To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on int...To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on integer linear programming(ILP)with flow balance constraints,ensuring the fair and efficient distribution of sub-areas among USVs and maintaining strong connectivity of assigned regions.In the established gridmap,a search-based path planning algorithm is performed on the sub-areas according to the allocation scheme.It uses the greedy algorithm and the A*algorithm to achieve complete coverage of the barrier-free area and obtain an efficient trajectory of each USV.The greedy algorithm enables fast local traversal of unvisited grids,while the A*algorithm ensures navigation to escape from deadlock areas and maintains global path continuity.The comparison of task allocation results proves that the task allocation algorithm based on ILP improves the mapping efficiency and task distribution fairness.The proposed allocation method and result analysis provide a certain reference for the practical application ofMulti-USV to perform survey tasks collaboratively.展开更多
Dear Editor,Underactuated autonomous surface vessels(ASVs)are increasingly attracting attention from researchers because of a wide range of applications[1].Consequently,path following,a typical functionality for ASVs,...Dear Editor,Underactuated autonomous surface vessels(ASVs)are increasingly attracting attention from researchers because of a wide range of applications[1].Consequently,path following,a typical functionality for ASVs,has become a research focus[2].Despite the abundant study results,some challenging issues are still worthy of exploration and resolution,two of which are addressed in this letter.The first one is related to the guidance law.Currently,common guidance methods in the ASV field include the line-of-sight(LOS)guidance[3]and vector field(VF)guidance[4].The response quality of LOS guidance is highly related to the lookahead distance;a constant lookahead distance may result in undesired phenomena such as the singularity problem and the reduction of trajectory smoothness of ASVs(see[5]).To this end,several works have proposed modified LOS guidance laws(see[6]).Although the above modifications,as pointed out by[7],the VF guidance exhibits smaller crosstrack errors and better performances than the LOS guidance.However,the existing VF guidance is only available for straight lines and orbits rather than curved paths,a considerable obstacle that limits its practical application(see[8],[9]).Thus,the VF guidance for curved path following deserves more in-depth study.展开更多
The trajectory planning and tracking control for an underactuated unmanned surface vessel(USV) were addressed.The reference trajectory was generated by a virtual USV,and the error equation of trajectory tracking for u...The trajectory planning and tracking control for an underactuated unmanned surface vessel(USV) were addressed.The reference trajectory was generated by a virtual USV,and the error equation of trajectory tracking for underactuated USV was obtained,which transformed the tracking and stabilization problem of underactuated USV into the stabilization problem of the trajectory tracking error equation.A nonlinear state feedback controller was proposed based on backstepping technique and Lyapunov's direct method.By means of Lyapunov analysis,it is proved that the proposed controller ensures that the solutions of closed loop system have the ultimate boundedness property.Numerical simulation results are presented to validate the effectiveness and robustness of the proposed controller.展开更多
This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined r...This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined relative to the leader. A robust adaptive target tracking law is proposed by using neural network and backstepping techniques. The advantage of the proposed control scheme is that the uncertain nonlinear dynamics caused by Coriolis/centripetal forces, nonlinear damping, unmodeled hydrodynamics and disturbances from the environment can be compensated by on line learning. Based on Lyapunov analysis, the proposed controller guarantees the tracking errors converge to a small neighborhood of the origin. Simulation results demonstrate the effectiveness of the control strategy.展开更多
A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous dist...A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous disturbances and measurement noise.The reference path can be a curve or a straight line.The proposed controller was designed by using Lyapunov’s direct method and sliding mode control and backstepping techniques.Because the sway axis of the vessel was not directly actuated,two sliding surfaces were introduced,the first one in terms of the surge motion tracking errors and the second one for the yaw motion tracking errors.The adaptive control law guaranteed the uniform ultimate boundedness of the tracking errors.Numerical simulation results were provided to validate the effectiveness of the proposed controller for path following of underactuated surface vessels.展开更多
