Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/432
Tue, 23 May 2017 10:55:52 GMT2017-05-23T10:55:52ZSensor fault detection in a damage detection approach based on piezodiagnostics
http://hdl.handle.net/2117/103182
Sensor fault detection in a damage detection approach based on piezodiagnostics
Ruiz Ordóñez, Magda; Camacho-Navarro, Jhonatan; Villamizar Mejía, Rodolfo; Mujica Delgado, Luis Eduardo
Online monitoring systems demand an adequate operation of sensor system used to acquire structural state measurements. If a damaged sensor record is incorporated in the diagnosis algorithm, it could be generate uncertainties and generate unsuitable alarms. Thus,
appropriate operation of sensor system is a critical requirement in order to obtain a high reliability for structural damage diagnosis algorithms. In this work a data-driven procedure is studied in order to mitigate the faulty sensor effect in a monitoring system. The studied
method takes advantage of piezo-diagnostics approach, where piezoelectric devices are attached to the surface of the monitored structure to produce guided waves. Thus, piezoelectric measurements are analyzed by applying principal component analysis and cross-correlation, in order to detect abnormal behaviors. In this sense, the squared prediction error Q and Hotelling squared statistical indices are used to observe a typical behaviour caused by sensor problems or structural damages. The methodology is validated on a lab carbon steel pipe section by using scenarios that include electric power failures,
disconnecting power cords as well as mass adding. As concluding remark, in this work was possible to separate structural damage and fault sensor states at different clusters.
Mon, 03 Apr 2017 08:15:28 GMThttp://hdl.handle.net/2117/1031822017-04-03T08:15:28ZRuiz Ordóñez, MagdaCamacho-Navarro, JhonatanVillamizar Mejía, RodolfoMujica Delgado, Luis EduardoOnline monitoring systems demand an adequate operation of sensor system used to acquire structural state measurements. If a damaged sensor record is incorporated in the diagnosis algorithm, it could be generate uncertainties and generate unsuitable alarms. Thus,
appropriate operation of sensor system is a critical requirement in order to obtain a high reliability for structural damage diagnosis algorithms. In this work a data-driven procedure is studied in order to mitigate the faulty sensor effect in a monitoring system. The studied
method takes advantage of piezo-diagnostics approach, where piezoelectric devices are attached to the surface of the monitored structure to produce guided waves. Thus, piezoelectric measurements are analyzed by applying principal component analysis and cross-correlation, in order to detect abnormal behaviors. In this sense, the squared prediction error Q and Hotelling squared statistical indices are used to observe a typical behaviour caused by sensor problems or structural damages. The methodology is validated on a lab carbon steel pipe section by using scenarios that include electric power failures,
disconnecting power cords as well as mass adding. As concluding remark, in this work was possible to separate structural damage and fault sensor states at different clusters.Sensor selection based on principal component analysis for fault detection in wind turbines
http://hdl.handle.net/2117/103181
Sensor selection based on principal component analysis for fault detection in wind turbines
Pozo Montero, Francesc; Vidal Seguí, Yolanda
Growing interest for improving the reliability of safety-critical structures, such as wind turbines, has led to the advancement of structural health monitoring (SHM). Existing techniques for fault detection can be broadly classified into two major categories: model-based methods and signal processing-based methods. This work focuses in the signal-processing-based fault detection by using principal component analysis (PCA) as a way to condense and extract information from the collected signals. In particular, the goal of this work is to select a reduced number of sensors to be used. From a practical point of view, a reduced number of sensors installed in the structure leads to a reduced cost of installation and maintenance. Besides, from a computational point of view, less sensors implies lower computing time, thus the detection time is shortened.
The overall strategy is to firstly create a PCA model measuring a healthy wind turbine. Secondly, with the model, and for each fault scenario and each possible subset of sensors, it measures the Euclidean distance between the arithmetic mean of the projections into the PCA model that come from the healthy wind turbine and the mean of the projections that come from the faulty one. Finally, it finds the subset of sensors that separate the most the data coming from the healthy wind turbine and the data coming from the faulty one.
