OCEANS 2019 MTS/IEEE SEATTLE最新文献

{"title":"Optimizing autonomous underwater vehicle routes with the aid of high resolution ocean models","authors":"Miguel Aguiar, J. D. de Sousa, J. Dias, J.E. da Silva, R. Mendes, A. Ribeiro","doi":"10.23919/OCEANS40490.2019.8962569","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962569","url":null,"abstract":"In underwater vehicle operations in areas such as estuaries, vehicles may face currents with magnitudes equal to or exceeding the vehicle's maximum forward speed. We propose a method which generates vehicle routes taking into account ocean current forecasts from high resolution ocean models, in order to both take advantage of the ocean current velocity and avoid its negative effects. We formulate the problem in an optimal control setting and derive the associated Hamilton-Jacobi-Bellman partial differential equation (PDE). We solve this PDE using a parallelized C++ implementation of a numerical method which allows us to obtain the solution in a few minutes on a mainstream computer. After obtaining the solution of the PDE, optimal trajectories with any initial condition can be computed efficiently. The method is illustrated using data from high-resolution ocean models of the Sado river estuary in Portugal. Two mission scenarios are analyzed, which highlight the influence of ocean currents on optimal trajectories and the benefits of considering ocean current forecasts in mission planning.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114708054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Worlds Most Efficient and Environmentaly Friendly Coastal Shipping","authors":"Anders L. Mikkelsen, Narve Mjøs","doi":"10.23919/OCEANS40490.2019.8962669","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962669","url":null,"abstract":"Norway has committed itself to reducing greenhouse gas emissions by 40 percent by 2030 - a massive challenge. The Green Shipping Program aims to find scalable solutions for efficient and environmentally friendly shipping. The results will be cost-effective emission cuts, economic growth, increased competitiveness, and new jobs in Norway. Both authorities and industry actors participate in the program and they are all working together to achieve these goals. The program started in 2015 with a Phase 1 with an objective of identifying emissions of greenhouse gases and toxic gases, to define the potential for emission reductions, and the resulting business effects and exports, including the startup of five pilots. In 2018 and 2019 Phase 3 started, where the most important questions related to the green shift are answered through studies of barriers, opportunities and possible measures. Numerous pilot projects keep reaching implementation stage creating real delivered value.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127710207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Debond Fracture Toughness of Sandwich Composites for Marine Current Turbine Blades","authors":"Alexander Gonzalez, H. Mahfuz, Morteza Sabet","doi":"10.23919/OCEANS40490.2019.8962799","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962799","url":null,"abstract":"Sandwich composites for marine current turbine blades were investigated. Sandwich with composite face-sheet and polymeric foam core is of particular interest. Foam as core materials can provide high stiffness and buckling strength to the blade which is required under water where the density is 800 times higher than air. In addition to stiffness and strength, simplicity in manufacturing, self-buoyancy, and superior fatigue performance of sandwich composites are other advantages. However, in sandwich composites, two failure modes are dominant; one is core shear, and the other is face-core debonding. To assess this debonding, mode-I fracture toughness, also known as debond-fracture toughness was determined. The sandwich composite was made of carbon/epoxy face sheet with syntactic and polyurethane foam cores. In order to improve upon the fracture toughness, chopped strand mat (CSM) were inserted at the face-core interface. ASTM D5528-01 test method was used in single cantilever beam (SCB) configuration to determine the fracture toughness. Sandwich composites with a syntactic and polyurethane foam core were found to have an average debond toughness of 177 J/m2 and 175 J/m2, respectively. After CSM was introduced at the interface, toughness increased by about 14% in both cases. Details of sandwich construction, their characterization, and source of improvement in fracture toughness is described in the paper.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125724897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tensor decomposition of multi-frequency echosounder time series","authors":"Wu-Jung Lee, Valentina Staneva","doi":"10.23919/OCEANS40490.2019.8962566","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962566","url":null,"abstract":"In this paper we use tensor decomposition to analyze multi-frequency ocean sonar time series recorded by a moored echosounder on a cabled ocean observatory. Echosounders are high-frequency sonar systems widely used to observe biological aggregations in the ocean. Conventional echo analysis procedures rely heavily on human experts to manually analyze and extract synoptic information from the observations, a procedure that is difficult to scale up for large volumes of data. Frequency-dependent echo features, which varies strongly depending on the size and material properties of the scatterer, is one of the main features human experts use in this process to identify biological aggregations of interest. Tensor decomposition generalizes standard latent decomposition techniques to multi-way analysis and thus is a natural fit for extracting patterns from multi-frequency echo data. We show that, by explicitly accounting for frequency information in the formulation, tensor decomposition discovers patterns that capture the dominant spatio-temporal structures in the echoes with frequency dependencies that are potentially biologically meaningful. The fully separable component contributions in the Kruskal form of tensor decomposition make the biological sources of these structures more interpretable, as all elements within the same component share an identical frequency signature. This research lays the foundation for further development of methodologies capable of handling large multi-modal echosounder data sets that stretch in time, space, and frequency.