• Framework for Modeling and Simulation of Household Appliances 

      Bjerknes Nilsen, Christian; Hoff, Bjarte; Østrem, Trond (Peer reviewed; Chapter, 2018-12-31)
      This paper describes a framework for simulating household appliances in Simulink. Typical Norwegian household equipment have been analyzed based on their characteristic behavior, to establish the requirement for synthesizing and recreating their current waveform, harmonic currents and phase shift. Both detailed simulation of the current waveform and RMS currents for simulation over longer time periods ...
    • Charging technology for small maritime vessels 

      Hoff, Bjarte (Conference object, 2019-01-21)
    • Preliminary Results on Waypoint Tracking for Spacecraft with Actuator Constraints 

      Oland, Espen; Andersen, Tom Stian (Peer reviewed; Chapter; Bokkapittel, 2019-07-22)
      This paper presents preliminary results on how to perform waypoint tracking with spacecraft with actuator constraints. It considers a simplified spacecraft model and can be considered a deep space model, and shows how to perform waypoint tracking with only one main thruster together with full attitude control. As the spacecraft reaches close to the waypoint during a deceleration phase that makes the ...
    • PD+ based trajectory tracking of the underactuated quadrotor platform using dual quaternions 

      Johansen, Tor-Aleksander; Andersen, Tom Stian; Kristiansen, Raymond (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-29)
      We address the problem of state feedback trajectory tracking of the underactuated quadrotor platform in the dual quaternion framework through a PD+ tracking controller. The control law negates the need of generating a desired attitude trajectory as the translational error is mapped directly onto the rotational actuators through a virtual frame. More precisely, we show uniform practical asymptotic ...
    • Swedish first-year engineering students’ views of mathematics, self-efficacy and motivation and their effect on task performance 

      Tossavainen, Timo; Rensaa, Ragnhild Johanne; Johansson, Monica (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-29)
      We examine a group (N = 88) of Swedish first-year engineering students, their motivation, self-efficacy, and beliefs about the nature of mathematics, and how these relate to their task performance in mathematics. In our data, engineering students who emphasized the exact reasoning in their view of mathematics performed significantly better in a set of mathematical tasks than those who emphasized ...
    • Themes within lecturers' views on the teaching of linear algebra 

      Rensaa, Ragnhild Johanne; Hogstad, Ninni Marie; Monaghan, John David (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-25)
      This paper reports on themes that arose in an investigation of university lecturers’ views on the teaching of linear algebra. This focus on themes was the initial part of a study concentrating on four areas: What is important to teach in a first course in linear algebra? Are there teaching methods which are particularly suited for such a course? Are there tools that should/should not be used; and ...
    • Controlling a Chain of Integrators with Constrained Actuation Using Exponential Activation Functions 

      Oland, Espen; Kristiansen, Raymond (Peer reviewed; Chapter; Bokkapittel, 2019-10-24)
      This paper shows how to control a chain of integrators with constrained actuation by using exponential activation functions. Specifically, it shows how the control law can be decomposed into several parts that can be activated as they are required, resulting in a simple control law that is able to make the states converge fast to zero.
    • Dual quaternion control: a review of recent results within motion control 

      Johansen, Tor-Aleksander; Sánchez, José J.; Kristiansen, Raymond (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-24)
      This paper presents a review of recent results in the field of dual quaternion based motion control. In addition, we derive two control laws for trajectory tracking control of a fully actuated rigid-body based on the resemblance of dual quaternion kinematics and dynamics to the quaternion based rotational kinematics and dynamics. A velocity error sliding surface and an integrator backstepping ...
    • Electric Ships in Norway - Experiences and Future trends. 

      Hoff, Bjarte (Conference object; Konferansebidrag, 2020)
    • Ny flåte og elektrifisering – Eksempel på grøne løysingar og utviklinga i dag 

      Hoff, Bjarte (Conference object; Konferansebidrag, 2020)
    • Elektrifiering av hamna 

      Hoff, Bjarte (Conference object; Konferansebidrag, 2020)
    • Adaptive Backstepping Control for a Fully-Actuated Rigid-Body in a Dual-Quaternion Framework 

      Andersen, Tom Stian; Kristiansen, Raymond (Chapter; Bokkapittel, 2020-03-12)
      We address the trajectory tracking problem for a fully actuated rigid-body with unknown mass and inertia parameters and unknown disturbance forces, using an adaptive backstepping controller based on dual-quaternions. We show that the proposed controller, in closed loop with a nonlinear model of the system, renders the equilibrium points uniformly asymptotically stable. The proposed controller ...
    • Perspectives and reflections on teaching linear algebra 

