Underwater diving | EPFL Graph Search

Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep dives. Atmos

"Velella Velella". Une île itinérante pour la musique acoustique

Quentin Nicolas Casimir Andreotti

Depuis les premiers rythmes et mélodies, en passant par la musique de chambre jusqu’à l’électro, la musique dans son ensemble a évolué au fil des siècles en étroite collaboration avec l’architecture et la technique. L’acoustique d’un lieu, ainsi que sa taille et son aspect visuel, impacte autant la qualité d’écoute et les sentiments du public que la composition d’une œuvre musicale. Les salles de concerts sont dès lors des espaces créés spécialement pour offrir une expérience musicale adaptée au type de musique choisi, et ce à l’aide d’une acoustique peaufinée et réfléchie. Afin d’optimiser l’écoute, différentes formes et stratégies acoustiques sont déterminées réglant et organisant les réflexions et la propagation des ondes sonores en fonction de la position des auditeurs. Les scènes en plein air – généralement destinées aux publics nombreux – valorisent leur environnement au détriment de l’acoustique, généralement médiocre, avec comme palliatif une sonorisation excessive. Ce projet propose une alternative pour la musique en plein air: une salle de concert ouverte qui flotte sur lac Léman et peut ainsi se déplacer facilement de ville en ville durant l’été. Ses panneaux acoustiques, entourant la scène et les gradins, distribuent le son sur le public afin de l’envelopper dans une atmosphère musicale unique, dans un cadre idyllique. Cette “île musicale” peut accueillir quelque 300 personnes et les embarquer dans une croisière acoustique immersive et expérimentale.

2018

Biomechanics at the workplace under hypogravity conditions

Tatiana Volkova

The main goal of my research is to establish guidelines for workplace design based on human biomechanics: specifically sitting workplaces and handling areas in 1/6G-1/3G (Moon, Mars) conditions. Such a workplace could be used in long-term space missions in order to maximize worker performance and minimize the risks of musculoskeletal injuries.Research objective is to formalize a baseline workplace design based on best practices limited to the tasks: operating a computer, assembling/maintenance operations.Proposed steps:1) Data collection and methods definitions2) Measurement and simulation of the human fatigue in the variation of sitting postures and handling areas (identification of typical poses, 3D simulation, graph analysis)3) Optimization of the workplace design based on human biomechanics (motion capture, factor analysis, optimization) 4) Simulation of workplace design in different environments (validation methods).Scientific & technological novelty: 1) Measurement of human muscular fatigue as a function of workload in reduced gravity conditions and integration of the results into the design model2) Modeling of the biomechanics of human movements in the workplace in reduced gravity conditions;3) Developing of sitting workplace design in reduced gravity conditions - taking into account human biomechanics.This research addresses problems revealed by workplace design in confined conditions found in Earth or near-Earth facilities in extreme environments including in underwater conditions, remote & non-remote locations and Low Earth Orbit (LEO), habitat simulators. Human-centered design strategies and biomechanics issues for creating an effective workplace design for long-term missions will also be addressed. The recommendations for design, maintenance, and usage of this workplace in different gravity conditions (1G, 1/6G,1/3G) will be provided. The design optimization of such a workplaces design based on human biomechanics will be done with the help of numerical simulations and digital human modeling. Physical experiments will validate these results by means of the suspension system, underwater experiment and possible by parabolic flights. This work may have a significant impact on workplace designs for both Earth and Space projects. Keywords: biomechanics, workplace, posture, extreme environments, human-centered design, Moon/Mars exploration, comfort conditions, task performance, reduced gravity, digital human modeling, motion capture

EPFL2022

Infiltrating the Zebrafish Swarm: Design, Implementation and Experimental Tests of a Miniature Robotic Fish Lure for Fish-Robot Interaction Studies

Frank Bonnet, Yuta Kato, Francesco Mondada

Robotic fish are nowadays developed for various types of research, such as bio-inspired robotics, biomimetics and animal behavior studies. In the context of our research on the social interactions of the zebrafish Danio Rerio, we developed a miniature robotic fish lure for direct underwater interaction with the living fish. This remotely controlled and waterproof device has a total length of 7.5 cm with the same size ratio as zebrafish and is able to beat its tail with different frequencies and amplitudes, while following the group of living animals using a mobile robot moving outside water that is coupled with the robotic lure using magnets. The robotic lure is also equipped with an easily rechargeable battery and can be used autonomously underwater for experiments of up to one hour. We performed experiments with the robot moving inside an aquarium with living fish in order to analyze its impact on the zebrafish behavior. We found that the beating rate of the tail increased the attractiveness of the lure among the zebrafish shoal. We also demonstrated that the lure could influence a collective decision of the zebrafish shoal, the swimming direction, when moving with a constant linear speed inside a circular corridor. This new robotic fish design and the experimental results are promising for the field of fish-robot interaction.

Springer2015

Biomechanics at the workplace under hypogravity conditions

Tatiana Volkova

EPFL2022