Browsing NTNU Open by Author "Hovd, Morten"

Convergent cross mapping (CCM) based approach for isolating the source of plant-wide disturbances

Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Chapter, 2017)

Disturbances originating in one control loop of a large industrial plant can propagate far from the source, giving rise to plant-wide oscillations. The underlying interactions among the different control loops make it hard ...

Detecting non-linearity induced oscillations via the dyadic filter bank property of multivariate empirical mode decomposition

Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article, 2017)

Non-linearity induced oscillations in control loops are characterized by the presence of higher order harmonics. In this paper the dyadic filter bank property of the multivariate empirical mode decomposition (MEMD) is ...

Dynamic Control and Simulation of Conveyor-Belt Dryers: Model-Based Control of Moisture in Fishfeed

Salvador, John Paul (Master thesis, 2008)

The removal of moisture from solids is an important and often necessary part of the production process withinseveral different industries. This especially includes the food industry, since almost all food products are dried ...

Dynamic Simulation of a Natural Gas Liquefaction Plant

Hammer, Morten (Doktoravhandlinger ved NTNU, 1503-8181; 2004:156, Doctoral thesis, 2004)

This thesis describes a new general purpose dynamic process simulator applied to a natural gas liquefaction plant. More specifically, the Multi Fluid Cascade Process (MFCP). MFCP is the “Statoil Linde LNG Technology Alliance” ...

Efficient Implementation of Dual First Order Algorithms - Application in Embedded MPC

Kvamme, Sverre (Master thesis, 2014)

In this Thesis, numerical implementation of optimization algorithms for convex quadratic problems that appear in model predictive control for embedded linear systems, are examined. Different versions of dual first order ...

Estimation with low measurement frequency

Leite, Martin (Master thesis, 2017)

The invention of the computer has triggered a technological revolution in many parts of society. For the process industry, computers have led to improvement in both production rates, safety and profits. One way this has ...

Explicit robustness and fragility margins for linear discrete systems with piecewise affine control law

Nguyen, Ngoc Anh; Olaru, Sorin; Rodriguez-Ayerbe, Pedro; Bitsoris, George; Hovd, Morten (Journal article; Peer reviewed, 2016)

In this paper, we focus on the robustness and fragility problem for piecewise affine (PWA) control laws for discrete-time linear system dynamics in the presence of parametric uncertainty of the state space model. A generic ...

Explicit robustness margin for contractive piecewise affine control laws

Koduri, Rajesh; Rodriguez-Ayerbe, Pedro; Olaru, Sorin; Hovd, Morten (Chapter, 2016)

This paper deals with the class of discrete-time linear dynamics affected by polytopic uncertainty in closed loop with contractive piecewise affine (PWA) control law. Starting from the hypothesis that the synthesis ensures ...

Extending a derivative-free model-based trust-region optimization algorithm to account for constraints and partial gradient information - Application to oil field development

Andersen, Joakim Rostrup (Master thesis, 2018)

This master's thesis is motivated by the oil field development challenge. This is a very big and complicated task and only one part of it will be in focus, namely, the well placement challenge. When planning a new oil field ...

Feedforward for Stabilization of an Ammonia Synthesis Reactor

Holter, Erik (Master thesis, 2010)

This thesis illustrates different control structures and tries to demonstrate how feedforward control can be used in stabilizing an unstable ammonia reactor with heat integration. The demonstration of feedforward is done ...

Hierarchical Decentralized State Estimation With Unknown Correlation for Multiple and Partially Overlapping State Vectors

Klemets, Jonatan Ralf Axel; Hovd, Morten (Chapter, 2018)

A fusion method for hierarchical decentralized state estimation is investigated with unknown cross-correlation. The process is divided into several local estimators for different subsystems that can operate independently ...

Improved oscillation detection via noise-assisted data analysis

Aftab, Muhammad Faisal; Hovd, Morten; Sivalingam, Selvanathan (Journal article; Peer reviewed, 2018)

Oscillation detection is usually a precursor to more advanced performance monitoring steps such as plant wide oscillation detection and root cause detection. Therefore any false or missed detection can have serious ...

Indirect Finite Control Set Model Predictive Control of Modular Multilevel Converters

Vatani, Mohsen; Behrooz, Bahrani; Saeedifard, Maryam; Hovd, Morten (Journal article; Peer reviewed, 2015)

The modular multilevel converter (MMC) is a potential candidate for medium/high-power applications, specifically for high-voltage direct current transmission systems. One of the main challenges in the control of an MMC ...

Limitations on control performance in the Czochralski crystal growth process using bright ring measurement as a controlled variable

Bukhari, Halima Zahra; Hovd, Morten; Winkler, Jan (Journal article; Peer reviewed, 2019)

This paper develops a dynamical model for crystal diameter in the Czochralski process for production of monocrystalline silicon. The model combines simplified crystal growth dynamics with rigorous ray tracing to describe ...