Thor I. Fossen

2006 “A Survey of Control Allocation Methods for Ships and Underwater (2009)

Thor I. Fossen, Tor A. Johansen

Abstract — Control allocation problems for marine vessels can be formulated as optimization problems, where the objective typically is to minimize the use of control effort (or power) subject to...

2007-01-0808 Nonlinear Observer for Vehicle Velocity with Friction and Road Bank Angle Adaptation – Validation and Comparison with an Extended Kalman Filter (2009)

Lars Imsl, H˚avard Fjær Grip, Tor A. Johansen, Thor I. Fossen, Jens C. Kalkkuhl, Avshalom Suissa

Copyright c ○ 2007 SAE International A nonlinear observer for automotive vehicle velocity estimation in presence of varying friction and road bank angles is presented, and validated and compared to...

Vehicle Velocity Estimation using Modular Nonlinear Observers ∗ (2009)

Lars Imsl, Tor A. Johansen, Thor I. Fossen

Abstract — Nonlinear observers for estimation of lateral and longitudinal velocity of automotive vehicles are proposed, based on acceleration and yaw rate measurements in addition to wheel speed...

OPTIMAL CONSTRAINED CONTROL ALLOCATION IN MARINE SURFACE VESSELS WITH RUDDERS (2009)

Thor I. Fossen

Abstract: A propeller with a rudder can produce a thrust vector within a range of directions and magnitudes in the horizontal plane for low-speed maneuvering and dynamic positioning. The set of...

2006-01-1282 Nonlinear observer for vehicle velocity estimation (2009)

Lars Imsl, Tor A. Johansen, Thor I. Fossen, Jens C. Kalkkuhl, Avshalom Suissa

Copyright c ○ 2006 SAE International A nonlinear observer for estimation of lateral and longitudinal velocity of automotive vehicles is proposed, based on acceleration and yaw rate measurements in...

Nonlinear Dynamic Positioning of Ships with Gain-Scheduled Wave Filtering (2008)

Guttorm Torsetnes, Jérôme Jouffroy, Thor I. Fossen

Abstract — This paper presents a globally contracting controller for regulation and dynamic positioning of ships, using only position measurements. For this purpose a globally contracting observer...

Semi-Global Results On Stabilization Of Linear Systems With Input Rate And Magnitude Saturations (2008)

Trygve Lauvdal, Thor I. Fossen

This paper gives some new semi-global results for linear systems with simultaneous magnitude and rate saturations. In particular, linear control laws giving a locally attractive equilibrium are...

A Passive Output Feedback Controller with Wave Filter for Marine Vehicles (2008)

Marit J. Paulsen, Olav Egeland, Thor I. Fossen

An output feedback controller with wave filter for regulation of nonlinear marine vehicles is derived. Only measurements of position and attitude are needed. Asymptotic stability for the position and...

y (2007)

Antonio Loria, Thor I. Fossen, Elena Panteley

A cascaded approach to a separation principle for dynamic ship positioning

Ship Steering Control System Optimisation Using Genetic Algorithms IFAC Journal of Control Engineering Practise, 1998 (2007)

Yun Li, Thor I. Fossen

Abstract: The optimisation of non-linear control systems by Genetic Algorithm (GA) is studied in this paper. It involves the performance of two systems for regulating the motion of a ship model....

Controlling Line Tension in Thruster Assisted Mooring Systems (2007)

Ole Morten Aamo, Thor I. Fossen

This paper addresses the potential for energy reduction obtained by using dynamic line tensioning in thruster assisted position mooring systems. Traditionally, mooring systems have been designed in...

Direct Nonlinear Observer Design For Integration Of Dgps And Strapdown Motion Sensors (2007)

Thor I. Fossen, Bjørnar Vik

: Integration of inertial measurement units with a GPS receiver, is in most cases achieved through Kalman-...ltering, where linear error models of the IMU and the GPS receiver are employed. If we...

Robust Adaptive Control Of Passive Systems With Unknown Disturbances (2007)

Antonio Loria, Elena Panteley, Henk Nijmeijer, Thor I. Fossen

: We address the problem of robust stabilisation of nonlinear systems affected by time-varying uniformly bounded affine perturbations. Our approach relies on the combination of sliding mode...

Experimental Results of Supply Ship Autopilot Optimisation Using Genetic Algorithms (2007)

Euan W. McGookin, Yun Li, Thor I. Fossen

: The optimisation by Genetic Algorithm (GA) of a non-linear autopilot for ship course changing is studied in this paper. The theory of the optimisation technique is presented from its basis in...

A Nonlinear Observer for Integration of GPS and INS Attitude (2007)

Bjørnar Vik, Thor I. Fossen

The dynamics that describe rotation between two reference frames are in general nonlinear. Consequently, most, if not all, approaches to integration of INS and GPS attitude use an Extended Kalman...

Robust Adaptive Ship Autopilot With Wave Filter And Integral Action (2007)

Trygve Lauvdal, Thor I. Fossen, I. Fossen

this paper, the input error direct adaptive control scheme of Sastry and Bodson

An Output Feedback Controller with Wave Filter for Marine Vehicles (2007)

Marit J. Paulsen, Olav Egeland, Thor I. Fossen

A controller with wave filter for marine vehicles in terms of the nonlinear dynamical model is derived by using a structure based on passive components. Only measurement of the position/attitude is...

Backstepping Designs For Nonlinear Way-Point Tracking Of Ships (2007)

Knut Eilif Husa, Thor I. Fossen

. Nonlinear tracking of ships in terms of way-points for route planning is discussed. A tracking control law that handles different curvatures of a path, e.g. combinations of straight-lines and...

Stabilization of Linear Unstable Systems with Control Constraints (2007)

Trygve Lauvdal, Thor I. Fossen

In this paper we consider linear systems with possibly exponentially unstable eigenvalues and with saturating input. It is shown that for a class of unstable systems there exists a bounded linear...

A New Method Of Thruster Control In Positioning Of Ships Based On Power Control (2007)

Asgeir J. Sørensen, Alf Kåre Ådnanes, Asgeir J. S��rensen, Thor I. Fossen, Jann-Peter Strand

. Positioning systems include different control functions for automatic positioning and guidance of marine vessels by means of proper action of the thruster and propeller devices. These may be...

Adaptive Feedback Linearization Applied to Steering of Ships (2007)

Thor I. Fossen, Thor I. Fossen, Marit J. Paulsen, Marit J. Paulsen

This paper describes the application of feedback linearization to automatic steering of ships. The flexibility of the design procedure allows the autopilot to be optimized for both course-keeping and...

Non-Linear Tanker Control System Parameter Optimisation Using Genetic Algorithms (2007)

Euan W. McGookin, Euan W. M, Yun Li, Thor I. Fossen

The optimisation of a non-linear control problem by Genetic Algorithm (GA) is studied in this paper. It involves the performance of a control system for course changing manoeuvres of an oil tanker....

Nonlinear Rudder-Roll Damping Of Non-Minimum Phase Ships Using Sliding Mode Control (2007)

Trygve Lauvdal, Thor I. Fossen

A non-minimum phase nonlinear ship model from rudder angle to roll angle is used to design a stable controller for simultaneous roll damping and course keeping. The controller is stable in presence...

Wave Synchronizing Crane Control during Water Entry in Offshore Moonpool Operations (2007)

Svein I. Sagatun, Tor A. Johansen, Thor I. Fossen, Finn G. Nielsen

A new strategy for active control in heavy-lift offshore crane operations is suggested, by introducing a new concept referred to as wave synchronization. Wave synchronization reduces the hydrodynamic...

OPTIMAL CONSTRAINED CONTROL ALLOCATION IN MARINE SURFACE VESSELS WITH RUDDERS (2007)

Thor I. Fossen

Abstract: A propeller with a rudder can produce a thrust vector within a range of directions and magnitudes in the horizontal plane for low-speed maneuvering and dynamic positioning. The set of...

A Model Based Wave Filter for Surface Vessels Using Position, Velocity and Partial Acceleration Feedback (2007)

Karl-petter Lindegaard, Thor I. Fossen

We propose a scalable state estimator with wave filter for surface vessels. The filter is shown to be either globally or locally exponentially stable depending on configuration. Performance is...