This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay ...This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay system is transformed into a structure consisting of an unknown residual term and a parameter term with control inputs using a local compact form dynamic linearization(local-CFDL).To take advantage of the resulting structure,use a discrete-time extended state observer(DESO)to estimate the unknown residual factor.Then,according to the study,the inclusion of a time delay has no effect on the linearization structure,and an improved control approach is provided,in which DESO is used to adjust for uncertainties.Furthermore,a DESO-based event-triggered model-free adaptive control(ET-DESO-MFAC)is established by designing event-triggered conditions to assure Lyapunov stability.Only when the system’s indicator fulfills the provided event-triggered condition will the control input signal be updated;otherwise,the control input will stay the same as it is at the last trigger moment.A coordinate compensation approach is developed to reduce the steady-state inaccuracy of trajectory tracking.Finally,simulation experiments are used to assess the effectiveness of the proposed technique for trajectory tracking.展开更多
High-resolution underwater digital elevation models(DEMs)are important for water and soil conservation,hydrological analysis,and river channel dredging.In this work,the underwater topography of the Panjing River in Sh...High-resolution underwater digital elevation models(DEMs)are important for water and soil conservation,hydrological analysis,and river channel dredging.In this work,the underwater topography of the Panjing River in Shanghai,China,was measured by an unmanned surface vessel.Five different interpolation methods were used to generate the underwater DEM and their precision and applicability for different underwater landforms were analyzed through cross-validation.The results showed that there was a positive correlation between the interpolation error and the terrain surface roughness.The five interpolation methods were all appropriate for the survey area,but their accuracy varied with different surface roughness.Based on the analysis results,an integrated approach was proposed to automatically select the appropriate interpolation method according to the different surface roughness in the surveying area.This approach improved the overall interpolation precision.The suggested technique provides a reference for the selection of interpolationmethods for underwater DEMdata.展开更多
A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean current...A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.展开更多
A model-free adaptive heading control strategy for unmanned surface vessels(USVs)is proposed by integrating extended state observer(ESO)with model-free adaptive control.To handle internal model perturbations and exter...A model-free adaptive heading control strategy for unmanned surface vessels(USVs)is proposed by integrating extended state observer(ESO)with model-free adaptive control.To handle internal model perturbations and external disturbances,a discrete linear ESO is employed to estimate the aggregate uncertainties.Then,the model-free adaptive heading controller is constructed by utilizing system input and output data,and the estimation information deriving from the ESO.Furthermore,a dynamic event-triggered mechanism(ETM)is designed and embedded in the controller to save communication data.Compared with the periodic sampling,the introduction of the dynamic ETM enables the controller to achieve a comparable control performance with only 5.35%of the communication frequency.Simulation comparison and analysis exhibit that the proposed heading controller can achieve superior heading control effect for USVs and show broader application prospect.展开更多
China Launches“Blue Whale”-World’s First High-speed Uncrewed Submersible.The"Blue Whale,"a cutting-edge high-speed submersible unmanned surface vessel,was launched on April 28 in Zhuhai,south China's ...China Launches“Blue Whale”-World’s First High-speed Uncrewed Submersible.The"Blue Whale,"a cutting-edge high-speed submersible unmanned surface vessel,was launched on April 28 in Zhuhai,south China's Guangdong Province.展开更多
