Generalization of Uncertainty Models in Stochastic Optimal Control and Its Application to Robust Trajectory Design

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15214
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Ozaki Naoya 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, 特任助教 (90836222)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 軌道力学 / 確率制御 / ロバスト制御 / ミッション設計

Outline of Final Research Achievements

In deep space exploration missions, evaluating the effects of uncertainties and designing trajectories that are robust against uncertainties is one of the most important issues to improve the success rate of space missions. In this study, we established a stochastic trajectory design method for spacecraft trajectory design problems that is robust against uncertainties by using the unscented transform. To further extend the uncertainty model, a robust orbital control method considering general stochastic models such as general gamma distribution is established using planetary orbit injection as an example problem. These robust trajectory design methods were applied to actual missions to be launched by JAXA, such as MMX (Martian Moons eXploration) mission and DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) mission, and their practicality was demonstrated.

Free Research Field

軌道力学

Academic Significance and Societal Importance of the Research Achievements

軌道設計分野の研究において，不確定性が与える影響度を評価する研究は多いが，その不確定性の影響を考慮して軌道設計を行う研究は更に難易度が高く，研究例が少ない．一方，制御分野の研究においては，非線形確率制御問題を解くための手法は研究されているが，それらは制約条件・大規模最適化の観点から軌道設計問題への適用性が乏しい．本研究成果を通して，軌道設計分野において，「確率的軌道設計」という新たな研究分野が拓かれた．また，DESTINY+を始めとして，実ミッションの軌道設計に関しても，不確定性を考慮した軌道設計のニーズが加速している．本研究成果は，これらの実ミッションを実現する上でのキー技術となる．