检索结果-南通市图书馆

Numerical Study of Viscous Wave-Making Resistance of ship navigation in Still Water

在线全文

学校读者我要写书评

暂无评论

Journal of Marine Science and Application 2014年第2期13卷 158-166页

作者： Ruosi Zha Haixuan Ye Zhirong Shen Decheng Wan State Key Laboratory of 0cean Engineering School of Naval Architecture 0cean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

The prediction of a ship＇s resistance especially the viscous wave-making resistance is an important issue in CFD applications. In this paper, the resistances of six ships from hull 1 to hull 6 with different hull forms advancing in still water are numerically studied using the solver naoe-FOAM-SJTU, which was developed based on the open source code package OpenFOAM. Different components of the resistances are computed and compared while considering two speed conditions （12 kn and 16 kn）. The resistance of hull 3 is the smallest while that of hull 5 is the largest at the same speed. The results show hull 3 is a good reference for the design of similar ships, which can provide some valuable guidelines for hull form optimization.

关键词： ship navigation CFD wave-making resistance viscous flow hull naoe-FOAM-SJTU solver OpenFOAM

Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第2期38卷 313-325页

作者： DONG Wen-bo ZHOU Li DING Shi-feng WANG Ai-ming CAI Jin-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of *** the Arctic,merchant ships with low ice class often navigate in channels opened up by *** in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large *** ship may get stuck if steered into ice fields off the *** this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable *** this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point *** first stage employs the image segmentation method to extract channel *** the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression *** training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel *** evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second.

关键词： ice channel ship navigation identification image segmentation corner point regression

An iterative calibration method for nonlinear coefficients of marine triaxial accelerometers

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2013年第11期20卷 3103-3115页

作者：杨杰吴文启武元新练军想 Department of Automatic Control College of Mechatronics and AutomationNational University of Defense Technology

Single-axis rotation technique is often used in the marine laser inertial navigation system so as to modulate the constant biases of non-axial gyroscopes and accelerometers to attain better navigation ***,two significant accelerometer nonlinear errors need to be attacked to improve the modulation ***,the asymmetry scale factor inaccuracy enlarges the errors of frequent zero-cross oscillating specific force measured by non-axial ***,the traditional linear model of accelerometers can hardly measure the continued or intermittent acceleration *** two nonlinear errors degrade the high-precision specific force measurement and the calibration of nonlinear coefficients because triaxial accelerometers is urgent for the marine *** on the digital signal sampling property,the square coefficients and cross-coupling coefficients of accelerometers are ***,the asymmetry scale factors are considered in the I-F conversion ***,a nonlinear model of specific force measurement is established compared to the linear *** on the three-axis turntable,the triaxial gyroscopes are utilized to measure the specific force observation for triaxial *** the nonlinear combination,the standard calibration parameters and asymmetry factors are separately estimated by a two-step iterative identification ***,an efficient specific force calculation model is approximately derived to reduce the real-time computation *** results illustrate the sufficient estimation accuracy of nonlinear *** experiments demonstrate that the nonlinear model shows much higher accuracy than the linear model in both the gravimetry and sway navigation validations.

关键词： ship navigation single-axis rotation inertial system laser gyroscopes quartz accelerometers nonlinear calibration

Remote Sensing Monitoring Method Based on BDS-Based Maritime Joint Positioning Model

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2021年第5期127卷 801-818页

作者： Xiang Wang Jingxian Liu Osamah Ibrahim Khalaf Zhao Liu Hubei Key Laboratory of Inland shipping Technology School of NavigationWuhan University of TechnologyWuhan430063China Donghai navigation Safety Administration Ministry of Transport of the People’s Republic of ChinaShanghai201206China Al-Nahrain Nanorenewable Energy Research Centre Al-Nahrain UniversityBaghdadIraq

Complicated sea conditions have a serious impact on ship navigation safety and even maritime ***,this paper proposes a remote sensing monitoring method based on the Beidou navigation Satellite System(BDS)maritime joint positioning *** method is mainly based on the BDS and multiple Global navigation Satellite Systems(GNSS)to build a data fusion model,which can capture more steady positioning,navigation,and timing(PNT)*** with the current Global Positioning System(GPS)and Global navigation Satellite System(GLONASS)mandatory used by the International Maritime Organization(IMO),this model has the characteristics of more accurate positioning data and stronger *** static and dynamic measurement show that such a model works for maritime ships and maritime *** with the ship’s Automatic Identification System(AIS)and Geographic Information System(GIS),a BDS-based remote sensing monitoring method can cover the world,serve maritime ships and construct maritime engineering.