Numerical simulations using a sophisticated wind turbine model (a modern 5MW turbine implemented in the FAST software) show the performance of the proposed method under actuators (pitch and torque) and sensors (pitch angle measurement) faults of different type: fixed value, gain factor, offset and changed dynamics.
Mon, 03 Apr 2017 08:05:19 GMThttp://hdl.handle.net/2117/1031812017-04-03T08:05:19ZPozo Montero, FrancescVidal Seguí, YolandaGrowing interest for improving the reliability of safety-critical structures, such as wind turbines, has led to the advancement of structural health monitoring (SHM). Existing techniques for fault detection can be broadly classified into two major categories: model-based methods and signal processing-based methods. This work focuses in the signal-processing-based fault detection by using principal component analysis (PCA) as a way to condense and extract information from the collected signals. In particular, the goal of this work is to select a reduced number of sensors to be used. From a practical point of view, a reduced number of sensors installed in the structure leads to a reduced cost of installation and maintenance. Besides, from a computational point of view, less sensors implies lower computing time, thus the detection time is shortened.
The overall strategy is to firstly create a PCA model measuring a healthy wind turbine. Secondly, with the model, and for each fault scenario and each possible subset of sensors, it measures the Euclidean distance between the arithmetic mean of the projections into the PCA model that come from the healthy wind turbine and the mean of the projections that come from the faulty one. Finally, it finds the subset of sensors that separate the most the data coming from the healthy wind turbine and the data coming from the faulty one.
Numerical simulations using a sophisticated wind turbine model (a modern 5MW turbine implemented in the FAST software) show the performance of the proposed method under actuators (pitch and torque) and sensors (pitch angle measurement) faults of different type: fixed value, gain factor, offset and changed dynamics.Fault tolerant control design of floating offshore wind turbines
http://hdl.handle.net/2117/103180
Fault tolerant control design of floating offshore wind turbines
Rodellar Benedé, José; Tutivén Gálvez, Christian; Acho Zuppa, Leonardo; Vidal Seguí, Yolanda
This work is concerned with active vibration mitigation in wind turbines (WT) but not through the use of specifically tailored devices. Instead, a general control scheme is designed for torque and pitch controllers based on a super-twisting algorithm, which uses additional feedback of the fore-aft and side-to-side acceleration signals at the top of the WT tower to mitigate the vibrational behavior. In general, proposed methods to improve damping through pitch and torque control suffer from increased blade pitch actuator usage. However, in this work the blade pitch angle is smoothed leading to a decrease of the pitch actuator effort, among other benefits evidenced through numerical experiments. The most frequent faults induce vibrations in the corresponding WT subsystems. In fact, vibration monitoring has been recently used for fault diagnosis Thus, by means of vibration mitigation, different faulty conditions can be alleviated leading to a passive fault tolerant control. In this work, coupled non-linear aero-hydro- servo-elastic simulations of a floating offshore wind turbine are carried out for one of the most common pitch actuator faults.
