1,467 research outputs found

    Subsea approach to work systems development

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    Self-contained undersea working environments with applications to space station EVA environments are discussed. Physiological limitations include decompression, inert gas narcosis, high-pressure nervous system, gas toxicity, and thermal limitations. Work task requirements include drilling support, construction, inspection, and repair. Work systems include hyperbaric diving, atmospheric work systems, tele-operated work systems, and hybrid systems. Each type of work system is outlined in terms of work capabilities, special interface requirements, and limitations. Various operational philosophies are discussed. The evolution of work systems in the subsea industry has been the result of direct operational experience in a competitive market

    Towards automated sample collection and return in extreme underwater environments

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Billings, G., Walter, M., Pizarro, O., Johnson-Roberson, M., & Camilli, R. Towards automated sample collection and return in extreme underwater environments. Journal of Field Robotics, 2(1), (2022): 1351–1385, https://doi.org/10.55417/fr.2022045.In this report, we present the system design, operational strategy, and results of coordinated multivehicle field demonstrations of autonomous marine robotic technologies in search-for-life missions within the Pacific shelf margin of Costa Rica and the Santorini-Kolumbo caldera complex, which serve as analogs to environments that may exist in oceans beyond Earth. This report focuses on the automation of remotely operated vehicle (ROV) manipulator operations for targeted biological sample-collection-and-return from the seafloor. In the context of future extraterrestrial exploration missions to ocean worlds, an ROV is an analog to a planetary lander, which must be capable of high-level autonomy. Our field trials involve two underwater vehicles, the SuBastian ROV and the Nereid Under Ice (NUI) hybrid ROV for mixed initiative (i.e., teleoperated or autonomous) missions, both equipped seven-degrees-of-freedom hydraulic manipulators. We describe an adaptable, hardware-independent computer vision architecture that enables high-level automated manipulation. The vision system provides a three-dimensional understanding of the workspace to inform manipulator motion planning in complex unstructured environments. We demonstrate the effectiveness of the vision system and control framework through field trials in increasingly challenging environments, including the automated collection and return of biological samples from within the active undersea volcano Kolumbo. Based on our experiences in the field, we discuss the performance of our system and identify promising directions for future research.This work was funded under a NASA PSTAR grant, number NNX16AL08G, and by the National Science Foundation under grants IIS-1830660 and IIS-1830500. The authors would like to thank the Costa Rican Ministry of Environment and Energy and National System of Conservation Areas for permitting research operations at the Costa Rican shelf margin, and the Schmidt Ocean Institute (including the captain and crew of the R/V Falkor and ROV SuBastian) for their generous support and making the FK181210 expedition safe and highly successful. Additionally, the authors would like to thank the Greek Ministry of Foreign Affairs for permitting the 2019 Kolumbo Expedition to the Kolumbo and Santorini calderas, as well as Prof. Evi Nomikou and Dr. Aggelos Mallios for their expert guidance and tireless contributions to the expedition

    Space Shuttle Orbiter And Subsystems

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    Considerable progress has been made in designing the Space Shuttle orbiter and defining its subsystems since the development contract was awarded by NASA to Rockwell International in August, 1972. During the past two years, NASA and Rockwell International, Space Division have been engaged in an intensive effort to refine orbiter preliminary design concepts and to translate them into reality. This paper describes the orbiter \u27s configuration and its major subsystems. The general arrangement of the vehicle and its major assemblies are described. Orbiter flight characteristics and mission profiles are summarized. Selected subsystems including structure, thermal protection, propulsion, power, reaction control, orbital maneuvering, environmental control and life support, hydraulics, avionics, and accommodations for crew and payloads are described

    SSGN Conversion to Host ALVIN

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    U.S. Navy, Naval Sea Systems Comman

