学会等発表 - 平山　寛

Collision Avoiding Control of Space Debris Removal Satellites with Operational Satellites

Hiroshi Hirayama, Shintaro Tan

第34回宇宙技術および科学の国際シンポジウム  (久留米)  2023年06月  -  2023年06月    日本航空宇宙学会

A calculation method to estimate survivability of net like tether system is explained in this paper. Electro-dynamic tether is a candidate device to decelerate an orbital debris without propellant. Major problem on using a tether in space is its vulnerability against collisions by space debris. Some conceptual designs are proposed to enhance the survivability of tether, such as tape tether, multiline tether or net-type tether. Authors formulated survivability of multi-segmented double-line tether in preceding study. In this study, the calculation method is extended to treat a net type triple tether which has been developed for the EDT by JAXA. Procedure of the calculation is as follows. First, fatality rates of each element in net type tether are calculated by integrating differential flux multiplied by cross-sectional area, then survivabilities of each tether element are obtained as a function of time. Next, considering topology of net, probabilities along possible severing paths are summed up, and survivability of whole tether is obtained. At last, a simplified method with desirable precision and faster computation time is introduced. Numerical example shows that the net tether has much higher survivability than that of the double tether.

航空機電動化における冗長アクチュエータモデルを用いた故障時応答解析

鈴木稜典, 沢田理帆, 平山寛

日本航空宇宙学会北部支部2023年講演会ならびに第4回再使用型宇宙輸送系シンポジウム  (宮城県角田市)  2023年03月  -  2023年03月    日本航空宇宙学会北部支部

In recent years, the global warming problem, rising fuel prices, and increasing demand for air transportation have created a demand for aircraft electrification. The electrification of equipment that requires high reliability and safety, such as engine auxiliaries and flight control actuators, has not yet been realized. In this study, we developed a model in MATLAB/Simulink that can simulate failures in redundancy design, which is an issue when using an electric actuator instead of a hydraulic actuator for the rudder surface. The performance of the assumed system was then verified by simulating possible failures in the model.

航空機電動化における冗長アクチュエータ試験機の制御モデルの評価

沢田理帆, 渡部恵, 平山寛

日本航空宇宙学会北部支部2023年講演会ならびに第4回再使用型宇宙輸送系シンポジウム  (宮城県角田市)  2023年03月  -  2023年03月    日本航空宇宙学会北部支部

In recent years, research on aircraft electrification has led to the use of starter generators and electrohydraulic actuators in Boeing 787 and other aircraft to optimize energy use. However, electromechanical actuators and engine auxiliaries, which require high reliability and safety, have not yet been electrified. In this study, for the purpose of changing the rudder surface from a hydraulic actuator to an electric actuator, a test machine simulating a redundant actuator was built, and the control logic was constructed and verified for evaluation using MATLAB/Simulink and dSPACE. The experimental results confirmed that the control was able to follow the command values. Future work will include modeling the test machine to simulate regenerative braking.

静止軌道上のスペースデブリの恒久的除去軌道の検討

小松健人, 平山寛

日本航空宇宙学会北部支部2023年講演会ならびに第4回再使用型宇宙輸送系シンポジウム  (宮城県角田市)  2023年03月  -  2023年03月    日本航空宇宙学会北部支部

Currently, satellites that have completed operations in geostationary orbit are injected into graveyard orbit, 200 to 300 km higher in altitude. Although injection into a graveyard orbit requires only a small ∆V, it is only a provisional processing, and the graveyard orbit becomes congested and there is a risk of debris collision. In this study, we propose an orbit with a relatively small ∆V necessary to permanently treat debris in a geostationary orbit, rather than temporarily.

小惑星土壌コアサンプラーの貫入および層序保持に関する研究

吉元翔, 秋山禄斗, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

Asteroid soil samples provide significant information about the processes of the solar system and the origin of life. However, there is concern that the surface of the asteroid may be degraded by solar winds, so there is a need to collect samples with higher information from the interior. Therefore, we are developing a tubular sampler that can collect soil samples from deeper than 50 mm without disturbing the stratigraphy of the asteroid. In this study, we are evaluating the penetration and stratigraphic retention performance of the tubular sampler through experiments and 3D simulations. We conducted two new experiments and found that the piston structure proposed in 2021 does not have the penetration performance advantage of a smaller sampling diameter as seen in the tubular sampler. Although the penetration performance improved with decreasing the thickness of the sampler, it was found that a certain amount of penetration could be obtained by selecting a soil with low density as the sampling point even when the plate was thick.

