Browsing NTNU Open by Author "Sørensen, Asgeir Johan"
Now showing items 1-20 of 138
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A brute-force spectral approach for wave estimation using measured vessel motions
Nielsen, Ulrik Dam; Brodtkorb, Astrid H.; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)The article introduces a spectral procedure for sea state estimation based on measurements of motion responses of a ship in a short-crested seaway. The procedure relies fundamentally on the wave buoy analogy, but the wave ... -
A new method for underwater archaeological surveying using sensors and unmanned platforms
Ødegård, Øyvind; Sørensen, Asgeir Johan; Hansen, Roy Edgar; Ludvigsen, Martin (Journal article; Peer reviewed, 2016)As most of the world’s oceans are inaccessible to diving archaeologists, we must rely on advanced underwater technology and marine robotics to explore, map and investigate ship wrecks in these areas. New sensors and unmanned ... -
A novel methodology for robust dynamic positioning of marine vessels: theory and experiments
Hassani, Vahid; Sørensen, Asgeir Johan; Pascoal, Antonio (Journal article, 2013)The paper describes a novel robust adaptive controller for Dynamic Positioning (DP) of marine vessels. The proposed Robust Multiple Model Adaptive Dynamic Positioning (RMMADP) structure consists of a bank of robust controllers ... -
A Voronoi-diagram-based dynamic path-planning system for underactuated marine vessels
Candeloro, Mauro; Lekkas, Anastasios M.; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2017)The main contribution of this paper is the development of a rapid, dynamic path-planning system for 3-DOF marine surface vessels navigating in environments where other marine vehicles might be operating too. The method is ... -
Active Load Mitigation to Counter the Fatigue Damage Contributions From Unavailability in Offshore Wind Turbines
Sørum, Stian Høegh; Smilden, Emil; Amdahl, Jørgen; Sørensen, Asgeir Johan (Chapter, 2018)The offshore wind industry continues to grow, but there is still a need for more economical designs. As unavailability conditions can be critical for the fatigue damage in support structures, design standards use conservative ... -
Active truncation of slender marine structures: Influence of the control system on Fidelity
Sauder, Thomas Michel; Marelli, Stefano; Larsen, Kjell; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2018)Performing hydrodynamic model testing of ultra-deep water floating systems at a reasonable scale ischallenging, due to the limited space available in existing laboratories and to the large spatial extent ofthe slender ... -
Adaptive Backstepping Control of Ship Speed Tracking and Hybrid Mode Selection.
Gao, Fan; Brodtkorb, Astrid H.; Mo, Sigrid Marie; Ren, Zhengru; Sørensen, Asgeir Johan (Peer reviewed; Journal article, 2021)This paper investigates the application of adaptive backstepping control to a hybrid power system for ship propulsion, using a main diesel engine in conjunction with a battery for auxiliary power supply. Fuel injection ... -
Adaptive Wave Filtering for Dynamic Positioning of Marine Vessels Using Maximum Likelihood Identification: Theory and Experiments
Hassani, Vahid; Sørensen, Asgeir Johan; Pascoal, Antonio (Chapter, 2016)This paper addresses a filtering problem that arises in the design of dynamic positioning systems for ships and offshore rigs subjected to the influence of sea waves. The dynamic model of the vessel captures explicitly the ... -
Agile smallsat operation tool-chain development: Hypso-1 hyperspectral earth observation experiences
Langer, Dennis David; Berg, Simen; Garrett, Joseph Landon; Birkeland, Roger; Bakken, Sivert; Johansen, Tor Arne; Sørensen, Asgeir Johan (Peer reviewed; Journal article, 2023)Satellite operations is important for a successful mission, but can be time consuming for inexperienced operators in new small satellite projects. We present a method for the continuous development of an earth observation ... -
AMOS DP Research Cruise 2016: Academic full-scale testing of experimental dynamic positioning control algorithms onboard R/V Gunnerus