关键词： ship navigation AIS BDS GPS data fusion

ship behavior prediction via trajectory extraction-based clustering for maritime situation awareness

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2022年第1期7卷 1-13页

作者： Brian Murray LokukalugePrasad Perera UiT The Arctic University of Norway TromsøNorway

This study presents a method in which historical AIS data are used to predict the future trajectory of a se-lected *** is facilitated via a system intelligence-based approach that can be subsequently utilized to provide enhanced situation awareness to navigators and future autonomous ships,aiding proactive col-lision *** evaluating the historical ship behavior in a given geographical region,the method applies machine learning techniques to extrapolate commonalities in relevant trajectory *** commonalities represent historical behavior modes that correspond to the possible future behavior of the selected ***,the selected vessel is classified to a behavior mode,and a trajectory with respect to this mode is *** is achieved via an initial clustering technique and subsequent tra-jectory *** extracted trajectories are then compressed using the Karhunen-Loéve transform,and clustered using a Gaussian Mixture *** approach in this study differs from others in that tra-jectories are not clustered for an entire region,but rather for relevant trajectory *** such,the extracted trajectories provide a much better basis for clustering relevant historical ship behavior modes.A selected vessel is then classified to one of these modes using its observed *** predic-tions are facilitated using an enhanced subset of data that likely correspond to the future behavior of the selected *** method yields promising results,with high classification accuracy and low prediction ***,vessels with abnormal behavior degrade the results in some situations,and have also been discussed in this study.

关键词： Maritime situation awareness ship navigation Trajectory prediction Collision avoidance Machine learning Unsupervised learning AIS

A machine learning based Bayesian decision support system for efficient navigation of double-ended ferries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2024年第6期9卷 605-615页

作者： Vergara Daniel Alexandersson Martin Lang Xiao Mao Wengang Department of Mechanics and Maritime Sciences Chalmers University of TechnologySweden SSPA Research Institutes of SwedenGothenburgSweden

ships can be operated more efficiently by utilizing intelligent decision support integrated with onboard data collection *** this study,a Bayesian optimization-based decision support system,which uti-lizes ship performance models built by machine learning methods,is proposed to help determine the operational set-points of two engines for double-ended *** optimizing the ferries’power alloca-tion between the stern and bow engines,the Decision Support System(DSS)will simultaneously attempt to keep the ETA of the ferry fixed under a set of operational constraints using the Bayesian *** objective is to minimize fuel consumption along individual *** on simulation environment,the DSS can reduce at maximum 40%fuel consumption with no significant change of the *** full-scale experiments of a double-ended ferry demonstrated an average of 15%,where at least half of this saving was achieved by the optimized power allocation between bow and stern engines.

关键词： Bayesian optimization Energy efficiency ship navigation Machine learning ship models

Research on Weather Routing Based on the Mobile Internet

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Meteorological and Environmental Research 2018年第4期9卷 55-60页

作者： Li Jian Deng Chuang Zheng Weicai Wei Chen Zhejiang Meteorological Service Center Hangzhou 310017 China

The combination and application of the mobile internet techniques with the weather radar monitoring data and the numerical weather pre-diction data were introduced, and the smart phone weather routing application software for both land and aquatic traffic safety, which is equipped with the function of analysis and warning of disastrous weather, was developed to reduce potential weather risks encountered during the journey as much as possible.

关键词： Traffic weathe Weather routing Automobile navigation ship navigation Mobile internet

A New Two-Step Method for Calibration of Magnetic Compass

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A New Two-Step Method for Calibration of Magnetic Compass