52 research outputs found

    Locomotion and Obstacle Avoidance of a Worm-like Soft Robot

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    This paper presents a soft earthworm robot that is capable of both efficient locomotion and obstacle avoidance. The robot is designed to replicate the unique locomotion mechanisms of earthworms, which enable them to move through narrow and complex environments with ease. The robot consists of multiple segments, each with its own set of actuators, that are connected through rigid plastic joints, allowing for increased adaptability and flexibility in navigating different environments. The robot utilizes proprioceptive sensing and control algorithms to detect and avoid obstacles in real-time while maintaining efficient locomotion. The robot uses a pneumatic actuation system to mimic the circumnutation behavior exhibited by plant roots in order to navigate through complex environments. The results demonstrate the capabilities of the robot for navigating through cluttered environments, making this development significant for various fields of robotics, including search and rescue, environmental monitoring, and medical procedures

    Machine Learning-Driven Burrowing with a Snake-Like Robot

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    Subterranean burrowing is inherently difficult for robots because of the high forces experienced as well as the high amount of uncertainty in this domain. Because of the difficulty in modeling forces in granular media, we propose the use of a novel machine-learning control strategy to obtain optimal techniques for vertical self-burrowing. In this paper, we realize a snake-like bio-inspired robot that is equipped with an IMU and two triple-axis magnetometers. Utilizing magnetic field strength as an analog for depth, a novel deep learning architecture was proposed based on sinusoidal and random data in order to obtain a more efficient strategy for vertical self-burrowing. This strategy was able to outperform many other standard burrowing techniques and was able to automatically reach targeted burrowing depths. We hope these results will serve as a proof of concept for how optimization can be used to unlock the secrets of navigating in the subterranean world more efficiently

    Stable Real-Time Feedback Control of a Pneumatic Soft Robot

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    Soft actuators offer compliant and safe interaction with an unstructured environment compared to their rigid counterparts. However, control of these systems is often challenging because they are inherently under-actuated, have infinite degrees of freedom (DoF), and their mechanical properties can change by unknown external loads. Existing works mainly relied on discretization and reduction, suffering from either low accuracy or high computational cost for real-time control purposes. Recently, we presented an infinite-dimensional feedback controller for soft manipulators modeled by partial differential equations (PDEs) based on the Cosserat rod theory. In this study, we examine how to implement this controller in real-time using only a limited number of actuators. To do so, we formulate a convex quadratic programming problem that tunes the feedback gains of the controller in real time such that it becomes realizable by the actuators. We evaluated the controller's performance through experiments on a physical soft robot capable of planar motions and show that the actual controller implemented by the finite-dimensional actuators still preserves the stabilizing property of the desired infinite-dimensional controller. This research fills the gap between the infinite-dimensional control design and finite-dimensional actuation in practice and suggests a promising direction for exploring PDE-based control design for soft robots

    Vocal Accuracy and Neural Plasticity Following Micromelody-Discrimination Training

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    Recent behavioral studies report correlational evidence to suggest that non-musicians with good pitch discrimination sing more accurately than those with poorer auditory skills. However, other studies have reported a dissociation between perceptual and vocal production skills. In order to elucidate the relationship between auditory discrimination skills and vocal accuracy, we administered an auditory-discrimination training paradigm to a group of non-musicians to determine whether training-enhanced auditory discrimination would specifically result in improved vocal accuracy.We utilized micromelodies (i.e., melodies with seven different interval scales, each smaller than a semitone) as the main stimuli for auditory discrimination training and testing, and we used single-note and melodic singing tasks to assess vocal accuracy in two groups of non-musicians (experimental and control). To determine if any training-induced improvements in vocal accuracy would be accompanied by related modulations in cortical activity during singing, the experimental group of non-musicians also performed the singing tasks while undergoing functional magnetic resonance imaging (fMRI). Following training, the experimental group exhibited significant enhancements in micromelody discrimination compared to controls. However, we did not observe a correlated improvement in vocal accuracy during single-note or melodic singing, nor did we detect any training-induced changes in activity within brain regions associated with singing.Given the observations from our auditory training regimen, we therefore conclude that perceptual discrimination training alone is not sufficient to improve vocal accuracy in non-musicians, supporting the suggested dissociation between auditory perception and vocal production

