Now showing items 1-20 of 311

    • 3D-LiDAR Localization and SLAM on a Multirotor UAV for Inspection 

      Nordmo, Rune (Master thesis, 2019)
      Selv om LiDAR-teknologi har vært brukt i stor grad innen forskning i robotikk, har 3D-LiDARer i stor grad vært for tunge og kostbare for å kunne brukes på mobile og lette roboter. Men nye utviklinger innen LiDAR-teknologi ...
    • A Computer Vision Approach for Autonomous Wind Turbine Inspection using a Multicopter 

      Stokkeland, Martin (Master thesis, 2014)
      This thesis studies the mission of autonomous inspection of a wind turbine using a multicopter. Emphasis was placed on recognition and tracking using image processing methods. The Hough line transform was used to extract ...
    • A Fault Tolerant Control Scheme Using the Feasible Constrained Control Allocation Strategy 

      Naderi, Mehdi; Johansen, Tor Arne; Sedigh, Ali K. (Journal article; Peer reviewed, 2019)
      This paper investigates the necessity of feasibility considerations in a fault tolerant control system using the constrained control allocation methodology where both static and dynamic actuator constraints are considered. ...
    • A Formation of Unmanned Vehicles for Tracking of an Acoustic Fish-Tag 

      Zolich, Artur Piotr; Johansen, Tor Arne; Alfredsen, Jo Arve; Kuttenkeuler, J; Erstorp, E (Chapter; Peer reviewed, 2017)
      In this paper we present a proof-of-concept for an hydro acoustic fish-tag position estimation and tracking system. In our field-tested concept, a formation of Unmanned Surface Vehicles (USV) creates a mobile array of ...
    • A homotopy-based moving horizon estimation 

      Abdollahpouri, Mohammad; Quirynen, Rien; Haring, Mark; Johansen, Tor Arne; Takacs, Gergely; Diehl, Moritz; Rohal-Ilkiv, Boris (Journal article; Peer reviewed, 2019)
      Moving horizon estimation (MHE) solves a constrained dynamic optimisation problem. Including nonlinear dynamics into an optimal estimation problem generally comes at the cost of tackling a non-convex optimisation problem. ...
    • A homotopy-based moving horizon estimation 

      Abdollahpouri, Mohammad; Quirynen, Rien; Haring, Mark; Johansen, Tor Arne; Takács, Gergely; Diehl, Moritz; Rohal'-Ilkiv, Boris (Journal article; Peer reviewed, 2017)
      Moving horizon estimation (MHE) solves a constrained dynamic optimisation problem. Including nonlinear dynamics into an optimal estimation problem generally comes at the cost of tackling a non-convex optimisation problem. ...
    • A Lightweight Payload for Hyperspectral Remote Sensing using Small UAVS 

      Fortuna, João; Johansen, Tor Arne (Journal article; Peer reviewed, 2018)
      In this paper we describe a lightweight hyperspectral imaging payload consisting of a push-broom imager, GPS and IMU sensors as well as data synchronization and acquisition systems. The payload is developed in a modular ...
    • A Machine Learning Approach for Estimating Air Data Parameters 

      Borup, Kasper Trolle; Fossen, Thor I.; Johansen, Tor Arne (Journal article; Peer reviewed, 2019)
      This paper presents a method for estimating the air data parameters for a small fixed-wing, unmanned aerial vehicle (UAV) using an arrangement of low-cost MEMS-based pressure sensors embedded in the surface of the UAV. The ...
    • A Parallel FPGA Implementation of the CCSDS-123 Compression Algorithm 

      Orlandic, Milica; Fjeldtvedt, Johan Austlid; Johansen, Tor Arne (Journal article; Peer reviewed, 2019)
      Satellite onboard processing for hyperspectral imaging applications is characterized by large data sets, limited processing resources and limited bandwidth of communication links. The CCSDS-123 algorithm is a specialized ...
    • A strategy for robust precision control of an endbody being towed by an orbiting UAV 