In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yi...In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yilong-10 high-altitude large unmanned aerial vehicle(UAV). The Yilong-10 UAV carried a self-developed dropsonde system and a millimeter-wave cloud radar system. In addition, a solar-powered unmanned surface vessel and two drifting buoys were used. The experiment was further supported by an intelligent, reciprocating horizontal drifting radiosonde system that was deployed from the Sansha Meteorological Observing Station, with the intent of producing a stereoscopic observation over the South China Sea. Comprehensive three-dimensional observations were collected using the system from 31 July to2 August, 2020. This information was used to investigate the formation and development processes of Typhoon Sinlaku(2020). The data contain measurements of 21 oceanic and meteorological parameters acquired by the five devices, along with video footage from the UAV. The data proved very helpful in determining the actual location and intensity of Typhoon Sinlaku(2020). The experiment demonstrates the feasibility of using a high-altitude, large UAV to fill in the gaps between operational meteorological observations of marine areas and typhoons near China, and marks a milestone for the use of such data for analyzing the structure and impact of a typhoon in the South China Sea. It also demonstrates the potential for establishing operational UAV meteorological observing systems in the future, and the assimilation of such data into numerical weather prediction models.展开更多
The submersible unmanned vessel(SUV)"Blue Whale"(Fig.1)serves as the core observation node within the Intelligent Swift Ocean Observing System(ISOOS),funded by the National Natural Science Foundation of Chin...The submersible unmanned vessel(SUV)"Blue Whale"(Fig.1)serves as the core observation node within the Intelligent Swift Ocean Observing System(ISOOS),funded by the National Natural Science Foundation of China[1].Developed by the marine intelligent unmanned equipment innovation team at the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),the SUV executes surface-underwater cross-domain observation missions,including operations under adverse sea states.Integrating the advantages of unmanned surface vessels and unmanned submersibles,the SUV platform achieves high-speed surface navigation,low-speed submerged operations,and fixed-point underwater hovering.展开更多
This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resou...This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resources.An event-triggered robust adaptive finite-time trajectory tracking control method for underactuated ships is designed by combining the existing trajectory tracking control methods and engineering needs in actual navigation.It can obviously improve the tracking accuracy of the ship,and complete the tracking task safely and efficiently.This scheme transforms the composite uncertain vector synthesized by uncertain parameters and external disturbances into a linear parameterized form.Next,considering the limitation of communication resources,a relative threshold event triggering mechanism is introduced to further extend the triggering time interval on the basis of the fixed threshold triggering scheme.Then,an event-triggered robust adaptive finite-time trajectory tracking control scheme is designed for underactuated ships,and a rigorous stability proof is provided through Lyapunov stability theory.Simulation experiment is carried out in MATLAB and the results show that the finite-time trajectory tracking control scheme proposed in this paper can effectively solve the problems of dynamic uncertainty.unknown time-varying external interference and limitation of communication resources.This paper can provide theoretical support for the autonomous navigation of intelligent ships.展开更多
A SMART‘WHALE’The Blue Whale,a cutting-edge high-speed submersible unmanned surface vessel,is launched in Zhuhai,Guangdong Province,on April 28.Its launch is a major step forward in the development of intelligent oc...A SMART‘WHALE’The Blue Whale,a cutting-edge high-speed submersible unmanned surface vessel,is launched in Zhuhai,Guangdong Province,on April 28.Its launch is a major step forward in the development of intelligent ocean equipment.Developed to operate both above and below the water's surface,the vessel can reach surface speeds of 36 knots(66.7 km/h),dive to avoid extreme weather such as typhoons and remain submerged in static suspension for over a month.It will be used for rapid emergency response and in meteorology,underwater mapping,photography,water sampling and infrastructure inspections.展开更多