Skjetne, Roger; Sørensen, Mikkel Eske Nørgaard; Breivik, Morten; Værnø, Svenn Are Tutturen; Brodtkorb, Astrid H.; Sørensen, Asgeir Johan; Kjerstad, Øivind Kåre; Calabrò, Vincenzo; Vinje, Bjørn Ole (Chapter; Peer reviewed, 2017)In order to validate relevant dynamic positioning (DP) control algorithms in a realistic environment, a full-scale DP test campaign, the AMOS DP Research Cruise 2016 (ADPRC’16), was organized in a collaboration between the ... -
An Output Feedback Controller with Improved Transient Response of Marine Vessels in Dynamic Positioning
Skjetne, Roger; Sørensen, Asgeir Johan; Værnø, Svenn Are Tutturen; Brodtkorb, Astrid H. (Journal article; Peer reviewed, 2016)An output feedback controller for dynamic positioning (DP) of marine surface vessels is developed. The proposed algorithm has good performance during transients as well as good steady state performance. The method achieves ... -
Analysis and control of drilling riser dynamics in dual gradient drilling
Fossum, Trygve Olav (Master thesis, 2013)The aim of this thesis is to investigate a dual gradient riser system, adapted for operations in the Gulf of Mexico and subjected to first- and second-order wave forces, current and rig/vessel motion.Deep water drilling ... -
Approaches to Economic Energy Management in Diesel-Electric Marine Vessels
Skjong, Espen; Johansen, Tor Arne; Molinas Cabrera, Maria Marta; Sørensen, Asgeir Johan (Journal article; Peer reviewed, 2017)Recently, the efficiency of diesel-electric marine vessels has been subject for discussion with focus on improving fuel efficiency, reducing the environmental footprint from emissions, as well as reducing running hours and ... -
Automatic simulation-based testing of autonomous ships using Gaussian processes and temporal logic
Torben, Tobias; Glomsrud, Jon Arne; Pedersen, Tom Arne; Utne, Ingrid Bouwer; Sørensen, Asgeir Johan (Peer reviewed; Journal article, 2022)A methodology for automatic simulation-based testing of control systems for autonomous vessels is proposed. The work is motivated by the need for increased test coverage and formalism in the verification efforts. It aims ... -
A Bayesian Approach to Supervisory Risk Control of AUVs Applied to Under-Ice Operations
Bremnes, Jens Einar; Thieme, Christoph Alexander; Sørensen, Asgeir Johan; Utne, Ingrid Bouwer; Norgren, Petter (Peer reviewed; Journal article, 2020)Autonomous underwater vehicles (AUVs) are efficient sensor-carrying platforms for mapping and monitoring undersea ice. However, under-ice operations impose demanding requirements to the system, as it must deal with uncertain ... -
Bayesian Estimation of Non-Stationary Ship Response Spectra
Møgster, Christian (Master thesis, 2015)The main topic of this master thesis is to obtain spectral information of non-stationary ship responses, with the motive of facilitating improvement of sea state estimation methods, that are using the wave buoy analogy. ... -
Boarding Control System - for Improved Accessibility to Offshore Wind Turbines
Auestad, Øyvind Fidje; Perez, Tristan; Gravdahl, Jan Tommy; Sørensen, Asgeir Johan; Espeland, Trygve H. (Journal article; Peer reviewed, 2015)This paper considers the dynamic modelling and motion control of a Surface Effect Ship (SES) for safer transfer of personnel and equipment from vessel to-and-from an offshore wind-turbine. Such a vessel is a key enabling ... -
Boarding control system for improved accessibility to offshore wind turbines: Full-scale testing
Auestad, Øyvind Fidje; Gravdahl, Jan Tommy; Perez, Tristan; Sørensen, Asgeir Johan; Espeland, Trygve H. (Journal article; Peer reviewed, 2015)This paper considers the dynamic modelling and motion control of a Surface Effect Ship (SES) for safer transfer of personnel and equipment from vessel to-and-from an offshore wind-turbine. The control system designed is ... -
Combined Dynamic Positioning and Optimal Wave Frequency Motion Damping of Surface Effect Ship
Sodeland, Per Sondre (Master thesis, 2015)The offshore wind industry is requesting high annual accessibility to wind-turbines. The turbines are located increasingly further from the shore. Simultaneously, operations & maintenance costs are to be minimized, therefore ... -
Combining reinforcement learning and historical AIS-data for simulating realistic ship paths
Klausen, Toni (Master thesis, 2020)Siden skip i økende grad blir mer komplekse og autonome, behøver man gode verktøy for å ivareta sikkerheten. Simuleringsbasert testing og verifikasjon av autonome skip utpeker seg som en lovende tilnærming. Denne metoden ...