の運動周期が共鳴する周期軌道について考察を行う。, Periodic orbits around non-equilibrium points are generated systematically by utilizing continuous low-thrust propulsion in the restricted three-body problem. Equations of motion are linearized in order to analytically generate periodic orbits with constant acceleration. The mass ratio between two primary bodies is assumed to vary from 0 to 1/2. Periodic orbits around artificial equilibrium points which exist on the line connecting two primaries are investigated. Then, the frequencies of these periodic motions are analyzed. By choosing the frequencies of motions that are small-integer resonant, we have found the existence of points at which in-plane and out-of-plane motions are synchronized., 資料番号: AA0063480002

本研究では、ガタを含む柔軟多体システムのモデルの定式化を行い、超小型衛星に発生する振動を解析した。その結果は、東京大学中須賀研究室および国立天文台が計画している超小型赤外線位置天文観測衛星プロジェクトNano-JASMINE(Japan Astrometry Satellite Mission for Infrared Exploration)における、姿勢安定性の面での実行可能性分析に用いられた。本論文では、先ず、Nano-JASMINEプロジェクトにおける実現可能性分析において、ガタを含む柔軟多体システムのモデルの定式化が必要となった背景を説明する。次いで、定式化の方法を説明し、最後に得られたモデルを用いた振動のシミュレーションの結果を述べる。, The flexible multi-body system model combined with the model of backlash was formulated in this study. Using the model the oscillation on the nano-class satellite was simulated. The result of the simulation was used for the feasibility analysis of the nano-class astrometric satellite project Nano-JASMINE (Japan Astrometry Satellite Mission for Infrared Exploration) in terms of its attitude stability. The first part of this paper explains the necessity of the flexible multi-body system model and the model of backlash for the feasibility analysis of Nano-JASMINE mission. The second part describes the formulation the model. The third part shows the result of the oscillation analysis in Nano-JASMINE., 資料番号: AA0063480066