Applied Ocean Research最新文献

英文中文

An isomorphic Froude scaling approach to bulbous-bottomed buoys in wave energy converters for smart floating cities

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-24 DOI: 10.1016/j.apor.2025.104485

Ammar Ahmed , Ali Azam , Zutao Zhang , Minyi Yi , Touqeer Aslam , Shoukat Ali Mugheri , Daning Hao , Mansour Abdelrahman , Alaeldin M. Tairab

Testing full-scale point absorber buoys with enhanced power absorption is challenging and crucial to improving their viability for applications in smart floating cities and marine infrastructure. Bulbous-bottomed (BB) buoys are efficient in hydrodynamics and power absorption for point absorber wave energy converters (PA-WEC). Their experimental validation demands adaptable scaling algorithms to facilitate model-scale tests. This study utilizes a state-of-the-art theoretical algorithm by combining Froude scaling with an isomorphic buoy design approach, facilitating model-scale tests to investigate whether the BB buoys would equally be efficient compared to the reference hemispherical-bottomed (CHS) buoy when deployed and tested experimentally under identical conditions. Additively manufactured scaled buoy models were tested in a laboratory-scale wave flume in both regular waves (inside and outside resonance) and irregular waves, followed by a similarity analysis for performance prediction on the prototype scale. A feasibility study was also established to justify the BB buoy application in real-time PA-WECs. The BB buoys outperformed the CHS buoys within and without resonance in regular and irregular waves, justifying that they can replace them for good. Under the same deployment and test settings, the model-scale BB buoy exhibited a 20

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27 % greater heave motion than the reference without resonance. A full-scale BB buoy could absorb significantly greater wave power than the reference. The case study showed that a CHS-to-BB transition resulted in a 35 % rise in the capture width ratio of a WEC. The WEC, combined with a 5G-IoT and LSTM network, could facilitate self-powered and self-sensing marine applications in a smart floating city.

{"title":"An isomorphic Froude scaling approach to bulbous-bottomed buoys in wave energy converters for smart floating cities","authors":"Ammar Ahmed , Ali Azam , Zutao Zhang , Minyi Yi , Touqeer Aslam , Shoukat Ali Mugheri , Daning Hao , Mansour Abdelrahman , Alaeldin M. Tairab","doi":"10.1016/j.apor.2025.104485","DOIUrl":"10.1016/j.apor.2025.104485","url":null,"abstract":"<div><div>Testing full-scale point absorber buoys with enhanced power absorption is challenging and crucial to improving their viability for applications in smart floating cities and marine infrastructure. Bulbous-bottomed (BB) buoys are efficient in hydrodynamics and power absorption for point absorber wave energy converters (PA-WEC). Their experimental validation demands adaptable scaling algorithms to facilitate model-scale tests. This study utilizes a state-of-the-art theoretical algorithm by combining Froude scaling with an isomorphic buoy design approach, facilitating model-scale tests to investigate whether the BB buoys would equally be efficient compared to the reference hemispherical-bottomed (C<img>HS) buoy when deployed and tested experimentally under identical conditions. Additively manufactured scaled buoy models were tested in a laboratory-scale wave flume in both regular waves (inside and outside resonance) and irregular waves, followed by a similarity analysis for performance prediction on the prototype scale. A feasibility study was also established to justify the BB buoy application in real-time PA-WECs. The BB buoys outperformed the C<img>HS buoys within and without resonance in regular and irregular waves, justifying that they can replace them for good. Under the same deployment and test settings, the model-scale BB buoy exhibited a 20<span><math><mo>−</mo></math></span>27 % greater heave motion than the reference without resonance. A full-scale BB buoy could absorb significantly greater wave power than the reference. The case study showed that a C<img>HS-to-BB transition resulted in a 35 % rise in the capture width ratio of a WEC. The WEC, combined with a 5G-IoT and LSTM network, could facilitate self-powered and self-sensing marine applications in a smart floating city.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104485"},"PeriodicalIF":4.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478596","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}

引用次数: 0

Experimental study of primary- and higher-mode resonant sloshing in a horizontally excited square-base tank

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-22 DOI: 10.1016/j.apor.2025.104482

