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  • Leak localization in water networks: a model-based methodology using pressure sensors applied to a real network in Barcelona

     Pérez Magrané, Ramon; Sanz Estapé, Gerard; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Cuguero Escofet, Miquel Àngel; Nejjari Akhi-elarab, Fatiha; Meseguer, Jordi; Cembrano Gennari, M.gabriela Elena; Mirats Tur, Josep Maria; Sarrate Estruch, Ramon
    IEEE control systems magazine
    Date of publication: 2014-08-01
    Journal article

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    The efficient distribution of water is a subject of major concern for water utilities and authorities [1]. While some leaks in water distribution networks (WDNs) are unavoidable, one of the main challenges in improving the efficiency of drinking water networks is to minimize leaks. Leaks can cause significant economic losses in fluid transportation and extra costs for the final consumer due to the waste of energy and chemicals in water treatment plants. Leaks may also damage infrastructure and cause third-party damage and health risks. In many WDNs, losses due to leakage are estimated to account up to 30% of the total amount of extracted water [2]; a very important issue in a world struggling to satisfy water demands of a growing population.

    The efficient distribution of water is a subject of major concern for water utilities and authorities [1]. While some leaks in water distribution networks (WDNs) are unavoidable, one of the main challenges in improving the efficiency of drinking water networks is to minimize leaks. Leaks can cause significant economic losses in fluid transportation and extra costs for the final consumer due to the waste of energy and chemicals in water treatment plants. Leaks may also damage infrastructure and cause third-party damage and health risks. In many WDNs, losses due to leakage are estimated to account up to 30% of the total amount of extracted water [2]; a very important issue in a world struggling to satisfy water demands of a growing population.

  • A virtual actuator and sensor approach for fault tolerant control of LPV systems

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    Journal of process control
    Date of publication: 2014-03-01
    Journal article

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    In this paper, a fault tolerant control (FTC) strategy using virtual actuators and sensors for linear parameter varying (LPV) systems is proposed. The main idea of this FTC method, initially developed for LTI systems, is to reconfigure the control loop such that the nominal controller could still be used without need of retuning it. The plant with the faulty actuator/sensor is modified adding the virtual actuator/sensor block that masks the actuator/sensor fault. The suggested technique is an active FTC strategy that reconfigures the virtual actuator/sensor on-line taking into account faults and operating point changes. The stability of the reconfigured control loop is guaranteed if the faulty plant is stabilizable/detectable. The LPV virtual actuator/sensor is designed using polytopic LPV techniques and linear matrix inequalities (LMIs). A two-tank system simulator is used to assess the performance of the proposed method. In particular, it is shown that the application of the proposed technique results in an improvement, in terms of performance, with respect to the LTI counterpart

    In this paper, a fault tolerant control (FTC) strategy using virtual actuators and sensors for linear parameter varying (LPV) systems is proposed. The main idea of this FTC method, initially developed for LTI systems, is to reconfigure the control loop such that the nominal controller could still be used without need of retuning it. The plant with the faulty actuator/sensor is modified adding the virtual actuator/sensor block that masks the actuator/sensor fault. The suggested technique is an active FTC strategy that reconfigures the virtual actuator/sensor on-line taking into account faults and operating point changes. The stability of the reconfigured control loop is guaranteed if the faulty plant is stabilizable/detectable. The LPV virtual actuator/sensor is designed using polytopic LPV techniques and linear matrix inequalities (LMIs). A two-tank system simulator is used to assess the performance of the proposed method. In particular, it is shown that the application of the proposed technique results in an improvement, in terms of performance, with respect to the LTI counterpart

  • Robust state-feedback control of uncertain LPV systems : an LMI-based approach

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    Journal of the Franklin Institute
    Date of publication: 2014-05-01
    Journal article

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    In this paper, the problem of designing an LPV state-feedback controller for uncertain LPV systems that can guarantee some desired bounds on the H-infinity and the H-2 performances and that satisfies some desired constraints on the closed-loop poles location is considered. In the proposed approach, the vector of varying parameters is used to schedule between uncertain LTI systems. The resulting idea consists in using a double-layer polytopic description so as to take into account both the variability due to the parameter vector and the uncertainty. The first polytopic layer manages the varying parameter and is used to obtain the vertex uncertain systems, where the vertex controllers are designed. The second polytopic layer is built at each vertex system so as to take into account the model uncertainties and add robustness into the design step. Under some assumptions, the problem reduces to finding a solution to a finite number of LMIs, a problem for which efficient solvers are available nowadays. The solution to the multiobjective design problem is found both in the case when a single fixed Lyapunov function is used and when multiple parameter-varying Lyapunov functions are used. The validity and performance of the theoretical results are demonstrated through a numerical example. (C) 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