Mon, 03 Apr 2017 08:00:22 GMThttp://hdl.handle.net/2117/1031802017-04-03T08:00:22ZRodellar Benedé, JoséTutivén Gálvez, ChristianAcho Zuppa, LeonardoVidal Seguí, YolandaThis work is concerned with active vibration mitigation in wind turbines (WT) but not through the use of specifically tailored devices. Instead, a general control scheme is designed for torque and pitch controllers based on a super-twisting algorithm, which uses additional feedback of the fore-aft and side-to-side acceleration signals at the top of the WT tower to mitigate the vibrational behavior. In general, proposed methods to improve damping through pitch and torque control suffer from increased blade pitch actuator usage. However, in this work the blade pitch angle is smoothed leading to a decrease of the pitch actuator effort, among other benefits evidenced through numerical experiments. The most frequent faults induce vibrations in the corresponding WT subsystems. In fact, vibration monitoring has been recently used for fault diagnosis Thus, by means of vibration mitigation, different faulty conditions can be alleviated leading to a passive fault tolerant control. In this work, coupled non-linear aero-hydro- servo-elastic simulations of a floating offshore wind turbine are carried out for one of the most common pitch actuator faults.Multidimensional big data processing for damage detection in real pipelines using a smart pig tool
http://hdl.handle.net/2117/102797
Multidimensional big data processing for damage detection in real pipelines using a smart pig tool
Ruiz Ordóñez, Magda; Mujica Delgado, Luis Eduardo; Alférez Baquero, Edwin Santiago; Quintero, Mario; Villamizar Mejía, Rodolfo
The history of the hydrocarbons business in Colombia dates back to the early twentieth century where mining and energy sector has been one of the principal pillars for the its development. Thus, the pipelines currently in service have over 30 years and most of them are buried and phenomena like metal losses, corrosion, mechanical stress, strike by excavation machinery and other type of damages are presented. Since it can generate social and environmental problems, monitoring tools and programs should be developed in order to prevent catastrophic situations. However, the maintaining of these structures is very expensive and it is normally developed by foreign companies. In order to overcome this situation, recently the native research institute “Research Institute of Corrosion - CIC (Corporación para la Investigación de la Corrosión)” developed an in-line inspection tool to be operated in Colombian pipelines (especially gas) to get valuable information of their current state along of thousand kilometres. The recorded data is of big size and its processing demand a high computational cost and adequate tool analysis to determine a certain pipeline damage condition. On other hand, the author from UPC and UIS have been bringing its expertise in processing and analysing this type of big data by using mainly Principal Component Analysis (PCA) as an effective tool to detect and locate different damages. In previous papers, multidimensional data matrix was used to locate possible damages along the pipeline, however most of activated points were considered false alarms since they corresponded to weld points. Thus, in this paper it is proposed no considering piecewise weld points (tube sections) and an extension of PCA named Multiway PCA (MPCA) is applied for each each one of the tube sections that form the pipeline. Therefore, if a tube section is found outside from overall indices found by using the MPCA model, an alarm activated in that section and a precise location can be obtained by analyzing only data from that specific tube section.
Wed, 22 Mar 2017 12:43:59 GMThttp://hdl.handle.net/2117/1027972017-03-22T12:43:59ZRuiz Ordóñez, MagdaMujica Delgado, Luis EduardoAlférez Baquero, Edwin SantiagoQuintero, MarioVillamizar Mejía, RodolfoThe history of the hydrocarbons business in Colombia dates back to the early twentieth century where mining and energy sector has been one of the principal pillars for the its development. Thus, the pipelines currently in service have over 30 years and most of them are buried and phenomena like metal losses, corrosion, mechanical stress, strike by excavation machinery and other type of damages are presented. Since it can generate social and environmental problems, monitoring tools and programs should be developed in order to prevent catastrophic situations. However, the maintaining of these structures is very expensive and it is normally developed by foreign companies. In order to overcome this situation, recently the native research institute “Research Institute of Corrosion - CIC (Corporación para la Investigación de la Corrosión)” developed an in-line inspection tool to be operated in Colombian pipelines (especially gas) to get valuable information of their current state along of thousand kilometres. The recorded data is of big size and its processing demand a high computational cost and adequate tool analysis to determine a certain pipeline damage condition. On other hand, the author from UPC and UIS have been bringing