The control system designing of unmanned wave glider(UWG) is challenging since the control system is weak maneuvering, large time-lag and large disturbance, which is difficult to establish accurate mathematical model....The control system designing of unmanned wave glider(UWG) is challenging since the control system is weak maneuvering, large time-lag and large disturbance, which is difficult to establish accurate mathematical model. The control system for the "Ocean Rambler" UWG is studied in this work. A heading control method based on S-surface controller is designed. For the "rudder zero drift" problem in trials, an improved S-surface control method based on rudder angle compensation is proposed, which can compensate the adverse effects from environmental forces and installation error. The tank test and sea trial results prove that the proposed control method has favorable control performance, and the feasibility and reliability of the designed control system are also verified.展开更多
Mobile observation platforms are widely used in oceanographic and marine resource exploration and other applications. Wave Glider is a mobile platform that can transform wave energy into locomotion power and overcome ...Mobile observation platforms are widely used in oceanographic and marine resource exploration and other applications. Wave Glider is a mobile platform that can transform wave energy into locomotion power and overcome the bottleneck of low energy supply. Wave Glider has recently been applied to tow underwater sensors fulfilling observation tasks. In this paper, the dynamic system of Wave Glider with a towed body is studied by applying multibody mechanics, and the relevant motion conditions of the system are investigated. Dynamic models of Wave Glider with a towed body and tether are first developed individually and then integrated into a whole model. The numerical method is used to obtain the dynamic responses and assess performance of the towed body pulled by the submerged glider of Wave Glider. The effects of sea state, mass of the towed body, and length of the towed cable are investigated on the basis of simulation results. This work can be used for the design and analysis of Wave Glider-towed body systems.展开更多
Latent and sensible heat fluxes based on observations from a Black Pearl wave glider were estimated along the main stream of the Kuroshio Current from the East China Sea to the east coast of Japan,from December 2018 t...Latent and sensible heat fluxes based on observations from a Black Pearl wave glider were estimated along the main stream of the Kuroshio Current from the East China Sea to the east coast of Japan,from December 2018 to January 2019.It is found that the data obtained by the wave glider were comparable to the sea surface temperature data from the Operational Sea Surface Temperature and Sea Ice Analysis and the wind field data from WindSat.The Coupled Ocean Atmosphere Response Experiment 3.0(COARE 3.0)algorithm was used to calculate the change in air-sea turbulent heat flux along the Kuroshio.The averaged latent heat flux(LHF)and sensible heat flux(SHF)were 235 W/m^(2)and 134 W/m^(2),respectively,and the values in the Kuroshio were significant larger than those in the East China Sea.The LHF and SHF obtained from Objectively Analyzed Air-Sea Fluxes for the Global Oceans(OAFlux)were closer to those measured by the wave glider than those obtained from National Centers for Environmental Prediction(NCEP)reanalysis products.The maximum deviation occurred in the East China Sea and the recirculation zone of the Kuroshio(deviation of SHF>200 W/m^(2);deviation of LHF>400 W/m^(2)).This indicates that the NCEP and OAFlux products have large biases in areas with complex circulation.The wave glider has great potential to observe air-sea heat fluxes with a complex circulation structure.展开更多
Wave glider is the first unmanned autonomous marine robot to use only the ocean’s endless supply of wave energy for propulsion. Wave glider comprises fin system, tether and float which harvest all of its energy from ...Wave glider is the first unmanned autonomous marine robot to use only the ocean’s endless supply of wave energy for propulsion. Wave glider comprises fin system, tether and float which harvest all of its energy from waves and sun to produce forward thrust. As a consequence of the lack of design information and data for the wave glider, the main aim of the study is using computational fluid dynamics (CFD) to present a method to predict calm water resistance for the floating hull through calculations of 3 different hull forms using the same mesh generation under the same conditions. Calculations are carried out using 3 different mesh sizes for Froude number in the range of 0.10 to 0.40 and compared for accuracy of the solution parameters. Wigley parabolic hull, high speed round bilge form (NPL) and Series 60 have been comparatively