    In this paper, the problem of designing an LPV state-feedback controller for uncertain LPV systems that can guarantee some desired bounds on the H-infinity and the H-2 performances and that satisfies some desired constraints on the closed-loop poles location is considered. In the proposed approach, the vector of varying parameters is used to schedule between uncertain LTI systems. The resulting idea consists in using a double-layer polytopic description so as to take into account both the variability due to the parameter vector and the uncertainty. The first polytopic layer manages the varying parameter and is used to obtain the vertex uncertain systems, where the vertex controllers are designed. The second polytopic layer is built at each vertex system so as to take into account the model uncertainties and add robustness into the design step. Under some assumptions, the problem reduces to finding a solution to a finite number of LMIs, a problem for which efficient solvers are available nowadays. The solution to the multiobjective design problem is found both in the case when a single fixed Lyapunov function is used and when multiple parameter-varying Lyapunov functions are used. The validity and performance of the theoretical results are demonstrated through a numerical example. (C) 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

  • On-line model-based fault detection and isolation for PEM fuel cell stack systems

     Rosich, Albert; Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha
    Applied mathematical modelling
    Date of publication: 2014-06-01
    Journal article

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    Efficient and reliable operation of Polymer Electrolyte Membrane (PEM) fuel cells are key requirements for their successful commercialization and application. The use of diagnostic techniques enables the achievement of these requirements. This paper focuses on model-based fault detection and isolation (FDI) for PEM fuel cell stack systems. The work consists in designing and selecting a subset of consistency relations such that a set of predefined faults can be detected and isolated. Despite a nonlinear model of the PEM fuel cell stack system will be used, consistency relations that are easily implemented by a variable back substitution method will be selected. The paper also shows the significance of structural models to solve diagnosis issues in complex systems.

    Efficient and reliable operation of Polymer Electrolyte Membrane (PEM) fuel cells are key requirements for their successful commercialization and application. The use of diagnostic techniques enables the achievement of these requirements. This paper focuses on model-based fault detection and isolation (FDI) for PEM fuel cell stack systems. The work consists in designing and selecting a subset of consistency relations such that a set of predefined faults can be detected and isolated. Despite a nonlinear model of the PEM fuel cell stack system will be used, consistency relations that are easily implemented by a variable back substitution method will be selected. The paper also shows the significance of structural models to solve diagnosis issues in complex systems.

  • Chlorine decay model calibration and comparison: application to a real water network

     Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Pérez Magrané, Ramon; Quevedo Casin, Joseba-jokin; Cuguero Escofet, Miquel Àngel; Sanz Estapé, Gerard; Mirats Tur, Josep Maria
    Computing and Control for the Water Industry
    Presentation's date: 2014-09-03
    Presentation of work at congresses

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    This work presents a methodology to efficiently calibrate chlorine decay models. The calibration consists in estimating the unknown parameters by comparing the measured and simulated chlorine concentrations at the monitored nodes within the distribution system in a least square sense using a normalized quadratic cost function. Since this function involves a non- explicit expression of the model, a genetic algorithm (GA) is applied to optimize the model parameters by minimizing the difference between the model-predicted values and the field-measured ones. The method is applied to a part of the Barcelona drinking water network.

    This work presents a methodology to efficiently calibrate chlorine decay models. The calibration consists in estimating the unknown parameters by comparing the measured and simulated chlorine concentrations at the monitored nodes within the distribution system in a least square sense using a normalized quadratic cost function. Since this function involves a non- explicit expression of the model, a genetic algorithm (GA) is applied to optimize the model parameters by minimizing the difference between the model-predicted values and the field-measured ones. The method is applied to a part of the Barcelona drinking water network.

  • Quasi-LPV modeling, identification and control of a twin rotor MIMO system

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    Control engineering practice
    Date of publication: 2013-03
    Journal article

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    This paper describes the quasi-linear parameter varying (quasi-LPV) modeling, identification and control of a Twin Rotor MIMO System (TRMS). The non-linear model of the TRMS is transformed into a quasi-LPV system and approximated in a polytopic way. The unknown model parameters have been calibrated by means of the non-linear least squares identification approach and validated against real data. Finally, an LPV state observer and state-feedback controller have been designed using an LPV pole placement method based on LMI regions. The effectiveness and performance of the proposed control approach have been proved both in simulation and on the real set-up.

  • FTC of LPV systems using a bank of visual sensors: application to wind turbines

     Rotondo, Damiano; Puig Cayuela, Vicenç; Acevedo Valle, Juan M.; Nejjari Akhi-elarab, Fatiha
    International Conference on Control and Fault-Tolerant Systems
    Presentation's date: 2013-10-10
    Presentation of work at congresses

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    In this paper, an FTC strategy using Linear Parameter Varying (LPV) virtual sensors is proposed and applied to the IFAC wind turbine case study. The novelty of the proposed strategy consists in that virtual sensors are applied to the FTC problem in a new original fashion. Instead of hiding the fault, the virtual sensors are used to expand the set of available sensors. Then, the state observer is designed using LPV techniques based on Linear Matrix Inequalities (LMIs) taking into account a varying parameter that is introduced in order to select which sensors are used by the observer among the physical and the virtual ones. In this sense, the proposed approach can be considered as a multisensor fusion strategy that integrates data provided by various sensors in order to obtain a better estimation.