In this paper,the formation control problem is investigated for a team of uncertain underactuated surface vessels(USVs)based on a directed graph.Considering the risk of collision and the limited communication range of...In this paper,the formation control problem is investigated for a team of uncertain underactuated surface vessels(USVs)based on a directed graph.Considering the risk of collision and the limited communication range of USVs,the prescribed performance control(PPC)methodology is employed to ensure collision avoidance and connectivity maintenance.An event-triggered mechanism is designed to reasonably use the limited communication resources.Moreover,neural networks(NNs)and an auxiliary variable are constructed to deal with the problems of uncertain nonlinearities and underactuation,respectively.Then,an event-triggered formation control scheme is proposed to ensure that all signals of the closed-loop system are uniformly ultimately bounded(UUB).Finally,simulation results are presented to demonstrate the effectiveness of the proposed control scheme.展开更多
Welcome to this special issue of The International Journal of Intelligent Control and Systems(IJICS),which is dedicated to Autonomous Intelligence for Unmanned Systems.In recent years,we have witnessed a rapid increas...Welcome to this special issue of The International Journal of Intelligent Control and Systems(IJICS),which is dedicated to Autonomous Intelligence for Unmanned Systems.In recent years,we have witnessed a rapid increase in the deployment of unmanned systems across a wide range of civilian and military applications,including unmanned aerial vehicles(UAVs),autonomous ground vehicles(AGVs),and unmanned surface vessels(USVs).It is critically important that effective analysis and control be carried out for these systems,especially when operating in complex and dynamic environments.The autonomous control capability has emerged as one of the key factors determining their success in task execution.Consequently,significant research efforts are now focused on enhancing the autonomy,robustness,and safety of unmanned systems,as well as exploring novel control strategies and advanced technical approaches to address these challenges.展开更多
基金supported in part by the International Science and Technology Project of Guangzhou Development District under Grant 2023GH08the Science and Technology Development Fund,MSAR,under Grants 0029/2022/AGJ and 0029/2023/RIA1the Program of Guangdong under Grant 2023A0505020003.
文摘To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on integer linear programming(ILP)with flow balance constraints,ensuring the fair and efficient distribution of sub-areas among USVs and maintaining strong connectivity of assigned regions.In the established gridmap,a search-based path planning algorithm is performed on the sub-areas according to the allocation scheme.It uses the greedy algorithm and the A*algorithm to achieve complete coverage of the barrier-free area and obtain an efficient trajectory of each USV.The greedy algorithm enables fast local traversal of unvisited grids,while the A*algorithm ensures navigation to escape from deadlock areas and maintains global path continuity.The comparison of task allocation results proves that the task allocation algorithm based on ILP improves the mapping efficiency and task distribution fairness.The proposed allocation method and result analysis provide a certain reference for the practical application ofMulti-USV to perform survey tasks collaboratively.
基金supported by the National Natural Science Foundation of China(62473243,62421004)the Fundamental Research Funds for the Provincial Universities(3072024 GH0404)+1 种基金the Key Research and Development Projects in Hainan Province(ZDYF2024GXJS009)the“Spring Wild Goose”Plan Project of Heilongjiang Province(CYQN24071).
文摘Dear Editor,Underactuated autonomous surface vessels(ASVs)are increasingly attracting attention from researchers because of a wide range of applications[1].Consequently,path following,a typical functionality for ASVs,has become a research focus[2].Despite the abundant study results,some challenging issues are still worthy of exploration and resolution,two of which are addressed in this letter.The first one is related to the guidance law.Currently,common guidance methods in the ASV field include the line-of-sight(LOS)guidance[3]and vector field(VF)guidance[4].The response quality of LOS guidance is highly related to the lookahead distance;a constant lookahead distance may result in undesired phenomena such as the singularity problem and the reduction of trajectory smoothness of ASVs(see[5]).To this end,several works have proposed modified LOS guidance laws(see[6]).Although the above modifications,as pointed out by[7],the VF guidance exhibits smaller crosstrack errors and better performances than the LOS guidance.However,the existing VF guidance is only available for straight lines and orbits rather than curved paths,a considerable obstacle that limits its practical application(see[8],[9]).Thus,the VF guidance for curved path following deserves more in-depth study.
