The Experts below are selected from a list of 5715 Experts worldwide ranked by ideXlab platform
Antonios Tsourdos - One of the best experts on this subject based on the ideXlab platform.
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coordinated trajectory planning for efficient communication relay using multiple uavs
Control Engineering Practice, 2013Co-Authors: Hyondong Oh, Antonios TsourdosAbstract:This paper investigates the use of small UAVs as communication relay nodes for expanding communication links and improving communication quality for a fleet of Naval Vessels. This paper firstly deals with the UAV deployment for stationary communication nodes, and then, proposes a decentralised nonlinear model predictive trajectory planning strategy for a dynamic environment. By exploiting motion estimates of Vessels and states of UAVs, the trajectory planning algorithm finds a control input sequence optimising network connectivity over a certain time horizon. Numerical simulations are performed for both stationary and manoeuvring Vessels to verify the feasibility and benefit of the proposed approach.
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coordinated trajectory planning for efficient communication relay using multiple uavs
Control Engineering Practice, 2013Co-Authors: Seungkeun Kim, Jinyoung Suk, Antonios TsourdosAbstract:This paper investigates the use of small UAVs as communication relay nodes for expanding communications links and improving communication quality, primarily for a fleet of ground or navy Vessels. An airborne relay in ground/maritime space can effectively connect to units operating over the horizon, beyond normal communication range, or under limited satellite communication environments. For efficient UAV communication relay, this paper firstly deals with the UAV deployment for stationary communication nodes, which finds the fixed optimal location of UAVs to improve the connectivity of a wireless network. Then, considering movements of Vessels and constraints of the fixed-wing UAV in a dynamic environment, this paper proposes a decentralised nonlinear model predictive trajectory planning strategy. By exploiting motion estimates of Vessels and states of UAVs, the trajectory planning algorithm finds a control input sequence over a certain time horizon, which optimises network connectivity. Numerical simulations are performed with different number of UAVs for both stationary and manoeuvring Naval Vessels to verify the feasibility and benefit of the proposed approach. © IFAC.
Dan M Frangopol - One of the best experts on this subject based on the ideXlab platform.
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optimal maintenance of Naval Vessels considering service life uncertainty
2019Co-Authors: Yan Liu, Dan M FrangopolAbstract:Life-cycle analysis is increasingly being used to assess the structural performance and total cost incurred during the service life of Naval Vessels. Decision making on maintenance scheduling is based on minimizing life-cycle cost and risk metrics. However, existing life-cycle frameworks generally consider deterministic service life in the analysis process. Due to budgetary reasons, Naval Vessels are often required to extend their service life beyond the originally designed life. Management plans based on deterministic service life concepts do not consider the uncertainties associated with service life assessment and prediction. Structural aging can have significant effects on operational costs and risks during the service life extension. This paper presents the modeling of service life uncertainty and its impacts on the life-cycle management of Naval Vessels. The proposed framework is aimed to provide robust maintenance strategies addressing service life uncertainties. The presented approach is applied to fatigue of a high speed Naval vessel.
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fatigue reliability and service life prediction of aluminum Naval ship details based on monitoring data
Structural Health Monitoring-an International Journal, 2015Co-Authors: Mohamed Soliman, Giorgio Barone, Dan M FrangopolAbstract:The evolution of Naval Vessels toward high-speed crafts subjected to severe sea conditions has promoted an increasing interest in lightweight high-strength materials. Due to its strength and weight characteristics, aluminum has been proven especially suitable as construction material for hull structures as well as other vessel parts. However, fatigue in aluminum Naval crafts needs to be effectively addressed for the proper life-cycle assessment. Structural health monitoring systems constitute effective tools for measuring the structural response and assessing the structural performance under actual operational conditions. In this article, an approach for using structural health monitoring information in the fatigue reliability analysis and service life prediction of aluminum Naval Vessels is presented. The accumulated fatigue damage and the fatigue reliability are quantified based on structural health monitoring data acquired under different operational conditions, specified by the ship speeds, sea states...
Jonathan Binns - One of the best experts on this subject based on the ideXlab platform.
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risk based maintenance scheduling with application to Naval Vessels and ships
Ocean Engineering, 2018Co-Authors: Jane Cullum, Jonathan Binns, Michael Lonsdale, Rouzbeh Abbassi, Vikram GaraniyaAbstract:Maintenance scheduling for Naval Vessels and ships requires ongoing improvement to manage rising maintenance costs within availability constraints. Existing maintenance scheduling approaches are not optimal as maintenance costs continue to rise without an improvement in vessel availability. This paper reviews the Risk-Based Maintenance Scheduling (RBM) framework as applied to ships and Naval Vessels, and provides a critical analysis of Risk Assessment and Maintenance Scheduling techniques used. Further, objectives and considerations are defined for future applications for ships and Naval Vessels, and the framework evaluated as an improvement on existing Preventative Maintenance (PM) and Reliability Centered Maintenance (RCM) methods. A probabilistic approach supported by condition monitoring data in combination with Decision Theory is suggested for the Risk Assessment and Maintenance Scheduling elements comprising an RBM Scheduling framework. Implementation of this framework from both periodic PM and RCM is presented. Development of applications from the component level upwards is suggested. Availability and overall maintenance cost are suggested as evaluation metrics against existing methods. The development of an application is formalized within a proposed framework. The development of an application within the RBM Scheduling framework is expected to result in reduced maintenance costs while meeting availability requirements for ship and Naval vessel applications.
