Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/432
2016-02-06T15:42:53ZFault tolerant control for wind turbine pitch actuators
http://hdl.handle.net/2117/81946
Fault tolerant control for wind turbine pitch actuators
Rodellar Benedé, José; Acho Zuppa, Leonardo; Tutivén Gálvez, Christian; Vidal Seguí, Yolanda
This paper develops a fault detection and isolation (FDI) and active fault tolerant control (FTC) of pitch actuators in wind turbines (WTs). This is accomplished combining a disturbance compensator with a controller, both of which are formulated in the discrete-time
domain. The disturbance compensator has a dual purpose: to reconstruct the actuator fault (which is used by the FDI technique) and to design the discrete-time controller to obtain an active FTC. That is, the actuator faults are reconstructed and then the control inputs are modified with the reconstructed fault signal to achieve a FTC in the presence of actuator faults with a comparable behavior to the fault-free case. The proposed techniques are validated using the aeroelastic wind turbine simulator FAST. This software is designed by the U.S. National Renewable Energy Laboratory and is widely used for studying wind turbine control systems.
2016-01-25T11:50:23ZRodellar Benedé, JoséAcho Zuppa, LeonardoTutivén Gálvez, ChristianVidal Seguí, YolandaThis paper develops a fault detection and isolation (FDI) and active fault tolerant control (FTC) of pitch actuators in wind turbines (WTs). This is accomplished combining a disturbance compensator with a controller, both of which are formulated in the discrete-time
domain. The disturbance compensator has a dual purpose: to reconstruct the actuator fault (which is used by the FDI technique) and to design the discrete-time controller to obtain an active FTC. That is, the actuator faults are reconstructed and then the control inputs are modified with the reconstructed fault signal to achieve a FTC in the presence of actuator faults with a comparable behavior to the fault-free case. The proposed techniques are validated using the aeroelastic wind turbine simulator FAST. This software is designed by the U.S. National Renewable Energy Laboratory and is widely used for studying wind turbine control systems.On the stability in probability of Markov jump systems with quadratic terms
http://hdl.handle.net/2117/80342
On the stability in probability of Markov jump systems with quadratic terms
Vargas, Alessandro N.; Pujol Vázquez, Gisela; Acho Zuppa, Leonardo; do Val, Joao B.R.
The note presents conditions to assure the stability in probability for a class of continuoustime quadratic Markov jump systems. From the viewpoint of the state-space evolution, the system has two parts: (i) a linear term, in which the matrix parameter jumps according to a Markov chain, and (ii) a quadratic term with no jumps. The stability in probability for the quadratic Markov jump system is then assured under mild conditions. A numerical example illustrates the usefulness of the derived results.; The note presents conditions to assure the stability in probability for a class of continuoustime quadratic Markov jump systems. From the viewpoint of the state-space evolution, the system has two parts: (i) a linear term, in which the matrix parameter jumps according to a Markov chain, and (ii) a quadratic term with no jumps. The stability in probability for the quadratic Markov jump system is then assured under mild conditions. A numerical example illustrates the usefulness of the derived results.
2015-12-09T16:39:41ZVargas, Alessandro N.Pujol Vázquez, GiselaAcho Zuppa, Leonardodo Val, Joao B.R.The note presents conditions to assure the stability in probability for a class of continuoustime quadratic Markov jump systems. From the viewpoint of the state-space evolution, the system has two parts: (i) a linear term, in which the matrix parameter jumps according to a Markov chain, and (ii) a quadratic term with no jumps. The stability in probability for the quadratic Markov jump system is then assured under mild conditions. A numerical example illustrates the usefulness of the derived results.
