Blar i NTNU Open på forfatter "Fossen, Thor I."
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A phase-time-path-difference approach for online wave direction and wave number estimation from measured ship motions in zero and forward speed using a single inertial measurement unit
Dirdal, Johann Alexander; Skjetne, Roger; Roháč, Jan; Fossen, Thor I. (Journal article; Peer reviewed, 2023)This study investigates the potential capability of a relatively new and unexplored signal-based approach for shipboard wave estimation. The approach uses the phase-time-path-differences (PTPDs) from an array of shipboard ... -
Reduced-Attitude Control of Fixed-Wing Unmanned Aerial Vehicles Using Geometric Methods on the Two-Sphere
Coates, Erlend Magnus Lervik; Reinhardt, Dirk Peter; Fossen, Thor I. (Peer reviewed; Journal article, 2020)As an alternative to reduced-attitude control of fixed-wing unmanned aerial vehicles using roll and pitch angles, we propose to use a global representation that evolves on the two-sphere. The representation of reduced ... -
Redundant MEMS-based Inertial Navigation using Nonlinear Observers
Rogne, Robert Harald; Bryne, Torleiv Håland; Fossen, Thor I.; Johansen, Tor Arne (Journal article; Peer reviewed, 2017)We present two alternative methods for fault detection and isolation (FDI) with redundant Microelectromechanical system (MEMS) inertial measurement units (IMUs) in inertial navigation systems (INS) based on nonlinear ... -
Robust Navigation of UAV using Inertial Sensors Aided by UWB and RTK GPS
Gryte, Kristoffer; Hansen, Jakob Mahler; Johansen, Tor Arne; Fossen, Thor I. (Chapter, 2017)Tight integration of ultra wideband (UWB) range measurements with real-time kinematic (RTK) aiding of inertial navigation for increased robustness to GNSS dropouts, is achieved using a double-differenced nonlinear observer. ... -
Secure and Efficient Transmission of Vision-Based Feedback Control Signals
Volden, Øystein; Solnør, Petter; Petrovic, Slobodan; Fossen, Thor I. (Peer reviewed; Journal article, 2021)An ever-increasing number of autonomous vehicles use bandwidth-greedy sensors such as cameras and LiDARs to sense and act to the world around us. Unfortunately, signal transmission in vehicles is vulnerable to passive and ... -
Sensor Synchronization and Navigation in GNSS-Denied Environments for Unmanned Aerial Vehicles
Albrektsen, Sigurd Mørkved (Doctoral theses at NTNU;2018:275, Doctoral thesis, 2018)In the last few years, the emergence of civilian unmanned aerial vehicles (UAVs) has sparked the interest of both the industry and the academic community. However, as systems become more popular and more widespread, the ... -
Signal-based sea state estimation: A phase-time-path-difference approach: A new shipboard wave estimation approach
Dirdal, Johann Alexander (Doctoral theses at NTNU;2024:79, Doctoral thesis, 2024)The safety and efficiency of marine operations at sea rely on accurate information about the sea state, which includes the dominant wave height, wave direction, and wave period. Unfortunately, many areas at sea lack this ... -
Spatially Indexed Clustering for Scalable Tracking of Remotely Sensed Drift Ice
Olofsson, Jonatan; Brekke, Edmund Førland; Fossen, Thor I.; Johansen, Tor Arne (Chapter, 2017)For operations in the Arctic, drift ice can be a major hazard. To be able to mitigate this, it is essential to know the position of viable threats. Many sensors can be employed, such as satellite Synthetic Aperture Radar ... -
Suspended Load Motion Control using Multicopters
Klausen, Kristian; Fossen, Thor I.; Johansen, Tor Arne (Journal article, 2014)This paper presents a distributed kinematic control law for group coordination for several multicopters and a payload suspended with wires from each multicopter. The complete system with constraints on the wires are modeled ... -
The eXogenous Kalman Filter (XKF)
Johansen, Tor Arne; Fossen, Thor I. (Journal article; Peer reviewed, 2017)It is well known that the time-varying Kalman Filter (KF) is globally exponentially stable and optimal in the sense of minimum variance under some conditions. However, nonlinear approximations such as the extended KF ... -
Towards Oblivious Guidance Systems for Autonomous Vehicles
Solnør, Petter; Petrovic, Slobodan; Fossen, Thor I. (Peer reviewed; Journal article, 2023)We consider encrypted guidance systems for straight-line path following. With cloud-computing technology, we can outsource computations in guidance systems to third-party providers, increasing scalability and enabling ... -
Tracking of Ocean Surface Objects from Unmanned Aerial Vehicles with a Pan/Tilt Unit using a Thermal Camera
Helgesen, Håkon Hagen; Leira, Frederik Stendahl; Fossen, Thor I.; Johansen, Tor Arne (Journal article, 2017)This paper presents four vision-based tracking system architectures for marine surface objects using a fixed-wing unmanned aerial vehicle (UAV) with a thermal camera mounted in a pan/tilt gimbal. The tracking systems ... -
UAV Path Planning for Maximum-Information Sensing in Spatiotemporal Data Acquisition
Vibeto, Andreas Nordby (Master thesis, 2017)Fixed-wing Unmanned Aerial Vehicles are extensively used for ground observation, as they allow for effective and precise methods of collecting information. They do however, have a downside as the quality of the information ... -
Underwater Position and Attitude Estimation Using Acoustic, Inertial, and Depth Measurements
Jørgensen, Erlend Kvinge; Fossen, Thor I.; Bryne, Torleiv Håland; Schjølberg, Ingrid (Peer reviewed; Journal article, 2019)This article considers the problem of constructing an observer for estimating position, velocity, attitude, underwater wave speed, rate sensor bias, and accelerometer bias that has both proven stability and close-to-optimal ... -
A Uniform Semiglobal Exponential Stable Adaptive Line-of-Sight (ALOS) Guidance Law for 3-D Path Following
Fossen, Thor I.; Aguiar, A Pedro (Peer reviewed; Journal article, 2024)This paper presents a 3-D adaptive line-of-sight (ALOS) path-following algorithm for autonomous vehicles, marine craft, and aircraft. The origins of the cross- and vertical-track errors are proven to be uniform semiglobal ... -
Uniformly semiglobally exponential stability of vector field guidance law and autopilot for path-following
Xu, Haitong; Fossen, Thor I.; Guedes Soares, Carlos (Journal article, 2019)A uniform semiglobal exponential stability (USGES) proof for a time-varying vector field guidance law used for path-following control of vehicles is presented. A sliding mode control is introduced for heading autopilot ... -
Vision-based positioning system for auto-docking of unmanned surface vehicles (USVs)
Volden, Øystein; Stahl, Annette; Fossen, Thor I. (Journal article, 2021) -
Wave motion compensation in dynamic positioning of small autonomous vessels
Halvorsen, Håkon Skogland; Øveraas, Henning; Landstad, Olav; Smines, Vidar; Fossen, Thor I.; Johansen, Tor Arne (Peer reviewed; Journal article, 2020)Conventional dynamic positioning (DP) systems on larger ships compensate primarily for slowly time-varying environmental forces. In doing so, they use wave filtering to prevent the DP from compensating for the first-order ...