Viser treff 641-660 av 914

    • Quadrotor attitude estimation using adaptive fading multiplicative EKF 

      Johansen, Tor-Aleksander; Kristiansen, Raymond (Konferansebidrag; Conference object, 2017-07-03)
      This paper presents the implementation of an adaptive fading multiplicative extended Kalman filter (AFMEKF), applied to the problem of attitude estimation in the context of quadrotors. The extended Kalman filter is adapted for use with quaternions and made adaptive to account for inaccurate measurement information. Simulations have been conducted in order to validate the filter performance.
    • Quadrotor modeling and control 

      Kristiansen, Stig Espen (Master thesis; Mastergradsoppgave, 2016-11-03)
      In this thesis a mathematical quadrotor model based on cascade modeling theory, using a passivity-based control solution is derived and presented. The rotation and translation cascades are rst decoupled, modeled mathematically and simulated separately to test individual control solutions and stability, followed by total system modeling and simulations to verify the control solutions and stability ...
    • A Qualitative Comparison of ANSYS and OpenFOAM results for Carbon dioxide Plume Transport 

      Madsen, Synne; Andleeb, Zahra; Khawaja, Hassan Abbas; Boiger, Gernot; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-02)
      This research presents Computational Fluid Dynamics (CFD) simulations in ANSYS® illustrating emissions of to the air. The CFD simulations is employed to study plume transport in urban environment, i.e., Breivika port in the city of Tromsø. The case study presents a two-phase model considering specific wind strength and direction in the city of Tromsø. Geographical coordinates, temperature, and wind ...
    • Qualitative visualization of the development of stresses through infrared thermography 

      Stange, Even; Andleeb, Zahra; Khawaja, Hassan (Journal article; Peer reviewed, 2019)
      In this work, the IR thermography was used to study the steel specimens (DIN 50125 Standard) undergoing the tensile tests. The tensile tests were performed using GUNT® Hamburg Universal Material Tester. The tensile specimens were clamped, and the test force was applied using a hand-operated hydraulic system. A dial gauge measured the elongation of the specimens. Using the WP 300.20 system for data ...
    • Quality parameters in evaluation of renovation projects 

      Regmi, Santosh (Master thesis; Mastergradsoppgave, 2016-11-07)
      In renovation processes there is always a risk of underestimating environmental, cultural, and social values in favor of energy efficiency and economy. As well as while upgrading the building’s exterior and interior it is very essential to study the physical sustainability of building element in the field climate condition. Therefore it is very important to follow scientific and systematic process ...
    • Quantitative analysis of accuracy of voidage computations in CFD-DEM Simulations 

      Khawaja, Hassan Abbas; Scott, Stuart A.; Virk, Muhammad Shakeel; Moatamedi, Mojtaba (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
    • Quaternion guidance and control of quadrotor 

      Andersen, Tom Stian; Kristiansen, Raymond (Konferansebidrag; Conference object, 2017-07-27)
      This paper addresses the problem of trajectory tracking for underactuated quadrotors. A quaternion based guidance law is proposed which feeds into an attitude control system based on a PD+ control law. The desired attitude from the guidance law is defined such that the attitude control system tries to align the position error along the axis of the translational actuator. Simulation results are ...
    • Quaternion Path-Following in Three Dimensions for a Fixed-Wing UAV Using Quaternion Blending 

      Andersen, Tom Stian; Kristiansen, Raymond (Peer reviewed; Book; Chapter, 2018-10-29)
      This paper presents a three dimensional guidance strategy for fixed-wing UAVs using quaternions. The algorithm is based on constructing two quaternions, one which makes the UAV fly towards the path and one that makes the UAV follow the path. These two quaternions are then blended together such that the path-following objective is reached. The guidance algorithm is applied to a simple kinematic model ...
    • Radon i eksisterende bygninger 

      Sundby, Robert Tarvudd (Master thesis; Mastergradsoppgave, 2021-05-15)
      Denne oppgaven er en studie om radon i eksisterende bygninger med en casestudie. I forkant av utarbeidelse og utførelse av en tiltakspakke, ble det gjort en litteraturstudie innenfor temaet om radon, situasjonen i Norge og anbefalte tiltak for å redusere radonnivåene i eksisterende boliger. Casestudien omhandler en enebolig i Beisfjord, Narvik kommune. Det har blitt utført bytte av innvendig radonbrønn ...
    • Railway operations in icing conditions: a review of issues and mitigation methods 

      Lotfi, Arefeh; Virk, Muhammad Shakeel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-14)
      This article focuses on studying the current literature about railway operations in icing conditions, identifying icing effects on railway infrastructure, rolling stock, and operations, and summarizing the existing solutions for addressing these issues. Even though various studies have been conducted in the past on the impact of winter, climate change, and low temperatures on railway operations, not ...
    • Railway transition curves: A review of the state-of-the-art and future research 

