Citation: Zhang, Q.; Zhao, C.; Fan, L.;
Zhang, Y. Taikobot: A Full-Size and
Free-Flying Humanoid Robot for
Intravehicular Astronaut Assistance
and Spacecraft Housekeeping.
Machines 2022, 10, 933. https://
doi.org/10.3390/machines10100933
Academic Editors: Shuai Li, Dechao
Chen, Mohammed Aquil Mirza,
Vasilios N. Katsikis, Dunhui Xiao and
Predrag S. Stanimirovic
Received: 12 September 2022
Accepted: 10 October 2022
Published: 13 October 2022
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Article
Taikobot: A Full-Size and Free-Flying Humanoid Robot for
Intravehicular Astronaut Assistance and Spacecraft Housekeeping
Qi Zhang
1,
* , Cheng Zhao
1
, Li Fan
2,3
and Yulin Zhang
2,3
1
College of Aerospace Science and Engineering, National University of Defense Technology,
Changsha 410073, China
2
College of Control Science and Engineering, Zhejiang University, Hangzhou 310000, China
3
Huzhou Institute of Zhejiang University, Huzhou 313000, China
* Correspondence: zhangqi9241@alumni.nudt.edu.cn
Abstract:
This paper proposes a full-size and free-flying humanoid robot named Taikobot that aims
to assist astronauts in a space station and maintain spacecrafts between human visits. Taikobot
adopts a compact and lightweight (
∼
25 kg) design to work in microgravity, which also reduces
launch costs and improves safety during human–robot collaboration. Taikobot’s anthropomorphic
dual arm system and zero-g legs allow it to share a set of intravehicular human–machine interfaces.
Unlike ground-walking robots, Taikobot maneuvers in a novel push–flight–park (PFP) strategy as
an equivalent astronaut in a space station to maximize workspace and flexibility. We propose a
PFP motion planning and control method based on centroidal dynamics and multi-contact model.
Based on the proposed method, we carried out extensive simulations and verified the feasibility
and advantages of the novel locomotion strategy. We also developed a prototype of Taikobot and
carried out several ground experiments on typical scenarios where the robot collaborates with human
astronauts. The experiments show that Taikobot can do some simple and repetitive tasks along with
astronauts and has the potential to help astronauts improve their onboard working efficiency.
Keywords: astronaut assistance; humanoid robot; microgravity; PFP locomotion
1. Introduction
Space habitats such as a low-Earth orbit space station have been providing long-term
platforms for human beings to conduct scientific research. The operation and maintenance
of a space station is a complex task where astronauts have been playing a significant
role. However, due to the launch cost and risk, human resources in space are scarce and
expensive. In the future, astronauts will become increasingly physically and cognitively
challenged as missions become longer and more varied [
1
]. Although many onboard
operations still need to be conducted by astronauts who are skilled at reasoning and
resolving system uncertainties, robots are being used as assistants and even replicants more
and more frequently to reduce the workload of astronauts.
Compared with human astronauts that require a complex array of machinery to live
in space, robotic assistants are capable of working 24/7 and consume only solar energy.
Moreover, future human habitats in deep space such as a space station in lunar orbit [
2
]
may not adapt to the long-term presence of human beings due to the cosmic radiation and
their distance from the Earth [
3
]. Robots can be used as housekeepers of these habitats and
conduct basic operations and maintenance when crew members are absent. Space tourism
is one of the most potential areas for the development of space economy [
4
]. Shortly, robots
could even serve mass space tourists. With the prosperity of manned space activities such
as space tourism and deep space exploration, robots are set to become our partners in space
and extend our strength and ability beyond our Earth cradle.
Up to now, several in-cabin robots of various types and functionalities have been devel-
oped to assist astronauts and improve their onboard working efficiency [
5
–
11
].
Int-Ball [6]
Machines 2022, 10, 933. https://doi.org/10.3390/machines10100933 https://www.mdpi.com/journal/machines
