Design and soft-landing control of a six-legged mobile repetitive lander for lunar exploration
Ke Yin, Feng Gao, Qiao Sun, Jimu Liu, Tao Xiao, Jianzhong Yang, Shuiqing Jiang, Xianbao Chen
Abstract
The autonomous robots consisting of an immovable lander and a rover are widely deployed to explore extraterrestrial planets. However, these robots have two main limitations: (1) the separate design for lander and rover respectively results in heavy mass and big volume of the whole system, which increases the launching cost sharply; (2) the rover’s detection area has to be restricted to the vicinity of the immovable lander. To overcome these problems, we designed a novel six-legged mobile repetitive lander called "HexaMRL", which integrates the functions of both lander and rover, including folding, deploying, repetitive soft-landing, and walking. A hybrid compliant mechanism taking advantages of both active and passive compliances was adopted on its leg. An integrated drive unit (IDU) was utilized to imitate the dynamics of a spring and a damper to absorb the landing impact energy, while the structure remains intact. Moreover, a control method based on state machine for soft-landing on the Moon was proposed. HexaMRL achieved repetitive soft-landing on a 5-DoF lunar gravity testing platform (5-DoF-LGTP) with a vertical landing velocity of 1.9 m/s and a payload of 140 kg. The drive torque safety margin is improved by 23.4%p based on the hybrid compliant leg comparing with the standalone active compliant leg.
BibTeX
@inproceedings{icra2021_designandsoftlan,
title = {Design and soft-landing control of a six-legged mobile repetitive lander for lunar exploration},
author = {Ke Yin and Feng Gao and Qiao Sun and Jimu Liu and Tao Xiao and Jianzhong Yang and Shuiqing Jiang and Xianbao Chen and Jing Sun and Renqiang Liu and Chenkun Qi},
booktitle = {ICRA 2021},
year = {2021}
}