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134216419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WireWalker Experiences with Two Navy-Funded Systems Utilizing Iridium Communications","authors":"S. C. Cumbee","doi":"10.23919/OCEANS40490.2019.8962651","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962651","url":null,"abstract":"The WireWalker wave-powered profiler system was designed by the Ocean Physics Group at Scripps Institution of Oceanography (SIO) University of California San Diego over 16 years ago [1]. The WireWalker system uses an ingenious ratcheting system to walk down a wire rope due to the wave action acting on a surface buoy, with a wire attached below the buoy and weights at the end of the wire for tautness. A rubber stopper attached to the wire rope at the desired depth trips the ratcheting mechanism to allow for a free-floating clean profile of data on ascent, while an upper stopper trips the mechanism to allow ratcheting down again. The Office of Naval Research and the National Science Foundation supported further development of these systems over the years. In 2016, the successful technology transition allowed for the formation of Del Mar Oceanographic, LLC to manufacture the WireWalker systems under license from the University of California San Diego. In 2017, the Navy funded the Multiscale Ocean Dynamics Group at SIO to provide two WireWalker systems with inductive modems and Iridium Router-Based Unrestricted Digital Internetworking Connectivity Solutions (RUDICS) communications for near-real-time data collection. The requirements of these two WireWalker systems were for transmission of conductivity, temperature, pressure, optical backscatter, chlorophyll a, irradiance, and radiance (along with system health) and for a Nortek Signature 1000 Acoustic Doppler Current Profiler to collect water current data and record the data internally. Within these WireWalkers, RBR Global in Canada integrated its conductivity-temperature-depth recorders with multiple channels and modem capability to transmit data inductively through the wire rope to the surface buoy. RBR Global also provided electronic integration for the surface buoy to transmit data through Iridium satellites utilizing RUDICS. Training at SIO [2] and onboard the R/V Robert Gordon Sproul in September 2017 will be discussed. Details of field experiences in February, September, and October 2018 and January-February 2019 will also be discussed. Technical problems encountered in the field and troubleshooting allowed Naval Oceanographic Office scientists to quickly learn the system and determine its deficiencies. This work helped to further debug and refine the WireWalker real-time system development and technical information required to ensure successful field operations by novice users of the WireWalker system.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134220054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D Model-Based UAV Pose Estimation using GPU","authors":"N. P. Santos, V. Lobo, A. Bernardino","doi":"10.23919/OCEANS40490.2019.8962704","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962704","url":null,"abstract":"It is presented a monocular RGB vision system to estimate the pose (3D position and orientation) of a fixed-wing Unmanned Aerial Vehicle (UAV) concerning the camera reference frame. Using this estimate, a Ground Control Station (GCS) can control the UAV trajectory during landing on a Fast Patrol Boat (FPB). A ground-based vision system makes it possible to use more sophisticated algorithms since we have more processing power available. The proposed method uses a 3D model-based approach based on a Particle Filter (PF) divided into five stages: (i) frame capture, (ii) target detection, (iii) distortion correction, (iv) appearance-based pose sampler, and (v) pose estimation. In the frame capture stage, we obtain a new observation (a new frame). In the target detection stage, we detect the UAV region on the captured frame using a detector based on a Deep Neural Network (DNN). In the distortion correction stage, we correct the frame radial and tangential distortions to obtain a better estimate. In the appearance-based pose sampler stage, we use a synthetically generated pre-trained database for a rough pose initialization. In the pose estimation stage, we apply an optimization algorithm to be able to obtain a UAV pose estimate in the captured frame with low error. The overall system performance is increased using the Graphics Processing Unit (GPU) for parallel processing. Results show that the GPU computational resources are essential to obtain a real-time pose estimation system.