Lightly tethered unmanned underwater vehicle for under-ice exploration

Bowen, A.; German, Christopher; Jakuba, Michael V.; Kinsey, James C.; Mayer, Larry A.; Yoerger, D.; Whitcomb, Louis L.

doi:10.1109/aero.2012.6187038

Cited by 7 publications

(3 citation statements)

References 29 publications

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“…Moreover, such remote exploration is not limited to littoral waters but may soon include a wide variety of under ice exploration such as exploration of Saturn's moon Europa, 4 which are becoming more approachable with new technologies. These underwater missions require vehicles with the ability to perform tight radius turns, burst-driven docking maneuvers, and low-speed course corrections.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Micro UUVs, or vehicles measuring between half a meter and a few centimeters in length, are advantageous for a variety of applications including characterization of 3D flow dynamics, remote oceanic environmental monitoring, and ocean floor surveying and reconnaissance; all of which shed new light on our understanding of marine life. Moreover, such remote exploration is not limited to littoral waters but may soon include a wide variety of under ice exploration such as exploration of Saturn’s moon Europa, which are becoming more approachable with new technologies. These underwater missions require vehicles with the ability to perform tight radius turns, burst-driven docking maneuvers, and low-speed course corrections .…”

Section: Introductionmentioning

confidence: 99%

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Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Chen

Garland

Geder

et al. 2016

ACS Appl. Mater. Interfaces

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Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP–SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP–SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2. The concomitance of facile fabrication, economic and scalable processing, and high performanceincluding a reduction in H2O2 decomposition activation energy of 40–50% over conventional material catalystspaves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems.

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Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Chen

Garland

Geder

et al. 2016

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…However, there can be multiple advantages for using a tether other than prolonged mission time with no need for on-board power supply. Not only the tether could be used as an anchor for navigating a steep and otherwise inaccessible terrain [18], but it could also serve as a high-speed lowlatency data connection to the robot in an environment where wireless communication would be problematic, like underground mines or deep underwater [4]. The main problem created by a tether, especially in environments with a large number of obstacles, is avoiding the tangling of the tether around the obstacles.…”

Section: Literature Reviewmentioning

confidence: 99%

Exploration of Unknown Environments Using a Tethered Mobile Robot

Шаповалов¹

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Exploration of Unknown Environments Using a Tethered Mobile RobotDanylo Shapovalov Exploration with mobile robots is a well known field of research, but current solutions cannot be directly applied for tethered robots. In some applications, tethers may be very important to provide power or allow communication with the robot. This thesis presents an exploration algorithm that guarantees complete exploration of arbitrary environments within the length constraint of the tether, while keeping the tether tangle-free at all times. While a generalized algorithm that can be used with several exploration strategies is also proposed, the presented implementation uses a modified frontier-based exploration approach, where the robot chooses its next goal in the frontier between explored and unexplored regions of the environment. The main modification from standard frontier-based method is the use of a cost function to sort multiple goals in one iteration and pick the cheapest one to go to, minimizing global path length in the process. The cost is calculated in terms of path length with tether constraints accounted for. The basic idea of the algorithm is to keep an estimate of the tether configuration, including length and homotopy, and decide the next robot path based on the length difference between the current tether length and the shortest tether length at the next goal position. The length difference is then used to determine whether it is safe for the robot to take the shortest path to the goal, or whether the robot has to take a different path to the goal in the way that would put the tether back into the most optimal configuration. The maximum length difference that would still guarantee global tangle-free paths has been shown to be the circumference of the smallest expected obstacle in the environment. The presented algorithm is provable correct and was tested and evaluated using both simulations and real-world experiments. Navigation of a planar robot is done with the aid of a Simultaneous Localization and Mapping (SLAM) system, with the data being provided by the on-board LiDAR scanner. The results from conducted experiments have demonstrated that the proposed algorithm results in the total path length increase of anywhere from 30% up to to 80% compared to untethered frontier-based approach, with the exact percentage increase dependent on the complexity of the environment. It is also approximately 6 times shorter than the total path length in a conservative approach of backtracking to the base to avoid tangling.

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Influence of ice thickness and surface properties on light transmission through Arctic sea ice

et al. 2015

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The observed changes in physical properties of sea ice such as decreased thickness and increased melt pond cover severely impact the energy budget of Arctic sea ice. Increased light transmission leads to increased deposition of solar energy in the upper ocean and thus plays a crucial role for amount and timing of sea‐ice‐melt and under‐ice primary production. Recent developments in underwater technology provide new opportunities to study light transmission below the largely inaccessible underside of sea ice. We measured spectral under‐ice radiance and irradiance using the new Nereid Under‐Ice (NUI) underwater robotic vehicle, during a cruise of the R/V Polarstern to 83°N 6°W in the Arctic Ocean in July 2014. NUI is a next generation hybrid remotely operated vehicle (H‐ROV) designed for both remotely piloted and autonomous surveys underneath land‐fast and moving sea ice. Here we present results from one of the first comprehensive scientific dives of NUI employing its interdisciplinary sensor suite. We combine under‐ice optical measurements with three dimensional under‐ice topography (multibeam sonar) and aerial images of the surface conditions. We investigate the influence of spatially varying ice‐thickness and surface properties on the spatial variability of light transmittance during summer. Our results show that surface properties such as melt ponds dominate the spatial distribution of the under‐ice light field on small scales (<1000 m 2 ), while sea ice‐thickness is the most important predictor for light transmission on larger scales. In addition, we propose the use of an algorithm to obtain histograms of light transmission from distributions of sea ice thickness and surface albedo.

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Lightly tethered unmanned underwater vehicle for under-ice exploration

Cited by 7 publications

References 29 publications

Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Exploration of Unknown Environments Using a Tethered Mobile Robot

Influence of ice thickness and surface properties on light transmission through Arctic sea ice

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Lightly tethered unmanned underwater vehicle for under-ice exploration

Cited by 7 publications

References 29 publications

Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Exploration of Unknown Environments Using a Tethered Mobile Robot

Influence of ice thickness and surface properties on light transmission through Arctic sea ice

Contact Info

Product

Resources

About

Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion