subject:(Eigensystem Realization Algorithm)

Iowa State University

1. Pati, Tarun. Modelling and optimal control of nanopositioning piezo stage.

Degree: 2020, Iowa State University

URL: https://lib.dr.iastate.edu/etd/17889

► Nanopositioners have a wide variety of applications in many fields, such as micro and nano manufacturing, medical research and study of micro and nano material… (more)

▼ Nanopositioners have a wide variety of applications in many fields, such as micro and nano manufacturing, medical research and study of micro and nano material properties. They are mainly used to induce forces and movements in micrometer and nanometer range. They are used as a part of special equipment's like atomic force microscope and scanning probe microscope which are widely used for the study of microscale or nanoscale material properties. Research efforts on nanopositioners can be broadly classified into two categories, modelling and control. Modelling of nanopositioners involve modelling of both their linear dynamics as well as their nonliner dynamics like creep and hysteresis. Many efforts are being made in understanding and control of these nonlinearities. Optimal control is one of the most widely used approach for a nanopositioner in order to achieve high speed high precision control. To address the modelling issue of creep nonlinearity, traditionally, approximate linear models or logarithmic models were used. Unlike creep, hysteresis nonlinearity is quite complex to model. Hence many efforts were made to understand and mathematically formulate hysteresis, the most popular of hysteresis models are Bouc-Wen models, Prandtl-Ishlinskii models, Duhem models etc. the problem with these models is that they are hard to linearize or invert for the purpose of control, especially if they are used for the control of wide range of frequency profiles. In the last decade numerous efforts were made in modelling the nonlinear behavior of the nanopositioners using neural networks. Due to the inherent nonlinearities the optimal control of a nanopositioner is difficult. Recently many tools were developed for the nonlinear optimal control using neural network models. Model Predictive control(MPC) is one of the most widely used optimal control techniques. The main advantage of MPC are that it provides essential tools to apply constraint to the control problem. Many techniques were developed in past for linear MPC control and nonlinear MPC control using neural networks. Due to this advantages, in this work we are using MPC for the optimal control of nanopositioners. Since nanopositioners are involved in high speed operations in sub-micrometer ranges, using purely physics-based models to formulate the dynamics may not result in accurate models. Consequently, purely data driven models or hybrid models (data+physics) are widely utilized. In the methods proposed in this work we make use of purely data driven models. The advantage of using data driven models is that they can be built without the prior knowledge of the internal physics of a system. After a data driven model is built it can latter be analyzed to understand the internal physics of a system. In this work we present the use of traditional linear methods for the purpose of modelling and control of nonlinear behavior of nanopositioners. A way to model nonlinear behavior using linear methods is by using adaptive linear models whose parameters depend on the operating point…

Subjects/Keywords: Adaptive Model Predictive Control; Data-Driven Modeling; Eigensystem Realization Algorithm; Iterative Learning Control; Nanopositioning Piezoelectric Actuator; System Identification

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APA (6^th Edition):

Pati, T. (2020). Modelling and optimal control of nanopositioning piezo stage. (Thesis). Iowa State University. Retrieved from https://lib.dr.iastate.edu/etd/17889

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Pati, Tarun. “Modelling and optimal control of nanopositioning piezo stage.” 2020. Thesis, Iowa State University. Accessed January 26, 2021. https://lib.dr.iastate.edu/etd/17889.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Pati, Tarun. “Modelling and optimal control of nanopositioning piezo stage.” 2020. Web. 26 Jan 2021.

Vancouver:

Pati T. Modelling and optimal control of nanopositioning piezo stage. [Internet] [Thesis]. Iowa State University; 2020. [cited 2021 Jan 26]. Available from: https://lib.dr.iastate.edu/etd/17889.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Pati T. Modelling and optimal control of nanopositioning piezo stage. [Thesis]. Iowa State University; 2020. Available from: https://lib.dr.iastate.edu/etd/17889

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Princeton University

2. Brunton, Steven L. Unsteady aerodynamic models for agile flight at low Reynolds numbers .

Degree: PhD, 2012, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp01wm117p01d

► This work develops low-order models for the unsteady aerodynamic forces on a wing in response to agile maneuvers at low Reynolds number. Model performance is… (more)

▼ This work develops low-order models for the unsteady aerodynamic forces on a wing in response to agile maneuvers at low Reynolds number. Model performance is assessed on the basis of accuracy across a range of parameters and frequencies as well as of computational efficiency and compatibility with existing control techniques and flight dynamic models. The result is a flexible modeling procedure that yields accurate, low-dimensional, state-space models. The modeling procedures are developed and tested on direct numerical simulations of a two-dimensional flat plate airfoil in motion at low Reynolds number, Re=100, and in a wind tunnel experiment at the Illinois Institute of Technology involving a NACA 0006 airfoil pitching and plunging at Reynolds number Re=65,000. In both instances, low-order models are obtained that accurately capture the unsteady aerodynamic forces at all frequencies. These cases demonstrate the utility of the modeling procedure developed in this thesis for obtaining accurate models for different geometries and Reynolds numbers. Linear reduced-order models are constructed from either the indicial response (step response) or realistic input/output maneuvers using a flexible modeling procedure. The method is based on identifying stability derivatives and modeling the remaining dynamics with the eigensystem realization algorithm. A hierarchy of models is developed, based on linearizing the flow at various operating conditions. These models are shown to be accurate and efficient for plunging, pitching about various points, and combined pitch and plunge maneuvers, at various angle of attack and Reynolds number. Models are compared against the classical unsteady aerodynamic models of Wagner and Theodorsen over a large range of Strouhal number and reduced frequency for a baseline comparison. Additionally, state-space representations are developed for Wagner's and Theodorsen's models, making them compatible with modern control-system analysis. A number of computational tools are developed throughout this work. Highly unsteady maneuvers are visualized using finite-time Lyapunov exponent fields, which highlight separated flows and wake structures. A new fast method of computing these fields is presented. In addition, we generalize the immersed boundary projection method computations to use a moving base flow, which allows for the simulation of complex geometries undergoing large motions with up to an order of magnitude speed-up. The methods developed in this thesis provide a systematic approach to identify unsteady aerodynamic models from analytical, numerical, or experimental data. The resulting models are shown to be reduced-order models of the linearized Navier-Stokes equations that are expressed in state-space form, and they are, therefore, both efficient and accurate. The specific form of the model, which separates added-mass forces, quasi-steady lift, and transient forces, guarantees that the resulting models are accurate over the entire range of frequencies. … Advisors/Committee Members: Rowley, Clarence W (advisor).

Subjects/Keywords: Eigensystem realization algorithm (ERA); Finite time Lyapunov exponent (FTLE); observer Kalman filter identification (OKID); Reduced order model; Theodorsen; Unsteady aerodynamics

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APA (6^th Edition):

Brunton, S. L. (2012). Unsteady aerodynamic models for agile flight at low Reynolds numbers . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01wm117p01d

Chicago Manual of Style (16^th Edition):

Brunton, Steven L. “Unsteady aerodynamic models for agile flight at low Reynolds numbers .” 2012. Doctoral Dissertation, Princeton University. Accessed January 26, 2021. http://arks.princeton.edu/ark:/88435/dsp01wm117p01d.

MLA Handbook (7^th Edition):

Brunton, Steven L. “Unsteady aerodynamic models for agile flight at low Reynolds numbers .” 2012. Web. 26 Jan 2021.

Vancouver:

Brunton SL. Unsteady aerodynamic models for agile flight at low Reynolds numbers . [Internet] [Doctoral dissertation]. Princeton University; 2012. [cited 2021 Jan 26]. Available from: http://arks.princeton.edu/ark:/88435/dsp01wm117p01d.

Council of Science Editors:

Brunton SL. Unsteady aerodynamic models for agile flight at low Reynolds numbers . [Doctoral Dissertation]. Princeton University; 2012. Available from: http://arks.princeton.edu/ark:/88435/dsp01wm117p01d

University of Melbourne

3. Mahmood, S. M. Faisal. State-space model identification for modal-based damage detection.

Degree: 2012, University of Melbourne

URL: http://hdl.handle.net/11343/37298

► A modal-based global method for identification, localization and quantification of damage of shear frame structures is presented in this thesis. The method involves identification of… (more)

▼ A modal-based global method for identification, localization and quantification of damage of shear frame structures is presented in this thesis. The method involves identification of modal parameters from the vibration responses of the structure only (output-only) using a combination of Natural Excitation Technique (NExT) and Eigensystem Realization Algorithm (ERA), and determination of stiffness values using very few identified modes by employing a least squares solution of the eigenvalue problem. Finally, damage is indicated by comparing the stiffnesses of the (possibly) damaged structure with that of the undamaged structure. The implementation of NExT-ERA requires a reference channel and an order of the state-space model for modal identification, but several limitations of using a single reference channel and a particular order of the state-space model have been identified from the investigation of this study. To overcome the limitations, a new approach called Multi-Reference Based Mode Selection is proposed in this study. The approach makes use of all the available degree-of-freedoms (DOFs) as reference channels, but one at a time, to identify the best representative modes of the structure. An autonomous modal identification algorithm is also developed for fast online application of the approach. The stiffness values of a shear frame structure can be determined by employing the least squares solution of the eigenvalue problem. Although the solution can be obtained by using a single natural frequency and the corresponding mode shape, it has been found from this study that the errors in the determination of stiffness values are significant when just one mode is used in the calculation. At least two modes are required to determine the stiffness values with reasonable accuracy. Consequently, two modes were used in the determination of stiffness values using the least squares solution of the eigenvalue problem. The proposed damage detection methodology was implemented on the analytical Phase I and the experimental Phase II of the IASC-ASCE SHM benchmark problem. The negligible errors in the determination of modal parameters affirm that the methodology is robust in the presence of noise, but the methodology is found to be mildly sensitive to modeling errors, and because of that minor damage locations cannot be identified with certainty. Overall, from the investigation, it can be reported that the proposed methodology has an accuracy of around 90% in damage localization, and the determined severities of damages using it are very close to the actual ones.

Subjects/Keywords: damage detection; modal identification; Natural Excitation Technique; NExT; Eigensystem Realization Algorithm; ERA; Multi-Reference Based Mode Selection approach; benchmark problem

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APA (6^th Edition):

Mahmood, S. M. F. (2012). State-space model identification for modal-based damage detection. (Masters Thesis). University of Melbourne. Retrieved from http://hdl.handle.net/11343/37298

Chicago Manual of Style (16^th Edition):

Mahmood, S M Faisal. “State-space model identification for modal-based damage detection.” 2012. Masters Thesis, University of Melbourne. Accessed January 26, 2021. http://hdl.handle.net/11343/37298.

MLA Handbook (7^th Edition):

Mahmood, S M Faisal. “State-space model identification for modal-based damage detection.” 2012. Web. 26 Jan 2021.

Vancouver:

Mahmood SMF. State-space model identification for modal-based damage detection. [Internet] [Masters thesis]. University of Melbourne; 2012. [cited 2021 Jan 26]. Available from: http://hdl.handle.net/11343/37298.

Council of Science Editors:

Mahmood SMF. State-space model identification for modal-based damage detection. [Masters Thesis]. University of Melbourne; 2012. Available from: http://hdl.handle.net/11343/37298

Ohio University

4. Bihl, Trevor Joseph. State Variable System Identification through Frequency Domain Techniques.

Degree: MS, Electrical Engineering (Engineering and Technology), 2011, Ohio University

URL: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307128475

► The thesis develops, tests and implements a hybrid frequency domain and state space system identification method. A frequency domain least squares system identification algorithm, along… (more)

Subjects/Keywords: Electrical Engineering; system identification; system-ID for control-system design; TFDC; ERA; Eigensystem Realization Algorithm; Transfer Function Determination Code

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bihl, T. J. (2011). State Variable System Identification through Frequency Domain Techniques. (Masters Thesis). Ohio University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307128475

Chicago Manual of Style (16^th Edition):

Bihl, Trevor Joseph. “State Variable System Identification through Frequency Domain Techniques.” 2011. Masters Thesis, Ohio University. Accessed January 26, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307128475.

MLA Handbook (7^th Edition):

Bihl, Trevor Joseph. “State Variable System Identification through Frequency Domain Techniques.” 2011. Web. 26 Jan 2021.

Vancouver:

Bihl TJ. State Variable System Identification through Frequency Domain Techniques. [Internet] [Masters thesis]. Ohio University; 2011. [cited 2021 Jan 26]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307128475.

Council of Science Editors:

Bihl TJ. State Variable System Identification through Frequency Domain Techniques. [Masters Thesis]. Ohio University; 2011. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307128475

Brno University of Technology

5. Ondra, Václav. Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis.

Degree: 2019, Brno University of Technology

URL: http://hdl.handle.net/11012/31863

► The aim of this diploma thesis is a creation of modal parameter estimation application. Modal properties (natural frequencies, damping factors and mode shapes) are used… (more)

Subjects/Keywords: experimentální modální analýza; modální vlastnosti; metody získání modálních parametrů; Peak Picking; Circle Fit; Least Square; Eigensystem Realization Algorithm; experimental modal analysis; modal properties; modal parameter estimation methods; Peak Picking; Circle Fit; Least Square; Eigensystem Realization Algorithm

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APA (6^th Edition):

Ondra, V. (2019). Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/31863

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Ondra, Václav. “Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis.” 2019. Thesis, Brno University of Technology. Accessed January 26, 2021. http://hdl.handle.net/11012/31863.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Ondra, Václav. “Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis.” 2019. Web. 26 Jan 2021.

Vancouver:

Ondra V. Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis. [Internet] [Thesis]. Brno University of Technology; 2019. [cited 2021 Jan 26]. Available from: http://hdl.handle.net/11012/31863.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ondra V. Vytvoření aplikace pro získání modálních parametrů při experimentální modální analýze: Creation of Modal Parameter Estimation Application for Experimental Modal Analysis. [Thesis]. Brno University of Technology; 2019. Available from: http://hdl.handle.net/11012/31863

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

6. Rizi, Mohamed Yazid. Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow.

Degree: Docteur es, Électronique, Électrotechnique et Automatique, 2015, Cachan, Ecole normale supérieure

URL: http://www.theses.fr/2015DENS0023

►

Les écoulements impactants auto-oscillants sont sources de bruit intenses dans diverses applications. La cavité représente une configuration privilégiée pour les étudier. L’objectif de la thèse… (more)

▼

Les écoulements impactants auto-oscillants sont sources de bruit intenses dans diverses applications. La cavité représente une configuration privilégiée pour les étudier. L’objectif de la thèse est de fournir une solution concrète aux problèmes d’oscillation de la couche cisaillée de l’écoulement de cavité, en exploitant des outils issus de la communauté des automaticiens. Un rappel des travaux menés ces dernières années est présenté ainsi que les difficultés rencontrées pour le contrôle d’un tel dispositif. La principale source de complexité est les équations de Navier- Stockes qui régissent sont fonctionnement. Il est actuellement impossible d’exploiter directement ce type d’équations dans la synthèse de correcteur. Outre cette difficulté, les oscillations de la couche limite sont qualitativement induites par une instabilité non-linéaire soumise à saturation. Par conséquent, l’identification empirique basée sur la réponse fréquentielle ne peut être appliquée, sauf si un correcteur stabilisant le point fixe est trouvé, de manière à préserver le principe de superposition lors de l’identification. Ainsi, comme première solution, une commande empirique en boucle fermée est obtenue à partir de la pression retardée. Un travail sur un choix optimal des paramètres est réalisé permettant ainsi l’élimination des oscillations de la couche cisaillée. De plus, ce contrôle se montre robuste face aux changements de configuration de cavité. Une variante de cette loi de commande aboutit à un signal de contrôle évanescent, induisant ainsi un gain considérable en terme de consommation énergétique. Malheureusement, une telle loi commande ne permet pas d’identifier, ni d’expliquer les phénomènes dynamiques associés à un tel bouclage. Par conséquent, une approche linéaire est utilisée pour identifier les dynamiques de l’écoulement de cavité. La méthode d’identification ERA (Eigensystem Realization Algorithm) en boucle fermée est utilisée pour extraire cette dynamique. Les modèles identifiés nous informent sur les modes responsables de l’apparition des oscillations de la couche cisaillée. En outre, nous avons une information précise sur le phénomène de commutation de mode observé dans plusieurs régimes d’écoulement. Le modèle permet d’extraire les modes instables de la dynamique linéaire de la cavité et les associer aux oscillations du régime saturé. Pour valider la procédure linéaire, un correcteur optimal a été synthétisé à partir du modèle identifié. Cette commande se révèle robuste aux variations paramétriques du modèle.

The cavity flow represents a preferred configuration to study the self-oscillating impingement flows, which constitute an intense noise source in various applications (rail, aviation, etc.). Several studies have been conducted in order to mitigate these oscillations by open or closed-loop control strategies. A reminder of undertaken studies in recent years is presented as well as the encountered difficulties to control of such a device. The main difficulty to control such flows is that their state results from the…

Advisors/Committee Members: Abou-Kandil, Hisham (thesis director).

Subjects/Keywords: Commande à retard; Commande en boucle fermée; Commande optimale; Réduction de modèle; Simulateur d'écoulement de cavité; Eigensystem Realization Algorithm; Oscillation frequencies of the saturated regime; Controller

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Rizi, M. Y. (2015). Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow. (Doctoral Dissertation). Cachan, Ecole normale supérieure. Retrieved from http://www.theses.fr/2015DENS0023

Chicago Manual of Style (16^th Edition):

Rizi, Mohamed Yazid. “Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow.” 2015. Doctoral Dissertation, Cachan, Ecole normale supérieure. Accessed January 26, 2021. http://www.theses.fr/2015DENS0023.

MLA Handbook (7^th Edition):

Rizi, Mohamed Yazid. “Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow.” 2015. Web. 26 Jan 2021.

Vancouver:

Rizi MY. Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow. [Internet] [Doctoral dissertation]. Cachan, Ecole normale supérieure; 2015. [cited 2021 Jan 26]. Available from: http://www.theses.fr/2015DENS0023.

Council of Science Editors:

Rizi MY. Commande performante et robuste d'un écoulement de cavité : Robust control of a cavity flow. [Doctoral Dissertation]. Cachan, Ecole normale supérieure; 2015. Available from: http://www.theses.fr/2015DENS0023

Delft University of Technology

7. Gasparis, Giorgos (author). A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines.

Degree: 2019, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:75c8bf27-9215-4ab3-8e65-57dca591a007

► Recently, Offshore Wind Turbines (OWT) have attracted great attention in an effort to make a shift from fossil-based energy sources towards an enhanced sustainable and… (more)

▼ Recently, Offshore Wind Turbines (OWT) have attracted great attention in an effort to make a shift from fossil-based energy sources towards an enhanced sustainable and renewable energy production. In order to achieve the renewables targets and reduce the cost of wind energy, OWTs are consistently increasing in size. Therefore, research has targeted the optimization of OWT design. For many years, System Identification has played a central role in obtaining the actual modal properties of existing structures. Operational Modal Analysis (OMA) is a subset of these technique that applies on measurement data obtained from a structure loaded by ambient excitation. In the case of an OWT, such methods would be highly important in validating and/or updating the design and monitoring the structural health of the structure, which would potentially lead into lifetime extension. In practice, using OMA techniques on operating OWT is not a straightforward procedure. Most of these techniques assume that the excitation is a white-noise process, which is not the case when waves and operational loads (e.g. rotational sampling) are present. Additionally, the system itself is considered to be Linear Time-Invariant. Unfortunately, the modal properties of the system are highly affected by the varying rotor speed and in general do violate the LTI assumptions. Given these challenges, the use-ability of existing methods need to be further investigated through application on OWTs under different operational conditions. Also, it is vital to asses and if possible eliminate the impact of the limitations related to loading on the identification. Thus, a benchmark study of OMA algorithms has been performed on simulated data obtained from two models. The first model is a simplified OWT numerical model in Matlab, which can be used to validate the algorithms, and the second is the NREL 5-MW baseline offshore wind turbine in FAST that was used to simulate multiple different operational conditions. Using the simulated responses, Eigensystem Realization Algorithm (ERA), Stochastic Subspace Identification (SSI), Frequency Domain Decomposition (FDD) Least-Squares Complex Frequency-domain (LSCF) estimator and Transmissibility-based Operational Modal Analysis (TOMA) were examined. Through this study the robustness of the algorithms against harmonic excitation and measurement noise were investigated, providing the user with guidelines. In the application on simulated data obtained from FAST, the results showed that all the algorithms were able to derive several stable modes, even when theoretically fundamental assumptions are violated. In general, the algorithms performed better for low wind speeds, while at high wind speeds they leaded in poorer identification. The greatest deviation compared to analytically obtained modal properties was observed in the damping ratios of the flapwise blade bending modes, where none of the algorithms was able to obtain such large damping ratios (>30%). However, most of them were still able to obtain two fore-aft tower modes… Advisors/Committee Members: Fallais, Dominik (graduation committee), Metrikine, Andrei (mentor), de Vries, Wybren (graduation committee), Delft University of Technology (degree granting institution).

Subjects/Keywords: System Identification; Operational Modal Analysis; Eigensystem Realization Algorithm; Stochastic Subspace Identification; Frequency Domain Decomposition; Least Squares Complex Frequency; Transmissibility-based Operational Modal Analysis; Offshore wind turbine; Operational conditions; OMA; SSIERA; SSI; FDD; LSCF; TOMA; benchmark study; Wind loading; rotational sampling

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gasparis, G. (. (2019). A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:75c8bf27-9215-4ab3-8e65-57dca591a007

Chicago Manual of Style (16^th Edition):

Gasparis, Giorgos (author). “A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines.” 2019. Masters Thesis, Delft University of Technology. Accessed January 26, 2021. http://resolver.tudelft.nl/uuid:75c8bf27-9215-4ab3-8e65-57dca591a007.

MLA Handbook (7^th Edition):

Gasparis, Giorgos (author). “A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines.” 2019. Web. 26 Jan 2021.

Vancouver:

Gasparis G(. A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines. [Internet] [Masters thesis]. Delft University of Technology; 2019. [cited 2021 Jan 26]. Available from: http://resolver.tudelft.nl/uuid:75c8bf27-9215-4ab3-8e65-57dca591a007.

Council of Science Editors:

Gasparis G(. A Benchmark Study on Operational Modal Analysis System Identification Algorithms for Operating Offshore Wind Turbines. [Masters Thesis]. Delft University of Technology; 2019. Available from: http://resolver.tudelft.nl/uuid:75c8bf27-9215-4ab3-8e65-57dca591a007

8. Majji, Manoranjan. System Identification: Time Varying and Nonlinear Methods.

Degree: PhD, Aerospace Engineering, 2010, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-637

► Novel methods of system identification are developed in this dissertation. First set of methods are designed to realize time varying linear dynamical system models from… (more)

