Year: 2024
Type: conference-paper
Abstract: In recent space missions, efforts to sustain human presence on the Moon have identified lunar lava tubes as potential shelters for humans and instruments. However, the knowledge about these geological formations in non-terrestrial conditions remains limited. To explore these areas, planetary surveillance missions have traditionally relied on wheeled rovers. Nonetheless, the size of obstacles over which these devices can tackle is limited by the size of their wheels. Alternatively, jumping robots can overcome obstacles using the reaction force from the substrate for propulsion. The best previous example has shown to jump up to 100 times its own size. However, previous research on jumping robots has focused on optimising the jump height or range on an idealised rigid substrate in controlled environments. These approaches are limited in that they often neglect the complexities of granular substrates like lunar regolith. This work presents the design and development of the Hopping And Rolling Explorer for the Moon (HARE), a wheeled jumping robot prototype specifically designed for lunar exploration. It also elucidates the underlying design philosophy to address the influence of lunar regolith on jumping dynamics. The prototype integrates a spring-driven jumping mechanism with wheeled mobility to enable jumping for long-range traversal with the thrust control and the self-righting abilities provided by the wheels. A low-order dynamic model is formulated for sizing such a system and characterising the relationship between jump range and the system mass and gravitational acceleration and how these change with the scales of the components. In the experiments, the prototype achieved a take-off velocity of 2.31 ms-1 on rigid ground under simulated lunar gravity and performed traversal, steering and self-righting manoeuvres on a sandy substrate. However, as anticipated due to limitations in the ground contact interface (‘foot’) design , during jumping tests on loose sand, the spring ground contact failed to interact with the granular substrate effectively. This resulted in inefficient energy transfer and unsuccessful jumps. The finding highlights the critical role of the robot's mechanical interfacewith the substrate, which will be addressed in future design iterations.
Source: IAF Space Exploration Symposium
DOI: 10.52202/078357-0175
Authors: John Lo, Katharine Smith, Ben Parslew, Matthew Roy, Katherine Joy, Hazem Az Eldin
Institution: University of Manchester
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4407017563