Review of dynamic positioning control in maritime microgrid systems

For many offshore activities, including offshore oil and gas exploration and offshore wind farm construction, it is essential to keep the position and heading of the vessel stable. The dynamic positioning system is a progressive technology, which is extensively used in shipping and other maritime structures. To maintain the vessels or platforms from displacement, its thrusters are used automatically to control and stabilize the position and heading of vessels in sea state disturbances. The theory of dynamic positioning has been studied and developed in terms of control techniques to achieve greater accuracy and reduce ship movement caused by environmental disturbance for more than 30 years. This paper reviews the control strategies and architecture of the DPS in marine vessels. In addition, it suggests possible control principles and makes a comparison between the advantages and disadvantages of existing literature. Some details for future research on DP control challenges are discussed in this paper

Sustainable seabed mining: guidelines and a new concept for Atlantis II Deep

The feasibility of exploiting seabed resources is subject to the engineering solutions, and economic prospects. Due to rising metal prices, predicted mineral scarcities and unequal allocations of resources in the world, vast research programmes on the exploration and exploitation of seabed minerals are presented in 1970s. Very few studies have been published after the 1980s, when predictions were not fulfilled. The attention grew back in the last decade with marine mineral mining being in research and commercial focus again and the first seabed mining license for massive sulphides being granted in Papua New Guinea’s Exclusive Economic Zone.Research on seabed exploitation and seabed mining is a complex transdisciplinary field that demands for further attention and development. Since the field links engineering, economics, environmental, legal and supply chain research, it demands for research from a systems point of view. This implies the application of a holistic sustainability framework of to analyse the feasibility of engineering systems. The research at hand aims to close this gap by developing such a framework and providing a review of seabed resources. Based on this review it identifies a significant potential for massive sulphides in inactive hydrothermal vents and sediments to solve global resource scarcities. The research aims to provide background on seabed exploitation and to apply a holistic systems engineering approach to develop general guidelines for sustainable seabed mining of polymetallic sulphides and a new concept and solutions for the Atlantis II Deep deposit in the Red Sea.The research methodology will start with acquiring a broader academic and industrial view on sustainable seabed mining through an online survey and expert interviews on seabed mining. In addition, the Nautilus Minerals case is reviewed for lessons learned and identification of challenges. Thereafter, a new concept for Atlantis II Deep is developed that based on a site specific assessment.The research undertaken in this study provides a new perspective regarding sustainable seabed mining. The main contributions of this research are the development of extensive guidelines for key issues in sustainable seabed mining as well as a new concept for seabed mining involving engineering systems, environmental risk mitigation, economic feasibility, logistics and legal aspects

Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Design and dynamic modeling of a solar electric boat power system

This thesis describes the system required for a solar electric boat power system with energy storage and a DC gas generator for sailing the boat at 10km/h with 20people. Details of existing diesel engine-driven boats in a river in Bangladesh were collected for the system design. Sizing assessment, sensitivity analysis, and optimization of required power are performed in HOMER. The system’s equipment is modeled in MATLAB Simulink platform and simulated to know the dynamic performance of system components. An Arduino-based basic control system also was proposed for the solar boat. The proposed system was simulated in Tinkercad.com web-based software to check the live functionality of the designed control system. Power system instruments were proposed, including solar PV panel, PMDC motor and driver, generator, lead-acid battery, circuit breaker, busbar, and a programmable display device to measure battery voltage and capacity and display data. Additionally, navigation instruments were proposed for measuring water depth, boat speed, and water temperature and display the values on a monitor. The projected payback period was calculated for the recommended solar boat. PV/diesel/battery hybrid power system is compared with PV/battery and the traditional diesel-only power system in this research. Economic analysis indicates that the proposed solar boat design is the best option for rivers in Bangladesh

