• A 3D Reactive Collision Avoidance Algorithm for Underactuated Vehicles 

      Syre Wiig, Martin; Pettersen, Kristin Ytterstad; Krogstad, Thomas Røbekk (Chapter, 2018)
      This paper presents a 3D reactive collision avoidance algorithm for vehicles with underactuated dynamics. The underactuated states cannot be directly controlled, but are controlled indirectly by steering the direction of ...
    • Autonomous docking using direct optimal control 

      Martinsen, Andreas Bell; Lekkas, Anastasios M.; Gros, Sebastien (Journal article; Peer reviewed, 2019)
      We propose a method for performing autonomous docking of marine vessels using numerical optimal control. The task is framed as a dynamic positioning problem, with the addition of spatial constraints that ensure collision ...
    • A combined informative and representative active learning approach for plankton taxa labeling 

      Haug, Martin Lund; Saad, Aya; Stahl, Annette (Peer reviewed; Journal article, 2021)
      With an ever-increasing amount of image data, the manual labeling process has become the bottleneck in many machine learning applications. Plankton taxa labeling is especially a challenge due to its complex nature, and the ...
    • Dynamics of dissolved oxygen inside salmon sea-cages with lice shielding skirts at two hydrographically different sites 

      Jónsdóttir, Kristbjörg Edda; Volent, Zsolt; Alfredsen, Jo Arve (Peer reviewed; Journal article, 2020)
      Shielding skirts are widely used as a non-invasive preventive measure against salmon lice Lepeophtheirus salmonis infestations on Atlantic salmon Salmo Salar L. in sea-cages. Low levels of dissolved oxygen (DO) are reported ...
    • Integral Line-of-Sight Guidance of Underwater Vehicles Without Neutral Buoyancy 

      Caharija, Walter; Syre Wiig, Martin; Krogstad, Thomas Røbekk; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2016)
      This paper analyzes an integral line-of-sight guidance law applied to an underac-tuated underwater vehicle. The vehicle is rigorously modeled in 5 degrees of freedom usingphysical principles, and it is ...
    • MIMO Feedback Linearization of Redundant Robotic Systems Using Task-Priority Operational Space Control 

      Basso, Erlend Andreas; Pettersen, Kristin Ytterstad (Peer reviewed; Journal article, 2020)
      Redundant robotic systems are designed to accomplish multiple tasks simultaneously. Task-priority control schemes exploit system redundancy by arranging tasks in priority and ensuring strict prioritization between tasks ...
    • Operation and Maintenance Modelling 

      Welte, Thomas Michael; Sperstad, Iver Bakken; Halvorsen-Weare, Elin Espeland; Netland, Øyvind; Nonås, Lars Magne; Stålhane, Magnus (Chapter, 2018)
      Operational expenditure (OPEX) is one of the major contributors to the levelized cost of energy (LCoE) for offshore wind farms. To assess different solutions and select the best ones, good models for maintenance and logistics ...
    • Optimal Positioning of Snake Robots in Vortex Wakes using Extremum-Seeking Control. 

      Orucevic, Amer; Lysø, Mads Erlend Bøe; Schmidt-Didlaukies, Henrik; Pettersen, Kristin Ytterstad; Gravdahl, Jan Tommy (Peer reviewed; Journal article, 2023)
      In this paper we explore the optimal positioning of an underwater snake robot (USR) for energy harvesting in the wake of a bluff body. The USR and fluid are simulated jointly using a coupled vortex particle-mesh method and ...
    • Path Planning for UGVs Based on Traversability Hybrid A* 

      Thoresen, Marius; Nielsen, Niels Hygum; Mathiassen, Kim; Pettersen, Kristin Ytterstad (Peer reviewed; Journal article, 2021)
      In this letter, a new method of path planning for unmanned ground vehicles (UGVs) on terrain is developed. For UGVs moving on terrain, path traversability and collision avoidance are important factors. If traversability ...
    • Ultrasound Strain Rate Imaging of Individual Muscle Motor Units 

      Heger, Max; Stavdahl, Øyvind; Torp, Hans (Journal article; Peer reviewed, 2014)
      Skeletal muscle is organized in motor units, each comprising a motor neuron and all its connected muscle fibres. The arrival of an action potential (a neural “impulse”) causes the fibers to contract, they exhibit a twitch. ...
    • Vehicle Guidance with Control Action Computed by a Rao-Blackwellized Particle Filter 

      Sans-Muntadas, Albert; Brekke, Edmund Førland; Pettersen, Kristin Ytterstad (Chapter, 2017)
      Particle filters can be used in navigation and state estimation problems. They can approximate arbitrary posterior distributions and do not require assumptions of Gaussianity or linearizations. This paper suggests to use ...