its expertise in processing and analysing this type of big data by using mainly Principal Component Analysis (PCA) as an effective tool to detect and locate different damages. In previous papers, multidimensional data matrix was used to locate possible damages along the pipeline, however most of activated points were considered false alarms since they corresponded to weld points. Thus, in this paper it is proposed no considering piecewise weld points (tube sections) and an extension of PCA named Multiway PCA (MPCA) is applied for each each one of the tube sections that form the pipeline. Therefore, if a tube section is found outside from overall indices found by using the MPCA model, an alarm activated in that section and a precise location can be obtained by analyzing only data from that specific tube section.Embedded piezodiagnostics for online structural damage detection based on PCA algorithm
http://hdl.handle.net/2117/102795
Embedded piezodiagnostics for online structural damage detection based on PCA algorithm
Camacho-Navarro, Jhonatan; Ruiz Ordóñez, Magda; Villamizar Mejía, Rodolfo; Mujica Delgado, Luis Eduardo; Ariza, Fabian
This work discusses a methodology used to implement a data-driven strategy for Structural Health Monitoring. First, the instrumentation of the equipment is detailed by describing the main components to be installed in the test structure in order to produce guide d waves. Specifically, an active piezo active system is used for this purpose , which consists of piezoelectric devices attached to the test structure surface and an ac quisition system. Then, the programming procedure to embed the damage detection algorithm is defined. In particular, the mathematical foundations and software requirements for impleme nting the preprocessing stage, baseline model building, and statistical index computation are specified. As a result, the Odroid-U3 computational core has the capability t o perform online damage assessment. Finally, some validation tests are presented through videos and short real time demonstration. Experimental data are recorded from two test specimens: i.) a lab carbon steel pipe loop built to emulate leak scenarios, and ii.) an aluminum plate, where mass adding is used to emulate reversible damages. The results reported i n this work show the high feasibility of the proposal methodology for obtaining an online embedded monitoring system with several advantages such as low cost, easy configuration, expandability and few computational resources
Wed, 22 Mar 2017 12:27:24 GMThttp://hdl.handle.net/2117/1027952017-03-22T12:27:24ZCamacho-Navarro, JhonatanRuiz Ordóñez, MagdaVillamizar Mejía, RodolfoMujica Delgado, Luis EduardoAriza, FabianThis work discusses a methodology used to implement a data-driven strategy for Structural Health Monitoring. First, the instrumentation of the equipment is detailed by describing the main components to be installed in the test structure in order to produce guide d waves. Specifically, an active piezo active system is used for this purpose , which consists of piezoelectric devices attached to the test structure surface and an ac quisition system. Then, the programming procedure to embed the damage detection algorithm is defined. In particular, the mathematical foundations and software requirements for impleme nting the preprocessing stage, baseline model building, and statistical index computation are specified. As a result, the Odroid-U3 computational core has the capability t o perform online damage assessment. Finally, some validation tests are presented through videos and short real time demonstration. Experimental data are recorded from two test specimens: i.) a lab carbon steel pipe loop built to emulate leak scenarios, and ii.) an aluminum plate, where mass adding is used to emulate reversible damages. The results reported i n this work show the high feasibility of the proposal methodology for obtaining an online embedded monitoring system with several advantages such as low cost, easy configuration, expandability and few computational resourcesParameter identification of large-scale magnetorheological dampers in a benchmark building
http://hdl.handle.net/2117/101577
Parameter identification of large-scale magnetorheological dampers in a benchmark building
Bahar, Arash; Pozo Montero, Francesc; Acho Zuppa, Leonardo; Rodellar Benedé, José; Barbat Barbat, Horia Alejandro
Magnetorheological (MR) dampers are devices that can be use d for vibration re- duction in structures. However, to use these devices in an ef fective way, a precise modeling is required. In this sense, in this paper we consider a modified p arameter identification method of large-scale magnetorheological dampers which are repre sented using the normalized Bouc- Wen model. The main benefit of the proposed identification alg orithm is the accuracy of the parameter estimation. The validation of the parameter iden tification method has been carried out using a black box model of an MR damper in a smart base-isol ated benchmark building. Magnetorheological dampers are used in this numerical plat form both as isolation bearings as well as semiactive control devices.
