arXiv subjects

Begona Arrue

Publications and source records attributed to Begona Arrue.

3 recordsLinked to original sources

arXiv2024

Thermally-Resilient Soft Gripper for On-Orbit Operations

Research in soft manipulators has significantly enhanced object grasping capabilities, thanks to their adaptability to various shapes and sizes. Applying this technology to on-orbit servicing, especially during the capture and containment stages of active space debris removal missions, might offer a secure, adaptable, and cost-effective solution compared to the trend of increasing the degrees of freedom and complexity of the manipulator (e.g. ClearSpace, Astroscale). This work aims to conduct an experimental proof of concept, for which challenges such as radiation, vacuum, and microgravity are significant, but the predominant issue is ensuring effective operation in the extreme temperature swings, where flexible materials may exhibit cryogenic crystallization or drastic shifts in their elasticity. This work addresses this challenge through an initial stage of analytical modeling of the thermal dynamics inside the manipulator in orbit; which is then used for the development of a first experimental prototype tested with liquid nitrogen and heat guns. The multi-layered design for Low Earth Orbit (LEO) leverages the properties of TPU at low infill rates for lightweight inherent flexibility, silicone rubber ensuring structural integrity, PTFE (Teflon) for unparalleled thermal stability, and aerogel for insulation. The tendon-actuated servo-driven gripper is tested in the laboratory by varying the shape and size of objects during the grasping. The results, based on servomotor force metrics to assess the flexible manipulator's adaptability and object capture efficiency across temperature changes, affirm the concept's viability. Forces increase up to 220$\%$ in cryogenic conditions and decrease by no more than 50$\%$ at high temperatures.

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arXiv2023

A novel concept for Titan robotic exploration based on soft morphing aerial robots

This work introduces a novel approach for Titan exploration based on soft morphing aerial robots leveraging the use of flexible adaptive materials. The controlled deformation of the multirotor arms, actuated by a combination of a pneumatic system and a tendon mechanism, provides the explorer robot with the ability to perform full-body perching and land on rocky, irregular, or uneven terrains, thus unlocking new exploration horizons. In addition, after landing, they can be used for efficient sampling as tendon-driven continuum manipulators, with the pneumatic system drawing in the samples. The proposed arms enable the drone to cover long distances in Titan's atmosphere efficiently, by directing rotor thrust without rotating the body, reducing the aerodynamic drag. Given that the exploration concept is envisioned as a rotorcraft planetary lander, the robot's folding features enable over a 30$\%$ reduction in the hypersonic aeroshell's diameter. Building on this folding capability, the arms can morph partially in flight to navigate tight spaces. As for propulsion, the rotor design, justified through CFD simulations, utilizes a ducted fan configuration tailored for Titan's high Reynolds numbers. The rotors are integrated within the robot's deformable materials, facilitating smooth interactions with the environment. The research spotlights exploration simulations in the Gazebo environment, focusing on the Sotra-Patera cryovolcano region, a location with potential to clarify Titan's unique methane cycle and its Earth-like features. This work addresses one of the primary challenges of the concept by testing the behavior of small-scale deformable arms under conditions mimicking those of Titan. Groundbreaking experiments with liquid nitrogen at cryogenic temperatures were conducted on various materials, with Teflon (PTFE) at low infill rates (15-30%) emerging as a promising option.

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arXiv2022

SOPHIE: SOft and flexible aerial vehicle for PHysical Interaction with the Environment

This paper presents the first design of a soft, 3D-printed in flexible filament, lightweight UAV, capable of performing full-body perching using soft tendons, specifically landing and stabilizing on pipelines and irregular surfaces without the need for an auxiliary system. The flexibility of the UAV can be controlled during the additive manufacturing process by adjusting the infill rate distribution. However, the increase in flexibility implies difficulties in controlling the UAV, as well as structural, aerodynamic, and aeroelastic effects. This article provides insight into the dynamics of the system and validates the flyability of the vehicle for densities as low as 6%. Within this range, quasi-static arm deformations can be considered, thus the autopilot is fed back through a static arm deflection model. At lower densities, strong non-linear elastic dynamics appear, which translates to complex modeling, and it is suggested to switch to data-based approaches.

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