• Autonomous Monitoring and Inspection Operations with UUVs in Fish Farms 

      Kelasidi, Eleni; Su, Biao; Caharija, Walter; Føre, Martin; Pedersen, Magnus Oshaug; Frank, Kevin (Peer reviewed; Journal article, 2022)
      In this study, a general control framework for autonomous operations in highly complex and dynamically changing environments such as fish farms is proposed and experimentally validated. Since fish farms feature an environment ...
    • Autonomous ROV inspections of aquaculture net pens using DVL 

      Amundsen, Herman Biørn; Caharija, Walter; Pettersen, Kristin Ytterstad (Peer reviewed; Journal article, 2021)
      This article presents a method for guiding a remotely operated vehicle (ROV) to autonomously traverse an aquaculture net pen. The method is based on measurements from a Doppler velocity log (DVL) and uses the measured ...
    • Path Following Control of Underactuated Surface Vessels in the Presence of Multiple Disturbances 

      Caharija, Walter; Sørensen, Asgeir Johan; Pettersen, Kristin Ytterstad; Greco, Marilena; Gravdahl, Jan Tommy (Chapter, 2019-06-25)
      An integral version of the line-of-sight guidance method is shown to compensate for both kinematic and dynamic disturbances generated by wind, waves and sea currents. The guidance law is designed for path following tasks ...
    • Robust adaptive backstepping DP control of ROVs 

      Ohrem, Sveinung Johan; Amundsen, Herman Biørn; Caharija, Walter; Holden, Christian (Peer reviewed; Journal article, 2022)
      Dynamic positioning is an important control feature for an underwater remotely operated vehicle. This paper presents a nonlinear dynamic positioning controller suited for application to vehicles with model uncertainties, ...
    • ROV Navigation in a Fish Cage with Laser-Camera Triangulation 

      Bjerkeng, Magnus Christian; Kirkhus, Trine; Caharija, Walter; Thielemann, Jens T; Amundsen, Herman Biørn; Ohrem, Sveinung Johan; Grøtli, Esten Ingar (Peer reviewed; Journal article, 2021)
      Aquaculture net cage inspection and maintenance is a central issue in fish farming. Inspection using autonomous underwater vehicles is a promising solution. This paper proposes laser-camera triangulation for pose estimation ...
    • Semiglobal exponential stability of a counter-current and co-current guidance scheme 

      Caharija, Walter; Grøtli, Esten Ingar; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2018)
      A control technique for counter-current and co-current guidance of underactuated marine vehicles is revisited and stronger stability properties are shown. In particular, the stronger property of uniform semiglobal exponential ...
    • Semiglobal exponential stability of a counter-current and co-current guidance scheme 

      Caharija, Walter; Grøtli, Esten Ingar; Pettersen, Kristin Ytterstad (Journal article; Peer reviewed, 2018)
      A control technique for counter-current and co-current guidance of underactuated marine vehicles is revisited and stronger stability properties are shown. In particular, the stronger property of uniform semiglobal exponential ...