Browsing Institutt for teknisk kybernetikk by Document Types "Journal article"
Now showing items 61-80 of 1194
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A waypoint guidance strategy for underwater snake robots
(Journal article; Peer reviewed, 2014)In this paper, a waypoint guidance strategy is proposed for an underwater snake robot. The robot is directed to follow a path which is derived using path planning techniques. A first version of the path is derived by ... -
Accelerating Reinforcement Learning with Suboptimal Guidance
(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 ... -
Accelerating support vector machines for remote platforms by increasing sparsity
(Peer reviewed; Journal article, 2022)The support vector machine (SVM) classification algorithm often achieves quite high accuracy on hyperspectral images, even when trained on small amounts of data. However, SVMs can still be computationally expensive relative ... -
Accounting for dynamics in self-optimizing control
(Journal article; Peer reviewed, 2019)Self-optimizing control focuses on minimizing the steady-state loss for processes in the presence of disturbances by holding selected controlled variables at constant set-points. The loss can further be reduced by controlling ... -
Accuracy of a slew maneuver for the HYPSO-1 hyperspectral imaging satellite — in-orbit results
(Peer reviewed; Journal article, 2023)In this paper, the accuracy of a slew maneuver performed by the HYPSO-1 satellite is analysed based on the data received during the satellite’s first months in orbit. The slew maneuver, during which the satellite turns ... -
Accurate aggregated modelling of wind farm systems in modified sequence domain for stability analysis
(Peer reviewed; Journal article, 2019)With the wind power penetration rate continuously rising, a suitable wind farm model considering both accuracy and simplicity is required for power system stability analysis. To accomplish this goal, an accurate aggregated ... -
Accurate position estimation methods based on electrical impedance tomography measurements
(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 ... -
Actuator multiplicative fault estimation in discrete-time LPV systems using switched observers
(Journal article; Peer reviewed, 2016)This paper proposes an observer for the joint state and fault estimation devoted to discrete-time linear parameter varying (LPV) systems subject to actuator faults. The major contribution of this work is that the observer ... -
ADAMA-II wind farm performance assessment in comparison to feasibility study
(Journal article, 2021)The objective of this paper was to assess the performance of the Adama-II Wind Farm in comparison to the feasibility study. Using 1-year mast data, the site potential was reassessed by WAsP software and the performance of ... -
Adaptation of Engineering Wake Models using Gaussian Process Regression and High-Fidelity Simulation Data
(Peer reviewed; Journal article, 2020)This article investigates the optimization of yaw control inputs of a nine-turbine wind farm. The wind farm is simulated using the high-fidelity simulator SOWFA. The optimization is performed with a modifier adaptation ... -
Adaptive approximation-based estimation of downhole pressure in managed pressure drilling
(Journal article; Peer reviewed, 2012)Low-complexity multi-model algorithms for adaptive bottomhole pressure estimation in drilling is derived, and theoretical and practical conditions for convergence (persistency of excitation) discussed, assuming a) topside ... -
Adaptive Boundary Observer for Nonlinear Hyperbolic Systems: Design and Field Testing in Managed Pressure Drilling
(Journal article; Peer reviewed, 2015)The present paper develops an adaptive boundary observer for systems modeled by nonlinear hyperbolic PDEs with limited number of measurements. The design is based on the backstepping method and relies only on one boundary ... -
Adaptive Control of a Linear Hyperbolic PDE with Uncertain Transport Speed and a Spatially Varying Coefficient
(Peer reviewed; Journal article, 2020)Recently, the first result on backstepping-based adaptive control of a 1-D linear hyperbolic partial differential equation (PDE) with an uncertain transport speed was presented. The system also had an uncertain, constant ... -
Adaptive Control of a Linear, Scalar Hyperbolic PDE with Time-Varying Coefficients
(Peer reviewed; Journal article, 2020)We extend a previous result regarding adaptive control of a linear hyperbolic partial differential equation (PDE) with time-varying in-domain source coefficient in two ways. Firstly, we introduce a parametrization of the ... -
Adaptive Control of a Nanopositioning Device
(Journal article; Peer reviewed, 2012)High-bandwidth tracking control is desirable in many nanopositioning applications, including scanning probe microscopy. Typical nanopositioner designs have several sources of uncertainty which can degrade control performance, ... -
Adaptive Control of a Scalar 1-D Linear Hyperbolic PDE with Uncertain Transport Speed Using Boundary Sensing
(Peer reviewed; Journal article, 2020)We solve an adaptive boundary control problem for an 1-D linear hyperbolic partial differential equation (PDE) with an uncertain in-domain source parameter and uncertain transport speed using boundary sensing only. Convergence ... -
Adaptive control of linear 2 x 2 hyperbolic systems
(Journal article; Peer reviewed, 2018)We design two closely related state feedback adaptive control laws for stabilization of a class of 2 × 2 linear hyperbolic system of partial differential equations (PDEs) with constant but uncertain in-domain and boundary ... -
Adaptive detection and prediction of performance degradation in off-shore turbomachinery
(Peer reviewed; Journal article, 2020)Performance-based maintenance of machinery relies on detection and prediction of performance degradation. Degradation indicators calculated from process measurements need to be approximated with degradation models that ... -
Adaptive feed-forward hysteresis compensation for piezoelectric actuators
(Journal article; Peer reviewed, 2012)Piezoelectric actuators are often employed for high-resolution positioning tasks. Hysteresis and creep nonlinearities inherent in such actuators deteriorate positioning accuracy. An online adaptive nonlinear hysteresis ...