The note presents conditions to assure the stability in probability for a class of continuoustime quadratic Markov jump systems. From the viewpoint of the state-space evolution, the system has two parts: (i) a linear term, in which the matrix parameter jumps according to a Markov chain, and (ii) a quadratic term with no jumps. The stability in probability for the quadratic Markov jump system is then assured under mild conditions. A numerical example illustrates the usefulness of the derived results.Principal component analysis and self-organizing maps for damage detection and classification under temperature variations
http://hdl.handle.net/2117/78716
Principal component analysis and self-organizing maps for damage detection and classification under temperature variations
Anaya Vejar, Maribel; Tibaduiza Burgos, Diego Alexander; Torres-Arredondo, Miguel Ángel; Pozo Montero, Francesc
The use of statistical techniques for data driven has proven very useful in multivariable analysis as a pattern recognition approach. Among their multiple advantages such as data reduction, multivariable analysis and the definition of statistical models built with data from experimental trials, they provide robustness and allow avoiding the need of the development of physical models which sometimes are difficult for modelling especially when the system is complex. In this paper, a methodology based on Principal Component Analysis (PCA) is developed and used for building statistical baseline models comprising the dynamics from the monitored healthystructureunderdifferenttemperatureconditions.Inasecondstep, fortesting the proposed methodology, data from the structure at different structural states and under different temperature conditions are projected into the baseline models in order to obtain statistical measures (Scores and Q-index) which are included as feature vectors in a Self-Organizing Map for the damage detection and classification tasks.
The methodology is evaluated using ultrasonic signals collected from an aluminium plate and a stiffened composite panel. Results show that all the simulated states are successfully classified no matter what the kind of damage or the temperature is present in both structures.
2015-11-03T11:52:04ZAnaya Vejar, MaribelTibaduiza Burgos, Diego AlexanderTorres-Arredondo, Miguel ÁngelPozo Montero, FrancescThe use of statistical techniques for data driven has proven very useful in multivariable analysis as a pattern recognition approach. Among their multiple advantages such as data reduction, multivariable analysis and the definition of statistical models built with data from experimental trials, they provide robustness and allow avoiding the need of the development of physical models which sometimes are difficult for modelling especially when the system is complex. In this paper, a methodology based on Principal Component Analysis (PCA) is developed and used for building statistical baseline models comprising the dynamics from the monitored healthystructureunderdifferenttemperatureconditions.Inasecondstep, fortesting the proposed methodology, data from the structure at different structural states and under different temperature conditions are projected into the baseline models in order to obtain statistical measures (Scores and Q-index) which are included as feature vectors in a Self-Organizing Map for the damage detection and classification tasks.
The methodology is evaluated using ultrasonic signals collected from an aluminium plate and a stiffened composite panel. Results show that all the simulated states are successfully classified no matter what the kind of damage or the temperature is present in both structures.Detection of structural changes through principal component analysis (PCA) and multivariate statistical inference
http://hdl.handle.net/2117/76979
Detection of structural changes through principal component analysis (PCA) and multivariate statistical inference
Pozo Montero, Francesc; Arruga Cantalapiedra, Ignacio; Mujica Delgado, Luis Eduardo; Podivilova, Elena
This paper is focused on the development of a damage detection indicator that combines a data driven baseline model (reference pattern obtained from the healthy structure) based on principal component analysis (PCA) and multivariate hypothesis testing. More pre- cisely, a test for the plausibility of a value for a normal population mean vector is performed. The results indicate that the test is able to accurately clasify random samples as healthy or not.
2015-09-21T09:51:07ZPozo Montero, FrancescArruga Cantalapiedra, IgnacioMujica Delgado, Luis EduardoPodivilova, ElenaThis paper is focused on the development of a damage detection indicator that combines a data driven baseline model (reference pattern obtained from the healthy structure) based on principal component analysis (PCA) and multivariate hypothesis testing. More pre- cisely, a test for the plausibility of a value for a normal population mean vector is performed. The results indicate that the test is able to accurately clasify random samples as healthy or not.A fault detection method for pitch actuators faults in wind turbines
http://hdl.handle.net/2117/28434
A fault detection method for pitch actuators faults in wind turbines
Tutivén Gálvez, Christian; Vidal Seguí, Yolanda; Acho Zuppa, Leonardo; Rodellar Benedé, José
The paper presents a model-based fault detection method for pitch actuators faults using the normalized gradient method to estimate the parameters of the pitch actuator. One major difficulty is that the input signal to the parametric estimation method must be a persistent excitation. To circumvent this, a chattering term
is added to the pitch control law and the usual low-pass filters are not used for the parametrization in the normalized gradient
method (thus acceleration information is used). In order to verify the proposed method, simulations are conducted within a Hardware in the Loop (HiL) platform using the wind turbine simulation software
FAST (Fatigue, Aerodynamics, Structures, and Turbulence).
