2023 |
Ethabet, Haifa; Dadi, Leila; Raissi, Tarek; Aoun, