Pub Date : 2025-04-07DOI: 10.1109/JOE.2024.3525190
Romolo Di Bernardo;Antonio Gloria;Stefano Papa;Domenico Speranza
In recent years, maritime industries have focused their attention on hydrofoils as one of the main technologies for the development of eco-sustainable solutions in the field of boating. The aim of the current research was to analyze the front wing of a Kohlkida class hydrofoil and to describe the methodology employed for the reconstruction of the 2-D airfoils by means of photogrammetry. Considering the limitations of the photogrammetry methods, some sections were extracted from the model. The airfoils were properly scaled and first compared with the model obtained by means of a laser scanner. Under the operating condition of the hydrofoil and with the use of Reynolds-averaged Navier–Stokes simulations, the behavior of the airfoils was simulated, allowing us to verify how the geometric differences due to the photogrammetry approach affect the fluid dynamics, in comparison to the model obtained from laser scanning. The proposed methodology led to a geometry reconstruction with adequate accuracy for the identification of both the characteristic curves for the lift and drag coefficients with a maximum error of 6% in the angle-of-attack range investigated in the study, also highlighting fluid dynamics problems that characterize this type of airfoils with a flat bottom and a knife-sharp leading edge.
{"title":"A Comparative Study of Reverse Engineering Approaches Toward the Design and Analysis of 2-D High-Speed Hydrofoils","authors":"Romolo Di Bernardo;Antonio Gloria;Stefano Papa;Domenico Speranza","doi":"10.1109/JOE.2024.3525190","DOIUrl":"https://doi.org/10.1109/JOE.2024.3525190","url":null,"abstract":"In recent years, maritime industries have focused their attention on hydrofoils as one of the main technologies for the development of eco-sustainable solutions in the field of boating. The aim of the current research was to analyze the front wing of a <italic>Kohlkida</i> class hydrofoil and to describe the methodology employed for the reconstruction of the 2-D airfoils by means of photogrammetry. Considering the limitations of the photogrammetry methods, some sections were extracted from the model. The airfoils were properly scaled and first compared with the model obtained by means of a laser scanner. Under the operating condition of the hydrofoil and with the use of Reynolds-averaged Navier–Stokes simulations, the behavior of the airfoils was simulated, allowing us to verify how the geometric differences due to the photogrammetry approach affect the fluid dynamics, in comparison to the model obtained from laser scanning. The proposed methodology led to a geometry reconstruction with adequate accuracy for the identification of both the characteristic curves for the lift and drag coefficients with a maximum error of 6% in the angle-of-attack range investigated in the study, also highlighting fluid dynamics problems that characterize this type of airfoils with a flat bottom and a knife-sharp leading edge.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1993-2004"},"PeriodicalIF":3.8,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-04DOI: 10.1109/JOE.2025.3538946
Waleed Akbar;Ahmed Allam;Fadel Adib
Underwater backscatter is an emerging technology for ultra-low-power communication and networking. Unlike traditional underwater acoustical modems, which communicate by generating their own acoustical signals, underwater backscatter nodes communicate by reflecting external acoustical signals, enabling them to operate at 5–6 orders of magnitude less power than existing low-power modems. Yet, before the practical adoption of this technology, it remains necessary to understand its link budget in practical ocean channels. In this article, we perform a comprehensive investigation of the underwater backscatter link budget in practical channels considering various sources of signal and noise that are unique to backscatter communication systems. We develop a closed-form end-to-end link-budget model of underwater backscatter and perform experimental validations in real-world environments. For the first time, we experimentally verify the end-to-end analytical model of the signal-to-noise ratio (SNR) as a function of distance and source level. Not only does this model enable us to predict the expected SNR within a median of 0.75 dB of the experimentally measured one, but also to identify new methods that improve the performance of underwater backscatter and extend its range over state-of-the-art past work. We then use this validated model to simulate backscatter performance under practical ocean channels and understand the impact of system and environmental parameters on the end-to-end performance. By developing and validating the link budget model, this article paves the way for the practical adoption of underwater backscatter in applications of ocean climate change monitoring, scientific studies, and coastal resilience.
{"title":"Underwater Backscatter Networking for Subsea IoT: A Link-Budget Analysis in Practical Ocean Channels","authors":"Waleed Akbar;Ahmed Allam;Fadel Adib","doi":"10.1109/JOE.2025.3538946","DOIUrl":"https://doi.org/10.1109/JOE.2025.3538946","url":null,"abstract":"Underwater backscatter is an emerging technology for ultra-low-power communication and networking. Unlike traditional underwater acoustical modems, which communicate by generating their own acoustical signals, underwater backscatter nodes communicate by reflecting external acoustical signals, enabling them to operate at 5–6 orders of magnitude less power than existing low-power modems. Yet, before the practical adoption of this technology, it remains necessary to understand its link budget in practical ocean channels. In this article, we perform a comprehensive investigation of the underwater backscatter link budget in practical channels considering various sources of signal and noise that are unique to backscatter communication systems. We develop a closed-form end-to-end link-budget model of underwater backscatter and perform experimental validations in real-world environments. For the first time, we experimentally verify the end-to-end analytical model of the signal-to-noise ratio (SNR) as a function of distance and source level. Not only does this model enable us to predict the expected SNR within a median of 0.75 dB of the experimentally measured one, but also to identify new methods that improve the performance of underwater backscatter and extend its range over state-of-the-art past work. We then use this validated model to simulate backscatter performance under practical ocean channels and understand the impact of system and environmental parameters on the end-to-end performance. By developing and validating the link budget model, this article paves the way for the practical adoption of underwater backscatter in applications of ocean climate change monitoring, scientific studies, and coastal resilience.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1703-1717"},"PeriodicalIF":3.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1109/JOE.2025.3553255
Alessandro Pozzebon;Gabriele Di Renzone;Duccio Bertoni;Giovanni Sarti;Gabor Domokos;Chiara Favaretto
In this article, we detail a novel technique for measuring volume and textural parameters of coarse-grained marine sediments. The technique combines radio frequency identification (RFID) technology for sediment tracking with 3-D scanning for volume measurement. The technique is applied to real marine sediments collected from the beach under study. In the preliminary phase, the sediments are scanned using a low-cost 3-D scanning system and then fitted with an embedded RFID transponder, which allows their unambiguous identification. The pebbles are then deployed on the beach and, after a predefined period of time, they are located and retrieved by means of an ad-hoc RFID reader used as a detector. After retrieval, the pebbles are 3-D scanned to collect data on the volumetric changes that result from the abrasion and chipping processes caused by intergranular friction on their surfaces from water movements (mostly sea waves). The technique allows for an accurate estimation of morphological variations of sediments, thereby providing essential insights into sediment stability and, on a broader scale, coastal erosive processes. Moreover, it allows the study of the evolution of a number of textural parameters, such as sphericity or angularity, which can be extracted from the 3-D model.
{"title":"A Technique for the Study of the Volume and Textural Parameter Evolution of Marine Coarse Sediments","authors":"Alessandro Pozzebon;Gabriele Di Renzone;Duccio Bertoni;Giovanni Sarti;Gabor Domokos;Chiara Favaretto","doi":"10.1109/JOE.2025.3553255","DOIUrl":"https://doi.org/10.1109/JOE.2025.3553255","url":null,"abstract":"In this article, we detail a novel technique for measuring volume and textural parameters of coarse-grained marine sediments. The technique combines radio frequency identification (RFID) technology for sediment tracking with 3-D scanning for volume measurement. The technique is applied to real marine sediments collected from the beach under study. In the preliminary phase, the sediments are scanned using a low-cost 3-D scanning system and then fitted with an embedded RFID transponder, which allows their unambiguous identification. The pebbles are then deployed on the beach and, after a predefined period of time, they are located and retrieved by means of an ad-hoc RFID reader used as a detector. After retrieval, the pebbles are 3-D scanned to collect data on the volumetric changes that result from the abrasion and chipping processes caused by intergranular friction on their surfaces from water movements (mostly sea waves). The technique allows for an accurate estimation of morphological variations of sediments, thereby providing essential insights into sediment stability and, on a broader scale, coastal erosive processes. Moreover, it allows the study of the evolution of a number of textural parameters, such as sphericity or angularity, which can be extracted from the 3-D model.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 2","pages":"608-621"},"PeriodicalIF":3.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143852370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-02DOI: 10.1109/JOE.2024.3474738
Ruiwen Zhao;Ye Li;Angus C. W. Creech;Alistair G. L. Borthwick;Stephen H. Salter;Vengatesan Venugopal;Fang Chen
In this article, we describe numerical simulations of an innovative design of close-packed contra-rotating vertical-axis turbines (VATs), which enable assessment of power performance, vorticity distribution, and wake deficit. The design comprises a large diameter rotor without traditional supporting arms, stable in pitch and roll. Close-packing reduces leakage between rotors and yields a high blockage fraction, which significantly enhances the performance of offshore wind and tidal VATs. Rotor rings that support blades at both ends help reduce bending moments, and ease the task of the bearings required to achieve variable-pitch. The contra-rotation concept is based on two opposite-signed vortices cancelling each other out and conditions the flow though the turbine, lowering turbulent kinetic energy in the wake. Flow downstream of the turbines then experiences less stream-wise variation, reducing mixing losses thus enhancing energy extraction. Two types of VATs are considered. The first derives from experimental two-bladed H-type wind turbines, whereby the VATs comprise four close-packed contra-rotating wind turbines. The second is based on a 1:6 scale UNH-RM2 VAT that is extended to an array of ten closely packed 36-bladed hydrokinetic turbines positioned in two rows. It is found that high blockage, contra-rotating, vertical-axis rotors could facilitate higher potential power generation and appear to be a promising near-term technology for sustainable energy. The findings should prove useful in future assessments of the commercial feasibility of multiple cross-flow turbine configurations for both offshore wind and tidal stream power generation.
{"title":"Design and Analysis of Large-Scale Contra-Rotating Offshore Vertical-Axis Turbines","authors":"Ruiwen Zhao;Ye Li;Angus C. W. Creech;Alistair G. L. Borthwick;Stephen H. Salter;Vengatesan Venugopal;Fang Chen","doi":"10.1109/JOE.2024.3474738","DOIUrl":"https://doi.org/10.1109/JOE.2024.3474738","url":null,"abstract":"In this article, we describe numerical simulations of an innovative design of close-packed contra-rotating vertical-axis turbines (VATs), which enable assessment of power performance, vorticity distribution, and wake deficit. The design comprises a large diameter rotor without traditional supporting arms, stable in pitch and roll. Close-packing reduces leakage between rotors and yields a high blockage fraction, which significantly enhances the performance of offshore wind and tidal VATs. Rotor rings that support blades at both ends help reduce bending moments, and ease the task of the bearings required to achieve variable-pitch. The contra-rotation concept is based on two opposite-signed vortices cancelling each other out and conditions the flow though the turbine, lowering turbulent kinetic energy in the wake. Flow downstream of the turbines then experiences less stream-wise variation, reducing mixing losses thus enhancing energy extraction. Two types of VATs are considered. The first derives from experimental two-bladed H-type wind turbines, whereby the VATs comprise four close-packed contra-rotating wind turbines. The second is based on a 1:6 scale UNH-RM2 VAT that is extended to an array of ten closely packed 36-bladed hydrokinetic turbines positioned in two rows. It is found that high blockage, contra-rotating, vertical-axis rotors could facilitate higher potential power generation and appear to be a promising near-term technology for sustainable energy. The findings should prove useful in future assessments of the commercial feasibility of multiple cross-flow turbine configurations for both offshore wind and tidal stream power generation.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"2182-2199"},"PeriodicalIF":3.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-01DOI: 10.1109/JOE.2025.3531959
Yajing Gu;Yonggang Lin;Danyang Li;Xinliang Lu;Hongwei Liu;Yong Sun
A pendulum wave energy converter (WEC) is one of the most important forms of wave energy harvesting devices. To obtain better performance under broader wave conditions, this article proposes an integrated piston-variable digital-controlled hydraulic cylinder (IPDC). A traditionally used single large cylinder is replaced by several pairs of subsidiary cylinders to compose a more compact and extendable integrated type. The working area of the IPDC can be regulated in real time using high-speed on–off valves to change power take-off (PTO) damping and achieve maximum energy extraction in the pendulum WEC. In performance experiments, the average mechanical efficiency is around 95% for all area combinations, and the leakage is relatively lower. The results indicate that the IPDC has a lower extra energy loss compared with a conventional single hydraulic cylinder. Based on the theoretical analysis for maximum power extraction, AMESim–Simulink co-simulation and prototype experiments are conducted to verify the feasibility and effectiveness of the IPDC. The IPDC can significantly improve the total captured energy by 37.04% compared with the fixed area cylinder in the experiment. The results illustrate that the IPDC exhibits excellent harvesting performance by effectively changing the connected area to impose compatible PTO resistance under broader wave conditions.
{"title":"An Integrated Piston-Variable Digital-Controlled Hydraulic Cylinder for Pendulum Wave Energy Converter","authors":"Yajing Gu;Yonggang Lin;Danyang Li;Xinliang Lu;Hongwei Liu;Yong Sun","doi":"10.1109/JOE.2025.3531959","DOIUrl":"https://doi.org/10.1109/JOE.2025.3531959","url":null,"abstract":"A pendulum wave energy converter (WEC) is one of the most important forms of wave energy harvesting devices. To obtain better performance under broader wave conditions, this article proposes an integrated piston-variable digital-controlled hydraulic cylinder (IPDC). A traditionally used single large cylinder is replaced by several pairs of subsidiary cylinders to compose a more compact and extendable integrated type. The working area of the IPDC can be regulated in real time using high-speed <sc>on–off</small> valves to change power take-off (PTO) damping and achieve maximum energy extraction in the pendulum WEC. In performance experiments, the average mechanical efficiency is around 95% for all area combinations, and the leakage is relatively lower. The results indicate that the IPDC has a lower extra energy loss compared with a conventional single hydraulic cylinder. Based on the theoretical analysis for maximum power extraction, AMESim–Simulink co-simulation and prototype experiments are conducted to verify the feasibility and effectiveness of the IPDC. The IPDC can significantly improve the total captured energy by 37.04% compared with the fixed area cylinder in the experiment. The results illustrate that the IPDC exhibits excellent harvesting performance by effectively changing the connected area to impose compatible PTO resistance under broader wave conditions.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"2135-2145"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-01DOI: 10.1109/JOE.2024.3523363
Nicholas Harmon;Mohammad Belal;Maria-Daphne Mangriotis;Carl Spingys;Catherine A. Rychert
Distributed acoustic sensing (DAS) provides a means of measuring dynamic changes in strain along a fiber-optic cable and has many potential applications for monitoring infrastructure, earthquake early warning, and hazard assessment. Previous work has focused on submarine telecommunications cables, which contain only fiber-optic cables. Here, we focus on the use of energy cables, which transmit electricity from offshore generators powered by tides or wind and contain fiber-optic cables for communications with the generators. Specifically, we focus on the European Marine Energy Center in Orkney, Eday, U.K., a tidal power station. Energy cables fluctuate in temperature due to energy transmission, and there is strong wave action and tidal flows, which all generate noise for DAS. We show that noise levels vary along the cable during a time with no energy transmission, but many phenomena reported on telecommunication cables are still observable, including ocean waves and nearby small vessels. The character of the small vessel signals in frequency band energy plots varies along the cable length, in some areas exhibiting multiple frequency band energy peaks. This variation is diagnostic of the burial state of the cable. Knowing the burial state of energy cables is important for understanding the mechanical protection of the system for minimizing thermal interactions with the surrounding environments and ecosystems.
{"title":"Distributed Acoustic Sensing Along a Shallow Water Energy Cable","authors":"Nicholas Harmon;Mohammad Belal;Maria-Daphne Mangriotis;Carl Spingys;Catherine A. Rychert","doi":"10.1109/JOE.2024.3523363","DOIUrl":"https://doi.org/10.1109/JOE.2024.3523363","url":null,"abstract":"Distributed acoustic sensing (DAS) provides a means of measuring dynamic changes in strain along a fiber-optic cable and has many potential applications for monitoring infrastructure, earthquake early warning, and hazard assessment. Previous work has focused on submarine telecommunications cables, which contain only fiber-optic cables. Here, we focus on the use of energy cables, which transmit electricity from offshore generators powered by tides or wind and contain fiber-optic cables for communications with the generators. Specifically, we focus on the European Marine Energy Center in Orkney, Eday, U.K., a tidal power station. Energy cables fluctuate in temperature due to energy transmission, and there is strong wave action and tidal flows, which all generate noise for DAS. We show that noise levels vary along the cable during a time with no energy transmission, but many phenomena reported on telecommunication cables are still observable, including ocean waves and nearby small vessels. The character of the small vessel signals in frequency band energy plots varies along the cable length, in some areas exhibiting multiple frequency band energy peaks. This variation is diagnostic of the burial state of the cable. Knowing the burial state of energy cables is important for understanding the mechanical protection of the system for minimizing thermal interactions with the surrounding environments and ecosystems.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1772-1781"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-01DOI: 10.1109/JOE.2025.3531933
Martin Aubard;Ana Madureira;Luís Teixeira;José Pinto
With the growing interest in underwater exploration and monitoring, autonomous underwater vehicles have become essential. The recent interest in onboard deep learning (DL) has advanced real-time environmental interaction capabilities relying on efficient and accurate vision-based DL models. However, the predominant use of sonar in underwater environments, characterized by limited training data and inherent noise, poses challenges to model robustness. This autonomy improvement raises safety concerns for deploying such models during underwater operations, potentially leading to hazardous situations. This article aims to provide the first comprehensive overview of sonar-based DL under the scope of robustness. It studies sonar-based DL perception task models, such as classification, object detection, segmentation, and simultaneous localization and mapping. Furthermore, this article systematizes sonar-based state-of-the-art data sets, simulators, and robustness methods, such as neural network verification, out-of-distribution, and adversarial attacks. This article highlights the lack of robustness in sonar-based DL research and suggests future research pathways, notably establishing a baseline sonar-based data set and bridging the simulation-to-reality gap.
{"title":"Sonar-Based Deep Learning in Underwater Robotics: Overview, Robustness, and Challenges","authors":"Martin Aubard;Ana Madureira;Luís Teixeira;José Pinto","doi":"10.1109/JOE.2025.3531933","DOIUrl":"https://doi.org/10.1109/JOE.2025.3531933","url":null,"abstract":"With the growing interest in underwater exploration and monitoring, autonomous underwater vehicles have become essential. The recent interest in onboard deep learning (DL) has advanced real-time environmental interaction capabilities relying on efficient and accurate vision-based DL models. However, the predominant use of sonar in underwater environments, characterized by limited training data and inherent noise, poses challenges to model robustness. This autonomy improvement raises safety concerns for deploying such models during underwater operations, potentially leading to hazardous situations. This article aims to provide the first comprehensive overview of sonar-based DL under the scope of robustness. It studies sonar-based DL perception task models, such as classification, object detection, segmentation, and simultaneous localization and mapping. Furthermore, this article systematizes sonar-based state-of-the-art data sets, simulators, and robustness methods, such as neural network verification, out-of-distribution, and adversarial attacks. This article highlights the lack of robustness in sonar-based DL research and suggests future research pathways, notably establishing a baseline sonar-based data set and bridging the simulation-to-reality gap.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1866-1884"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10947005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advancements in ocean reanalysis and satellite remote sensing products have opened unprecedented opportunities for using large-scale data sets to analyze and model ocean dynamics. This article utilizes the China Ocean Reanalysis Second Edition (CORA2) data set to model and estimate parameters for the ocean dynamics off the East Coast of China. A novel approach combining physics-informed neural networks with characteristic-based split is innovatively proposed to effectively analyze dynamics issues, such as surface waves and tides under open boundary conditions. This method estimates the boundary amplitude of incoming waves using multiple time-series flow field data from coastal areas in China, and uses these estimates to predict future flow field changes. By comparing with the CORA2 data set, the method not only confirms its high accuracy and reliability but also significantly improves the alignment between model predictions and actual observational data by incorporating estimates of seabed friction coefficients. This reveals the effectiveness of using large-scale data sets in conjunction with physical equations to enhance the accuracy and computational precision of ocean dynamics modeling.
{"title":"Physics-Informed Neural Networks for Modeling Ocean Dynamics and Parameter Estimation: Leveraging Ocean Reanalysis Data","authors":"Shuang Hu;Meiqin Liu;Senlin Zhang;Shanling Dong;Ronghao Zheng","doi":"10.1109/JOE.2025.3538927","DOIUrl":"https://doi.org/10.1109/JOE.2025.3538927","url":null,"abstract":"Advancements in ocean reanalysis and satellite remote sensing products have opened unprecedented opportunities for using large-scale data sets to analyze and model ocean dynamics. This article utilizes the China Ocean Reanalysis Second Edition (CORA2) data set to model and estimate parameters for the ocean dynamics off the East Coast of China. A novel approach combining physics-informed neural networks with characteristic-based split is innovatively proposed to effectively analyze dynamics issues, such as surface waves and tides under open boundary conditions. This method estimates the boundary amplitude of incoming waves using multiple time-series flow field data from coastal areas in China, and uses these estimates to predict future flow field changes. By comparing with the CORA2 data set, the method not only confirms its high accuracy and reliability but also significantly improves the alignment between model predictions and actual observational data by incorporating estimates of seabed friction coefficients. This reveals the effectiveness of using large-scale data sets in conjunction with physical equations to enhance the accuracy and computational precision of ocean dynamics modeling.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"2248-2260"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to their underactuation, motion control for autonomous marine vehicles (AMVs) has always been a tricky problem. Most current path following control methods for underactuated autonomous marine vehicles apply geometric projection to map position error to yaw angle in order to decouple the yaw thrust moment in the controller design. However, there will be deviations in the geometric projection because of sideslip, especially when external disturbances exist. Moreover, the performance of the geometric projection method is greatly affected by the look-ahead distance. In this article, a novel path following control method for underactuated AMVs is proposed. This method directly takes the position of a point as the control object, with the process of geometric projection eliminated, thereby getting rid of the negative impact of sideslip. The desired path is modeled as a scalar field, and the commanded position is taken to lie along the direction of the gradient of this scalar field at the kinematics level. At the kinetics level, disturbance rejection capability is constructed by applying disturbance observers and compensating for the estimated disturbances in the control effort. It is proved that all signals in the closed-loop system are uniformly ultimately bounded. Simulation and experimental results demonstrate that the proposed method is effective.