▼ Novel methods of system identification are developed in this dissertation. First set of methods are designed to realize time varying linear dynamical system models from input-output experimental data. The preliminary results obtained in a recent paper by the author are extended to establish a new algorithm called the Time Varying Eigensystem Realization Algorithm (TVERA). The central aim of this algorithm is to obtain a linear, time varying, discrete time model sequence of the dynamic system directly from the input-output data. Important results relating to concepts concerning coordinate systems for linear time varying systems are developed (discrete time theory) and an intuitive understanding of equivalent realizations is provided. A procedure to develop first few time step models is detailed, providing a unified solution to the time varying identification problem. The practical problem of identifying the time varying generalized Markov parameters required for TVERA is presented as the next result. In the process, we generalize the classical time invariant input output AutoRegressive model with an eXogenous input (ARX) models to the time varying case and realize an asymptotically stable observer as a byproduct of the calculations. It is further found that the choice of the generalized time varying ARX model (GTV-ARX) can be set to realize a time varying dead beat observer. Methods to use the developed algorithm(s) in this research are then considered for application to the identification of system models that are bilinear in nature. The fact that bilinear plant models become linear for constant inputs is used in the development of an algorithm that generalizes the classical developments of Juang. An intercept problem is considered as a candidate for application of the time varying identification scheme, where departure motion dynamics model sequence is calculated about a nominal trajectory with suboptimal performance owing to the presence of unstructured perturbations. Control application is subsequently demonstrated. The dynamics of a particle in a rotating tube is considered next for identification using the time varying eigensystem realization algorithm. Continuous time bilinear system identification method is demonstrated using the particle example and the identification of an automobile brake model. Advisors/Committee Members: Junkins, John L. (advisor), Juang, Jer-Nan (committee member), Vadali, Srinivas R. (committee member), Mortari, Daniele (committee member), Rednioitis, Othon K. (committee member), Datta, Aniruddha (committee member).

Subjects/Keywords: System Identification; Linear Time Varying Systems; Eigensystem Realization Algorithm; Bilinear Systems; Guidance and Control; Dynamics.

…and love. x NOMENCLATURE ERA Eigensystem Realization Algorithm OKID Observer/Kalman… …Autoregressive Model with Exogenous Input TVERA Time Varying Eigensystem Realization Algorithm TOKID… …EIGENSYSTEM REALIZATION ALGORITHM… …Systems and Transformations .............. Time Varying Eigensystem Realization Algorithm… …164 Time Varying Eigensystem Realization Algorithm ....................... 164 Observer…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Majji, M. (2010). System Identification: Time Varying and Nonlinear Methods. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-637

Chicago Manual of Style (16^th Edition):

Majji, Manoranjan. “System Identification: Time Varying and Nonlinear Methods.” 2010. Doctoral Dissertation, Texas A&M University. Accessed January 26, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-637.

MLA Handbook (7^th Edition):

Majji, Manoranjan. “System Identification: Time Varying and Nonlinear Methods.” 2010. Web. 26 Jan 2021.

Vancouver:

Majji M. System Identification: Time Varying and Nonlinear Methods. [Internet] [Doctoral dissertation]. Texas A&M University; 2010. [cited 2021 Jan 26]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-637.

Council of Science Editors:

Majji M. System Identification: Time Varying and Nonlinear Methods. [Doctoral Dissertation]. Texas A&M University; 2010. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-637

Ohio University

9. Thomas, Joshua Bryan. Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification.

Degree: MS, Electrical Engineering & Computer Science (Engineering and Technology), 2007, Ohio University

URL: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1166476245

► The most widely used engineering analysis and design techniques depend highly on having accurate linear time-invariant (LTI) models; therefore, developing LTI models of physical… (more)

Subjects/Keywords: Frequency Domain Least Squares; Time Domain Least Squares; System Identification; Flexible Structures; Mathematical Modeling; Coherence Function; ERA; System ID; Eigensystem Realization Algorithm

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Thomas, J. B. (2007). Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification. (Masters Thesis). Ohio University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1166476245

Chicago Manual of Style (16^th Edition):

Thomas, Joshua Bryan. “Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification.” 2007. Masters Thesis, Ohio University. Accessed January 26, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1166476245.

MLA Handbook (7^th Edition):

Thomas, Joshua Bryan. “Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification.” 2007. Web. 26 Jan 2021.