      Merz, Mariann; Johansen, Tor Arne (Chapter; Conference object, 2017)
      This paper presents a strategy for end-body positioning maneuvers using a towed cablebody system where a fixed wing Unmanned Aerial Vehicle (UAV) is stabilized in a circular orbit. High precision maneuvers such as object ...
    • A Structure Preserving Power System Frequency Model for Dynamic Positioning Vessels 

      Dahl, Andreas Reason; Skjetne, Roger; Johansen, Tor Arne (Chapter; Peer reviewed, 2017)
      This paper adapts a structure preserving model to on-board power plants. The model, originally developed for land-based power systems, is expanded for the larger frequency range allowable to on-board plants. State-space ...
    • A Survey of Design Considerations of Optical Imaging Stabilization Systems for Small Unmanned Aerial Systems 

      Rodin, Christopher D; Andrade, Fabio; Hovenburg, Anthony Reinier; Johansen, Tor Arne (Journal article; Peer reviewed, 2019)
      Optical imaging systems are one of the most common sensors used for collecting data with small Unmanned Aerial Systems (sUAS). Plenty of research exists which present custom-made optical imaging systems for specific missions. ...
    • A tether system for industrial inspection UAVs — Wired power and data 

      Yttersian, Torbjørn (Master thesis, 2019)
      Denne masteroppgaven presenterer et komplett system som leverer strøm til en drone over en høyvoltskabel. Systemet inkluderer et sikkerthetsbatteri som kan overta dersom forsyningen ryker, i tillegg til en høyhastighets ...
    • A UAV Ice Tracking Framework for Autonomous Sea Ice Management 

      Leira, Frederik Stendahl; Johansen, Tor Arne; Fossen, Thor I. (Chapter; Peer reviewed, 2017)
      This paper describes an unmanned aerial vehicle (UAV) ice tracking framework for use in sea ice management applications. The framework is intended to be used in an ice management scenario where the UAV should detect and ...
    • A Uniformly Semiglobally Exponentially Stable Nonlinear Observer for GNSS- and Camera-Aided Inertial Navigation 

      Fusini, Lorenzo; Fossen, Thor I.; Johansen, Tor Arne (Conference object; Journal article; Peer reviewed, 2014)
      In this paper a nonlinear observer for estimation of position, velocity, acceleration, attitude and gyro bias of an Unmanned Aerial Vehicle (UAV) is proposed. The sensor suite consists of an Inertial Measurement Unit (IMU), ...
    • A vertical stack approach to cooperative drone lifting 

      Låte, Stian (Master thesis, 2018)
      In the Pyeongchang 2018 Winter Olympics, over 1200 coordinated drones displayed an impressive lightshow for the opening ceremony. This is a testimony of the fact that the field of drone swarm technology has advanced rapidly ...
    • A virtual vertical reference concept for aided inertial navigation at the sea surface 

      Bryne, Torleiv Håland; Rogne, Robert Harald; Fossen, Thor I.; Johansen, Tor Arne (Journal article; Peer reviewed, 2017)
      When trying to capture the heaving motion of a marine vessel in waves, conventional position references such as global navigation satellite systems fall short in many cases. Because of design and satellite geometry, the ...
    • Accelerating Reinforcement Learning with Suboptimal Guidance 

      Bøhn, Eivind Eigil; Moe, Signe; Johansen, Tor Arne (Peer reviewed; Journal article, 2020)
      Reinforcement learning in domains with sparse rewards is a difficult problem, and a large part of the training process is often spent searching the state space in a more or less random fashion for learning signals. For ...
    • Accuracy of Sea Ice Floe Size Observation from an Aerial Camera at Slant Angles 

      Rodin, Christopher D; Johansen, Tor Arne (Chapter; Peer reviewed, 2017)
      The importance of measuring the size of ice floes in e.g. marine navigation and environmental sciences has made it a frequently performed procedure. When real-time data is required, images from a camera on-board an aerial ...
    • Accurate position estimation methods based on electrical impedance tomography measurements 

      Vergara, Samuel; Sbarbaro, Daniel; Johansen, Tor Arne (Journal article; Peer reviewed, 2017)
      Electrical impedance tomography (EIT) is a technology that estimates the electrical properties of a body or a cross section. Its main advantages are its non-invasiveness, low cost and operation free of radiation. The ...