Browsing NTNU Open by Author "Andersson, Leif Erik"
Now showing items 1-18 of 18
-
A study on an iceberg drift trajectory
Andersson, Leif Erik; Scibilia, Francesco; Imsland, Lars Struen (Chapter, 2017)Iceberg drift forecast is a challenging process. Large uncertainties in iceberg geometry and in the driving forces — current, wind and waves — make accurate forecasts difficult. This article illustrates from a data set ... -
Adaptation of Engineering Wake Models using Gaussian Process Regression and High-Fidelity Simulation Data
Andersson, Leif Erik; Doekemeijer, Bart; van der Hoek, Daan; van Wingerden, W.; Imsland, Lars Struen (Peer reviewed; Journal article, 2020)This article investigates the optimization of yaw control inputs of a nine-turbine wind farm. The wind farm is simulated using the high-fidelity simulator SOWFA. The optimization is performed with a modifier adaptation ... -
An estimation-forecast set-up for iceberg drift prediction
Andersson, Leif Erik; Scibilia, Francesco; Imsland, Lars Struen (Journal article; Peer reviewed, 2016)Iceberg drift forecasting is challenging. Large uncertainties in iceberg geometry and in iceberg driving forces – current, wind and waves – make accurate forecasts difficult. In this work, a new estimation-forecast scheme ... -
An iceberg forecast approach based on a statistical ocean current model
Andersson, Leif Erik; Scibilia, Francesco; Imsland, Lars Struen (Journal article; Peer reviewed, 2019)This article proposes a statistical model for short-term iceberg drift forecasts by transforming the problem of forecasting the iceberg velocity into a problem of forecasting the ocean current velocity. A Vector-autoregression ... -
Analysis of Iceberg Drift Trajectories Using the Multivariate Empirical Mode Decomposition
Andersson, Leif Erik; Scibilia, Francesco; Copland, Luke; Aftab, Muhammad Faisal; Imsland, Lars Struen (Journal article; Peer reviewed, 2018)In this study we show how to detect and extract the tidal and inertial oscillation from iceberg velocity data by using the multivariate empirical model decomposition. Due to the similar frequencies of both oscillations in ... -
Comparison of statistical iceberg forecast models
Andersson, Leif Erik; Scibilia, Francesco; Copland, Luke; Imsland, Lars Struen (Journal article; Peer reviewed, 2018)Short-term iceberg drift prediction is challenging. Large uncertainties in the driving forces – current, wind and waves – usually prevent accurate forecasts. Recently several statistical iceberg forecast models have been ... -
Constrained Posterior Cramér-Rao Bound for Discrete-Time Systems
Andersson, Leif Erik; Brekke, Edmund Førland; Imsland, Lars Struen; Scibilia, Francesco (Journal article, 2017)This article presents a Cramér-Rao lower bound for the discrete-time filtering problem under linear state constraints. A simple recursive algorithm is presented that extends the computation of the Cramér-Rao lower bound ... -
Data Driven Filtering of Bowel Sounds Using Multivariate Empirical Mode Decomposition
Kölle, Konstanze; Aftab, Muhammad Faisal; Andersson, Leif Erik; Fougner, Anders Lyngvi; Stavdahl, Øyvind (Journal article; Peer reviewed, 2019)Background The analysis of abdominal sounds can help to diagnose gastro-intestinal diseases. Sounds originating from the stomach and the intestine, the so-called bowel sounds, occur in various forms. They are described ... -
Distributed learning for wind farm optimization with Gaussian processes
Andersson, Leif Erik; Bradford, Eric; Imsland, Lars Struen (Journal article; Peer reviewed, 2020) -
Hybrid Dynamic Surrogate Modelling for a Once-Through Steam Generator
Blakseth, Sindre Stenen; Andersson, Leif Erik; Mocholí Montañés, Rubén; Mazzetti, Marit Jagtoyen (Peer reviewed; Journal article, 2023)Four surrogate modelling techniques are compared in the context of modelling once-through steam generators (OTSGs) for offshore combined cycle gas turbines (GTCCs): Linear and polynomial regression, Gaussian process ... -
Model Predictive Control of multi-rotor wind turbines
Urdal, Jørgen (Master thesis, 2020)Skalering av konvensjonelle vindturbiner for å imøtekomme det økende kraftbehovet kommer med en rekke utfordringer. Ved å skalere vindturbiner øker effekten med kvadratet, mens vekten øker med kuben til rotorradiusen. Et ... -
On Kalman filtering with linear state equality constraints
Andersson, Leif Erik; Imsland, Lars Struen; Brekke, Edmund Førland; Scibilia, Francesco (Journal article; Peer reviewed, 2019)This article is concerned with the state estimation problem for linear systems with linear state equality constraints. We re-examine constrained Kalman filter variations and propose an alternative derivation of the optimal ... -
Predicting the benefit of wake steering on the annual energy production of a wind farm using large eddy simulations and Gaussian process regression
van der Hoek, Daan; Doekemeijer, Bart; Andersson, Leif Erik; van Wingerden, Jan Willem (Peer reviewed; Journal article, 2020)In recent years, wake steering has been established as a promising method to increase the energy yield of a wind farm. Current practice in estimating the benefit of wake steering on the annual energy production (AEP) ... -
Real-time optimization of wind farms using modifier adaptation and machine learning
Andersson, Leif Erik; Imsland, Lars Struen (Peer reviewed; Journal article, 2020)Coordinated wind farm control takes the interaction between turbines into account and improves the performance of the overall wind farm. Accurate surrogate models are the key to model-based wind farm control. In this article ... -
Short-term Iceberg Drift Estimation and Prediction
Andersson, Leif Erik (Doctoral theses at NTNU;2018:186, Doctoral thesis, 2018)Short-term iceberg drift forecast is part of the Ice Management framework, which is a key component of the International Standard, ISO 19906 specifying requirements and guidance for the design, construction, transportation, ... -
State Estimation of a Multi-Rotor Wind Turbine
Rønnestad, Erik Ramsland (Master thesis, 2020)Storskala Multi-Rotor Turbiner (MRT) for elektrisk kraftproduksjon introduserer nye utfordringer med hensyn til levetiden til støttestrukturen. Vestas Control Challenge fasiliterer utviklingen av avanserte belastningsreduserende ... -
Unmanned Aerial Vehicle Mission Planning for Combined Iceberg Detection and Tracking Missions
Langeveld, Sindre Matthijs (Master thesis, 2017)In this master thesis, iceberg detection and tracking by Unmanned Aerial Vehicles has been studied. Currently, most systems for ice management separate these two tasks. However, combining these tasks into a single algorithm ... -
Wind farm control - Part I: A review on control system conceptsand structures
Andersson, Leif Erik; Anaya-Lara, Olimpo; Tande, John Olav Giæver; Merz, Karl Otto; Imsland, Lars Struen (Journal article; Peer reviewed, 2021)Wind farm control design is a recently new area of research that has rapidly become a key enabler for the development of large wind farm projects and their safe and efficient connection to the power grid. A comprehensive ...