171 research outputs found
Underwater Vehicles
For the latest twenty to thirty years, a significant number of AUVs has been created for the solving of wide spectrum of scientific and applied tasks of ocean development and research. For the short time period the AUVs have shown the efficiency at performance of complex search and inspection works and opened a number of new important applications. Initially the information about AUVs had mainly review-advertising character but now more attention is paid to practical achievements, problems and systems technologies. AUVs are losing their prototype status and have become a fully operational, reliable and effective tool and modern multi-purpose AUVs represent the new class of underwater robotic objects with inherent tasks and practical applications, particular features of technology, systems structure and functional properties
Review of Computational Fluid Dynamics Analysis in Biomimetic Applications for Underwater Vehicles
Biomimetics, which draws inspiration from nature, has emerged as a key approach in the development of underwater vehicles. The integration of this approach with computational fluid dynamics (CFD) has further propelled research in this field. CFD, as an effective tool for dynamic analysis, contributes significantly to understanding and resolving complex fluid dynamic problems in underwater vehicles. Biomimetics seeks to harness innovative inspiration from the biological world. Through the imitation of the structure, behavior, and functions of organisms, biomimetics enables the creation of efficient and unique designs. These designs are aimed at enhancing the speed, reliability, and maneuverability of underwater vehicles, as well as reducing drag and noise. CFD technology, which is capable of precisely predicting and simulating fluid flow behaviors, plays a crucial role in optimizing the structural design of underwater vehicles, thereby significantly enhancing their hydrodynamic and kinematic performances. Combining biomimetics and CFD technology introduces a novel approach to underwater vehicle design and unveils broad prospects for research in natural science and engineering applications. Consequently, this paper aims to review the application of CFD technology in the biomimicry of underwater vehicles, with a primary focus on biomimetic propulsion, biomimetic drag reduction, and biomimetic noise reduction. Additionally, it explores the challenges faced in this field and anticipates future advancements
Selected Papers from the 2018 IEEE International Workshop on Metrology for the Sea
This Special Issue is devoted to recent developments in instrumentation and measurement techniques applied to the marine field. ¶The sea is the medium that has allowed people to travel from one continent to another using vessels, even today despite the use of aircraft. It has also been acting as a great reservoir and source of food for all living beings. However, for many generations, it served as a landfill for depositing conventional and nuclear wastes, especially in its deep seabeds, and we are assisting in a race to exploit minerals and resources, different from foods, encompassed in it. Its health is a great challenge for the survival of all humanity since it is one of the most important environmental components targeted by global warming. ¶ As everyone may know, measuring is a step that generates substantial knowledge about a phenomenon or an asset, which is the basis for proposing correct solutions and making proper decisions. However, measurements in the sea environment pose unique difficulties and opportunities, which is made clear from the research results presented in this Special Issue
Unmanned Vehicle Systems & Operations on Air, Sea, Land
Unmanned Vehicle Systems & Operations On Air, Sea, Land is our fourth textbook in a series covering the world of Unmanned Aircraft Systems (UAS) and Counter Unmanned Aircraft Systems (CUAS). (Nichols R. K., 2018) (Nichols R. K., et al., 2019) (Nichols R. , et al., 2020)The authors have expanded their purview beyond UAS / CUAS systems. Our title shows our concern for growth and unique cyber security unmanned vehicle technology and operations for unmanned vehicles in all theaters: Air, Sea and Land – especially maritime cybersecurity and China proliferation issues. Topics include: Information Advances, Remote ID, and Extreme Persistence ISR; Unmanned Aerial Vehicles & How They Can Augment Mesonet Weather Tower Data Collection; Tour de Drones for the Discerning Palate; Underwater Autonomous Navigation & other UUV Advances; Autonomous Maritime Asymmetric Systems; UUV Integrated Autonomous Missions & Drone Management; Principles of Naval Architecture Applied to UUV’s; Unmanned Logistics Operating Safely and Efficiently Across Multiple Domains; Chinese Advances in Stealth UAV Penetration Path Planning in Combat Environment; UAS, the Fourth Amendment and Privacy; UV & Disinformation / Misinformation Channels; Chinese UAS Proliferation along New Silk Road Sea / Land Routes; Automaton, AI, Law, Ethics, Crossing the Machine – Human Barrier and Maritime Cybersecurity.Unmanned Vehicle Systems are an integral part of the US national critical infrastructure The authors have endeavored to bring a breadth and quality of information to the reader that is unparalleled in the unclassified sphere. Unmanned Vehicle (UV) Systems & Operations On Air, Sea, Land discusses state-of-the-art technology / issues facing U.S. UV system researchers / designers / manufacturers / testers. We trust our newest look at Unmanned Vehicles in Air, Sea, and Land will enrich our students and readers understanding of the purview of this wonderful technology we call UV.https://newprairiepress.org/ebooks/1035/thumbnail.jp
Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) 2019 Annual Report
Prepared for: Dr. Brian Bingham, CRUSER DirectorThe Naval Postgraduate School (NPS) Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) provides a collaborative environment and community of interest for the advancement of unmanned systems (UxS) education and research endeavors across the Navy (USN), Marine Corps (USMC) and Department of Defense (DoD). CRUSER is a Secretary of the Navy (SECNAV) initiative to build an inclusive community of interest on the application of unmanned systems (UxS) in military and naval operations. This 2019 annual report summarizes CRUSER activities in its eighth year of operations and highlights future plans.Deputy Undersecretary of the Navy PPOIOffice of Naval Research (ONR)Approved for public release; distribution is unlimited
Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) 2019 Annual Report
Prepared for: Dr. Brian Bingham, CRUSER DirectorThe Naval Postgraduate School (NPS) Consortium for Robotics and Unmanned Systems Education and Research (CRUSER) provides a collaborative environment and community of interest for the advancement of unmanned systems (UxS) education and research endeavors across the Navy (USN), Marine Corps (USMC) and Department of Defense (DoD). CRUSER is a Secretary of the Navy (SECNAV) initiative to build an inclusive community of interest on the application of unmanned systems (UxS) in military and naval operations. This 2019 annual report summarizes CRUSER activities in its eighth year of operations and highlights future plans.Deputy Undersecretary of the Navy PPOIOffice of Naval Research (ONR)Approved for public release; distribution is unlimited
Aeronautical engineering: A continuing bibliography with indexes (supplement 212)
This bibliography lists 493 reports, articles and other documents introduced into the NASA scientific and technical information system in March, 1987
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Applications of slow-moving autonomous platforms for passive acoustic monitoring and density estimation of marine mammals
Advances in mobile autonomous vehicles for oceanographic sensing provide new opportunities for passive acoustic monitoring of marine mammals. Acoustically equipped mobile autonomous platforms, including gliders, deep-water profiling floats, and drifting surface buoys can survey for a variety of marine mammal species over intermediate spatiotemporal scales. Additionally, such mobile platforms may provide an effective tool for population density estimation of marine mammals. This dissertation advances our understanding of how gliders, deep-water floats, and surface drifters can be used for passive acoustic monitoring and density estimation of two cetacean species, fin whales (Balaenoptera physalus), and Cuvier’s beaked whales (Ziphius cavirostris).
One glider and two drifting deep-water floats were simultaneously deployed in the vicinity of a deep-water cabled hydrophone array offshore of San Clemente Island, California, USA. The glider was able to follow a pre-defined track while float movement was somewhat unpredictable. Fin whale 20 Hz pulses were recorded by all recorders throughout the two-week deployment and presence at hourly and daily scales were comparable across all recorders. Performance of an automated template detector did not differ by recorder type. However, the glider data contained up to 78% fewer fin whale detections per hour compared to the floats or stationary hydrophones because of increased low-frequency flow noise present during glider descents. Flow noise was related to glider speed through water and dive state. Glider speeds through water of 25 cm/s or less are suggested to minimize flow noise.
The cabled hydrophone array was also used to estimate fin whale localizations and tracks concurrently with the glider survey. These tracks were used in a trial-based approach to estimate a detection function for six-minute snapshots containing fin whale 20 Hz pulses. Detection probability was strongly dependent on 40 Hz noise levels (flow noise) recorded on the glider. At the median noise level of 97 kHz dB re 1 μPa2/Hz, maximum detection range was nearly 40 km and the estimated effective survey was 870 km2. Density of fin whales was estimated as 2.4 whales per 1000 km2 (coefficient of variation, CV 0.55) using a group size estimate from the tracked whales and an externally derived vocal rate from tagged fin whales. The framework presented here could be applied to other baleen whale species to advance the use of autonomous gliders for density estimation of cetacean species.
