8 research outputs found
Science and technology requirements to explore caves in our Solar System
Research on planetary caves requires cross-planetary-body investigations spanning multiple disciplines, including geology, climatology, astrobiology, robotics, human exploration and operations. The community determined that a roadmap was needed to establish a common framework for planetary cave research. This white paper is our initial conception
Non-Periodic Gait Planning Based on Salient Region Detection for a Planetary Cave Exploration Robot
A limbed climbing robot can traverse uneven and steep terrain, such as Lunar/Martian caves. Towards the autonomous operation of the robot, we first present a method to detect topographically salient regions in 3D point cloud as the robot ’s graspable targets, and next, we introduce a strategy to plan a non-periodic gait for the robot from the detected discrete graspable options. The proposed gait planner is implemented and validated in our open dynamic climbing robot simulation platform assuming the 3 kg class four-limbed climbing robot testbed moving over steep and uneven Lunar terrain.International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS 2020), October 19-23, 2020, Los Angles, CA, USA(新型コロナ感染拡大に伴い、オンライン開催に変更
Optimization Based Motion Planning for Multi-Limbed Vertical Climbing Robots
Motion planning trajectories for a multi-limbed robot to climb up walls
requires a unique combination of constraints on torque, contact force, and
posture. This paper focuses on motion planning for one particular setup wherein
a six-legged robot braces itself between two vertical walls and climbs
vertically with end effectors that only use friction. Instead of motion
planning with a single nonlinear programming (NLP) solver, we decoupled the
problem into two parts with distinct physical meaning: torso postures and
contact forces. The first part can be formulated as either a mixed-integer
convex programming (MICP) or NLP problem, while the second part is formulated
as a series of standard convex optimization problems. Variants of the two wall
climbing problem e.g., obstacle avoidance, uneven surfaces, and angled walls,
help verify the proposed method in simulation and experimentation.Comment: IROS 2019 Accepte
Mobility Analysis of Hopping and Tumbling Motion in Microgravity
This paper presents the analyses of the tumbling and hopping mobility of a novel moving mechanism on small celestial bodies in microgravity. The robot consists of an inner motor with a flywheel and eight elastic spikes connected to the perimeter of the robot. The tumbling and hopping motion of the robot can be switched by controlling the torque of the motor. Hence, the robot can traverse a large region with high moving accuracy. In this paper, we conduct several numerical simulations to analyze the characteristics of the mobility by assigning various values of elastic and damping coefficient of spikes, and the torque of the motor. The results are useful to construct the feasible motion planning for real missions.International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS 2020), October 19-23, 2021, Los Angles, CA, USA(新型コロナ感染拡大に伴い、オンライン開催に変更
PERISCOPE: PERIapsis Subsurface Cave Optical Explorer
The PERISCOPE study focuses primarily on lunar caves, due to the potential for being imaged in orbital scenarios. In the intervening years, from 2012-2015, scientists developed further rationales and interest in the scientific value of lunar caves. It does not appear that they are likely to be sinks for water-ice due to the relatively warm temperatures(~-20 degrees Celsius) in the caves leading to geologically-rapid migration of unbound water due to sublimation, and inevitable loss through any skylights. However, the skylights themselves reveal apparent complex layering, which may speak to a more complex multi-stage evolution of mare flood basalts than previously considered, and so their examination may provide even more insight into the lunar mare, which in turn provide a primary record of early solar system crustal formal and evolution processes. Further extrapolation of these insights can be found within the exoplanet community of researchers,who find the information useful for calibrating star formation and planetary evolution models. In addition, catalogues of lunar and martian skylights, "caves" or "atypical pit craters" have been developed, with numbers for both bodies now in the low hundreds thanks to additional high resolution surveys and revisiting the existing image databases
Development of microstructures for application on a controllable bioinspired adhesive mechanism for gripping system in pick-n-place task
Dissertação de mestrado integrado em Engenharia MecânicaA natureza oferece uma variedade de ideias para uma adesão transitória e reversível a
diferentes substratos. Até agora, os soft dry adhesives (SDAs) bioinspirados mais estudados
são superfícies com matrizes de micropilares. A inspiração veio de espécies terrestres, como
as osgas, cujas almofadas dos pés são cobertas por intrincadas fibrilhas que permitem uma
forte adesão (que se deve a forças intermoleculares) bem como uma fácil libertação.
Um dos objetivos atuais dos esforços da investigação é transferir a solução da natureza
para estruturas artificiais que possam um dia encontrar aplicações tecnológicas. Este trabalho
visa replicar os comportamentos de agarra e libertação das osgas, utilizando como base as
suas estruturas fibrilares pegajosas. Para este objetivo, serão utilizadas várias técnicas de
fabrico e ensaios experimentais para determinar o melhor protocolo para a criação de
microestruturas. Foram estudados micropilares cilíndricos lisos e micropilares com forma de
cogumelo, tendo sido escolhidos estes últimos dado que aderem melhor aos substratos lisos
em comparação com pilares cilíndricos.
O presente trabalho começou por delinear o estado de arte, no qual se investiga o
desenvolvimento de SDAs bioinspirados e as suas qualidades adesivas. Além disso, também
foram abordados os fundamentos de adesão fibrilar. Prosseguiu-se para o desenvolvimento
de amostras em polidimetilsiloxano (PDMS) com o objetivo de caracterizar este material num
equipamento de ensaio universal (UTM).
Neste trabalho foram examinadas várias técnicas de microfabricação. Tendo em
consideração a dimensão das micropartículas utilizadas, foram produzidas microestruturas
utilizando uma metodologia de baixo custo. Foram utilizados e testados vários tipos de
métodos para fabricar os moldes, ou seja, para produzir pilares cilíndricos lisos foi utilizada
fresagem e para produzir micropilares em forma de cogumelo foi utilizada impressão 3D.
Devido à sua forma, os micropilares em forma de cogumelo requerem uma dupla moldagem,
com um molde intermediário constituído por um material altamente flexível.
Finalmente, com o auxílio do UTM para realizar testes de aderência, foi avaliada a
eficiência das microestruturas.Nature offers a variety of ideas for transient and reversible adhesion to different
substrates. Geckos and insects use hairy structures whose adhesion is due to intermolecular
forces. So far, the most widely studied SDAs are surfaces with arrays of micropillars. The
inspiration came from terrestrial species including lizards and geckos whose toe pads are
covered by intricate fibrils that enable strong attachment as well as easy release.
The current goal of research and development efforts is to transfer nature's solution
into artificial structures that might someday be applied in different technologies. Hence, this
work aims to replicate the grasping and releasing behaviors of geckos using their fibrillar sticky
structures as a basis. In order to achieve this goal, different kinds of designs, fabrications, and
testing will be used to determine the best protocol for creating microstructures. Smooth
cylindrical and mushroom-shaped micropillars were studied. The latter were chosen because
they adhere to smooth substrates better than cylindrical micropillars.
This work began by outlining the state of the art on the development of soft dry
adhesives (SDAs) with natural inspiration and an examination of their dry adhesive properties.
Additionally, the fundamentals of fibrillar adhesion were also covered. The work then
proceeded to the development of polydimethylsiloxane (PDMS) specimens with the goal of
characterizing this material in a universal testing machine (UTM).
A number of microfabrication techniques were examined. Based on the size of the
employed microparticles, microstructures were produced applying a low-cost method.
Different methods were employed depending on the shape of the molds, i. e., to produce
cylindrical flat pillars, it was used a CNC milling machine whereas to produce mushroom
shaped micropillars, it was used 3D printing. Due to their design, the micropillars with the
mushroom shape required double molding with an intermediary mold made of a highly
flexible material.
Finally, using the UTM to perform adhesion tests, the efficiency of the microstructure
was evaluated
Fundamental Science and Engineering Questions in Planetary Cave Exploration
32 páginas.- 3 figuras.- 2 tablas.- 260 referenciasNearly half a century ago, two papers postulated the likelihood of lunar lava tube caves using mathematical models. Today, armed with an array of orbiting and fly-by satellites and survey instrumentation, we have now acquired cave data across our solar system-including the identification of potential cave entrances on the Moon, Mars, and at least nine other planetary bodies. These discoveries gave rise to the study of planetary caves. To help advance this field, we leveraged the expertise of an interdisciplinary group to identify a strategy to explore caves beyond Earth. Focusing primarily on astrobiology, the cave environment, geology, robotics, instrumentation, and human exploration, our goal was to produce a framework to guide this subdiscipline through at least the next decade. To do this, we first assembled a list of 198 science and engineering questions. Then, through a series of social surveys, 114 scientists and engineers winnowed down the list to the top 53 highest priority questions. This exercise resulted in identifying emerging and crucial research areas that require robust development to ultimately support a robotic mission to a planetary cave-principally the Moon and/or Mars. With the necessary financial investment and institutional support, the research and technological development required to achieve these necessary advancements over the next decade are attainable. Subsequently, we will be positioned to robotically examine lunar caves and search for evidence of life within Martian caves; in turn, this will set the stage for human exploration and potential habitation of both the lunar and Martian subsurface.The following funding sources are recognized for supporting several of the contributing authors: Human Frontiers Science Program grant #RGY0066/2018 (for AAB), NASA Innovative Advanced Concepts Grant #80HQTR19C0034 (HJ, UYW, and WLW), and European Research Council, ERC Consolidator Grant #818602 (AGF), the Spanish Ministry of Science and Innovation (project PID2019-108672RJ-I00) and the "Ramon y Cajal" post-doctoral contract (grant #RYC2019-026885-I (AZM)), and Contract #80NM0018D0004 between the Jet Propulsion Laboratory, California Institute of Technology and the National Aeronautics and Space Administration (AA, MJM, KU, and LK).Peer reviewe