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the whipping response of a submerged free free cylinder due to underwater explosions
Pacific 2017 International Maritime Conference, 2017Co-Authors: S M De Candia, Roberto Ojeda, W Reid, M Ratcliffe, Jonathan BinnsAbstract:Underwater explosions (UNDEX) generated by torpedos and mines present one of the most significant threats to the survivability of Naval Vessels. A non-contact UNDEX event produces two distinct pressure loading phenomena: an initial short duration, high frequency shock wave followed by a relatively low frequency pulsating bubble containing the gaseous products of detonation. The pulsating bubble may excite global, beam-like, structural response modes of the vessel, known as UNDEX induced whipping. Depending on the size and position of the explosive charge relative to the vessel, the maximum strain levels during whipping may exceed those during the initial shock phase. Due to the large costs of full-scale explosive trials, development of validated numerical modelling procedures for UNDEX whipping and shock response are required to assess the survivability of Naval Vessels. An experiment has been conducted to investigate the UNDEX whipping response of a fully submerged cylindrical pipe structure considering the effects of different charge sizes, stand-off distances and longitudinal positions along the hull. It was found that the longitudinal stand-off location has a significant influence on the whipping response and that the peak whipping response may not always occur at the stand-off point.
Dossi Simone - One of the best experts on this subject based on the ideXlab platform.
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Italia-Cina: le interazioni in ambito Navale e la proiezione cinese nel Mediterraneo allargato - Italy-China: Naval Interactions and Chinese Projection in the Wider Mediterranean
OrizzonteCina, 2020Co-Authors: Dossi SimoneAbstract:In October 1979, the Italian Naval Vessels “Ardito” and “Lupo” were welcomed in Shanghai in the first visit by the Italian Navy to the People’s Republic of China. Despite this promising start, exchanges with the People’s Liberation Army Navy remained limited for a long time. Since the early 2010s, however, interactions have intensified, mostly amid China’s growing projection towards the wider Mediterranean region. On the one hand, the two navies have increasingly interacted in the Gulf of Aden, in the context of their respective anti-piracy missions. On the other, such interactions have gradually extended to the Mediterranean Sea, with an increasing frequency of Chinese visits to Italian ports. While China’s Naval projection towards the wider Mediterranean region has fostered stability in the region, as demonstrated by Beijing’s contribution to anti-piracy efforts in the Gulf of Aden, its broader strategic implications for Italy should not be overlooked.In October 1979, the Italian Naval Vessels “Ardito” and “Lupo” were welcomed in Shanghai in the first visit by the Italian Navy to the People’s Republic of China. Despite this promising start, exchanges with the People’s Liberation Army Navy remained limited for a long time. Since the early 2010s, however, interactions have intensified, mostly amid China’s growing projection towards the wider Mediterranean region. On the one hand, the two navies have increasingly interacted in the Gulf of Aden, in the context of their respective anti-piracy missions. On the other, such interactions have gradually extended to the Mediterranean Sea, with an increasing frequency of Chinese visits to Italian ports. While China’s Naval projection towards the wider Mediterranean region has fostered stability in the region, as demonstrated by Beijing’s contribution to anti-piracy efforts in the Gulf of Aden, its broader strategic implications for Italy should not be overlooked
Simone Dossi - One of the best experts on this subject based on the ideXlab platform.
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Italia-Cina: le interazioni in ambito Navale e la proiezione cinese nel Mediterraneo allargato - Italy-China: Naval Interactions and Chinese Projection in the Wider Mediterranean
Università degli Studi di Torino, 2020Co-Authors: Simone DossiAbstract:In October 1979, the Italian Naval Vessels “Ardito” and “Lupo” were welcomed in Shanghai in the first visit by the Italian Navy to the People’s Republic of China. Despite this promising start, exchanges with the People’s Liberation Army Navy remained limited for a long time. Since the early 2010s, however, interactions have intensified, mostly amid China’s growing projection towards the wider Mediterranean region. On the one hand, the two navies have increasingly interacted in the Gulf of Aden, in the context of their respective anti-piracy missions. On the other, such interactions have gradually extended to the Mediterranean Sea, with an increasing frequency of Chinese visits to Italian ports. While China’s Naval projection towards the wider Mediterranean region has fostered stability in the region, as demonstrated by Beijing’s contribution to anti-piracy efforts in the Gulf of Aden, its broader strategic implications for Italy should not be overlooked
