Covering about three quarters of the surface area of the earth,the ocean is a critical source of sustenance,medicine,and commerce.However,such vast expanse in both surface area and depth,presents myriad observing chal...Covering about three quarters of the surface area of the earth,the ocean is a critical source of sustenance,medicine,and commerce.However,such vast expanse in both surface area and depth,presents myriad observing challenges for researchers,such as corrosion,attenuation of electromagnetic waves,and high pressure.Ocean observation technologies are progressing from the conventional single node,static and short-term modalities to multiple nodes,dynamic and long-term modalities,to increase the density of both temporal and spatial samplings.Although people’s knowledge of the oceans has been still quite limited,the contributions of many nations cooperating to develop the Global Ocean Observing System(GOOS)have remarkably promoted the development of ocean observing technologies.This paper reviews the typical observing technologies deployed from the sea surface to the seafloor,and discusses the future trend of the ocean observation systems with the docking technology and sustained ocean energy.展开更多
Compressed gas is usually used for the pressure compensation of the deep-sea pressure-maintaining sampler.The pressure and volume of the recovered fluid sample are highly related to the precharged gas. To better under...Compressed gas is usually used for the pressure compensation of the deep-sea pressure-maintaining sampler.The pressure and volume of the recovered fluid sample are highly related to the precharged gas. To better understand the behavior of the gas under high pressure, we present a new real gas state equation based on the compression factor Z which was derived from experimental data. Then theoretical calculation method of the pressure and volume of the sample was introduced based on this empirical gas state equation. Finally, the proposed calculation method was well verified by the high-pressure vessel experiment of the sampler under 115 MPa.展开更多
The movement mode of snakes is crawling,and the living environment of snakes with numerous branches and stones will cause plenty of wear for the snake scales.There are plenty of surface structures and morphology on sn...The movement mode of snakes is crawling,and the living environment of snakes with numerous branches and stones will cause plenty of wear for the snake scales.There are plenty of surface structures and morphology on snake scales to avoid severe wear.Among them,the research towards the keeled structure on snake scales is missing.Therefore,in this research,the wear resistance improvement of the keeled structure on the snake scales and the overlapped distribution of snake scales are investigated.The keeled and smooth snake scales were 3D printed and they were distributed on the substrate in the overlapped or paralleled ways.Besides these four samples with keeled/smooth scales and overlapped/paralleled distributed,there is also a reference sample with the same thickness.Based on the tribology test,the number of grooves of samples with the keeled structures is higher than that of samples with smooth surfaces,which indicates that the keeled structure dramatically enhances the wear resistance of snake scales,especially during the wear in the vertical direction.The experiment on surface morphology greatly compromised the result of the tribology test.In addition,the bottom portion of the keeled snake scales can be protected by the keeled structure.Besides,the overlapped distribution can protect the central region of snake scales and provide double-layer protection of the snake body.Overall,the keeled structure and the overlapped distribution play a significant part in the improvement of wear resistance of the snake skin.These findings can enhance the knowledge of the reptiles-mimic surface structure and facilitate the application of military uniforms under high-wear conditions.展开更多
It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipula...It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipulator(UM)imposes a considerable cognitive and physical load on the operator.In this paper,we propose a unifed shared control(USC)architecture for the UVMS,integrating divisible shared control(DSC)and interactive shared control(ISC)to alleviate the operator's workload.By applying task priority based on DSC,we divide the whole-body task into constraints,operation,and posture optimization subtasks.The robot autonomously avoids self-collisions and adjusts its posture according to the user's visual preferences.IsC incorporates haptic feedback to enhance human-robot collaboration,seamlessly integrating it into the operation task via a whole-body controller for the UVMS.Simulations and pool experiments are conducted to verify the feasibility of the method.Compared to manual control(MC),the proposed method reduces completion time by 17.50%,operator input length by 25.00%,and cognitive load by 35.53%in the simulations,with corresponding reductions of 22.73%,40.00%,and 29.91%in the pool experiments.Subjective measurements demonstrate the reduction in operator workload with the proposed method.展开更多
The conversion from constant current(CC)to constant voltage(CV)is one of the key technologies of CC underwater observatory systems.A shunt regulator with high stability and high reliability is usually used.Application...The conversion from constant current(CC)to constant voltage(CV)is one of the key technologies of CC underwater observatory systems.A shunt regulator with high stability and high reliability is usually used.Applications,however,are limited by high heat dissipation and low efficiency.In this paper,with an improved shunt regulation method,a novel concept of stepless power reconfiguration(SPR)for the CC/CV module is proposed.In cases with stable or slowly changing load,two modes of CC/CV conversion are proposed to reduce unnecessary power loss of the shunt regulator while being able to retain any operatorpreset power margin in the system:(1)the manual SPR(MSPR)method based on single-loop control method;(2)the automatic SPR(ASPR)method based on inner-outer loop control method.The efficiency of the system is analyzed.How to select some key parameters of the system is discussed.Experimental results show that MSPR and ASPR are both effective and practical methods to reduce heat dissipation and improve the efficiency of the CC/CV module,while the high stability of the shunt regulator remains.展开更多
基金Supported in part by the Marine S&T Fund of Shandong Province (Grant No. 2018SDKJ0211)part by the Fund of Platform for Technical Innovation Ningbo Research Institute of Zhejiang University (Grant No. NRI-ZJU-2019001)part by the Fundamental Research Funds for the Central Universities (Grant No. 2019XZZX003-07).
