a hardware-in-the-loop simulator for deep space touchdown operation training of hayabusa2

Paper number

IAC-17,B6,3,1,x40744

Author

Dr. Yuto Takei, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Mr. Tadateru Takahashi, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Tomohiro Yamaguchi, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Takanao Saiki, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Akira Miura, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Dr. Hiroshi Takeuchi, Japan Aerospace Exploration Agency (JAXA), Japan

Coauthor

Dr. Yuichi Tsuda, Japan Aerospace Exploration Agency (JAXA), Japan

Year

2017

Abstract

An asteroid explorer Hayabusa2 will arrive at the vicinity of C-type asteroid 162173 Ryugu in the Summer 2018 and start its asteroid proximity phase consists of various descent operations including three touchdowns aiming to obtain surface sample of the asteroid. The spacecraft will return back to the Earth in the end of 2020, to separate its re-entry capsule which is being planned to be retrieved in Australia.\vspace{0.2in}

During descent operations, guidance, navigation and control of lateral position of the spacecraft is basically executed by the command from the ground station under round trip time up to 40 minutes. This navigation scheme is called as GCP-NAV (Ground Control Points Navigation). In the process, the horizontal position with respect to the asteroid is estimated by human operator implementing GCP pattern matching between images obtained by the onboard optical navigation camera and GCP database prepared beforehand. The vertical position from the asteroid surface is measured by the LIDAR (Light Detection and Ranging) sensor and is controlled by on-board controller. This navigation scheme is unique since ground operators are integrated inside the closed control loop in spite of the large round-trip communication delay.\vspace{0.2in}

To increase reliability in each of the critical operations adopting above mentioned navigation scheme, Realtime Integrated Operation (RIO) trainings are planned in the end of this year. A Hardware-in-the-Loop (HIL) simulator is implemented to emulate the actual operational environment with the spacecraft behaviour. The HIL simulator is composed of electrically-equivalent components including attitude and orbit control system unit paired with a software-simulated asteroid proximity dynamics environment. Also the simulator is equipped with a real-time rendering capability of realistic asteroid image based on the high-definition shape models to be input toward the onboard optical navigation system, and a round-trip communication delay (max. 40min) of telemetry/command are emulated to realize realistic closed-loop operational environment. \vspace{0.2in}

This paper first presents the system configuration and major functions of the HIL simulator which enables the ground operator to perform closed-loop descending operation training using unique GCP-NAV scheme. Also, preparation of data (e.g. asteroid 3D model, GCP database) is described, which is necessary for the asteroid image rendering function and the manual pattern matching during the GCP-NAV. Then the results of the simulator validation in terms of consistency among spacecraft dynamics, image rendering function, and guidance command from ground operators are reported. Finally, detail schedule of RIO training campaign using the HIL simulator are introduced.

Abstract document

IAC-17,B6,3,1,x40744.brief.pdf

Manuscript document

IAC-17,B6,3,1,x40744.pdf (🔒 authorized access only).

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