A review presents the state-of-the-art path-following control systems for maritime autonomous surface ships,where the special focus is placed on the guidance subsystem and control subsystem.The path following control ...A review presents the state-of-the-art path-following control systems for maritime autonomous surface ships,where the special focus is placed on the guidance subsystem and control subsystem.The path following control system is one of the basic requirements for autonomous ships since it guarantees that the ship can track the predefined path with small crosstrack errors.The path following problem is firstly defined,and the cross-track error dynamics are derived from the kinematic equations of marine surface ships.The classical guidance laws are introduced,and the governing equations are also presented in this paper.A review of the guidance laws and controllers for the maritime autonomous surface ships has been carried out based on relevant journal and conference papers.Several important properties and characteristics,such as control structure,guidance law,control method,stability,environmental disturbance and vessel dynamics,are defined for the comparative analysis.Finally,the summary and a discussion on the most used technologies for the path following control of marine autonomous surface ships are presented and highlighted.展开更多
Global ports and maritime shipping networks are important carriers for global supply chain networks, but they are also the main sources of energy consumption and pollution. To limit ship emissions in ports and offshor...Global ports and maritime shipping networks are important carriers for global supply chain networks, but they are also the main sources of energy consumption and pollution. To limit ship emissions in ports and offshore areas, the International Maritime Organization, as well as some countries, has issued a series of policies. This study highlights the importance and necessity of investigating emergent research problems in the operation management of green ports and maritime shipping networks. Considerable literature related to this topic is reviewed and discussed. Moreover, a comprehensive research framework on green port and shipping operation management is proposed for future research opportunities. The framework mainly comprises four research areas related to emission control and grading policies. This review may provide new ideas to the academia and industry practitioners for improving the performance and efficiency of the operation management of green ports and maritime shipping networks.展开更多
In maritime safety research,risk is assessed usually within the framework of formal safety assessment(FSA),which provides a formal and systematic methodology to improve the safety of lives,assets,and the environment.A...In maritime safety research,risk is assessed usually within the framework of formal safety assessment(FSA),which provides a formal and systematic methodology to improve the safety of lives,assets,and the environment.A bespoke application of FSA to mitigate accidents in marine seismic surveying is put forward in this paper,with the aim of improving the safety of seismic vessel operations,within the context of developing an economically viable strategy.The work herein takes a close look at the hazards in North Sea offshore seismic surveying,in order to identify critical risk factors,leading to marine seismic survey accidents.The risk factors leading to undesirable events are analysed both qualitatively and quantitatively.A risk matrix is introduced to screen the identified undesirable events.Further to the screening,Fault Tree Analysis(FTA)is presented to investigate and analyse the most critical risks of seismic survey operation,taking into account the lack of historical data.The obtained results show that man overboard(MOB)event is a major risk factor in marine seismic survey operation;lack of training on safe work practice,slippery deck as a result of rain,snow or water splash,sea state affecting human judgement,and poor communication are identified as the critical risk contributors to the MOB event.Consequently,the risk control options are focused on the critical risk contributors for decision-making.Lastly,suggestions for the introduction and development of the FSA methodology are highlighted for safer marine and offshore operations in general.展开更多
The maritime communication network(MCN)plays an important role in the 6th generation(6G)system development.In MCNs,packet transport over long-distance lossy links will be ubiquitous.Transmission control protocol(TCP),...The maritime communication network(MCN)plays an important role in the 6th generation(6G)system development.In MCNs,packet transport over long-distance lossy links will be ubiquitous.Transmission control protocol(TCP),the dominant transport protocol in the past decades,have had performance issues in such links.In this paper,we propose a novel transport approach which uses user datagram protocol(UDP)along with a simple yet effective bandwidth estimator for congestion control,and with a proactive packet-level forward erasure correction(FEC)code called streaming code to provide low-delay loss recovery without data retransmissions at all.We show that the approach can effectively address two issues of the state-of-the-art TCP variants in the long-distance lossy links,namely 1)the low bandwidth utilization caused by the slow increase of the congestion window(CWND)due to long roundtrip time(RTT)and the frequent CWND drop due to random and congestion losses,and 2)the high endto-end in-order delivery delay when re-transmissions are incurred to recover lost packets.In addition,we show that the scheme’s goodput has good smoothness and short-term intra-protocol fairness properties,which are beneficial for multimedia streaming and interactive applications that are prominent parts of today’s wireless traffic.展开更多
文摘A review presents the state-of-the-art path-following control systems for maritime autonomous surface ships,where the special focus is placed on the guidance subsystem and control subsystem.The path following control system is one of the basic requirements for autonomous ships since it guarantees that the ship can track the predefined path with small crosstrack errors.The path following problem is firstly defined,and the cross-track error dynamics are derived from the kinematic equations of marine surface ships.The classical guidance laws are introduced,and the governing equations are also presented in this paper.A review of the guidance laws and controllers for the maritime autonomous surface ships has been carried out based on relevant journal and conference papers.Several important properties and characteristics,such as control structure,guidance law,control method,stability,environmental disturbance and vessel dynamics,are defined for the comparative analysis.Finally,the summary and a discussion on the most used technologies for the path following control of marine autonomous surface ships are presented and highlighted.