自己位置推定と自律制御を用いた軌道上微小デブリ衝突痕観測ロボットの開発

八木宗一郎, 中山元晴, 平山寛

第10回スペースデブリワークショップ  (調布)  2022年11月  -  2022年11月    宇宙航空研究開発機構 研究開発部門

軌道上における微小デブリの存在密度情報にはデータギャップが存在する。回収した宇宙機による解析や観測が比較的困難であるSSOや静止軌道において特に顕著である。我々はこれらの軌道上にある宇宙機の観測機器の１つとして、デブリ衝突痕観測システムODIMを開発している。ODIMは搭載した宇宙機の外観のデブリ衝突痕を自律的に観測することが可能であり、その情報を集約することで微小デブリの存在密度情報の取得を目的としたシステムである。ODIMの観測部は深度カメラと外力を加えても形状維持が可能な構造材料Morphable Beam(MB)にて構成されている。課題点として、MB制御はアップリンクによる手動の操作に依存している点が挙げられる。これはMBの柔軟性によって曲げの精度が十分ではないこと、非ホロノミック系であることにより先端位置制御が容易ではことに起因している。本研究ではこれを解決するため、新たなMBを搭載した統合システムMBD-4とMBの自律制御システムの開発と評価を行った。宇宙機全体の形状データをもとに３次元的に地図情報を作成し、深層学習によって画像処理と自己位置推定技術により，MB先端位置を割り出すというものである。これにより、ODIM単体でデブリ衝突痕観測の完全な自動化が見込める。

微小デブリ衝突痕の軌道上観測装置の開発および深層学習と自律制御の適用

八木宗一郎, 中山元晴, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

This study proposes a new in-situ observation system for micro space debris impact marks, ODIM, and describes a new coordinate estimation system for creating a debris impact marks database. The newly developed debris impact scar database system combines ArUco markers and SCAN, which can detect debris impact traces in real time, and is capable of estimating coordinates with an accuracy of a few percent relative error at any imaging angle.

火星極冠での走行を想定した車輪評価と考察

石塚誠人, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

The polar caps on Mars are covered with ice made of carbon dioxide and water. There have been many explorations of Mars for the past 60 years, but there has never been any exploration of the Martian polar caps. In this study, a wheel with less slippage and more driving force was investigated for running on ice. The wheel shape was evaluated by first measuring the static friction coefficient from the static load and friction force, and then measuring the traction force during rotation.

テザー式小惑星土壌サンプラー回収時の探査機の運動制御

小出凌平, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

A soil core sampler has been proposed as a sampler mechanism for asteroid spacecraft to collect soil cores while maintaining stratification. The sampler is connected to the spacecraft by a tether, and there is a risk of collision due to inertial forces during recovery. In this study, a safe recovery method that avoids collision between the sampler and the spacecraft was investigated. An attitude control model combining attitude control by reaction wheels and translation control by thrusters was calculated, feedback control was proposed, and evaluated by simulation.

月の縦孔降下探査機における力学的分析とシステム構成に関する研究

新沢隆, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

Lunar vertical holes are considered to be candidates for future lunar activity sites because of their thermal safety and low risk of cosmic radiation and falling meteorite. In this study, we analyzed the mechanics of the spacecraft during descent by installing multiple anchors at the upper rim of the borehole and suspending the spacecraft by a tether at a certain height to indicate the area where the spacecraft can move. The shape of the anchor is also evaluated. In addition, the configuration of the system such as the attitude control of the spacecraft was discussed.

網状テザーにおける同時切断のリスク評価

丹慎太朗, 平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

Net-type tethers have the advantages of excellent debris removal performance, as well as redundancy and high cut resistance. However, it is difficult to evaluate the risk of severing due to the complexity of the structure compared to conventional ones. In this study, we conducted a risk assessment of multiple simultaneous severing of tethers in Net-type tethers. As a result, we will examine whether the current structural design can ignore the simultaneous cutting, and if not, we will derive a guideline for what geometrical parameters should be set to ignore the simultaneous cutting.

受動的デブリ除去衛星と稼働中衛星の衝突リスク抑制のための姿勢制御

平山寛

第66回宇宙科学技術連合講演会  (熊本)  2022年11月  -  2022年11月    日本航空宇宙学会

This paper describes analysis of a passive debris removal based on the conceptual designs, cylinder type and panel type. Expected removal numbers of small debris are calculated using the debris environment models, MASTER and ORDEM. Some ideas are introduced to shrink temporarily the cross-sectional area, in order to reduce risk of unexpected collision with operating satellites or large orbiting objects. The result of calculation shows effectiveness of the shrinking.