      Brustad, Tanita Fossli; Dalmo, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-18)
      Transition curves are a useful tool for lateral alignment of railway segments. Their design is important to ensure safe and comfortable travel for passengers and cargo. Well designed transition curves can lead to reduced wear of tracks and vehicles, which is beneficial from a maintenance point of view. Extensive studies have been performed through decades to find transition curves that can replace ...
    • Rammeverk for modellering og simulering av husholdningsapparater 

      Nilsen, Christian Bjerknes (Master thesis; Mastergradsoppgave, 2018-08-16)
      Denne oppgaven har hatt til hensikt å utarbeide et rammeverk for modellering og simulering av husholdningsapparater i Simulink, hvor det er muligheter for sammenkobling av flere enheter basert på typiske utstyr i norske husholdninger. Tilkoblingen av modellene kan være via TN-nett, IT-nett eller andre mindre kilder i Simulink. Videre er det gjennomført en litteraturstudie av ulike typer utstyr ...
    • Re- design of a multipurpose snowmobile sled for Norwegian volunteer (SAR organizations) 

      Johansen, Kari Wilhelmsen (Master thesis; Mastergradsoppgave, 2017-06-15)
      "This master thesis is written for Norwegian volunteer organization “Hjelpekorpset” that is a search and rescue organization. The organization performs different kinds of activities in addition to rescue missions. During wintertime, they transport materials, furniture and other cargo to local huts to raise funds for the organization. This is the basis for the thesis, where the aim was to redesign a ...
    • 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 ...
    • A Readiness Model for Facilitating the Implementation of Metal Additive Manufacturing at SMEs 

      Sæterbø, Mathias; Solvang, Wei Deng (Chapter; Bokkapittel, 2023-05-23)
      SMEs constitute the backbone of the global economy possessing a vital role in future economic prosperity. Today, with the increasing competition due to globalization of markets and mass customization, as well as the increasing focus on green shift and sustainability, the need to take advantage of new technological innovations has never been more prominent. Metal Additive Manufacturing (MAM) is one ...
    • Real-Time Implementation of Two Grid-Forming Power Converter Controls to Emulate Synchronous Generators 

      Azuara-Grande, Luis Santiago; Gonzalez-Longatt, Francisco; Tricarico, Gioacchino; Wagle, Raju; Arnaltes, Santiago; Granizo, Ricardo (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-09)
      Modern power systems are experiencing unprecedented penetration of integrating renewable energy sources (RES) to tackle the so-called climate emergency. But the transition from synchronous generators to converter-interfaced generators also produces a few issues, some of them directly related to the reduction (or lack) of rotational inertia. The voltage source converters (VSCs) enabled with the ...
    • Real-Time Particle Tracking using a Formation of UAVs 

      Oland, Espen; Kristiansen, Raymond (Journal article; Peer reviewed; Tidsskriftartikkel, 2013)
      In this paper the problem of real-time particle tracking is studied. Using sensor measurements, a formation of UAVs autonomously find the closest point with high particle density where they enter a holding pattern. After converging to the holding pattern, one UAV will remain, while the rest will go looking for other maxima. To avoid collisions between the UAVs during the mission, a controller is ...
    • Real-Time Price-Based Optimal Energy Mix in Smart Distribution Network 

      Wagle, Raju; Sharma, Pawan; Charu, Sharma; Amin, Mohammad (Chapter; Bokkapittel, 2023-04-29)
      With the increasing penetration of Distributed Energy Resources (DERs) in Smart Distribution Networks (SDNs), balancing energy mix is a crucial task for distribution system operators. The aggregate consumption, generation, and power exchanged from the upstream network are essential for the energy management system. Appropriate allocation and scheduling of DERs and Energy Storage can minimize the ...
    • Real-time Volt-Var control of grid forming converters in DER-enriched distribution network 

      Wagle, Raju; Sharma, Pawan; Charu, Sharma; Amin, Mohammad; Gonzalez-Longatt, Francisco (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-06)
      The growing installation of distributed energy resources (DERs) in a distribution network (DN) poses substantial issues related to voltage regulation. Due to constrained switching operation and slower response time, traditional voltage regulation devices cannot handle current voltage-related challenges. One alternative to solve these problems is to use smart converters to control the reactive ...
    • Real-Time Voxel-based 2D to 3D CT Visualisation Framework for Volumetric Capacity Estimation 

      Schuchter, Arthur; Petrarolo, Giovanni; Grießner, Dominik (Journal article; Tidsskriftartikkel, 2022)
      Over the decades medical analyses have grown in importance and practice possibilities. Digital operations like split-image procedures have become an integral part of modern medical practices and are still gaining momentum. Through the application of this technique medical computed tomography (CT) and magnetic resonance imaging scans (MRI) can be converted to three-dimensional bodies. This paper ...