investigated in order to estimate the hydrodynamics performance of the hull. The linear seakeeping analysis, coupled heave and pitch motions, roll motion, in irregular waves, with one parameter Bretschneider and JONSWAP spectra. Numerical computations have been performed for motion response predictions of the three hulls which cover wave angles from 0? to 180? at 45? intervals for six different forward speeds from 0 to 4.304 knots using Maxsurf Motion software. The close agreement between the numerical predictions shows the importance of CFD applications in estimating the hydrodynamics performance to design the floating hull and the numerical method is useful in glider design. The fine grid is fit to the calculation and shows the most appropriate results because convergent results are obtained as the mesh size decrease so the fine grid is the one which will be applied for the other hulls. Also it can be observed that the added resistance and the RAOs for NPL hull are less than the other hulls. Therefore from the comparisons, the NPL hull is the optimum hull compared to the other hulls from the resistance and seakeeping point of view.展开更多
The evaporation duct,a result of evaporation from the ocean,is a region above the sea surface in which radio waves are refracted downward.This duct has strong effects on microwave instruments.Typhoons cause huge anoma...The evaporation duct,a result of evaporation from the ocean,is a region above the sea surface in which radio waves are refracted downward.This duct has strong effects on microwave instruments.Typhoons cause huge anomalies in marine meteorological parameters that influence the evaporation duct distribution and structure,which in turn affects the propagation of electromagnetic(EM)waves.However,EM wave propagation under the typhoon process has seldom been reported.Thus,taking Typhoon Phanfone(201929)as an example,this study uses a dataset from the European Centre for Medium-Range Weather Forecasts,combined with the Naval Atmospheric Vertical Surface Layer Model and the parabolic equation model,to study the evaporation duct’s impact on EM wave propagation during a typhoon.The spatial and temporal path loss distributions reveal that large amounts of EM wave energy are emitted from the evaporation duct when the EM wave passes through a typhoon eye.On average,a typhoon eye causes an approximately 20 dB increase in path loss for EM wave propagation at low antenna height.Furthermore,the effects of a typhoon eye on EM wave propagation at different signal frequencies and antenna heights are studied.The results show that a typhoon has a larger impact on EM wave propagation with low signal frequency and high antenna height.展开更多
基金Project(51409061)supported by the National Natural Science Foundation of ChinaProject(QC2016062)supported by the Natural Science Foundation of Heilongjiang Province of China+1 种基金Project(2013M540271)supported by the China Postdoctoral Science FoundationProject(LBH-Z13055)supported by Heilongjiang Postdoctoral Financial Assistance,China
文摘The control system designing of unmanned wave glider(UWG) is challenging since the control system is weak maneuvering, large time-lag and large disturbance, which is difficult to establish accurate mathematical model. The control system for the "Ocean Rambler" UWG is studied in this work. A heading control method based on S-surface controller is designed. For the "rudder zero drift" problem in trials, an improved S-surface control method based on rudder angle compensation is proposed, which can compensate the adverse effects from environmental forces and installation error. The tank test and sea trial results prove that the proposed control method has favorable control performance, and the feasibility and reliability of the designed control system are also verified.
基金support of the National Natural Science Foundation of China (No.51875540)。
文摘Mobile observation platforms are widely used in oceanographic and marine resource exploration and other applications. Wave Glider is a mobile platform that can transform wave energy into locomotion power and overcome the bottleneck of low energy supply. Wave Glider has recently been applied to tow underwater sensors fulfilling observation tasks. In this paper, the dynamic system of Wave Glider with a towed body is studied by applying multibody mechanics, and the relevant motion conditions of the system are investigated. Dynamic models of Wave Glider with a towed body and tether are first developed individually and then integrated into a whole model. The numerical method is used to obtain the dynamic responses and assess performance of the towed body pulled by the submerged glider of Wave Glider. The effects of sea state, mass of the towed body, and length of the towed cable are investigated on the basis of simulation results. This work can be used for the design and analysis of Wave Glider-towed body systems.