2015-06-26T11:24:28ZTutivén Gálvez, ChristianVidal Seguí, YolandaAcho Zuppa, LeonardoRodellar Benedé, JoséThe paper presents a model-based fault detection method for pitch actuators faults using the normalized gradient method to estimate the parameters of the pitch actuator. One major difficulty is that the input signal to the parametric estimation method must be a persistent excitation. To circumvent this, a chattering term
is added to the pitch control law and the usual low-pass filters are not used for the parametrization in the normalized gradient
method (thus acceleration information is used). In order to verify the proposed method, simulations are conducted within a Hardware in the Loop (HiL) platform using the wind turbine simulation software
FAST (Fatigue, Aerodynamics, Structures, and Turbulence).Semi-active control of flexible structures using acceleration information via peak-detector systems
http://hdl.handle.net/2117/26770
Semi-active control of flexible structures using acceleration information via peak-detector systems
Pujol Vázquez, Gisela; Acho Zuppa, Leonardo
This paper presents an implementation of a novel semi-active controller that uses only acceleration information, via a magnetorheorological damper, on a flexible structure. This controller was motivated by the scheme of a peak-detector system used on electronics circuits. That is, given a peak-detector system, we modify it to develop a novel semi-active controller. The experimental setup consisting of a two-story flexible structure, where the magnetorheorological damper is connected in a ‘semi’-brace connection, demonstrates an acceptable performance of our semi-active controller when it is compared with classical semi-active controllers.
2015-03-17T16:05:53ZPujol Vázquez, GiselaAcho Zuppa, LeonardoThis paper presents an implementation of a novel semi-active controller that uses only acceleration information, via a magnetorheorological damper, on a flexible structure. This controller was motivated by the scheme of a peak-detector system used on electronics circuits. That is, given a peak-detector system, we modify it to develop a novel semi-active controller. The experimental setup consisting of a two-story flexible structure, where the magnetorheorological damper is connected in a ‘semi’-brace connection, demonstrates an acceptable performance of our semi-active controller when it is compared with classical semi-active controllers.Automatic damage classification based on wave cluster and principal component analysis
http://hdl.handle.net/2117/24938
Automatic damage classification based on wave cluster and principal component analysis
Garibnezhad, Fahit; Mujica Delgado, Luis Eduardo; Rodellar Benedé, José; Fritzen, Claus-Peter
Principal Component Analysis (PCA) plays a significant role in SHM field. There
are plenty of algorithms that use PCA either directly or indirectly to detect damages
in structures. Although PCA shows a successful role in damage detection but it still
needs a complimentary step for automatic damage classification. It means a human
effort still is required to classify different clusters that exists. Among different clas-
sifiers, the wavelet classifier posses many dedicated merits. This work concentrates
on automatic classification of damages with different severities. To do this, PCA is
used as a tool for dimensionality reduction and then a wavelet classifier is applied
on the result to classify different patterns in the structure each of which associated
to significant state of the structure. This work involves experiments with composite
plates powered by piezoelectric transducers as sensors and actuators. Damages are
introduced into the structure as mass with different weights.
2014-12-05T12:48:45ZGaribnezhad, FahitMujica Delgado, Luis EduardoRodellar Benedé, JoséFritzen, Claus-PeterPrincipal Component Analysis (PCA) plays a significant role in SHM field. There
are plenty of algorithms that use PCA either directly or indirectly to detect damages
in structures. Although PCA shows a successful role in damage detection but it still
needs a complimentary step for automatic damage classification. It means a human
effort still is required to classify different clusters that exists. Among different clas-
sifiers, the wavelet classifier posses many dedicated merits. This work concentrates
on automatic classification of damages with different severities. To do this, PCA is
used as a tool for dimensionality reduction and then a wavelet classifier is applied
on the result to classify different patterns in the structure each of which associated
to significant state of the structure. This work involves experiments with composite
plates powered by piezoelectric transducers as sensors and actuators. Damages are
introduced into the structure as mass with different weights.A secure communication system based on a modified chaotic chua oscillator
http://hdl.handle.net/2117/24135
A secure communication system based on a modified chaotic chua oscillator
Zapateiro, Mauricio; Acho Zuppa, Leonardo; Vidal Seguí, Yolanda
In this paper we propose a new scheme for secure communications us- ing a modified Chua oscillator. A modification of the oscillator is proposed in order to facilitate the decryption. The communication system requires two channels for transmitting the message. One of the channels transmits a chaotic signal generated by the oscillator and is used for synchronization. The second channel transmits the message encrypted by a nonlinear function. This function is built in terms of one of the chaotic signals, different from that sent on the first channel. In the receiver side, a synchronizer reconstructs the chaotic oscillator signals, one of which is used for the decryption of the message. The synchronization system is designed via Lyapunov theory and chaoticity proves via Poincar ´e maps and Lyapunov exponents will be pro- vided in order to demonstrate the feasibility of our system. Numerical simulations will be used to evaluate the performance of the system.