Ship steering control system optimisation using genetic algorithms Abstract (2007)

Euan W. Mcgookin, Yun Li, Thor I. Fossen

The optimisation of non-linear control systems by genetic algorithm is studied in this paper. It involves the performance of two systems for regulating the motion of a ship model. These systems allow...

Wave Synchronizing Crane Control during Water (2007)

Entry In Offshore, Tor A. Johansen, Thor I. Fossen, Svein I. Sagatun, Finn G. Nielsen

A new strategy for active control in heavy-lift offshore crane operations is suggested, by introducing a new concept referred to as wave synchronization. Wave synchronization reduces the hydrodynamic...

Constrained Nonlinear Control Allocation with Singularity Avoidance Using Sequential Quadratic Programming (2007)

Tor A. Johansen, Thor I. Fossen, Svein P. Berge

Control allocation problems can be formulated as optimization problems, where the objective is typically to minimize the use of control effort (or power) subject to actuator rate and position...

Passivity-Based Designs for Synchronized Path Following (2006)

Murat Arcak, Thor I. Fossen

We consider a formation control system where individual systems are controlled by a path-following design and the path variables are to be synchronized. We first show a passivity property for the...

Formation control of marine surface craft: A Lagrangian approach (2006)

Student Member, Jérôme Jouffroy, Thor I. Fossen, Senior Member

Abstract — This article presents a method for formation control of marine surface craft inspired by Lagrangian mechanics. The desired formation configuration and response of the marine surface...

Motion Planning and Its Feedback Stabilization for Underactuated Ships: Virtual Constraints Approach (2005)

Shiriaev, Anton, Robertsson, Anders, Pacull, Paul, Fossen, Thor I.

The paper suggests a method for motion generating and stabilization with application to dynamical models for underactuated ships.

Formation control of marine craft using constraint functions (2005)

Jerome Jouffroy, Thor I. Fossen

Abstract — This article presents a method for formation controlof marine surface vessels inspired by Lagrangian mechanics. The desired formation configuration is given as a set of constraint...

Mathematical Modelling of Diesel-Electric Propulsion Systems for Marine Vessels (2001)

Jan Fredrik Hansen, Alf Kare Adnanes, Alf Kaê, Re Aê Dnanes, Thor I. Fossen

This article presents a mathematical model of a complete diesel-electric propulsion system, including components as diesel generators, distribution network, variable speed thruster-drives, and...

Dynamic model for thrust generation of marine propellers,” presented at the (2000)

Mogens Blanke, Karl-petter Lindegaard, Thor I. Fossen

Abstract: Mathematical models of propeller thrust and torque are traditionally based on steady state thrust and torque characteristics obtained in model basin or cavitation tunnel tests. Experimental...

A Separation Principle for Dynamic Positioning of Ships: Theoretical and Experimental Results (2000)

Antonio Loria, Thor I. Fossen, Elena Panteley

This paper presents a globally asymptotically stabilizing (GAS) controller for regulation and dynamic positioning of ships, using only position measurements. It is assumed that these are corrupted...

Nonlinear Analysis of GPS Aided by INS (1999)

Bjørnar Vik, Thor I. Fossen

The advantages of integrating GPS and INS are well known. One of the benefits is that in the event of jamming or high dynamics, the GPS correlator loops can be aided by corrected INS measurements....

Nonlinear output feedback control of dynamically positioned ships using vectorial observer backstepping (1998)

Thor I. Fossen, Mogens Blanke, Senior Member, Senior Member

Abstract—Accurate propeller shaft speed controllers can be designed by using nonlinear control theory and feedback from the axial water velocity in the propeller disc. In this paper, an output...

UGAS and ULES of Nonautonomous Systems: Applications to Integral Control of Ships and Manipulators (1998)

Antonio Loría, Thor I. Fossen, Andrew Teel

Nonlinear, adaptive backstepping design is applied to the tracking control problem for a class of mechanical systems with constant disturbances. The adaptive algorithm provides integral action that...

Rudder Roll Stabilization of Ships Subject to Input Rate Saturation Using a Gain Scheduled Control Law (1998)

Trygve Lauvdal, Trygve Lauvdal, Trygve Lauvdal, Thor I. Fossen, Thor I. Fossen

: This paper describes a new gain scheduling algorithm for handeling the problem of hard nonlinearities like input rate and magnitude saturations. The proposed algorithm was originally designed for...