基金Project(2013M540271)supported by the Postdoctoral Science Foundation of ChinaProject(HEUCF1321003)support by the Basic Research Foundation of Central University,ChinaProject(51209050)supported by the National Natural Science Foundation of China
文摘The trajectory planning and tracking control for an underactuated unmanned surface vessel(USV) were addressed.The reference trajectory was generated by a virtual USV,and the error equation of trajectory tracking for underactuated USV was obtained,which transformed the tracking and stabilization problem of underactuated USV into the stabilization problem of the trajectory tracking error equation.A nonlinear state feedback controller was proposed based on backstepping technique and Lyapunov's direct method.By means of Lyapunov analysis,it is proved that the proposed controller ensures that the solutions of closed loop system have the ultimate boundedness property.Numerical simulation results are presented to validate the effectiveness and robustness of the proposed controller.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60674037,61074017 and 61074004)the Program for New Century Excellent Talents in Universities (Grant No. NCET-09-0674)the Program for Liaoning Excellent Talents in Universities (Grant No. 2009R06)
文摘This paper is concerned with the formation control problem of multiple underactuated surface vessels moving in a leader-follower formation. The formation is achieved by the follower to track a virtual target defined relative to the leader. A robust adaptive target tracking law is proposed by using neural network and backstepping techniques. The advantage of the proposed control scheme is that the uncertain nonlinear dynamics caused by Coriolis/centripetal forces, nonlinear damping, unmodeled hydrodynamics and disturbances from the environment can be compensated by on line learning. Based on Lyapunov analysis, the proposed controller guarantees the tracking errors converge to a small neighborhood of the origin. Simulation results demonstrate the effectiveness of the control strategy.
基金Supported by the National Natural Science Foundation of China （Grant No. 61074053）the Applied Basic Research Program of Ministry of Transport of China （Grant No. 2011-329-225-390）
文摘A robust adaptive control strategy was developed to force an underactuated surface vessel to follow a reference path,despite the presence of uncertain parameters and unstructured uncertainties including exogenous disturbances and measurement noise.The reference path can be a curve or a straight line.The proposed controller was designed by using Lyapunov’s direct method and sliding mode control and backstepping techniques.Because the sway axis of the vessel was not directly actuated,two sliding surfaces were introduced,the first one in terms of the surge motion tracking errors and the second one for the yaw motion tracking errors.The adaptive control law guaranteed the uniform ultimate boundedness of the tracking errors.Numerical simulation results were provided to validate the effectiveness of the proposed controller for path following of underactuated surface vessels.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20201159).
文摘This paper provides an improved model-free adaptive control(IMFAC)strategy for solving the surface vessel trajectory tracking issue with time delay and restricted disturbance.Firstly,the original nonlinear time-delay system is transformed into a structure consisting of an unknown residual term and a parameter term with control inputs using a local compact form dynamic linearization(local-CFDL).To take advantage of the resulting structure,use a discrete-time extended state observer(DESO)to estimate the unknown residual factor.Then,according to the study,the inclusion of a time delay has no effect on the linearization structure,and an improved control approach is provided,in which DESO is used to adjust for uncertainties.Furthermore,a DESO-based event-triggered model-free adaptive control(ET-DESO-MFAC)is established by designing event-triggered conditions to assure Lyapunov stability.Only when the system’s indicator fulfills the provided event-triggered condition will the control input signal be updated;otherwise,the control input will stay the same as it is at the last trigger moment.A coordinate compensation approach is developed to reduce the steady-state inaccuracy of trajectory tracking.Finally,simulation experiments are used to assess the effectiveness of the proposed technique for trajectory tracking.
基金supported by the NationalNatural Science Foundation of China(Grant No.42102318)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘High-resolution underwater digital elevation models(DEMs)are important for water and soil conservation,hydrological analysis,and river channel dredging.In this work,the underwater topography of the Panjing River in Shanghai,China,was measured by an unmanned surface vessel.Five different interpolation methods were used to generate the underwater DEM and their precision and applicability for different underwater landforms were analyzed through cross-validation.The results showed that there was a positive correlation between the interpolation error and the terrain surface roughness.The five interpolation methods were all appropriate for the survey area,but their accuracy varied with different surface roughness.Based on the analysis results,an integrated approach was proposed to automatically select the appropriate interpolation method according to the different surface roughness in the surveying area.This approach improved the overall interpolation precision.The suggested technique provides a reference for the selection of interpolationmethods for underwater DEMdata.