A second two-week glider and float deployment was conducted concurrently with the deployment of a commonly used deep-water stationary recorder, the High-frequency Acoustic Recording Package (HARP) and an array of drifting near-surface recorders in the Catalina Basin, California, USA. Acoustic recordings were analyzed for the presence of multiple marine mammal species, including beaked whales, delphinids, and minke whales and were compared across the glider, float, and HARPs. Detections of beaked whale echolocation clicks were variable across recorders, likely due to differences in the recording limits of each system, the spatial distribution of the recorders, and the short detection radius of such a high-frequency, directional signal type. Delphinid whistles and clicks were prevalent across all recorders, and at levels that may have masked beaked whale vocalizations. Minke whale (Balaenoptera acutorostrata) boing sounds were detected almost identically across all recorder types, as was expected given the relatively long detection range of the boing call type.
Spatially explicit capture-recapture was used to estimate density of Cuvier’s beaked whales from the near-surface drifting array of acoustic recorders. A snapshot approach was used with presence or absence of echolocation clicks within a 1-minute snapshot acting as the sampling unit. Using external estimates of group size and echolocation probability in a 1-minute snapshot, the density of Cuvier’s beaked whales, from the two best models was estimated at 5.48 animals per 1000 km2 (CV 0.46). This estimate was similar to estimates calculated using trial-based and distance sampling approaches applied to the same data set. Simulation experiments were conducted to investigate potential bias in estimated density caused by the configuration of the drifting array. Bias from the array configuration was found to be negligible, increased array spacing (approximately doubling and tripling between-sensor spacing) decreased bias, and the drifting aspect of the recorders also decreased bias, compared to simulations with stationary sensors.
This work provides evidence that animal presence and absence at broad spatial scales such as hours and days are comparable across gliders, deep-water floats, and stationary recorders. The spatial advantage of mobile instruments is most pronounced for species with short acoustic detection ranges, such as beaked whales. Marine mammal density can be estimated from gliders and mobile drifters using either a trial-based or SECR approach examples presented here provide an exciting advance in marine mammal population monitoring
Underwater & out of sight: towards ubiquity in underwater robotics
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2019.The Earth's oceans holds a wealth of information currently hidden from us. Effective measurement of its properties could provide a better understanding of our changing climate and insights into the creatures that inhabit its waters. Autonomous underwater vehicles (AUVs) hold the promise of penetrating the ocean environment and uncovering its mysteries; and progress in underwater
robotics research over the past three decades has resulted in vehicles that can navigate reliably and operate consistently, providing oceanographers with an additional tool for studying the ocean.
Unfortunately, the high cost of these vehicles has stifled the democratization of this technology. We believe that this is a consequence of two factors. Firstly, reliable navigation on conventional AUVs has been achieved through the use of a sophisticated sensor system, namely the Doppler velocity log (DVL)-aided inertial navigation system (INS), which drives up vehicle cost, power use and size. Secondly, deployment of these vehicles is expensive and unwieldy due to their complexity, size and cost, resulting in the need for specialized personnel for vehicle operation and maintenance.
The recent development of simpler, low-cost, miniature underwater robots provides a solution that mitigates both these factors; however, removing the expensive DVL-aided INS means that they perform poorly in terms of navigation accuracy. We address this by introducing a novel acoustic system that enables AUV self-localization without requiring a DVL-aided INS or on-board active acoustic transmitters. We term this approach Passive Inverted Ultra-Short Baseline (piUSBL) positioning. The system uses a single acoustic beacon and a time-synchronized, vehicle-mounted, passive receiver array to localize the vehicle relative to this beacon. Our approach has two unique advantages: first, a single beacon lowers cost and enables easy deployment;
second, a passive receiver allows the vehicle to be low-power, low-cost and small, and enables multi-vehicle scalability.
Providing this new generation of small and inexpensive vehicles with accurate navigation can potentially lower the cost of entry into underwater robotics research and further its widespread use for ocean science. We hope that these contributions in low-cost underwater navigation will enable the ubiquitous and coordinated use of robots to explore and understand the underwater
domain.This research was funded and supported by a number of sponsors; we gratefully acknowledge
them below.
Defense Advanced Research Projects Agency (DARPA) and SSC Pacific via Applied Physical
Sciences Corp. (APS) under contract number N66001-11-C-4115.
SSC Pacific via Applied Physical Sciences Corp. (APS) under award number
N66001-14-C-4031.
Air Force via Lincoln Laboratory under award number FA8721-05-C-0002.
Office of Naval Research (ONR) via University of California-San Diego under award number
N00014-13-1-0632.
Defense Advanced Research Projects Agency (DARPA) via Applied Physical Sciences
Corp. (APS) under award number HR0011-18-C-0008.
Office of Naval Research (ONR) under award number N00014-17-1-2474
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