Vancouver:

Thomas JB. Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification. [Internet] [Masters thesis]. Ohio University; 2007. [cited 2021 Jan 26]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1166476245.

Council of Science Editors:

Thomas JB. Using the Coherence Function as a Means to Improve Frequency Domain Least Squares System Identification. [Masters Thesis]. Ohio University; 2007. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1166476245

University of Southern California

10. Yun, Hae-Bum. Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems.

Degree: PhD, Civil Engineering (Structural Mechanics), 2007, University of Southern California

URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/528810/rec/819

► The development of effective structural health monitoring (SHM) methodologies is imperative for the efficient maintenance of important structures in aerospace, mechanical and civil engineering. Based… (more)

▼ The development of effective structural health monitoring (SHM) methodologies is imperative for the efficient maintenance of important structures in aerospace, mechanical and civil engineering. Based on reliable condition assessment, the owners of monitored structures can expect two important benefits: to avoid catastrophic accidents by detecting various types of structural deterioration during operation, and to establish efficient maintenance means and time schedule to reduce maintenance costs.; A vibration-based SHM methodology is evaluated for change detection in nonlinear systems that can be frequently seen in many engineering fields. The proposed methodology is advantageous over existing SHM methodologies regarding the following aspects: feasible to detect small changes in complex nonlinear systems, possible to make physical interpretation of detected changes, and possible to quantify the uncertainty associated with the change detection.; A series of analytical and experimental studies was performed to investigate various important issues in modeling and monitoring of uncertain nonlinear systems. Different parametric and non-parametric identification methods were compared for monitoring purpose using full-scale nonlinear viscous dampers for seismic mitigation in civil structures. Then, the effects of uncertainty on change detection performance were investigated. Two types of uncertainty were studied: measurement uncertainty and system characteristic uncertainty. For measurement uncertainty, three different types of full-scale nonlinear viscous dampers were used to validate the proposed SHM methodology when the dampers' response was polluted with random noise. For system characteristic uncertainty, a semi-active magneto-rheological damper whose system characteristics were determined through user controllable input current was used. Statistical pattern recognition methods were studied to detect relatively small changes in nonlinear systems with different uncertainty types. The Bootstrap method, a statistical data resampling technique, was also studied to estimate the uncertainty bounds of change detection when the measurement data are insufficient for reliable statistical inference.; A web-based real-time bridge monitoring system was developed and used for a forensic study involving a cargo ship collision with the Vincent Thomas Bridge, a critical suspension bridge in the metropolitan Los Angeles region. Advisors/Committee Members: Sami F. Masri (Committee Chair), Carter Wellford (Committee Member), Jiin-Jen Lee (Committee Member), John P. Caffrey (Committee Member), Roger G. Ghanem (Committee Member).

Subjects/Keywords: structural health monitoring; system identification; Restoring Force Method; artificial neural networks; Hypothesis Test; Bootstrap Method; statistical pattern recognition; support vector machines; k-means clustering; error analysis; detection theory; Natural Excitation Technique; Eigensystem Realization Algorithm; full-scale viscous dampers; magneto-rheological dampers; suspension bridge; web-based real-time bridge monitoring system; ship-bridge collision

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Yun, H. (2007). Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/528810/rec/819

Chicago Manual of Style (16^th Edition):

Yun, Hae-Bum. “Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems.” 2007. Doctoral Dissertation, University of Southern California. Accessed January 26, 2021. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/528810/rec/819.

MLA Handbook (7^th Edition):

Yun, Hae-Bum. “Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems.” 2007. Web. 26 Jan 2021.

Vancouver:

Yun H. Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems. [Internet] [Doctoral dissertation]. University of Southern California; 2007. [cited 2021 Jan 26]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/528810/rec/819.

Council of Science Editors:

Yun H. Analytical and experimental studies of modeling and monitoring uncertain nonlinear systems. [Doctoral Dissertation]. University of Southern California; 2007. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/528810/rec/819

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