Dynamic life cycle assessment for electric propulsion with net-zero fuels

In recent decades, Life Cycle Assessment (LCA) has been widely adopted as a method to determine the holistic environmental impacts of products and systems across various industrial and academic sectors. The methodological soundness of LCA has been demonstrated during this period. Although the marine industry was a latecomer to LCA, with few studies reported until 2000, there has since been a gradual increase in the number of LCA applications for marine ships and fuels. Initially developed as a standardised model to assess the holistic environmental impacts of static activities, LCA has been criticised for its inadequacy when applied to the maritime sector, where ships are subject to dynamic changes. Shipping activities operate in an ever-changing environment of wind speed and direction, solar radiation, ship speed, load, routes, and voyage schedules. As a result, it is essential to estimate the environmental impact of ships on a real-time basis. This thesis highlights the research gaps inherent in the conventional LCA method and their applications in the maritime sector, which can be summarised into two fundamental issues: 1) the traditional LCA is overly dependent on past data, and 2) their results are deterministic while no real-time processes are involved. To address these gaps, this thesis introduces Dynamic LCA, which comprises two packages of LCA models: Live-LCA and Real-time LCA. The effectiveness of these LCA models was evaluated through a series of case studies. Live-LCA was applied to ships using solar PV systems, revealing a difference of up to 44% in the environmental impacts of the case ship compared to the traditional LCA. This case study also contributed to demystifying the lifecycle impacts of PV systems for marine applications. The second case study with Live-LCA was conducted to determine the viability of alternative fuels for Scotland's short-route ferries. The study proved that a key feature of Live-LCA, data generation through simulations, was effective under circumstances where real data is not available. Unlike Live-LCA, Real-Time LCA (RT-LCA) was designed to be applied to case studies where real-time data is accessible. The real-time data was transmitted through a digital platform developed by LAB021, a Korean ship digital solution provider. The format of outcomes, as real-time observation, was shown to be highly appreciable, while possibly encouraging ship operators to take immediate action to reduce lifecycle emissions if they are plotted too high. Overall, a key novelty of this thesis is the introduction of Dynamic LCA, which has been proven effective in resolving the fundamental limitations of conventional LCA. Key findings through a series of demonstrative works via case studies are also believed to make a sound contribution to the maritime industry while providing valuable insights into maritime decarbonisation in a holistic way. Lastly, Dynamic LCA can be a new standardised LCA method, challenging rules and policymakers for future regulatory frameworks.In recent decades, Life Cycle Assessment (LCA) has been widely adopted as a method to determine the holistic environmental impacts of products and systems across various industrial and academic sectors. The methodological soundness of LCA has been demonstrated during this period. Although the marine industry was a latecomer to LCA, with few studies reported until 2000, there has since been a gradual increase in the number of LCA applications for marine ships and fuels. Initially developed as a standardised model to assess the holistic environmental impacts of static activities, LCA has been criticised for its inadequacy when applied to the maritime sector, where ships are subject to dynamic changes. Shipping activities operate in an ever-changing environment of wind speed and direction, solar radiation, ship speed, load, routes, and voyage schedules. As a result, it is essential to estimate the environmental impact of ships on a real-time basis. This thesis highlights the research gaps inherent in the conventional LCA method and their applications in the maritime sector, which can be summarised into two fundamental issues: 1) the traditional LCA is overly dependent on past data, and 2) their results are deterministic while no real-time processes are involved. To address these gaps, this thesis introduces Dynamic LCA, which comprises two packages of LCA models: Live-LCA and Real-time LCA. The effectiveness of these LCA models was evaluated through a series of case studies. Live-LCA was applied to ships using solar PV systems, revealing a difference of up to 44% in the environmental impacts of the case ship compared to the traditional LCA. This case study also contributed to demystifying the lifecycle impacts of PV systems for marine applications. The second case study with Live-LCA was conducted to determine the viability of alternative fuels for Scotland's short-route ferries. The study proved that a key feature of Live-LCA, data generation through simulations, was effective under circumstances where real data is not available. Unlike Live-LCA, Real-Time LCA (RT-LCA) was designed to be applied to case studies where real-time data is accessible. The real-time data was transmitted through a digital platform developed by LAB021, a Korean ship digital solution provider. The format of outcomes, as real-time observation, was shown to be highly appreciable, while possibly encouraging ship operators to take immediate action to reduce lifecycle emissions if they are plotted too high. Overall, a key novelty of this thesis is the introduction of Dynamic LCA, which has been proven effective in resolving the fundamental limitations of conventional LCA. Key findings through a series of demonstrative works via case studies are also believed to make a sound contribution to the maritime industry while providing valuable insights into maritime decarbonisation in a holistic way. Lastly, Dynamic LCA can be a new standardised LCA method, challenging rules and policymakers for future regulatory frameworks