{"title":"A Gradient-Based Path Following Control Method for Underactuated Autonomous Marine Vehicle","authors":"Zishi Xu;Shiming He;Weijun Zhou;Yanjun Li;Ji Xiang","doi":"10.1109/JOE.2025.3529126","DOIUrl":"https://doi.org/10.1109/JOE.2025.3529126","url":null,"abstract":"Due to their underactuation, motion control for autonomous marine vehicles (AMVs) has always been a tricky problem. Most current path following control methods for underactuated autonomous marine vehicles apply geometric projection to map position error to yaw angle in order to decouple the yaw thrust moment in the controller design. However, there will be deviations in the geometric projection because of sideslip, especially when external disturbances exist. Moreover, the performance of the geometric projection method is greatly affected by the look-ahead distance. In this article, a novel path following control method for underactuated AMVs is proposed. This method directly takes the position of a point as the control object, with the process of geometric projection eliminated, thereby getting rid of the negative impact of sideslip. The desired path is modeled as a scalar field, and the commanded position is taken to lie along the direction of the gradient of this scalar field at the kinematics level. At the kinetics level, disturbance rejection capability is constructed by applying disturbance observers and compensating for the estimated disturbances in the control effort. It is proved that all signals in the closed-loop system are uniformly ultimately bounded. Simulation and experimental results demonstrate that the proposed method is effective.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1855-1865"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Underwater images often suffer from multiple degradation issues, such as color casting, low contrast levels, and blurry details, which limits the applicability of underwater images in ocean exploration tasks. An underwater image enhancement method implemented via piecewise color balancing and pyramid-based contrast enhancement (PBPE) is proposed in this article. Concretely, PBPE first uses a reference channel with the maximum mean and two gain factors to balance the differences among the r, g, and b channels. PBPE presents a pixelwise transmission estimation method that is based on the mapping between the transmission and the backscattered light. Specifically, an adaptive compensation strategy is proposed to adaptively refine the transmission. Finally, PBPE captures a detail pyramid via multiscale Gaussian decomposition and uses the estimated transmission to remove haze and increase the degree of detail, thereby enhancing the overall contrast level of the underwater image. Comprehensive experiments conducted on two underwater image enhancement data sets indicate that our PBPE approach achieves better results and outperforms the state-of-the-art methods; i.e., compared with those of the second-best method, the average blur and density of the fog assessment-based defogger values of our method decrease by at least 2.67% and 4.55%, respectively, which shows that our method achieves enhancement results with high contrast levels and natural appearances.
{"title":"Underwater Image Enhancement via Piecewise Colour Balancing and Multiscale Enhancement Fusion","authors":"Zheng Liang;Haohui Huang;Weidong Zhang;Hang Song;Xinwen Wan;Chuanjian Wang;Linsheng Huang;Peixian Zhuang","doi":"10.1109/JOE.2025.3555684","DOIUrl":"https://doi.org/10.1109/JOE.2025.3555684","url":null,"abstract":"Underwater images often suffer from multiple degradation issues, such as color casting, low contrast levels, and blurry details, which limits the applicability of underwater images in ocean exploration tasks. An underwater image enhancement method implemented via piecewise color balancing and pyramid-based contrast enhancement (PBPE) is proposed in this article. Concretely, PBPE first uses a reference channel with the maximum mean and two gain factors to balance the differences among the r, g, and b channels. PBPE presents a pixelwise transmission estimation method that is based on the mapping between the transmission and the backscattered light. Specifically, an adaptive compensation strategy is proposed to adaptively refine the transmission. Finally, PBPE captures a detail pyramid via multiscale Gaussian decomposition and uses the estimated transmission to remove haze and increase the degree of detail, thereby enhancing the overall contrast level of the underwater image. Comprehensive experiments conducted on two underwater image enhancement data sets indicate that our PBPE approach achieves better results and outperforms the state-of-the-art methods; i.e., compared with those of the second-best method, the average blur and density of the fog assessment-based defogger values of our method decrease by at least 2.67% and 4.55%, respectively, which shows that our method achieves enhancement results with high contrast levels and natural appearances.","PeriodicalId":13191,"journal":{"name":"IEEE Journal of Oceanic Engineering","volume":"50 3","pages":"1960-1977"},"PeriodicalIF":3.8,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144646462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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