基金The National Key R&D Program of China under contract Nos 2017YFC0305904,2017YFC0305902 and 2017YFC0305804the National Natural Science Foundation of China under contract No.44006020+3 种基金the Guangdong Science and Technology Project under contract No.2019A1515111044the Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)under contract No.2019JZZY020701the Wenhai Program of Pilot National Laboratory for Marine Science and Technology(Qingdao)under contract No.2017WHZZB0101the CAS Key Technology Talent Program under contract No.202012292205。
文摘Latent and sensible heat fluxes based on observations from a Black Pearl wave glider were estimated along the main stream of the Kuroshio Current from the East China Sea to the east coast of Japan,from December 2018 to January 2019.It is found that the data obtained by the wave glider were comparable to the sea surface temperature data from the Operational Sea Surface Temperature and Sea Ice Analysis and the wind field data from WindSat.The Coupled Ocean Atmosphere Response Experiment 3.0(COARE 3.0)algorithm was used to calculate the change in air-sea turbulent heat flux along the Kuroshio.The averaged latent heat flux(LHF)and sensible heat flux(SHF)were 235 W/m^(2)and 134 W/m^(2),respectively,and the values in the Kuroshio were significant larger than those in the East China Sea.The LHF and SHF obtained from Objectively Analyzed Air-Sea Fluxes for the Global Oceans(OAFlux)were closer to those measured by the wave glider than those obtained from National Centers for Environmental Prediction(NCEP)reanalysis products.The maximum deviation occurred in the East China Sea and the recirculation zone of the Kuroshio(deviation of SHF>200 W/m^(2);deviation of LHF>400 W/m^(2)).This indicates that the NCEP and OAFlux products have large biases in areas with complex circulation.The wave glider has great potential to observe air-sea heat fluxes with a complex circulation structure.
文摘Wave glider is the first unmanned autonomous marine robot to use only the ocean’s endless supply of wave energy for propulsion. Wave glider comprises fin system, tether and float which harvest all of its energy from waves and sun to produce forward thrust. As a consequence of the lack of design information and data for the wave glider, the main aim of the study is using computational fluid dynamics (CFD) to present a method to predict calm water resistance for the floating hull through calculations of 3 different hull forms using the same mesh generation under the same conditions. Calculations are carried out using 3 different mesh sizes for Froude number in the range of 0.10 to 0.40 and compared for accuracy of the solution parameters. Wigley parabolic hull, high speed round bilge form (NPL) and Series 60 have been comparatively investigated in order to estimate the hydrodynamics performance of the hull. The linear seakeeping analysis, coupled heave and pitch motions, roll motion, in irregular waves, with one parameter Bretschneider and JONSWAP spectra. Numerical computations have been performed for motion response predictions of the three hulls which cover wave angles from 0? to 180? at 45? intervals for six different forward speeds from 0 to 4.304 knots using Maxsurf Motion software. The close agreement between the numerical predictions shows the importance of CFD applications in estimating the hydrodynamics performance to design the floating hull and the numerical method is useful in glider design. The fine grid is fit to the calculation and shows the most appropriate results because convergent results are obtained as the mesh size decrease so the fine grid is the one which will be applied for the other hulls. Also it can be observed that the added resistance and the RAOs for NPL hull are less than the other hulls. Therefore from the comparisons, the NPL hull is the optimum hull compared to the other hulls from the resistance and seakeeping point of view.
基金Project supported by the National Natural Science Foundation of China （Nos. 51305396 and U1509210） and the Fundamental Research Funds for the Central Universities, China
基金supported in part by the National Natural Science Foundation of China(Nos.42076198 and 41906160)in part by the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2022008)。
文摘The evaporation duct,a result of evaporation from the ocean,is a region above the sea surface in which radio waves are refracted downward.This duct has strong effects on microwave instruments.Typhoons cause huge anomalies in marine meteorological parameters that influence the evaporation duct distribution and structure,which in turn affects the propagation of electromagnetic(EM)waves.However,EM wave propagation under the typhoon process has seldom been reported.Thus,taking Typhoon Phanfone(201929)as an example,this study uses a dataset from the European Centre for Medium-Range Weather Forecasts,combined with the Naval Atmospheric Vertical Surface Layer Model and the parabolic equation model,to study the evaporation duct’s impact on EM wave propagation during a typhoon.The spatial and temporal path loss distributions reveal that large amounts of EM wave energy are emitted from the evaporation duct when the EM wave passes through a typhoon eye.On average,a typhoon eye causes an approximately 20 dB increase in path loss for EM wave propagation at low antenna height.Furthermore,the effects of a typhoon eye on EM wave propagation at different signal frequencies and antenna heights are studied.The results show that a typhoon has a larger impact on EM wave propagation with low signal frequency and high antenna height.