    Development of actuating organ for electric intervention tool

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    Master's thesis in Offshore technologyThis thesis describes the initial steps towards development of a modularized all-electric toolbox, to use during ROV intervention. Based on a vision of future subsea systems, which will rely on electrification and standardization. Inspired by standardized interfaces and interchangeability in tool kits used on land, the objective has been to research the possibility of implementing such concepts into the offshore industry. The primary objective of this thesis was to create an understanding of ROV systems and their capabilities. The secondary objective of this thesis was to expand our understanding of relevant markets, and the services involved in these. What kind of tools are necessary to complete the given tasks? What characteristics are mandatory of an ROV to operate relevant tools in a safe and efficient manner? These questions determine what market segments are favorable and should be focused on, and thereby which tools are relevant. The third objective was to analyze the chosen tools to determine preferable properties towards electrification and modularization. The fourth objective is to determine what tools are best suited to proceed into concept and design evaluations. The properties of the selected tools are then reviewed, where necessities related to power input and outputs are established. Electric actuator solutions are then analyzed to find viable candidates within the suggested electric motor types. Several motors containing viable qualities where found. The qualities and restrictions that one must comply with during design and operation where adhered to, following these guidelines the best tooling solutions where sought out. These objectives culminate into a goal of making it possible to enter the ROV market with limited experience, by learning the basics of the ROV business and thereby gaining insight into this trade. Based on the knowledge gained in every step of the process, datasheets containing recommended properties for four electric actuators are presented. These are capable of performing the criterions set for tooling actuators. Development processes might now proceed with the suggested candidates as the basis for further research

    Stronger at Depth: Jamming Grippers as Deep Sea Sampling Tools

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    In this work we experimentally demonstrate (a) that the holding strength of universal jamming grippers increases as a function of the jamming pressure to greater than three atmospheres, and (b) that jamming grippers can be used for deep sea grasping tasks in ambient pressures exceeding one hundred atmospheres, where such high jamming pressures can be readily achieved. Laboratory experiments in a pressurized, water filled test cell are used to measure the holding force of a \u27universal\u27 style jamming gripper as a function of the pressure difference between internal membrane pressure and ambient pressure. Experiments at sea are used to demonstrate that jamming grippers can be installed on, and operated from, remotely operated vehicles (ROVs) at depths in excess of 1200m. In both experiments, the jamming gripper consists of a latex balloon filled with a mixture of fresh water and ~200 micron glass beads, which are cheaply available in large quantities as sand blasting media. The use of a liquid, rather than gas, as the fluid media allows operation of the gripper with a closed loop fluid system; jamming pressure is controlled with an electrically driven water hydraulic cylinder in the lab, and with an oil hydraulic driven large-bore water hydraulic cylinder at sea

    An ROV operated undersea hydraulic hose repair coupling

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    A hydraulic hose repair system is presented that was developed for use at the Deepwater Horizon accident site. The system can be deployed with a single ROV with two controllable arms. One arm holds the device and the other arm pushes a severed hose into the device. Hydraulic pressure is applied from the ROV to the device and a hydraulic coupling within the device is crimped into one end of the hose. The second hose end to be spliced to the first is pushed into the other side of the device and the second half of the coupling is crimped onto the second hose end. The device itself is left in place as part of the splice. The design, on-shore testing, and fabrication of multiple devices ready to deploy at the accident site took on the order of a week to complete. They stand ready to be deployed in the case of another deep-water accident. Keywords: Deepwater Horizon; Hydraulic; Hose; Repair; Couplin

    Study of extravehicular protection and operations

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    Extravehicular protection and operation

    Task-space dynamic control of underwater robots

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    This thesis is concerned with the control aspects for underwater tasks performed by marine robots. The mathematical models of an underwater vehicle and an underwater vehicle with an onboard manipulator are discussed together with their associated properties. The task-space regulation problem for an underwater vehicle is addressed where the desired target is commonly specified as a point. A new control technique is proposed where the multiple targets are defined as sub-regions. A fuzzy technique is used to handle these multiple sub-region criteria effectively. Due to the unknown gravitational and buoyancy forces, an adaptive term is adopted in the proposed controller. An extension to a region boundary-based control law is then proposed for an underwater vehicle to illustrate the flexibility of the region reaching concept. In this novel controller, a desired target is defined as a boundary instead of a point or region. For a mapping of the uncertain restoring forces, a least-squares estimation algorithm and the inverse Jacobian matrix are utilised in the adaptive control law. To realise a new tracking control concept for a kinematically redundant robot, subregion tracking control schemes with a sub-tasks objective are developed for a UVMS. In this concept, the desired objective is specified as a moving sub-region instead of a trajectory. In addition, due to the system being kinematically redundant, the controller also enables the use of self-motion of the system to perform sub-tasks (drag minimisation, obstacle avoidance, manipulability and avoidance of mechanical joint limits)

    Discovery of the Depths

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    Throughout history the oceans have directly or indirectly influenced humans. The importance of knowing how to protect this valuable resource and insure it for future generations is vital. Underwater Vehicles are tools essential for this process, and therefore research and development to perfect these devices is needed. However, the main goal of these devices--to transmit images from places where humans cannot go--remains the same, and their importance to future discoveries remains vital. This article discusses the different types of underwater vehicles and describes an activity wherein students will fabricate an underwater remotely operated vehicle
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