    Altimetry for the future: Building on 25 years of progress

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    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Altimetry for the future: building on 25 years of progress

    Get PDF
    In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

    Bosetningsspor fra bronsealder, jernalder og tidlig mellomalder, en rÞys og flere trolige flatmarksgraver fra fÞrkristen tid, og veifar fra vikingtid og mellomalder : Id 141995, 141996, 141998 og 216998, pÄ Nordre Sunde gnr. 41, Stavanger kommune, Rogaland

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    Oppdragsgiver: Nore Sunde Utviklingsselskap AS, Statens vegvesen Region VestAm, UiS gjennomfĂžrte arkeologiske undersĂžkelser av lokalitetene id 141995, 141996, 141998 og 216998 i lĂžpet av feltsesongen 2015. Lokalitetene lĂ„ i tilknytning til Nore Sunde, gnr 41, i Stavanger kommune, Rogaland. UndersĂžkelsene pĂ„viste spor etter fĂžrreformatorisk bosetning innen alle de tre flateavdekkede lokalitetene (id 141995, 141996, 141998), og spor etter fĂžrreformatorisk veifar under dagens veilĂžp tilhĂžrende Sundeveien (id 216998, jf. ogsĂ„ 222522). De klart daterte bosetningssporene stammet fra henholdsvis eldre bronsealder (til stede pĂ„ id 141995, 141996, 141998), fĂžrromersk tid (til stede pĂ„ id 141996), romertid – folkevandringstid (til stede pĂ„ id 141996, 141998), og yngre jernalder – tidlig middelalder (til stede pĂ„ id 141996). Utviklingen var slik at mens alle de tre flateavdekkede lokalitetene inneholdt bygningsrester etter gĂ„rdsdrift i eldre bronsealder, sĂ„ fikk man etter hvert en situasjon i romertid – folkevandringstid med gĂ„rdsanlegg bĂ„de pĂ„ id 141996 og 141998, men ingen bosetning pĂ„ id 141995. Og mens gĂ„rdsanlegget pĂ„ id 141998 ble fraflyttet og nedlagt ved overgangen til yngre jernalder, sĂ„ fortsatte driften av gĂ„rden pĂ„ id 141996 helt frem til tidlig middelalder. Trolig ble da gĂ„rdstunet pĂ„ id 141996 flyttet til dagens tunomrĂ„det, det historisk kjente «gamletunet». Id 141996 inneholdt flere mulige gravminner, i form av potensielle flatmarksgraver og en rĂžys. Ved undersĂžkelsene av disse ble det ikke pĂ„vist klare, diagnostiske funn av menneskerester eller gravfunn, sĂ„ tolkningen av dem som gravanlegg er ikke sikker

    The Modular Oceanic Autonomous Underwater Vehicle for Novel Actuation

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    A low-drag, high endurance, and high efficiency Long Range Autonomous Underwater Vehicle is a desired asset to Santa Clara University to aid future underwater vehicle development efforts. Such an vehicle will demonstrate novel actuation methods and provide the on-campus Robotics Systems Laboratory with a modular prototype to aid research and academic efforts. In this paper, we document the construction of a low cost, modular, demonstration vehicle that satisfies the requirements for high-efficiency operation and modular interfaces. The completed vehicle features standard actuation abilities utilizing low-drag methods that qualify it for shallow water operation. Furthermore, the vehicle demonstrates the feasibility of distributed command and control, featuring a linear bus to communicate between subsystems that can facilitate the easy implementation of additional subsystems. Overall, the vehicle satisfies the majority of it\u27s original requirements, and provides the university with a functional prototype that will support future research and academic efforts. Future work for the program involves honing in control methods, including pitch and depth control. These functions will bring the vehicle to it\u27s full operational capabilities, and further support research activities

    A weak cipher that generates the symmetric group

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