Passive Nonlinear Observer Design for Ships Using Lyapunov Methods: Full-Scale Experiments with a Supply Vessel (1998)

Thor I. Fossen, Jann Peter Strand

this paper a nonlinear observer is derived. The observer is proven to be passive and GES. The number of tuning parameters is reduced to a minimum by using passivity theory. This results in a simple...

Semi-global Exponential Output Feedback Control of Ships (1997)

Bjørnar Vik, Bj Rnar Vik, Thor I. Fossen

This paper describes a semi-global exponentially stable output feedback control law for automatic heading control of ships described by a nonlinear model. Only compass #yaw angle# feedback is used....

Robust Control Allocation Of Overactuated Ships; Experiments With A Model Ship (1997)

Svein P. Berge, Thor I. Fossen

. This paper adresses the problem of nonlinear control allocation applied to marine vessels. An energy optimal solution combining a static and a dynamic non-recursive algorithm is proposed. Ships...

Stabilization of Integrator Chains in the Presence of Magnitude and Rate Saturations; a Gain Scheduling Approach (1997)

Trygve Lauvdal, Richard M. Murray, Thor I. Fossen

In this paper we present a gain scheduling technique for stabilizing integrator chains in the presence of magnitude and rate limitations on the input. The controller was first presented in [4] where...

Stabilization of Integrator Chains in the Presence of Magnitude and Rate Saturations: A Gain Scheduling Approach (1997)

Trygve Lauvdal, Richard M. Murray, Thor I. Fossen

Motivated by some specific problems in flight control and roll stabilization of ships, we present a gain scheduling technique for stabilizing integrator chains in the presence of magnitude and rate...

Parameter Optimisation of a Non-linear Tanker Control System using Genetic Algorithms (1997)

Euan W. McGookin, Y. Li, T.I. Fossen, Yun Li, Thor I. Fossen

The optimisation of a non-linear control problem by Genetic Algorithm (GA) is studied in this paper. It involves the performance of a fully autonomous control system for regulating the course keeping...

Nonlinear Control of Dynamic Positioned Ships Using Only Position Feedback: An Observer Backstepping Approach (1996)

Aslaug Gr Vlen, Thor I. Fossen, Professor Thor, I. Fossen, Åslaug Grøvlen

Dynamic positioning #DP# systems for ships are usually designed under the assumption that the kinematic equations can be linearized about a constantyaw angle such that linear theory can be applied....

A Globally Stable Adaptive Ship Autopilot With Wave Filter Using Only Yaw Angle Measurements (1996)

Trygve Lauvdal, Thor I. Fossen

. A stable minimum phase transfer function from rudder angle to yaw angle is used to design a globally stable adaptive ship autopilot. 1st-order wave disturbances in yaw are filtered by applying a...

Nonlinear Control of Dynamic Positioned Ships Using Only Position Feedback: An Observer Backstepping Approach (1996)

Åslaug Grøvlen, Professor Thor, I. Fossen, Thor I. Fossen, Thor I. Fossen

Dynamic positioning (DP) systems for ships are usually designed under the assumption that the kinematic equations can be linearized about a constant yaw angle such that linear theory can be applied....

Identification Of Dynamically Positioned Ships (1996)

Thor I. Fossen, Svein I. Sagatun, Asgeir J. Sørensen, Asgeir J. S��rensen

. Todays model-based dynamic positioning (DP) systems require that the ship and thruster dynamics are known with some accuracy in order to use linear quadratic optimal control theory. However, it is...

Nonlinear Non-Minimum Phase Rudder-Roll Damping System For Ships Using Sliding Mode Control (1996)

Trygve Lauvdal, Thor I. Fossen

. A non-minimum phase nonlinear ship model from rudder angle to roll angle is used to design a stable controller for simultaneous roll damping and course keeping. The controller is stable in presence...

Identification Of Dynamically Positioned Ships (1996)

Thor I. Fossen, Svein I. Sagatun, Asgeir J. Sørensen, Asgeir J. S��rensen

. Today's model-based dynamic positioning (DP) systems require that the ship and thruster dynamics are known with some accuracy in order to use linear quadratic optimal control theory. However,...