航空機電動化におけるフライホイールバッテリーモデルの開発と評価

渡部恵, 平山寛

第60回飛行機シンポジウム  (新潟)  2022年10月  -  2022年10月    日本航空宇宙学会

In recent years, increasing awareness of environmental issues and rising fuel prices have promoted the use of electric power in aircraft. However, the use of electro-mechanical actuators, which had been expected in the past, has not been realized. A flywheel battery (FWB) system has been proposed to achieve this. The purpose of this study is to create and validate a FWB model for model-based development of FWB.

Electromagnetic Design of Dual Winding Permanent Magnet Synchronous Motor for Electromechanical Actuators of Flight Control Systems

Yutaka Terao, Hiroshi Hirayama, Hirotaka Sugawara, Hitoshi Oyori

International Power Electronics Conference  (姫路市)  2022年05月  -  2022年05月   

This paper deals with PM motors using multipole anisotropic ring magnet for electro mechanic actuators (EMAs) of future aircraft flight control systems. The electromagnetic design via FEM software and evaluations of motor torque, losses in healthy and failure state are carried out. The results showed that even if one-phase open circuit of an inverter occurred or one-side of the 3-phase current supply system failed, the PM motor could operate at 100% of the average torque of 5.5 Nm or over 14.6 Nm, which is over 97 % of the maximum torque of 15.0 Nm.

DOI

航空機電動化におけるフライホイールバッテリーのモデルの研究と開発

猪狩匡平, 井野翔, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

In aircraft electrification, electric actuators have a problem that a sudden voltage rise occurs due to current backflow during operation. A system using flywheel battery (FWB) is being considered to cope with the problem, but it requires fail safe and system redundancy. In this study, we develop a flywheel battery model that simulates and introduces a detailed failure model using MATLAB/Simulink to realize a power bus system using a flywheel battery, and investigate redundancy to realize a power bus system using a flywheel battery. As a result, we were able to confirm the effectiveness of duplexing.

航空機電動化における冗長アクチュエータのモデルの研究と開発

井野翔, 猪狩匡平, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

Aircraft electrification has been attracting attention in recent years. One of the problems in using electric actuators for control surfaces is their fault tolerance. In this study, we developed a model of a system that is more resistant to failures on MATLAB/Simulink, and investigated its effectiveness and countermeasures by simulating its behavior in case of failure. As a result of the failure simulation using a model with a double-winding motor, it was confirmed that good operation could be continued even after a failure, and the effectiveness of the system was demonstrated.

航空機電動化における冗長アクチュエータ試験機の開発と評価

沢田理帆, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

In recent years, research on aircraft electrification has led to the use of starter generators and electrohydraulic actuators in Boeing 787 and other aircraft to optimize energy use. However, electromechanical actuators and engine auxiliaries, which require high reliability and safety, have not yet been electrified. In this study, a test machine simulating a redundant actuator was fabricated, and its controllability and performance were verified for the purpose of using an electric actuator instead of a hydraulic actuator for the rudder surface. As a result of the experiments, the redundant actuator test machine produced in this study was found to be highly accurate and easy to operate. In future research, we will use the control model to achieve more advanced control.

航空機電動化におけるフライホイールバッテリー試験機の開発と評価

渡部恵, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

In recent years, increasing awareness of environmental issues and rising fuel prices have promoted the use of electric power in aircraft. However, the use of electro-mechanical actuators, which had been expected in the past, has not been realized. A flywheel battery (FWB) system has been proposed to achieve this. The purpose of this study is to create and validate a FWB model for model-based development of FWB.

火星極冠での走行を想定した車輪形状の提案と評価

石塚誠人, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

The polar caps on Mars are covered with ice made of carbon dioxide and water. There have been many explorations of Mars for the past 60 years, but there has never been any exploration of the Martian polar caps. In this study, a wheel with less slippage and more driving force was investigated for running on ice. The wheel shape was evaluated by first measuring the static friction coefficient from the static load and friction force, and then measuring the traction force during rotation.

小惑星土壌コアサンプラー搭載探査機の姿勢制御に関する研究

小出凌平, 平山寛

日本航空宇宙学会北部支部2022年講演会ならびに第3回再使用型宇宙輸送系シンポジウム  (オンライン)  2022年03月  -  2022年03月    日本航空宇宙学会

A soil core sampler has been proposed as a sampler mechanism for asteroid probes to collect soil samples while maintaining the stratigraphy. The sampler is designed to be retrieved by a tether, but without tension, the tether cannot be controlled and there is a risk of collision with the spacecraft. In this study, we investigated a safe recovery method that avoids collision between the sampler and the spacecraft. We evaluated the safety of a tethered sampler and a spacecraft by applying tension to the tether so that the two samplers tumbled each other to maintain a certain distance, and by using a thruster to control the angular velocity increased by the recovery.