    In this paper, an FTC strategy using Linear Parameter Varying (LPV) virtual sensors is proposed and applied to the IFAC wind turbine case study. The novelty of the proposed strategy consists in that virtual sensors are applied to the FTC problem in a new original fashion. Instead of hiding the fault, the virtual sensors are used to expand the set of available sensors. Then, the state observer is designed using LPV techniques based on Linear Matrix Inequalities (LMIs) taking into account a varying parameter that is introduced in order to select which sensors are used by the observer among the physical and the virtual ones. In this sense, the proposed approach can be considered as a multisensor fusion strategy that integrates data provided by various sensors in order to obtain a better estimation.

  • Sensor placement for leak detection and location in water distribution networks

     Sarrate Estruch, Ramon; Blesa Izquierdo, Joaquin; Nejjari Akhi-elarab, Fatiha; Quevedo Casin, Joseba-jokin
    IWA Specialist Conference on Efficient Use and Management of Water "Water Efficiency Strategies for Difficult Times"
    Presentation's date: 2013-10-23
    Presentation of work at congresses

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    Robust fault detection and isolation of wind turbines using interval observers  Open access

     Blesa Izquierdo, Joaquin; Nejjari Akhi-elarab, Fatiha; Rotondo, Damiano; Puig Cayuela, Vicenç
    International Conference on Control and Fault-Tolerant Systems
    Presentation's date: 2013-10-10
    Presentation of work at congresses

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    In order to improve reliability and safety of wind turbines, it is important to detect and isolate faults as fast as possible. In this work, an approach based on interval observers is used for robust Fault Detection and Isolation (FDI) of wind turbines. Fault detection is addressed using interval observers and unknown but bounded descriptions of the noise and modeling errors, while fault isolation is based on a row-reasoning approach. The performance of the proposed robust FDI scheme is assessed using a set of fault scenarios considered in a wind turbine benchmark.

    In order to improve reliability and safety of wind turbines, it is important to detect and isolate faults as fast as possible. In this work, an approach based on interval observers is used for robust Fault Detection and Isolation (FDI) of wind turbines. Fault detection is addressed using interval observers and unknown but bounded descriptions of the noise and modeling errors, while fault isolation is based on a row-reasoning approach. The performance of the proposed robust FDI scheme is assessed using a set of fault scenarios considered in a wind turbine benchmark.

    Postprint (author’s final draft)

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    Chlorine decay model calibration and comparison: application to a real water network  Open access

     Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Pérez Magrané, Ramon; Quevedo Casin, Joseba-jokin; Cuguero Escofet, Miquel Àngel; Sanz Estapé, Gerard; Mirats Tur, Josep Maria
    Computing and Control for the Water Industry
    Presentation's date: 2013-09-03
    Presentation of work at congresses

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    This work presents a methodology to efficiently calibrate chlorine decay models. The calibration consists in estimating the unknown parameters by comparing the measured and simulated chlorine concentrations at the monitored nodes within the distribution system in a least square sense using a normalized quadratic cost function. Since this function involves a non- explicit expression of the model, a genetic algorithm (GA) is applied to optimize the model parameters by minimizing the difference between the model-predicted values and the field-measured ones. The method is applied to a part of the Barcelona drinking water network.

    This work presents a methodology to efficiently calibrate chlorine decay models. The calibration consists in estimating the unknown parameters by comparing the measured and simulated chlorine concentrations at the monitored nodes within the distribution system in a least square sense using a normalized quadratic cost function. Since this function involves a non- explicit expression of the model, a genetic algorithm (GA) is applied to optimize the model parameters by minimizing the difference between the model-predicted values and the field-measured ones. The method is applied to a part of the Barcelona drinking water network.

  • Fault tolerant control design for polytopic uncertain LPV systems: application to a quadrotor

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Torren, Abel; Puig Cayuela, Vicenç
    International Conference on Control and Fault-Tolerant Systems
    Presentation's date: 2013-10-11
    Presentation of work at congresses

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    This paper presents a Fault Tolerant Control (FTC) design for polytopic uncertain Linear Parameter-Varying (LPV) systems, applied to an aerospace application: a quadrotor. Depending on the information available about the fault, the FTC strategy could be passive FTC, active FTC without controller reconfiguration or active FTC with controller reconfiguration. The FTC strategy is designed taking into account the robust LPV polytopic framework. The effectiveness of the proposed method is demonstrated by its application to a quadrotor.

    This paper presents a Fault Tolerant Control (FTC) design for polytopic uncertain Linear Parameter-Varying (LPV) systems, applied to an aerospace application: a quadrotor. Depending on the information available about the fault, the FTC strategy could be passive FTC, active FTC without controller reconfiguration or active FTC with controller reconfiguration. The FTC strategy is designed taking into account the robust LPV polytopic framework. The effectiveness of the proposed method is demonstrated by its application to a quadrotor.

  • A shifting pole placement approach for the design of parameter-scheduled state-feedback controllers

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    European Control Conference
    Presentation's date: 2013-07-18
    Presentation of work at congresses

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    In this paper, the problem of designing a parameter-scheduled state-feedback controller is investigated. The main novelty and contribution of this paper is the extension of the classical regional pole placement problem, that will be referred to as shifting pole placement, to the design of parameter scheduled controller taking advantage of polytopes and LMIs properties. By introducing some parameters, or using existing ones, the controller can be designed in such a way that different values of these parameters imply different regions where the closed-loop poles are situated. The problem is analyzed in both linear time-invariant (LTI) and parameter-varying (LPV) cases, and some results obtained in simulation are shown so as to demonstrate the effectiveness of the proposed approach

    In this paper, the problem of designing a parameter-scheduled state-feedback controller is investigated. The main novelty and contribution of this paper is the extension of the classical regional pole placement problem, that will be referred to as shifting pole placement, to the design of parameter scheduled controller taking advantage of polytopes and LMIs properties. By introducing some parameters, or using existing ones, the controller can be designed in such a way that different values of these parameters imply different regions where the closed-loop poles are situated. The problem is analyzed in both linear time-invariant (LTI) and parameter-varying (LPV) cases, and some results obtained in simulation are shown so as to demonstrate the effectiveness of the proposed approach.

  • Passive and active FTC comparison for polytopic LPV systems

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    European Control Conference
    Presentation's date: 2013-07-18
    Presentation of work at congresses

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    Fault-tolerant control (FTC) allows to preserve performance and stability despite the presence of faults. The literature considers two main groups of techniques: the passive and the active FTC techniques. In case of the passive techniques, the fault is taken into account as a system perturbation, so that the control law has fault capabilities that allow the system to cope with the fault presence. On the other hand, in the case of the active FTC techniques, the control law uses some information given by a Fault Detection and Isolation (FDI) module, so that through some automatic adjustment in the control loop, the fault is tolerated with minimum performance degradation. In this paper, a linear parameter-varying (LPV)/linear matrix inequalities (LMIs)-based technique is used to achieve fault tolerance and to compare benefits and drawbacks of passive and active FTC. The proposed approach is applied to a twowheel differential robot.

    Fault-tolerant control (FTC) allows to preserve performance and stability despite the pres nce of faults. The literature considers two main groups of techniques: the passive and the active FTC techniques. In case of the passive techniques, the fault is taken into account as a system perturbation, so that the control law has fault capabilities that allow the system to cope with the fault presence. On the other hand, in the case of the active FTC techniques, the control law uses some information given by a Fault Detection and Isolation (FDI) module, so that through some automatic adjustment in the control loop, the fault is tolerated with minimum performance degradation. In this paper, a linear parameter-varying (LPV)/linear matrix inequalities (LMIs)-based technique is used to achieve fault tolerance and to compare benefits and drawbacks of passive and active FTC. The proposed approach is applied to a twowheel differential robot.

  • Fault tolerant control design for polytopic uncertain LPV systems

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    Mediterranean Conference on Control & Automation
    Presentation's date: 2013-06-26
    Presentation of work at congresses

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    This paper presents a fault tolerant control (FTC) design for polytopic uncertain linear parameter-varying (LPV) systems. Depending on the information available about the fault, the FTC strategy could be passive FTC, active FTC without controller reconfiguration or active FTC with controller reconfiguration. The FTC strategy is designed taking into account the robust LPV polytopic framework extending known results from the robust polytopic and the traditional LPV polytopic control areas. The effectiveness of the proposed method is demonstrated by its application to a two-tank system simulator.

    This paper presents a fault tolerant control (FTC) design for polytopic uncertain linear parameter-varying (LPV) systems. Depending on the information available about the fault, the FTC strategy could be passive FTC, active FTC without controller reconfiguration or active FTC with controller reconfiguration. The FTC strategy is designed taking into account the robust LPV polytopic framework extending known results from the robust polytopic and the traditional LPV polytopic control areas. The effectiveness of the proposed method is demonstrated by its application to a two-tank system simulator.

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    Self-video recording for the integration and assessment of generic competencies  Open access

     Masip Alvarez, Albert; Hervada Sala, Carme; Pamies Gomez, Teresa; Arias Pujol, Antoni; Jaen Fernandez, Carlos; Rodriguez Sorigue, Maria Cristina; Romero Duran, David; Nejjari Akhi-elarab, Fatiha; Alvarez Del Castillo, M. Dolores; Roca Lefler, Marta; Hernández Farràs, Jorge; Montferrer Liñan, Raul
    IEEE Global Engineering Education Conference
    Presentation of work at congresses

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    This document presents the use of a self-video-recording service for the integration and assessment of certain generic competences (oral and written communication, teamwork and third (English) language) in all degree programs related to the Industrial area at the Terrassa School of Engineering (EET). The resulting service allows to carry out the assessment through active and collaborative learning methodologies using ICT as a support, becoming an educational resource where students are encouraged to evaluate their own activity, individually and in groups (co-evaluation), and with which the faculty can enhance certain sections of the syllabus while also evaluating generic competences. This paper outlines the rationale and design of the system based on self-recording-video that assists work on some generic competences. A preliminary experience has taken place and it has been carried out by volunteer students and some professors from the promoting team. It consisted of following all steps to obtain the video-recording as a result and fulfil the further assessment. Preparing the defence of the final project career, explaining the way a problem is faced are examples of use of the service endowed to assist the assessment of some generic competences. A good number of students and professors have participated in this preliminary experiment carried out on some subjects and in which oral effective communication will be assessed. A specific rubric for the assessment of generic competences has been used both for students and faculty. There is a summary of qualitative feedback from both students and instructors, and where several issues related to improving the self-assessment and self-video-recording system, are discussed. Finally, a survey is proposed, whose results will be helpful for its improvement.

    This document presents the use of a self-video-recording service for the integration and assessment of certain generic competences (oral and written communication, teamwork and third (English) language) in all degree programs related to the Industrial area at the Terrassa School of Engineering (EET). The resulting service allows to carry out the assessment through active and collaborative learning methodologies using ICT as a support, becoming an educational resource where students are encouraged to evaluate their own activity, individually and in groups (co-evaluation), and with which the faculty can enhance certain sections of the syllabus while also evaluating generic competences. This paper outlines the rationale and design of the system based on self-recording-video that assists work on some generic competences. A preliminary experience has taken place and it has been carried out by volunteer students and some professors from the promoting team. It consisted of following all steps to obtain the video-recording as a result and fulfil the further assessment. Preparing the defence of the final project career, explaining the way a problem is faced are examples of use of the service endowed to assist the assessment of some generic competences. A good number of students and professors have participated in this preliminary experiment carried out on some subjects and in which oral effective communication will be assessed. A specific rubric for the assessment of generic competences has been used both for students and faculty. There is a summary of qualitative feedback from both students and instructors, and where several issues related to improving the self-assessment and self-video-recording system, are discussed. Finally, a survey is proposed, whose results will be helpful for its improvement.

  • Fault diagnosis based on causal computations

     Rosich Oliva, Albert; Frisk, Erik; Åslund, Jan; Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha
    IEEE transactions on systems man and cybernetics Part A-systems and humans
    Date of publication: 2012-03-23
    Journal article

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    This paper focuses on residual generation for model-based fault diagnosis. Specifically, a methodology to derive residual generators when nonlinear equations are present in the model is developed. A main result is the characterization of computation sequences that are particularly easy to implement as residual generators and that take causal information into account. An efficient algorithm, based on the model structure only, which finds all such computation sequences, is derived. Furthermore, fault detectability and isolability performances depend on the sensor configuration. Therefore, another contribution is an algorithm, also based on the model structure, that places sensors with respect to the class of residual generators that take causal information into account. The algorithms are evaluated on a complex highly nonlinear model of a fuel cell stack system. A number of residual generators that are, by construction, easy to implement are computed and provide full diagnosability performance predicted by the model.

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    Abnormal quality detection and isolation in water distribution networks using simulation models  Open access

     Nejjari Akhi-elarab, Fatiha; Pérez Magrané, Ramon; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Sarrate Estruch, Ramon; Cuguero Escofet, Miquel Àngel; Sanz Estapé, Gerard; Mirats Tur, Josep Maria
    Drinking water engineering and science
    Date of publication: 2012-11-16
    Journal article

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    This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

    This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

  • Localización de fugas en redes de distribución de agua potable

     Pérez Magrané, Ramon; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Nejjari Akhi-elarab, Fatiha; Pascual Pañach, Josep; Sanz Estapé, Gerard; Cuguero Escofet, Miquel Àngel; Cembrano Gennari, M.gabriela Elena; Landeros, Edson; Peralta, Antoni; Mirats Tur, Josep Maria; Meseguer, Jordi
    Automática e instrumentación
    Date of publication: 2012-02
    Journal article

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  • Combining health monitoring and control

     Escobet Canal, Teresa; Quevedo Casin, Joseba-jokin; Puig Cayuela, Vicenç; Nejjari Akhi-elarab, Fatiha
    Date of publication: 2012-09
    Book chapter

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  • Model-based optimal sensor placement approaches to fuel cell stack system fault diagnosis

     Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha; Rosich Oliva, Albert
    IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes
    Presentation's date: 2012-08-29
    Presentation of work at congresses

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  • FTC design for polytopic LPV systems subject to actuator saturations

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    Mediterranean Conference on Control & Automation
    Presentation's date: 2012-07-04
    Presentation of work at congresses

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    In this paper, a Fault Tolerant Control (FTC) scheme using virtual actuators for discrete-time polytopic Linear Parameter Varying (LPV) systems subject to actuator saturations is proposed. The plant with the faulty actuator is augmented to take into account the saturations and modified adding the virtual actuator block that masks the fault. The elements of the FTC control loop are designed using Linear Matrix Inequalities (LMIs) in order to achieve the Pole Placement and the H2 norm specifications. To assess the performance of the proposed approach an aeronautical application is used.

  • Health aware control and model-based prognosis

     Escobet Canal, Teresa; Puig Cayuela, Vicenç; Nejjari Akhi-elarab, Fatiha
    Mediterranean Conference on Control & Automation
    Presentation's date: 2012-07-05
    Presentation of work at congresses

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  • Sensor placement for fault diagnosis performance maximization under budgetary constraints

     Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha; Rosich Oliva, Albert
    International Conference on Systems and Control
    Presentation's date: 2012-06-21
    Presentation of work at congresses

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  • Optimal sensor placement for leakage detection and isolation in water distribution networks

     Rosich Oliva, Albert; Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha
    IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes
    Presentation's date: 2012-08-30
    Presentation of work at congresses

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    In this paper, the problem of leakage detection and isolation in water distribution networks is addressed applying an optimal sensor placement methodology. The chosen technique is based on structural models and thus it is suitable to handle non-linear and large scale systems. A drawback of this technique arises when costs are assigned uniformly. A main contribution of this paper is the proposal of an iterative methodology that focuses on identifying essential sensors which ultimately leads to an improvement of the optimal search efficiency. The algorithm presented in this work is successfully applied to a District Metered Area (DMA) in the Barcelona water distribution network.