文摘A constructive method was presented to design a global robust and adaptive output feedback controller for dynamic positioning of surface ships under environmental disturbances induced by waves, wind, and ocean currents. The ship's parameters were not required to be known. An adaptive observer was first designed to estimate the ship's velocities and parameters. The ship position measurements were also passed through the adaptive observer to reduce high frequency measurement noise from entering the control system. Using these estimate signals, the control was then designed based on Lyapunov's direct method to force the ship's position and orientation to globally asymptotically converge to desired values. Simulation results illustrate the effectiveness of the proposed control system. In conclusion, the paper presented a new method to design an effective control system for dynamic positioning of surface ships.
基金supported by the Shandong Provincial Natural Science Foundation(Nos.ZR2023QF039 and ZR2024MF068)the Taishan Scholars Project of Shandong Province of China(No.tstp20230624)the National Natural Science Foundation of China(No.62373205).
文摘A model-free adaptive heading control strategy for unmanned surface vessels(USVs)is proposed by integrating extended state observer(ESO)with model-free adaptive control.To handle internal model perturbations and external disturbances,a discrete linear ESO is employed to estimate the aggregate uncertainties.Then,the model-free adaptive heading controller is constructed by utilizing system input and output data,and the estimation information deriving from the ESO.Furthermore,a dynamic event-triggered mechanism(ETM)is designed and embedded in the controller to save communication data.Compared with the periodic sampling,the introduction of the dynamic ETM enables the controller to achieve a comparable control performance with only 5.35%of the communication frequency.Simulation comparison and analysis exhibit that the proposed heading controller can achieve superior heading control effect for USVs and show broader application prospect.
基金supported by the Petrel Meteorological Observation Experiment Project of the China Meteorological Administration and the “Adaptive Improvement of New Observation Platform for Typhoon Observation (2018YFC1506401)” of the Ministry of Science and Technology。
文摘In collaboration with 12 other institutions, the Meteorological Observation Center of the China Meteorological Administration undertook a comprehensive marine observation experiment in the South China Sea using the Yilong-10 high-altitude large unmanned aerial vehicle(UAV). The Yilong-10 UAV carried a self-developed dropsonde system and a millimeter-wave cloud radar system. In addition, a solar-powered unmanned surface vessel and two drifting buoys were used. The experiment was further supported by an intelligent, reciprocating horizontal drifting radiosonde system that was deployed from the Sansha Meteorological Observing Station, with the intent of producing a stereoscopic observation over the South China Sea. Comprehensive three-dimensional observations were collected using the system from 31 July to2 August, 2020. This information was used to investigate the formation and development processes of Typhoon Sinlaku(2020). The data contain measurements of 21 oceanic and meteorological parameters acquired by the five devices, along with video footage from the UAV. The data proved very helpful in determining the actual location and intensity of Typhoon Sinlaku(2020). The experiment demonstrates the feasibility of using a high-altitude, large UAV to fill in the gaps between operational meteorological observations of marine areas and typhoons near China, and marks a milestone for the use of such data for analyzing the structure and impact of a typhoon in the South China Sea. It also demonstrates the potential for establishing operational UAV meteorological observing systems in the future, and the assimilation of such data into numerical weather prediction models.
基金supported by the National Natural Science Foundation of China(grant no.42227901).
文摘The submersible unmanned vessel(SUV)"Blue Whale"(Fig.1)serves as the core observation node within the Intelligent Swift Ocean Observing System(ISOOS),funded by the National Natural Science Foundation of China[1].Developed by the marine intelligent unmanned equipment innovation team at the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),the SUV executes surface-underwater cross-domain observation missions,including operations under adverse sea states.Integrating the advantages of unmanned surface vessels and unmanned submersibles,the SUV platform achieves high-speed surface navigation,low-speed submerged operations,and fixed-point underwater hovering.
基金National Natural Science Foundation of China(Grant No.51911540478)Shandong Pr ovincial Key Research and Development Plan(Grant No.2019JZZY020712)+3 种基金Shandong Provincial Graduate Education and Teaching Reform Research Project(Grant No.SDYJG19217)Shandong Jiaotong University Doctoral Research and Entrepr eneurship Fund and Shandong Jiaotong University Climbing Research and Innovation Team Plan(Grant No.SDJTUC1802)Shandong Provincial Natural Science Foundation(Grant No.ZR2022ME087)Shandong Intelligent Transportation Key Labor atory(under preparation).
文摘This paper aims to solve the finite-time trajectory tracking problem of underactuated surface ships under the influence of dynamic uncertainty,unknown external time-varying interference and limited communication resources.An event-triggered robust adaptive finite-time trajectory tracking control method for underactuated ships is designed by combining the existing trajectory tracking control methods and engineering needs in actual navigation.It can obviously improve the tracking accuracy of the ship,and complete the tracking task safely and efficiently.This scheme transforms the composite uncertain vector synthesized by uncertain parameters and external disturbances into a linear parameterized form.Next,considering the limitation of communication resources,a relative threshold event triggering mechanism is introduced to further extend the triggering time interval on the basis of the fixed threshold triggering scheme.Then,an event-triggered robust adaptive finite-time trajectory tracking control scheme is designed for underactuated ships,and a rigorous stability proof is provided through Lyapunov stability theory.Simulation experiment is carried out in MATLAB and the results show that the finite-time trajectory tracking control scheme proposed in this paper can effectively solve the problems of dynamic uncertainty.unknown time-varying external interference and limitation of communication resources.This paper can provide theoretical support for the autonomous navigation of intelligent ships.
文摘A SMART‘WHALE’The Blue Whale,a cutting-edge high-speed submersible unmanned surface vessel,is launched in Zhuhai,Guangdong Province,on April 28.Its launch is a major step forward in the development of intelligent ocean equipment.Developed to operate both above and below the water's surface,the vessel can reach surface speeds of 36 knots(66.7 km/h),dive to avoid extreme weather such as typhoons and remain submerged in static suspension for over a month.It will be used for rapid emergency response and in meteorology,underwater mapping,photography,water sampling and infrastructure inspections.
基金partially supported by the National Natural Science Foundation of China under Grant Nos.62033003,62003098,61973091the Local Innovative and Research Teams Project of Guangdong Special Support Program under Grant No.2019BT02X353the China Postdoctoral Science Foundation under Grant Nos.2019M662813 and 2020T130124。
文摘In this paper,the formation control problem is investigated for a team of uncertain underactuated surface vessels(USVs)based on a directed graph.Considering the risk of collision and the limited communication range of USVs,the prescribed performance control(PPC)methodology is employed to ensure collision avoidance and connectivity maintenance.An event-triggered mechanism is designed to reasonably use the limited communication resources.Moreover,neural networks(NNs)and an auxiliary variable are constructed to deal with the problems of uncertain nonlinearities and underactuation,respectively.Then,an event-triggered formation control scheme is proposed to ensure that all signals of the closed-loop system are uniformly ultimately bounded(UUB).Finally,simulation results are presented to demonstrate the effectiveness of the proposed control scheme.
文摘Welcome to this special issue of The International Journal of Intelligent Control and Systems(IJICS),which is dedicated to Autonomous Intelligence for Unmanned Systems.In recent years,we have witnessed a rapid increase in the deployment of unmanned systems across a wide range of civilian and military applications,including unmanned aerial vehicles(UAVs),autonomous ground vehicles(AGVs),and unmanned surface vessels(USVs).It is critically important that effective analysis and control be carried out for these systems,especially when operating in complex and dynamic environments.The autonomous control capability has emerged as one of the key factors determining their success in task execution.Consequently,significant research efforts are now focused on enhancing the autonomy,robustness,and safety of unmanned systems,as well as exploring novel control strategies and advanced technical approaches to address these challenges.
