• 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; Preprint, 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 ...
    • 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) ...
    • 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 ...