Robust Adaptive Control Of Underwater Vehicles: A Comparative Study (1995)

Thor I. Fossen, Ola-erik Fjellstad

. Robust adaptive control of underwater vehicles in 6 DOF is analyzed in the context of measurement noise. The performance of the adaptive control laws of Sadegh and Horowitz (1990) and Slotine and...

Nonlinear Non-Minimum Phase Rudder-Roll Damping System For Ships Using Sliding Mode Control (1995)

Trygve Lauvdal, Thor I. Fossen

A non-minimum phase nonlinear ship model from rudder to roll angle is used to design a stable controller for simultaneous roll damping and course keeping. The controller is stable in presence of...

Singularity-Free Tracking of Unmanned Underwater Vehicles in 6 DOF (1994)

Ola-erik Fjellstad, Ola-erik Fjellstad, Thor I. Fossen, Thor I. Fossen

Nonlinear tracking control of unmanned underwater vehicles (UUVs) in 6 degrees of freedom (DOF) is discussed. The 4-parameter unit quaternion is used in a singularity-free representation of attitude....

Nonlinear Stability Analysis of Ship Autopilots in Sway, Roll and Yaw (1994)

In Sway, Thor Fossen, Thor I. Fossen, Trygve Lauvdal, Trygve Lauvdal

Combined heading control and rudder-roll damping systems are difficult to analyze due to the complexity of the mathematical model required to describe the nonlinear couplings in sway, roll and yaw....

Modelling and Control of Underwater Vehicle-Manipulator Systems (1994)

Ingrid Schjølberg, Thor I. Fossen

In this paper a dynamic model of an underwater vehicle--manipulator system is derived. The iterative Newton--Euler algorithm has been extended to include the most dominating hydrodynamical forces....

Quaternion Feedback Regulation of Underwater Vehicles (1994)

Ola-erik Fjellstad, Ola-erik Fjellstad, Thor I. Fossen, Thor I. Fossen

: Position and attitude set-point regulation of autonomous underwater vehicles (AUVs) in 6 degrees of freedom (DOF) is presented. Euler parameters are used in the representation of global attitude....

Cascaded Adaptive Control of Ocean Vehicles With Significant Actuator Dynamics (1993)

Thor I. Fossen, Ola-Erik Fjellstad

This paper presents a cascaded adaptive control scheme for marine vehicles where the nonlinear equations of motion include a model of the actuator dynamics. The adaptive controller does not require...

Comments on "Hamiltonian Adaptive Control of Spacecraft" (1993)

Thor Fossen, Thor I. Fossen

\Gamma In the adaptive scheme presented by Slotine and Benedetto (1990) for attitude tracking control of rigid spacecraft, the spacecraft is parameterized in terms of the inertial frame. This paper...

High Performance Ship Autopilot With Wave Filter (1993)

Thor I. Fossen, Thor I. Fossen

This paper describes the application of Lyapunov stability theory to automatic steering of ships. The motivation for using nonlinear control theory is that nonlinearities can be compensated for in a...

The NEROV Autonomous Underwater Vehicle (1991)

Thor I. Fossen, Jens G. Balchen

The Norwegian Experimental Remotely Operated Vehicle (NEROV) is described. The vehicle is designed and built at the Department of Engineering Cybernetics, The Norwegian Institute of Technology (NTH)....

Adaptive Control of Nonlinear Underwater Robotic Systems (1991)

Thor I. Fossen, Svein I. Sagatun

The problem of controlling underwater mobile robots in 6 degrees of freedom (DOF) is addressed. Uncertainties in the input matrix due to partly known nonlinear thruster characteristics are modelled...

Sliding Control of MIMO Nonlinear Systems (1991)

Thor I. Fossen, Bjarne A. Foss

. Sliding control of MIMO (multivariable input-multivariable output) nonlinear minimum phase systems is discussed. Stability conditions related to model errors are emphasized. Global asymptotic...

Position and Attitude Tracking of AUVs: A Quaternion Feedback Approach

Ola-erik Fjellstad, Thor I. Fossen

: A position and attitude tracking control law for autonomous underwater vehicles (AUVs) in 6 degrees of freedom (DOF) is derived. The 4-parameter unit quaternion (Euler parameters) is used in a...