Mon, 27 Feb 2017 08:34:47 GMThttp://hdl.handle.net/2117/1015772017-02-27T08:34:47ZBahar, ArashPozo Montero, FrancescAcho Zuppa, LeonardoRodellar Benedé, JoséBarbat Barbat, Horia AlejandroMagnetorheological (MR) dampers are devices that can be use d for vibration re- duction in structures. However, to use these devices in an ef fective way, a precise modeling is required. In this sense, in this paper we consider a modified p arameter identification method of large-scale magnetorheological dampers which are repre sented using the normalized Bouc- Wen model. The main benefit of the proposed identification alg orithm is the accuracy of the parameter estimation. The validation of the parameter iden tification method has been carried out using a black box model of an MR damper in a smart base-isol ated benchmark building. Magnetorheological dampers are used in this numerical plat form both as isolation bearings as well as semiactive control devices.A continuous-time delay chaotic system obtained from a chaotic logistic map
http://hdl.handle.net/2117/101290
A continuous-time delay chaotic system obtained from a chaotic logistic map
Acho Zuppa, Leonardo
This paper presents a procedure to transform a chaotic logistic map into a continuous-time delay chaotic system by using sampled-data representation of continuous-time models. Because of this, the chaotic behavior of the resultant scheme is easy to proofread. A numerical illustration is also realized by utilizing Matlab/Simulink, where the new resultant chaotic attractor is shown
Tue, 21 Feb 2017 10:56:40 GMThttp://hdl.handle.net/2117/1012902017-02-21T10:56:40ZAcho Zuppa, LeonardoThis paper presents a procedure to transform a chaotic logistic map into a continuous-time delay chaotic system by using sampled-data representation of continuous-time models. Because of this, the chaotic behavior of the resultant scheme is easy to proofread. A numerical illustration is also realized by utilizing Matlab/Simulink, where the new resultant chaotic attractor is shownOn the set of periods of the 2-periodic Lyness' equation
http://hdl.handle.net/2117/99190
On the set of periods of the 2-periodic Lyness' equation
Bastien, Guy; Mañosa Fernández, Víctor; Rogalski, Marc
We study the periodic solutions of the non-autonomous periodic Lyness’ recurrence un+2=(an+un+1)/un, where {an}n is a cycle with positive values a,b and with positive initial conditions. Among other methodological issues we give an outline of the proof of the following results: (1) If (a,b)¿(1,1), then there exists a value p0(a,b) such that for any p>p0(a,b) there exist continua of initial conditions giving rise to 2p-periodic sequences. (2) The set of minimal periods arising when (a,b)¿(0,8)2 and positive initial conditions are considered, contains all the even numbers except 4, 6, 8, 12 and 20. If a¿b, then it does not appear any odd period, except 1.
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-662-52927-0_22
Fri, 13 Jan 2017 09:24:26 GMThttp://hdl.handle.net/2117/991902017-01-13T09:24:26ZBastien, GuyMañosa Fernández, VíctorRogalski, MarcWe study the periodic solutions of the non-autonomous periodic Lyness’ recurrence un+2=(an+un+1)/un, where {an}n is a cycle with positive values a,b and with positive initial conditions. Among other methodological issues we give an outline of the proof of the following results: (1) If (a,b)¿(1,1), then there exists a value p0(a,b) such that for any p>p0(a,b) there exist continua of initial conditions giving rise to 2p-periodic sequences. (2) The set of minimal periods arising when (a,b)¿(0,8)2 and positive initial conditions are considered, contains all the even numbers except 4, 6, 8, 12 and 20. If a¿b, then it does not appear any odd period, except 1.Novel results on decentralized H-infinity controller design for structural vibration control of large buildings
http://hdl.handle.net/2117/98974
Novel results on decentralized H-infinity controller design for structural vibration control of large buildings
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
In this paper, we present a novel control design methodology for structural vibration control of large buildings. The main idea consists in decomposing the overall building system into decoupled single-story subsystems and modeling the subsystem interactions as external disturbances. Then, a complete set of local decentralized controllers can be efficiently computed using the existing LMI solvers. In the proposed approach, two different levels of decentralization can be distinguished: decentralized design and decentralized implementation, which are both of critical importance in large-scale control problems. From the design point of view, the local controllers are independently synthesized using only the low-dimensional subsystem models. The implementation phase is through the overall decentralized controller defined by the set of local controllers, which can drive the actuation devices using only local state-feedback information. To illustrate the proposed methodology, decentralized H8 controllers are designed for the seismic protection of a five-story building and a twenty-story building. A proper set of numerical simulations is carried out to demonstrate the effectiveness of the proposed decentralized controllers and the computation times are considered to assess the computational effectiveness of the decentralized design methodology.