基金the Key Program of National Natural Science Foundation of China (Grant No. 71831008).
文摘Global ports and maritime shipping networks are important carriers for global supply chain networks, but they are also the main sources of energy consumption and pollution. To limit ship emissions in ports and offshore areas, the International Maritime Organization, as well as some countries, has issued a series of policies. This study highlights the importance and necessity of investigating emergent research problems in the operation management of green ports and maritime shipping networks. Considerable literature related to this topic is reviewed and discussed. Moreover, a comprehensive research framework on green port and shipping operation management is proposed for future research opportunities. The framework mainly comprises four research areas related to emission control and grading policies. This review may provide new ideas to the academia and industry practitioners for improving the performance and efficiency of the operation management of green ports and maritime shipping networks.
基金This project"Formal Safety Assessment of a Marine Seismic Survey Vessel Operation,Incorporating Risk Matrix and Fault Tree Analysis"has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 730888.
文摘In maritime safety research,risk is assessed usually within the framework of formal safety assessment(FSA),which provides a formal and systematic methodology to improve the safety of lives,assets,and the environment.A bespoke application of FSA to mitigate accidents in marine seismic surveying is put forward in this paper,with the aim of improving the safety of seismic vessel operations,within the context of developing an economically viable strategy.The work herein takes a close look at the hazards in North Sea offshore seismic surveying,in order to identify critical risk factors,leading to marine seismic survey accidents.The risk factors leading to undesirable events are analysed both qualitatively and quantitatively.A risk matrix is introduced to screen the identified undesirable events.Further to the screening,Fault Tree Analysis(FTA)is presented to investigate and analyse the most critical risks of seismic survey operation,taking into account the lack of historical data.The obtained results show that man overboard(MOB)event is a major risk factor in marine seismic survey operation;lack of training on safe work practice,slippery deck as a result of rain,snow or water splash,sea state affecting human judgement,and poor communication are identified as the critical risk contributors to the MOB event.Consequently,the risk control options are focused on the critical risk contributors for decision-making.Lastly,suggestions for the introduction and development of the FSA methodology are highlighted for safer marine and offshore operations in general.
基金supported by Natural Science Foundation of China(NSFC)under Grant no.61801248,62171240by the Key Research and Development Program of Jiangsu Province of China under Grant BE2021013-1+2 种基金by Science and Technology Program of Nantong under JC2021121by State Key Laboratory of Advanced Optical Communication Systems and Networks under Grant 2021GZKF006by the Postgraduate Research&Practice Innovation Program of Jiangsu Province KYCX223346。
文摘The maritime communication network(MCN)plays an important role in the 6th generation(6G)system development.In MCNs,packet transport over long-distance lossy links will be ubiquitous.Transmission control protocol(TCP),the dominant transport protocol in the past decades,have had performance issues in such links.In this paper,we propose a novel transport approach which uses user datagram protocol(UDP)along with a simple yet effective bandwidth estimator for congestion control,and with a proactive packet-level forward erasure correction(FEC)code called streaming code to provide low-delay loss recovery without data retransmissions at all.We show that the approach can effectively address two issues of the state-of-the-art TCP variants in the long-distance lossy links,namely 1)the low bandwidth utilization caused by the slow increase of the congestion window(CWND)due to long roundtrip time(RTT)and the frequent CWND drop due to random and congestion losses,and 2)the high endto-end in-order delivery delay when re-transmissions are incurred to recover lost packets.In addition,we show that the scheme’s goodput has good smoothness and short-term intra-protocol fairness properties,which are beneficial for multimedia streaming and interactive applications that are prominent parts of today’s wireless traffic.