2014-09-22T12:16:06ZZapateiro, MauricioAcho Zuppa, LeonardoVidal Seguí, YolandaIn this paper we propose a new scheme for secure communications us- ing a modified Chua oscillator. A modification of the oscillator is proposed in order to facilitate the decryption. The communication system requires two channels for transmitting the message. One of the channels transmits a chaotic signal generated by the oscillator and is used for synchronization. The second channel transmits the message encrypted by a nonlinear function. This function is built in terms of one of the chaotic signals, different from that sent on the first channel. In the receiver side, a synchronizer reconstructs the chaotic oscillator signals, one of which is used for the decryption of the message. The synchronization system is designed via Lyapunov theory and chaoticity proves via Poincar ´e maps and Lyapunov exponents will be pro- vided in order to demonstrate the feasibility of our system. Numerical simulations will be used to evaluate the performance of the system.Static output-feedback controller design for structural vibration control: a two-step LMI approach
http://hdl.handle.net/2117/24047
Static output-feedback controller design for structural vibration control: a two-step LMI approach
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
This paper presents a novel controller design strategy, which allows computing static output-feedback controllers by
solving two successive linear matrix inequality (LMI) optimization problems. This strategy is conceptually simple, easy
to implement, computationally efficient, and it can be potentially applied to a wide variety of control problems, in which
effective state-feedback controllers can be synthesized by using standard LMI optimization tools. To illustrate the application
of the new approach in the field of structural vibration control of large structures, a static velocity-feedback H1 controller
for the seismic protection of a five-story building is designed with excellent results.
2014-09-12T10:32:16ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaThis paper presents a novel controller design strategy, which allows computing static output-feedback controllers by
solving two successive linear matrix inequality (LMI) optimization problems. This strategy is conceptually simple, easy
to implement, computationally efficient, and it can be potentially applied to a wide variety of control problems, in which
effective state-feedback controllers can be synthesized by using standard LMI optimization tools. To illustrate the application
of the new approach in the field of structural vibration control of large structures, a static velocity-feedback H1 controller
for the seismic protection of a five-story building is designed with excellent results.Discrete-time static output-feedback H-infinity controller design for vehicle suspensions
http://hdl.handle.net/2117/23579
Discrete-time static output-feedback H-infinity controller design for vehicle suspensions
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
This paper provides a direct and practical presentation of a novel methodology for static output feedback controller design. The proposed design strategy has been successfully applied in the fields of control systems for seismic protection of large
buildings and multi-building structures, control of offshore wind
turbines, and active control of vehicle suspensions. The positive
results obtained in these initial applications clearly indicate that
this approach could be an effective tool in a large variety of
control problems, for which an LMI formulation of the statefeedback
version of the problem is available. The main objective
of the paper is to facilitate a brief and friendly presentation of the
main ideas involved in the new design methodology. To this end,
a discrete-time static output-feedback H1 controller is designed
for a simplified quarter-car suspension system. Numerical simulations
indicate that the proposed controller exhibits a remarkably
good behavior when compared with the corresponding statefeedback
H1 controller.
2014-07-21T11:46:38ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaThis paper provides a direct and practical presentation of a novel methodology for static output feedback controller design. The proposed design strategy has been successfully applied in the fields of control systems for seismic protection of large
buildings and multi-building structures, control of offshore wind
turbines, and active control of vehicle suspensions. The positive
results obtained in these initial applications clearly indicate that
this approach could be an effective tool in a large variety of
control problems, for which an LMI formulation of the statefeedback
version of the problem is available. The main objective
of the paper is to facilitate a brief and friendly presentation of the
main ideas involved in the new design methodology. To this end,
a discrete-time static output-feedback H1 controller is designed
for a simplified quarter-car suspension system. Numerical simulations
indicate that the proposed controller exhibits a remarkably
good behavior when compared with the corresponding statefeedback
H1 controller.