    In this paper, the problem of leakage detection and isolation in water distribution networks is addressed applying an optimal sensor placement methodology. The chosen technique is based on structural models and thus it is suitable to handle non-linear and large scale systems. A drawback of this technique arises when costs are assigned uniformly. A main contribution of this paper is the proposal of an iterative methodology that focuses on identifying essential sensors which ultimately leads to an improvement of the optimal search efficiency. The algorithm presented in this work is successfully applied to a District Metered Area (DMA) in the Barcelona water distribution network.

  • Fault estimation and virtual actuator FTC approach for LPV systems

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes
    Presentation's date: 2012-08-29
    Presentation of work at congresses

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    In this paper, a Fault Tolerant Control (FTC) strategy using a virtual actuator for Linear Parameter Varying (LPV) systems is proposed. The main idea of this FTC method is to reconfigure the control loop such that the nominal controller could still be used without need of retuning it. The plant with the faulty actuator is modified adding the virtual actuator block that masks the fault. The suggested strategy is an active FTC strategy that reconfigures the virtual actuator on-line taking into account faults and operating point changes. In order to implement the virtual actuator approach, a fault estimation is required. In this work, the fault estimation is formulated as a parameter estimation problem. The LPV virtual actuator is designed using polytopic LPV techniques and Linear Matrix Inequalities (LMIs). To assess the performance of the proposed approach an aeronautical application is used.

  • Fault tolerant control of the wind turbine benchmark using virtual sensors/actuators  awarded activity

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Blesa Izquierdo, Joaquin
    IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes
    Presentation's date: 2012-08-29
    Presentation of work at congresses

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    In this paper, the problem of Fault Tolerant Control (FTC) of the wind turbine benchmark is addressed. The paper proposes the use of virtual sensor/actuator approaches to deal with sensor and actuator faults, respectively. The paper suggests the reformulation of these FTC schemes that have been already proposed in state space form in input/output form. The FTC module will use the information from the Fault Detection and Isolation (FDI) module previously designed using set-membership techniques. A fault estimation scheme is also proposed based on batch least squares approach. The performance of the proposed FTC schemes will be assessed using the proposed fault scenarios considered in the FTC benchmark.

    In this paper, the problem of Fault Tolerant Control (FTC) of the wind turbine benchmark is addressed. The paper proposes the use of virtual sensor/actuator approaches to deal with sensor and actuator faults, respectively. The paper suggests the reformulation of these FTC schemes that have been already proposed in state space form in input/output form. The FTC module will use the information from the Fault Detection and Isolation (FDI) module previously designed using set-membership techniques. A fault estimation scheme is also proposed based on batch least squares approach. The performance of the proposed FTC schemes will be assessed using the proposed fault scenarios considered in the FTC benchmark.

    Primer lloc de la "Competition on Fault Detection and Fault Tolerant Control for Wind Turbines", com la millor solució al problema de control tolerant a fallades per a aerogeneradors. El premi el dóna l’Aalborg University/MathWorks/kk-electronic.

  • Quasi-LPV modelling and non-linear identification of a twin rotor system

     Nejjari Akhi-elarab, Fatiha; Rotondo, Damiano; Puig Cayuela, Vicenç; Innocenti, Mario
    Mediterranean Conference on Control & Automation
    Presentation's date: 2012-07-04
    Presentation of work at congresses

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  • Sensor placement for fault diagnosis performance maximization in distribution networks

     Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha; Rosich Oliva, Albert
    Mediterranean Conference on Control & Automation
    Presentation's date: 2012-07-04
    Presentation of work at congresses

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  • SYSTEM HEALTH MANAGEMENT AND RELIABLE CONTROL OF COMPLEX SYSTEMS

     Puig Cayuela, Vicenç; Escobet Canal, Teresa; Saludes Closa, Jordi; Nejjari Akhi-elarab, Fatiha; Morcego Seix, Bernardo; De Las Heras Jimenez, Salvador Augusto; Escobet Canal, Antoni; Comasolivas Font, Ramon; Sarrate Estruch, Ramon; Pérez Magrané, Ramon; Tornil Sin, Sebastian; Masip Alvarez, Albert; Rotondo, Damiano; Vento Maldonado, Jorge Isaac; Blesa Izquierdo, Joaquin; Cuguero Escofet, Miquel Àngel; Romera Formiguera, Juli; Pascual Pañach, Josep; Sanz Estapé, Gerard; Cuguero Escofet, Josep; Quevedo Casin, Joseba-jokin
    Participation in a competitive project

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  • Safeprocess 2012

     Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Blesa Izquierdo, Joaquin
    Award or recognition

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  • Competition Fault Detection and Fault Tolerant Control for Wind Turbines