Tue, 10 Jan 2017 15:52:43 GMThttp://hdl.handle.net/2117/989742017-01-10T15:52:43ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaIn this paper, we present a novel control design methodology for structural vibration control of large buildings. The main idea consists in decomposing the overall building system into decoupled single-story subsystems and modeling the subsystem interactions as external disturbances. Then, a complete set of local decentralized controllers can be efficiently computed using the existing LMI solvers. In the proposed approach, two different levels of decentralization can be distinguished: decentralized design and decentralized implementation, which are both of critical importance in large-scale control problems. From the design point of view, the local controllers are independently synthesized using only the low-dimensional subsystem models. The implementation phase is through the overall decentralized controller defined by the set of local controllers, which can drive the actuation devices using only local state-feedback information. To illustrate the proposed methodology, decentralized H8 controllers are designed for the seismic protection of a five-story building and a twenty-story building. A proper set of numerical simulations is carried out to demonstrate the effectiveness of the proposed decentralized controllers and the computation times are considered to assess the computational effectiveness of the decentralized design methodology.Computational effectiveness of LMI design strategies for vibration control of large structures
http://hdl.handle.net/2117/98633
Computational effectiveness of LMI design strategies for vibration control of large structures
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
Distributed control systems for vibration control of large structures involve a large number of actuation devices and sensors that work coordinately to produce the desired control actions. Design strategies based on linear matrix inequality (LMI) formulations allow obtaining controllers for these complex control problems, which are characterized by large dimensionality, high computational cost and severe information constraints. In this paper, we conduct a comparative study of the computational effectiveness of three different LMI-based controller design strategies: H-infinity, energy-to-peak and energy-to-componentwise-peak. The H-infinity approach is a well-known design methodology and has been widely used in the literature. The
energy-to-peak approach is a particular case of generalized H2 design that is gaining a growing relevance in structural vibration control. Finally, the energy-to-componentwise-peak approach is a less common case of generalized H2 design that produces promising results among the three considered approaches. These controller design strategies are applied to synthesize active state-feedback controllers for the seismic protection of a five-story building and a twenty-story building both equipped with complete systems of interstory actuation devices. To evaluate the computational effectiveness of the proposed LMI design methodologies, the corresponding
computation times are compared and a suitable set of numerical simulations is carried out to assess the performance of the obtained controllers. As positive results, two main facts can be highlighted: the computational effectiveness of the energy-to-peak control design strategy
and the particularly well-balanced behavior exhibited by the energy-to-componentwise-peak controllers. On the negative side, it has to be mentioned the computational inefficiency of the considered LMI design methodologies to properly deal with very-large-scale control problems.
Tue, 20 Dec 2016 14:30:19 GMThttp://hdl.handle.net/2117/986332016-12-20T14:30:19ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaDistributed control systems for vibration control of large structures involve a large number of actuation devices and sensors that work coordinately to produce the desired control actions. Design strategies based on linear matrix inequality (LMI) formulations allow obtaining controllers for these complex control problems, which are characterized by large dimensionality, high computational cost and severe information constraints. In this paper, we conduct a comparative study of the computational effectiveness of three different LMI-based controller design strategies: H-infinity, energy-to-peak and energy-to-componentwise-peak. The H-infinity approach is a well-known design methodology and has been widely used in the literature. The
energy-to-peak approach is a particular case of generalized H2 design that is gaining a growing relevance in structural vibration control. Finally, the energy-to-componentwise-peak approach is a less common case of generalized H2 design that produces promising results among the three considered approaches. These controller design strategies are applied to synthesize active state-feedback controllers for the seismic protection of a five-story building and a twenty-story building both equipped with complete systems of interstory actuation devices. To evaluate the computational effectiveness of the proposed LMI design methodologies, the corresponding
computation times are compared and a suitable set of numerical simulations is carried out to assess the performance of the obtained controllers. As positive results, two main facts can be highlighted: the computational effectiveness of the energy-to-peak control design strategy
and the particularly well-balanced behavior exhibited by the energy-to-componentwise-peak controllers. On the negative side, it has to be mentioned the computational inefficiency of the considered LMI design methodologies to properly deal with very-large-scale control problems.