Dongxi Liu , Qiyang Cai , Yiran Li , Yudi He , Jin Wang

This study experimentally investigates primary- and higher-mode resonant sloshing induced by horizontal excitations in a square-base tank with finite depth. Due to the equal length and width of the three-dimensional rectangular tank, two predominant sloshing modes (the transverse mode and longitudinal mode) emerge simultaneously, even when the tank is subjected to unidirectional external excitation. Consequently, direct excitation of one mode leads to indirect excitation of the other through nonlinear coupling, a complex phenomenon known as autoparametric interaction. This phenomenon is widely observed in (i, j) sloshing modes, where i ≠ j. However, the coupling of autoparametric interaction is stable only in the lowest mode, higher modes are found to be unstable. The experiment also reveals that when the natural frequencies of two modes are very close, applying external excitation at one natural frequency causes a shift in the dominant frequency towards the natural frequency of the other mode. In summary, the findings of this study highlight that liquid sloshing in a square-base tank involves more complex physics compared to sloshing in a two-dimensional rectangular tank.

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引用次数: 0

Wave basin testing of hydrodynamic interactions in centralized controlled wave energy converter arrays for irregular short- and long-crested waves

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-22 DOI: 10.1016/j.apor.2025.104467

Timothy Vervaet , Laurens Cromheeke , Nicolas Quartier, Maximilian Streicher, Vasiliki Stratigaki, Peter Troch

To increase the total installed capacity, multiple wave energy converters (WECs) will be installed in an array configuration. Within these WEC arrays, hydrodynamic interactions occur and the sea state is modified accordingly. These WECs are equipped with a Power Take-Off (PTO) which converts the kinetic energy of the waves to mechanical energy. An optimal PTO can be obtained by setting the PTO control impedance equal to the complex conjugate of the intrinsic impedance of the WEC. Within a WEC array constituting of n closely spaced WECs, where hydrodynamic interactions between the WECs occur through radiation and diffraction of waves, the n x n PTO control impedance matrix should be equal to the complex conjugate of the n x n intrinsic impedance matrix. This paper discusses the incremental experimental modelling of five ‘WECfarm’ WECs: Modelling of the five isolated WECs, a two-WEC array, a three-WEC array, a four-WEC array, and a five-WEC array. System identification (SID) tests are performed to obtain an accurate dynamic model of the isolated WECs and the WEC arrays. Based on this model, causal impedance matching Proportional (P) controllers are designed, and tested for a selection of irregular long- and short-crested waves. This paper presents the dataset and results of the experimental campaign performed at the Coastal & Ocean Basin Ostend (COB), Belgium. With high measurement accuracy and repeatability, the presented dataset is reliable, while by considering controlled WECs, and operational and extreme wave conditions, it is realistic.

{"title":"Wave basin testing of hydrodynamic interactions in centralized controlled wave energy converter arrays for irregular short- and long-crested waves","authors":"Timothy Vervaet , Laurens Cromheeke , Nicolas Quartier, Maximilian Streicher, Vasiliki Stratigaki, Peter Troch","doi":"10.1016/j.apor.2025.104467","DOIUrl":"10.1016/j.apor.2025.104467","url":null,"abstract":"<div><div>To increase the total installed capacity, multiple wave energy converters (WECs) will be installed in an array configuration. Within these WEC arrays, hydrodynamic interactions occur and the sea state is modified accordingly. These WECs are equipped with a Power Take-Off (PTO) which converts the kinetic energy of the waves to mechanical energy. An optimal PTO can be obtained by setting the PTO control impedance equal to the complex conjugate of the intrinsic impedance of the WEC. Within a WEC array constituting of <em>n</em> closely spaced WECs, where hydrodynamic interactions between the WECs occur through radiation and diffraction of waves, the <em>n x n</em> PTO control impedance matrix should be equal to the complex conjugate of the <em>n x n</em> intrinsic impedance matrix. This paper discusses the incremental experimental modelling of five ‘WECfarm’ WECs: Modelling of the five isolated WECs, a two-WEC array, a three-WEC array, a four-WEC array, and a five-WEC array. System identification (SID) tests are performed to obtain an accurate dynamic model of the isolated WECs and the WEC arrays. Based on this model, causal impedance matching Proportional (P) controllers are designed, and tested for a selection of irregular long- and short-crested waves. This paper presents the dataset and results of the experimental campaign performed at the Coastal & Ocean Basin Ostend (COB), Belgium. With high measurement accuracy and repeatability, the presented dataset is reliable, while by considering controlled WECs, and operational and extreme wave conditions, it is realistic.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104467"},"PeriodicalIF":4.3,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464213","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}

引用次数: 0

Explainable AI for ship collision avoidance: Decoding decision-making processes and behavioral intentions

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-21 DOI: 10.1016/j.apor.2025.104471

Hitoshi Yoshioka, Hirotada Hashimoto

Most ship collision accidents are attributed to human errors. Autonomous navigation technology is heralded as a potential solution to mitigate human error-related collisions. Recent advancements have enabled the application of deep reinforcement learning (DRL) in developing autonomous navigation artificial intelligence (AI). However, the decision-making process of AI is not transparent, and its potential for misjudgment could lead to severe accidents. Consequently, the explainability of DRL-based AI emerges as a critical hurdle in deploying autonomous collision avoidance systems. This study developed an explainable AI for ship collision avoidance. Initially, a critic network composed of sub-task critic networks was proposed to individually evaluate each sub-task to clarify the AI decision-making processes in collision avoidance. Additionally, an attempt was made to discern behavioral intentions through a Q-value analysis and an Attention mechanism. The former focused on interpreting intentions by examining the increment of the Q-value resulting from AI actions, while the latter incorporated the significance of other ships in the decision-making process for collision avoidance into the learning objective. AI's behavioral intentions in collision avoidance were visualized by combining the perceived increment of Q-value with the degree of attention to other ships. The proposed method was evaluated through a numerical experiment. The developed AI was confirmed to be able to safely avoid collisions under various congestion levels, and the decision-making process and behavioral intention of AI for collision avoidance were rendered comprehensible to humans. It is comprehensible to seafarers onboard and could contribute to the future practical implementation of autonomous navigation AI systems.

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引用次数: 0

Analysis of sediment disturbance and plume dispersion characteristics induced by deep-sea polymetallic nodule hydraulic collectors

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-20 DOI: 10.1016/j.apor.2025.104462

Zhengqi Wu , Xiuzhan Zhang , Shuai Jin , Jiancheng Liu , Xixi Liu , Lei Li , Fengluo Chen , Xuguang Chen , Jiakang Wei , Hao Li

Environmental disturbances caused by seabed mining have garnered significant international attention. Deep-sea hydraulic mining inevitably disrupts seafloor sediments, transforming them into fine particles that remain suspended, posing long-term threats to marine ecosystems. This study systematically investigates sediment disturbance characteristics under varying jet parameters through model experiments, aiming to assess the environmental impact of jetting operations and optimize jet parameters. The jet parameters investigated include jet velocity, target distance, and nozzle height. Results indicate that seabed disturbance process can be divided into three stages: critical suspension, critical erosion, and plume dispersion. Seabed morphology exhibits distinct V-shaped or U-shaped features, with target-to-nozzle height ratios (B/H) equals to 1 identified as the critical threshold for shape transition. Plume transformation rate increases with jet velocity, ranging from 15% to 55%. After disturbance, the plume suspended concentration decreases with increasing nozzle height, reaching a maximum reduction of up to 70%. These findings provide valuable data for minimizing environmental disturbance in deep-sea jetting operations. Based on experimental results, a new method for calculating the relationship between jet parameters and plume dispersion is proposed, offering a theoretical and technical basis for reducing environmental impact in deep-sea mining.

{"title":"Analysis of sediment disturbance and plume dispersion characteristics induced by deep-sea polymetallic nodule hydraulic collectors","authors":"Zhengqi Wu , Xiuzhan Zhang , Shuai Jin , Jiancheng Liu , Xixi Liu , Lei Li , Fengluo Chen , Xuguang Chen , Jiakang Wei , Hao Li","doi":"10.1016/j.apor.2025.104462","DOIUrl":"10.1016/j.apor.2025.104462","url":null,"abstract":"<div><div>Environmental disturbances caused by seabed mining have garnered significant international attention. Deep-sea hydraulic mining inevitably disrupts seafloor sediments, transforming them into fine particles that remain suspended, posing long-term threats to marine ecosystems. This study systematically investigates sediment disturbance characteristics under varying jet parameters through model experiments, aiming to assess the environmental impact of jetting operations and optimize jet parameters. The jet parameters investigated include jet velocity, target distance, and nozzle height. Results indicate that seabed disturbance process can be divided into three stages: critical suspension, critical erosion, and plume dispersion. Seabed morphology exhibits distinct V-shaped or U-shaped features, with target-to-nozzle height ratios (<em>B</em>/<em>H</em>) equals to 1 identified as the critical threshold for shape transition. Plume transformation rate increases with jet velocity, ranging from 15% to 55%. After disturbance, the plume suspended concentration decreases with increasing nozzle height, reaching a maximum reduction of up to 70%. These findings provide valuable data for minimizing environmental disturbance in deep-sea jetting operations. Based on experimental results, a new method for calculating the relationship between jet parameters and plume dispersion is proposed, offering a theoretical and technical basis for reducing environmental impact in deep-sea mining.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104462"},"PeriodicalIF":4.3,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445959","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}

引用次数: 0

Linear active disturbance rejection control with linear quadratic regulator for Stewart platform in active wave compensation system

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-20 DOI: 10.1016/j.apor.2025.104469

Wenxuan Wang , Yinghao Ning , Yang Zhang , Peng Xu , Bing Li

Offshore operations are vulnerable to the vessel motions caused by waves in harsh sea conditions. To compensate for the wave-included motions of the vessel, the shipborne Stewart platform with a gangway mechanism offers an effective means to enhance operator safety and extend the window period for offshore activities. The gangway endures off-center heavy loads and low-frequency vibrations, while the shipborne Stewart platform faces time-varying ship motions caused by waves. In addition, there is a strong motion coupling between the limbs of the Stewart platform. These challenges pose a formidable task in attaining precise control accuracy for wave compensation. In this study, a linear active disturbance rejection control with a linear quadratic regulator is proposed for the shipborne Stewart platform. The original proportional-derivative gain is substituted with a linear quadratic regulator (LQR), thereby effectively addressing the previous challenge of channel parameter tuning. Additionally, a linear extended state observer is devised to enhance system robustness by estimating and counteracting overall disturbance. The proposed controller is designed based on joint-space and its stability is verified using the Lyapunov theory. Simulation results validate that the proposed controller demonstrates superior performance in terms of compensation accuracy, anti-disturbance capability, and decoupling effect compared to the PI and LQR controllers.

{"title":"Linear active disturbance rejection control with linear quadratic regulator for Stewart platform in active wave compensation system","authors":"Wenxuan Wang , Yinghao Ning , Yang Zhang , Peng Xu , Bing Li","doi":"10.1016/j.apor.2025.104469","DOIUrl":"10.1016/j.apor.2025.104469","url":null,"abstract":"<div><div>Offshore operations are vulnerable to the vessel motions caused by waves in harsh sea conditions. To compensate for the wave-included motions of the vessel, the shipborne Stewart platform with a gangway mechanism offers an effective means to enhance operator safety and extend the window period for offshore activities. The gangway endures off-center heavy loads and low-frequency vibrations, while the shipborne Stewart platform faces time-varying ship motions caused by waves. In addition, there is a strong motion coupling between the limbs of the Stewart platform. These challenges pose a formidable task in attaining precise control accuracy for wave compensation. In this study, a linear active disturbance rejection control with a linear quadratic regulator is proposed for the shipborne Stewart platform. The original proportional-derivative gain is substituted with a linear quadratic regulator (LQR), thereby effectively addressing the previous challenge of channel parameter tuning. Additionally, a linear extended state observer is devised to enhance system robustness by estimating and counteracting overall disturbance. The proposed controller is designed based on joint-space and its stability is verified using the Lyapunov theory. Simulation results validate that the proposed controller demonstrates superior performance in terms of compensation accuracy, anti-disturbance capability, and decoupling effect compared to the PI and LQR controllers.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104469"},"PeriodicalIF":4.3,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445960","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}

引用次数: 0

Energy-harvesting performance of a fully-passive coupled-pitching hydrofoil: A numerical study

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-19 DOI: 10.1016/j.apor.2025.104468

Zhen Liu , Xinyu Song , Yangshun Zhu

A fully-passive coupled-pitching hydrofoil is a developing trend for tidal-current power capture in the future. A two-dimensional numerical model was established to investigate the hydrodynamic characteristics and energy-harvesting performances of the hydrofoil under this operating mode, which was validated by corresponding experimental data. A benchmark case with a successful self-starting and stable working state was proposed. Effects of the Reynolds number, initial angle of attack, and primary moment of inertia on the operating mechanism of the hydrofoil were studied with the analysis of the flow structure around the hydrofoil and pressure and torque distributions. The variations of these parameters significantly influenced the generation of the leading-edge vortex, resulting in different phase differences between the primary and secondary passive pitching motions. The power coefficient and energy-harvesting efficiency peaked at 0.57 and 0.22, respectively.

引用次数: 0

Data-driven dynamic modeling for precise trajectory tracking of a bio-inspired robotic fish

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-17 DOI: 10.1016/j.apor.2025.104463

Zhiping Wang , Zonggang Li , Guangqing Xia , Huifeng Kang , Bin Li , Qingquan Li , Lixin Zheng

We propose utilizing an attention mechanism and deep neural networks to develop a hydrodynamic identification model, integrated with a time-triggered nonlinear model predictive controller (ENMPC) for precise trajectory tracking of a robotic fish. A central pattern generator (CPG) network was employed to design a synergistic gait controller for the robotic fish that could coordinate its pectoral fins and flexible body/caudal fins to enable multimodal motion. We derived a nonlinear map between the driving parameters and the thrust/torque of the robotic fish using a computational fluid dynamics (CFD) simulation dataset. The attention mechanism was applied to incorporate laminar flow effects and construct a hydrodynamic identification model based on a bidirectional long short-term memory (Bi-LSTM) network. This identification model serves as the foundation for learning a control transformation model that operates as its inverse. Finally, event-triggered nonlinear model predictive constraints were adjusted to account for external disturbances and thereby ensure the convergence of robotic fish tracking errors while minimizing computational costs.

{"title":"Data-driven dynamic modeling for precise trajectory tracking of a bio-inspired robotic fish","authors":"Zhiping Wang , Zonggang Li , Guangqing Xia , Huifeng Kang , Bin Li , Qingquan Li , Lixin Zheng","doi":"10.1016/j.apor.2025.104463","DOIUrl":"10.1016/j.apor.2025.104463","url":null,"abstract":"<div><div>We propose utilizing an attention mechanism and deep neural networks to develop a hydrodynamic identification model, integrated with a time-triggered nonlinear model predictive controller (ENMPC) for precise trajectory tracking of a robotic fish. A central pattern generator (CPG) network was employed to design a synergistic gait controller for the robotic fish that could coordinate its pectoral fins and flexible body/caudal fins to enable multimodal motion. We derived a nonlinear map between the driving parameters and the thrust/torque of the robotic fish using a computational fluid dynamics (CFD) simulation dataset. The attention mechanism was applied to incorporate laminar flow effects and construct a hydrodynamic identification model based on a bidirectional long short-term memory (Bi-LSTM) network. This identification model serves as the foundation for learning a control transformation model that operates as its inverse. Finally, event-triggered nonlinear model predictive constraints were adjusted to account for external disturbances and thereby ensure the convergence of robotic fish tracking errors while minimizing computational costs.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104463"},"PeriodicalIF":4.3,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419353","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}

引用次数: 0

Integrated path planning for AUV communication efficiency and obstacle avoidance based on ant colony optimization and three-dimensional dynamic window algorithm

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-16 DOI: 10.1016/j.apor.2025.104465

Xiaoyu Yuan , Jiawei Wang , Chengchang Tong , Hongbo Wang

In tasks such as deep-sea exploration, underwater resource surveying, and archaeological excavation, autonomous underwater vehicles (AUVs) significantly improve the success rate of missions while lowering costs and safety risks. However, AUVs encounter challenges such as poor communication environments, low acoustic communication rates, and dynamic obstacle avoidance during underwater operations. To tackle these issues, this study proposes a multiobjective path planning approach that involves combining improved ant colony optimization (ACO) with a three-dimensional (3D) dynamic window approach (DWA) to optimize the global path planning of AUVs while avoiding obstacles and minimizing path length and communication propagation loss. By introducing nondominated sorting, enhanced heuristic functions, and pheromone update rules, the improved 3D ACO algorithm successfully solves multiobjective optimization problems and balances path length and propagation loss. Moreover, by incorporating the improved 3D-DWA method, the AUV can dynamically avoid obstacles in real time based on the global route supplied by the 3D ACO, guaranteeing safe navigation in dynamic marine environments. By allocating diverse weights to the pitch velocity regions in the DWA method, AUVs can respond to dynamic obstacles in the environment more flexibly, further increasing mission efficiency and safety. Experimental results show that compared with the traditional methods, this method demonstrates significant benefits in terms of path length and communication efficiency, stressing its potential application in complex marine environments.

{"title":"Integrated path planning for AUV communication efficiency and obstacle avoidance based on ant colony optimization and three-dimensional dynamic window algorithm","authors":"Xiaoyu Yuan , Jiawei Wang , Chengchang Tong , Hongbo Wang","doi":"10.1016/j.apor.2025.104465","DOIUrl":"10.1016/j.apor.2025.104465","url":null,"abstract":"<div><div>In tasks such as deep-sea exploration, underwater resource surveying, and archaeological excavation, autonomous underwater vehicles (AUVs) significantly improve the success rate of missions while lowering costs and safety risks. However, AUVs encounter challenges such as poor communication environments, low acoustic communication rates, and dynamic obstacle avoidance during underwater operations. To tackle these issues, this study proposes a multiobjective path planning approach that involves combining improved ant colony optimization (ACO) with a three-dimensional (3D) dynamic window approach (DWA) to optimize the global path planning of AUVs while avoiding obstacles and minimizing path length and communication propagation loss. By introducing nondominated sorting, enhanced heuristic functions, and pheromone update rules, the improved 3D ACO algorithm successfully solves multiobjective optimization problems and balances path length and propagation loss. Moreover, by incorporating the improved 3D-DWA method, the AUV can dynamically avoid obstacles in real time based on the global route supplied by the 3D ACO, guaranteeing safe navigation in dynamic marine environments. By allocating diverse weights to the pitch velocity regions in the DWA method, AUVs can respond to dynamic obstacles in the environment more flexibly, further increasing mission efficiency and safety. Experimental results show that compared with the traditional methods, this method demonstrates significant benefits in terms of path length and communication efficiency, stressing its potential application in complex marine environments.</div></div>","PeriodicalId":8261,"journal":{"name":"Applied Ocean Research","volume":"156 ","pages":"Article 104465"},"PeriodicalIF":4.3,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419351","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}

引用次数: 0

Combination of backscatter calculation and image segmentation for denoising gated light ranging and imaging in fishing net detection

IF 4.3 2区工程技术 Q1 ENGINEERING, OCEAN

Applied Ocean Research

Pub Date : 2025-02-16 DOI: 10.1016/j.apor.2025.104455

Zhensong Xu , Xinwei Wang , Liang Sun , Bo Song , Yue Zhang , Pingshun Lei , Jianan Chen , Jun He , Yan Zhou , Yuliang Liu

Underwater fishing net detection and location plays a crucial role in applications such as safe navigation of unmanned underwater vehicles, protection of marine ecology and marine ranching. However, due to difficulties in detecting fishing nets and noise interference in underwater environments, underwater fishing net detection and location at long distance remains unsolved. In this paper, we use gated light ranging and imaging (LiRAI) as the detection hardware, and propose an underwater fishing net location algorithm based on the physical prior of backscatter noise. The proposed method utilizes the prior knowledge about the distributions of backscatter noise in the target and background regions. An image segmentation network based on deep learning and the initial depth information provided by gated LiRAI are employed to estimate the backscatter noise based on the prior knowledge. Our method can effectively eliminate the backscatter noise and obtain accurate fishing net location results. Field experiments show our method achieves 0.001 absolute relative error (Abs Rel) and 0.156 root mean square error (RMSE) at 27 m in water with

0 .26 m^{- 1}

attenuation coefficient. Moreover, experiments in underwater environments with different turbidity further validate the effectiveness and generalization of our method.

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