     Nejjari Akhi-elarab, Fatiha; Rotondo, Damiano; Puig Cayuela, Vicenç; Blesa Izquierdo, Joaquin
    Award or recognition

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  • EFFICIENT INTEGRATED REAL TIME MONITORING AND CONTROL OF DRINKING WATER NETWORKS

     Cuguero Escofet, Josep; Ocampo Martinez, Carlos A.; Quevedo Casin, Joseba-jokin; Sarrate Estruch, Ramon; Nejjari Akhi-elarab, Fatiha; Pérez Magrané, Ramon; Puig Cayuela, Vicenç
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  • Abnormal Quality Detection and Isolation in Water Distribution Networks using Simulation Models

     Nejjari Akhi-elarab, Fatiha; Pérez Magrané, Ramon; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Sarrate Estruch, Ramon; Cuguero Escofet, Miquel Àngel; Sanz Estapé, Gerard; Mirats Tur, Josep Maria
    Computing and Control for the Water Industry
    Presentation's date: 2011-09-06
    Presentation of work at congresses

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    This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

    This paper proposes a model based fault localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals, generated by comparing the available chlorine measurements with their estimation using a model, with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

  • Heading control system design for an unmanned helicopter

     Nejjari Akhi-elarab, Fatiha; Saldívar, Eleazar; Morcego Seix, Bernardo
    Mediterranean Conference on Control & Automation
    Presentation's date: 2011-06-23
    Presentation of work at congresses

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  • Leakage location in water distribution networks based on correlation measurement of pressure sensors

     Quevedo Casin, Joseba-jokin; Cuguero Escofet, Miquel Àngel; Pérez Magrané, Ramon; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Mirats Tur, Josep Maria
    IWA Symposium on Systems Analysis and Integrated Assessment
    Presentation's date: 2011-06-21
    Presentation of work at congresses

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  • Fault estimation and virtual sensor FTC approach for LPV systems

     Montes de Oca, Saúl; Rotondo, Damiano; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç
    IEEE Conference on Decision and Control and European Control Conference
    Presentation's date: 2011-12-13
    Presentation of work at congresses

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  • Leakage isolation in water distribution networks: a comparative study of two methodologies on a real case study

     Pérez Magrané, Ramon; Puig Cayuela, Vicenç; Nejjari Akhi-elarab, Fatiha; Cuguero Escofet, Miquel Àngel; Sanz Estapé, Gerard; Mirats Tur, Josep Maria; Quevedo Casin, Joseba-jokin
    Mediterranean Conference on Control & Automation
    Presentation's date: 2011-06-21
    Presentation of work at congresses

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  • Tail motion model identification for control design of an unmanned helicopter

     Morcego Seix, Bernardo; Saldívar, Eleazar; Nejjari Akhi-elarab, Fatiha
    Research, Development and Education on Unmanned Aerial Systems
    Presentation's date: 2011-12-01
    Presentation of work at congresses

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  • Study of the isolability of leaks in a network depending on calibration of demands

     Pérez Magrané, Ramon; Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Sanz Estapé, Gerard; Cuguero Escofet, Miquel Àngel; Peralta, Antoni
    Computing and Control for the Water Industry
    Presentation's date: 2011-09-06
    Presentation of work at congresses

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    Using the simulation models a methodology was developed for leakage detection and localisation in a water distribution network [4]. Such methodology is based on fault detection and isolation techniques. Sensitivity matrix of pressures to leaks [8] is generated using simulation models [1]. Such models are available in water companies. The methodology showed promising results but two main issues appeared. Calibration in models and precision in sensors was required. Investment in sensors could be afforded [6] as long as models were well calibrated enough. The main uncertainty in models lies on demands. This paper presents a study of the effect of an improvement in demand calibration on isolability of leaks. The aim is to quantify the return of an effort in calibrating in terms of leak detection one of the main issues in water industry [2].

  • LPV modelling and control of a twin rotor MIMO system

     Nejjari Akhi-elarab, Fatiha; Rotondo, Damiano; Puig Cayuela, Vicenç; Innocenti, Mario
    Mediterranean Conference on Control & Automation
    Presentation's date: 2011-06-23
    Presentation of work at congresses

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  • Coordinació d'assignatures per a la introducció de la competència genèrica tercera llengua als nous estudis de grau de l'escola tècnica superior d'enginyeries industrial i aeronàutica de Terrassa (ETSEIAT)

     Garcia Almiñana, Daniel; Rodríguez-Donaire, Silvia; Domenech Mas, Jose M.; Gassó Domingo, Santiago; Amante García, Beatriz; Gonçalves Ageitos, Maria; Lopez Grimau, Victor; Morera Escude, Maria Teresa; Nejjari Akhi-elarab, Fatiha; Fernández Alarcón, Vicenç; Salán Ballesteros, Mª Núria; Sureda Anfres, Miquel; Del Campo Sud, David; Del Campo Gatell, Vanessa; Forcada Matheu, Nuria; Gangolells Solanellas, Marta; Garcia Espinosa, Antonio; Arencón Osuna, David; Casals Casanova, Miquel
    Participation in a competitive project