      Rensaa, Ragnhild Johanne; Hogstad, Ninni Marie; Monaghan, John David (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-03)
      This paper presents ‘expert opinions’ on what should be taught in a first-year linear algebra course at university; the aim is to gain a generic picture and general guiding principles for such a course. Drawing on a Delphi method, 14 university professors—called ‘experts’ in this study—addressed the following questions: What should be on a first-year linear algebra undergraduate course for engineering ...
    • Reactive-Based Position Control of an Underactuated Quadrotor 

      Andersen, Tom Stian; Kristiansen, Raymond (Chapter; Bokkapittel, 2020-07-20)
      This paper addresses the problem of position control or waypoint tracking for an underactuated quadrotor. The proposed control law is what is known as reaction based in the way that the attitude system reacts to errors in the translational motion. This methodology requires no generation of desired attitude or angular velocity and the resulting control law is model-independent in that it does ...
    • Coordinated Power Management and Control of Standalone PV-Hybrid System with Modified IWO-Based MPPT 

      Pradhan, Chittaranjan; Senapati, Manoj Kumar; Malla, Siva Ganesh; Nayak, Paresh Kumar; Gjengedal, Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-14)
      To augment the photovoltaic (PV) power generation conversion, a maximum power point tracking (MPPT) technique plays a very significant role. This article introduces a hybrid MPPT algorithm integrating modified invasive weed optimization (MIWO) and perturb and observe (P&O) technique under the rapid weather change and partial shading scenarios for the efficient extraction of the maximum power from ...
    • First-year engineering students’ mathematics task performance and its relation to their motivational values and views about mathematics 

      Tossavainen, Timo; Rensaa, Ragnhild Johanne; Haukkanen, Pentti; Mattila, Mika; Johansson, Monica (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-26)
      This study investigates Finnish, Norwegian, and Swedish first-year engineering students’ task performance in mathematics and examines how it relates to their motivational values and beliefs about the nature of mathematics. In a set of seven mathematical tasks, female students outperformed male students, for example, in the simplification of symbolic expressions. Our findings also show that ...
    • Load modeling from smart meter data using neural network methods 

      Kianpoor, Nasrin; Hoff, Bjarte; Østrem, Trond (Chapter; Bokkapittel, 2021)
      Electricity load modeling plays a critical role to conduct load forecasting or other applications such as non-intrusive load monitoring. For such a reason, this paper investigates a comparison study of two common artificial neural network methods (Multilayer perceptron (MLP) and radial basis function neural network (RBF-NN) for home load modeling application. The accuracy of load modeling using ...
    • PSO and Kalman Filter-Based Node Motion Prediction for Data Collection from Ocean Wireless Sensors Network with UAV 

      Ho, Tu Dac; Johansen, Tor Arne; Grøtli, Esten Ingar (Conference object; Konferansebidrag, 2021-01)
      In this paper, we consider a wireless sensor network of nodes at the sea surface drifting due to wind and sea currents. In our scenario an Unmanned Aerial Vehicle (UAV) will be used to gather data from the sensor nodes. The goal is to find a flyable path which is optimal in terms of sensor node energy consumption, total channel throughput between the UAV and sensor nodes, flight time for the ...
    • Bio‐inspired hybrid BFOA‐PSO algorithm‐based reactive power controller in a standalone wind‐diesel power system 

      Wagle, Raju; Sharma, Pawan; Charu, Sharma; Gjengedal, Terje; PRADHAN, CHITTARANJAN (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-05)
      With an increase in the penetration of renewable energy sources such as wind into the power systems, the operation and control of voltage/reactive power have become more complicated and challenging than ever. As a result, the reactive power imbalance between reactive power generation and demand instigates a reduction in system voltage stability. To deal with the aforesaid scenarios, automatic voltage ...
    • Modified demagnetisation control strategy for low-voltage ride-through enhancement in DFIG-based wind systems 

      Senapati, Manoj Kumar; Nayak, Paresh Kumar; Padmanaban, Sanjeevikumar; Gjengedal, Terje (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-16)
      The large-scale wind energy conversion systems (WECSs) based on doubly-fed induction generators (DFIGs) are very popular in recent years due to the numerous technical and economic benefits. With the increasing penetration level of wind energy, the latest grid codes require the DFIG-based WECSs to remain connected to the grid under grid fault scenarios and deliver the required reactive power into ...