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133868222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Autonomous Surface Vehicle Control and Applications in Environmental Monitoring","authors":"N. Karapetyan, Jason Moulton, Ioannis M. Rekleitis","doi":"10.23919/OCEANS40490.2019.8962820","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962820","url":null,"abstract":"This paper addresses the problem of robotic operations in the presence of adversarial forces. We presents a complete framework for survey operations: waypoint generation, modelling of forces and tuning the control. In many applications of environmental monitoring, search and exploration, and bathymetric mapping, the vehicle has to traverse in straight lines parallel to each other, ensuring there are no gaps and no redundant coverage. During operations with an Autonomous Surface Vehicle (ASV) however, the presence of wind and/or currents produces external forces acting on the vehicle which quite often divert it from its intended path. Similar issues have been encountered during aerial or underwater operations. By measuring these phenomena, wind and current, and modelling their impact on the vessel, actions can be taken to alleviate their effect and ensure the correct trajectory is followed.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131655537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the CODAR Tsunami Detection Algorithm and Software","authors":"H. Roarty, G. Garcia, Terry Nichols","doi":"10.23919/OCEANS40490.2019.8962604","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962604","url":null,"abstract":"Coastal hazards pose a threat to human life and property around the globe. Tsunami waves and storm surge are some examples of coastal hazards we must try to mitigate over the coming decades. High Frequency radars have emerged as possible technology capable of mitigating the destruction from these hazards by providing early detection of these disturbances out at sea. Rutgers University has worked with CODAR Ocean Sensors by collecting and analyzing data from four HF radar stations for potential tsunami signals from October 2016 to June 2019. CODAR has developed a pattern recognition process to detect the presence of tsunami waves. The output of the process is quantified as an alongshore and cross shore q-factor. If there is a spike in the q-factor measurement then arrival of a tsunami could be imminent. The statistics of the q-factor measurements at the four stations were calculated and compared against the radio noise spectrum and other environmental data like nearby water level and atmospheric pressure. Recently, on May 30, 2019 a weather system moved through the region that generated a small meteotsunami (amplitude 15-30 cm) that was detected by a DART buoy, water level gauges and one of the HF radar stations. The data from all three system covered a large spatial area which allowed us to study the propagation of the wave through the region. The different detection schemes with each technology also allowed us to study the characteristics of the tsunami signal.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130803782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary Exterior Design and Hydrodynamic Evaluation of a Small-Scale Underwater Glider","authors":"Philip LaMothe, Mali Christian, P. Brodsky, Sarah E. Webster, Chanelle Cadot, Owen Williams","doi":"10.23919/OCEANS40490.2019.8962620","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962620","url":null,"abstract":"Autonomous underwater gliders (AUGs) use complex control algorithms to navigate that balance power consumption and adherence to mission parameters. Testing of these algorithms on large scale gliders, such as Deepglider and Seaglider, requires deployments that can be labor and time intensive. We examine the feasibility of using a small-scale glider as a test platform to replicate flight dynamics of traditional gliders. In particular, in this paper, we are demonstrating the experimental determination of the coefficients of lift and drag as parameters in the glider's hydrodynamic model using three different regression methods.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133639337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Simulation of Upper Ocean's Vertical Dynamic Response to A Tropical Cyclone: pumping and mixing","authors":"Xinyue Wei, Zhuoyi Xu, Xu Chen","doi":"10.23919/OCEANS40490.2019.8962570","DOIUrl":"https://doi.org/10.23919/OCEANS40490.2019.8962570","url":null,"abstract":"The dynamic response of the ocean to a tropical cyclone in the vertical direction can be simplified into two processes theoretically: pumping and mixing. Based on the mechanism of these two responses, an index is defined to represent the relative strength between mixing and pumping (referred as RMP hereinafter). The larger RMP is, the stronger the mixing compared to the pumping is. In this paper, we took the variable-controlling approach to change the rotational speed and the immersion depth of the dynamic rotary plate, respectively. Then the vertical density profile before and after tropical cyclone was depicted to calculate index RMP. The trend of RMP after tropical cyclone shows that the attenuation of mixing is much slower than pumping at first. Besides, it turns out that RMP is negatively correlated with rotational speed (vorticity magnitude) and positively correlated with immersion depth, meaning that vorticity magnitude of tropical cyclone has a more powerful effect on pumping than mixing, while immersion depth has a more powerful effect on mixing than pumping. This experiment helps us attain a better understanding of the vertical dynamic response of the ocean to tropical cyclones. And the introduction of the index RMP helps provide a new idea for the quantitative research on the relative strength between mixing and pimping in the future.","PeriodicalId":208102,"journal":{"name":"OCEANS 2019 MTS/IEEE SEATTLE","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132626737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}