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  • GEstió i COntrol de Zones Inundables per minimitzar els Impactes mediambientals de les crescudes dels rius. Aplicació a la conca Pirenaica (CTP-DGR)

     Puig Cayuela, Vicenç; Cembrano Gennari, M.gabriela Elena; Escobet Canal, Antoni; Nejjari Akhi-elarab, Fatiha; Morcego Seix, Bernardo; Pérez Magrané, Ramon; Saludes Closa, Jordi; Ocampo Martinez, Carlos A.; Romera Formiguera, Juli; Quevedo Casin, Joseba-jokin
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  • MAKING SENSE OF NONSENSE

     Puig Cayuela, Vicenç; Rotondo, Damiano; Ocampo Martinez, Carlos A.; Rosich Oliva, Albert; Saludes Closa, Jordi; Garcia Valverde, Diego; Sarrate Estruch, Ramon; Blesa Izquierdo, Joaquin; Nejjari Akhi-elarab, Fatiha; Comasolivas Font, Ramon; Cuguero Escofet, Miquel Àngel; Quevedo Casin, Joseba-jokin
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  • Sensor placement for fault diagnosis based on structural models: application to a fuel cell stak system  Open access

     Rosich Oliva, Albert
    Defense's date: 2011-06-03
    Department of Automatic Control, Universitat Politècnica de Catalunya
    Theses

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    The present work aims to increase the diagnosis systems capabilities by choosing the location of sensors in the process. Therefore, appropriate sensor location will lead to better diagnosis performance and implementation easiness. The work is based on structural models ands some simplifications are considered in order to only focus on the sensor placement analysis. Several approaches are studied to solve the sensor placement problem. All of them find the optimal sensor configuration. The sensor placement techniques are applied to a fuel cell stack system. The model used to describe the behaviour of this system consists of non-linear equations. Furthermore, there are 30 candidate sensors to improve the diagnosis specifications. The results obtained from this case study are used to strength the applicability of the proposed approaches.

    El present treball té per objectiu incrementar les prestacions dels diagnosticadors mitjançant la localització de sensors en el procés. D'aquesta manera, instal·lant els sensors apropiats s'obtenen millors diagnosticador i més facilitats d'implementació. El treball està basat en models estructurals i contempla una sèrie de simplificacions per tal de entrar-se només en la problemàtica de la localització de sensors. S'utilitzen diversos enfocs per tal de resoldre la localització de sensors, tot ells tenen com objectiu trobar la configuració òptima de sensors. Les tècniques de localització de sensors són aplicades a un sistema basat en una pila de combustible. El model d'aquest sistema està format per equacions no lineals. A més, hi ha la possibilitat d'instal·lar fins a 30 sensors per tal de millorar la diagnosis del sistema. Degut a aquestes característiques del sistema i del model, els resultats obtinguts mitjançant aquest cas d'estudi reafirmen l'aplicabilitat dels mètodes proposats.

  • Multi-objective optimisation for aircraft departure trajectories minimising noise annoyance

     Prats Menéndez, Xavier; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Nejjari Akhi-elarab, Fatiha
    Transportation research. Part C, emerging technologies
    Date of publication: 2010
    Journal article

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  • Lexicographic optimisation for optimal departure aircraft trajectories

     Prats Menéndez, Xavier; Puig Cayuela, Vicenç; Quevedo Casin, Joseba-jokin; Nejjari Akhi-elarab, Fatiha
    Aerospace science and technology
    Date of publication: 2010
    Journal article

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  • Optimal Sensor Placement For Fuel Cell System Diagnosis using BILP Formulation

     Nejjari Akhi-elarab, Fatiha; Sarrate Estruch, Ramon; Rosich Oliva, Albert
    Mediterranean Conference on Control & Automation
    Presentation's date: 2010-06-25
    Presentation of work at congresses

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  • Robust Fault Detection for LPV Systems Using a Consistency-Based State Estimation Approach and Zonotopes

     Puig Cayuela, Vicenç; Nejjari Akhi-elarab, Fatiha; Guerra, Pedro; Montes de Oca, Saúl
    European Control Conference
    Presentation's date: 2009-08-23
    Presentation of work at congresses

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  • Passive Robust Fault Detection for Interval LPV Systems using Zonotopes

     Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Montes de Oca, Saúl; Sadeghzadeh, Atefeh
    International Workshop on Principles of Diagnosis
    Presentation's date: 2009-09-15
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  • Access to the full text
    Robust fault detection for LPV systems using interval observers and zonotopes  Open access

     Nejjari Akhi-elarab, Fatiha; Puig Cayuela, Vicenç; Montes de Oca, Saúl; Sadeghzadeh, Atefeh
    IEEE Conference on Decision and Control
    Presentation's date: 2009-12-16
    Presentation of work at congresses

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    In this paper, the problem of robust fault detection using an interval observer for dynamic systems characterized by LPV (Linear Parameter Varying) models is presented. The observer faces the robustness problem using two complementary strategies. Modeling uncertainties are considered unknown but bounded by intervals. Their effect is addressed using an interval state observation method based on zonotope representation of the set of possible states. The observer gain is designed via pole placement using LMI formulation. The method is applied to a LPV representation of a Twin Rotor MIMO System.