文摘Covering about three quarters of the surface area of the earth,the ocean is a critical source of sustenance,medicine,and commerce.However,such vast expanse in both surface area and depth,presents myriad observing challenges for researchers,such as corrosion,attenuation of electromagnetic waves,and high pressure.Ocean observation technologies are progressing from the conventional single node,static and short-term modalities to multiple nodes,dynamic and long-term modalities,to increase the density of both temporal and spatial samplings.Although people’s knowledge of the oceans has been still quite limited,the contributions of many nations cooperating to develop the Global Ocean Observing System(GOOS)have remarkably promoted the development of ocean observing technologies.This paper reviews the typical observing technologies deployed from the sea surface to the seafloor,and discusses the future trend of the ocean observation systems with the docking technology and sustained ocean energy.
基金The National Key Research and Development Program of China under contract Nos 2018YFC0310600 and2016YFC0300500。
文摘Compressed gas is usually used for the pressure compensation of the deep-sea pressure-maintaining sampler.The pressure and volume of the recovered fluid sample are highly related to the precharged gas. To better understand the behavior of the gas under high pressure, we present a new real gas state equation based on the compression factor Z which was derived from experimental data. Then theoretical calculation method of the pressure and volume of the sample was introduced based on this empirical gas state equation. Finally, the proposed calculation method was well verified by the high-pressure vessel experiment of the sampler under 115 MPa.
基金funded By Key Scientific And Technological Program Of Ningbo City(No.2021Z108)Yongjiang Talent Introduction Programme(No.2021A-154-G).
文摘The movement mode of snakes is crawling,and the living environment of snakes with numerous branches and stones will cause plenty of wear for the snake scales.There are plenty of surface structures and morphology on snake scales to avoid severe wear.Among them,the research towards the keeled structure on snake scales is missing.Therefore,in this research,the wear resistance improvement of the keeled structure on the snake scales and the overlapped distribution of snake scales are investigated.The keeled and smooth snake scales were 3D printed and they were distributed on the substrate in the overlapped or paralleled ways.Besides these four samples with keeled/smooth scales and overlapped/paralleled distributed,there is also a reference sample with the same thickness.Based on the tribology test,the number of grooves of samples with the keeled structures is higher than that of samples with smooth surfaces,which indicates that the keeled structure dramatically enhances the wear resistance of snake scales,especially during the wear in the vertical direction.The experiment on surface morphology greatly compromised the result of the tribology test.In addition,the bottom portion of the keeled snake scales can be protected by the keeled structure.Besides,the overlapped distribution can protect the central region of snake scales and provide double-layer protection of the snake body.Overall,the keeled structure and the overlapped distribution play a significant part in the improvement of wear resistance of the snake skin.These findings can enhance the knowledge of the reptiles-mimic surface structure and facilitate the application of military uniforms under high-wear conditions.
基金Project supported by the National Natural Science Foundation of China(No.52071292)。
文摘It is challenging for underwater vehicle-manipulator systems(UVMSs)to operate autonomously in unstructured underwater environments.Relying solely on teleoperation for both underwater vehicle(UV)and underwater manipulator(UM)imposes a considerable cognitive and physical load on the operator.In this paper,we propose a unifed shared control(USC)architecture for the UVMS,integrating divisible shared control(DSC)and interactive shared control(ISC)to alleviate the operator's workload.By applying task priority based on DSC,we divide the whole-body task into constraints,operation,and posture optimization subtasks.The robot autonomously avoids self-collisions and adjusts its posture according to the user's visual preferences.IsC incorporates haptic feedback to enhance human-robot collaboration,seamlessly integrating it into the operation task via a whole-body controller for the UVMS.Simulations and pool experiments are conducted to verify the feasibility of the method.Compared to manual control(MC),the proposed method reduces completion time by 17.50%,operator input length by 25.00%,and cognitive load by 35.53%in the simulations,with corresponding reductions of 22.73%,40.00%,and 29.91%in the pool experiments.Subjective measurements demonstrate the reduction in operator workload with the proposed method.
基金Project supported by the National Natural Science Foundation of China(No.51979246)the Ningbo Science and Technology Innovation 2025 Major Special Project,China(No.2020Z075)。
文摘The conversion from constant current(CC)to constant voltage(CV)is one of the key technologies of CC underwater observatory systems.A shunt regulator with high stability and high reliability is usually used.Applications,however,are limited by high heat dissipation and low efficiency.In this paper,with an improved shunt regulation method,a novel concept of stepless power reconfiguration(SPR)for the CC/CV module is proposed.In cases with stable or slowly changing load,two modes of CC/CV conversion are proposed to reduce unnecessary power loss of the shunt regulator while being able to retain any operatorpreset power margin in the system:(1)the manual SPR(MSPR)method based on single-loop control method;(2)the automatic SPR(ASPR)method based on inner-outer loop control method.The efficiency of the system is analyzed.How to select some key parameters of the system is discussed.Experimental results show that MSPR and ASPR are both effective and practical methods to reduce heat dissipation and improve the efficiency of the CC/CV module,while the high stability of the shunt regulator remains.
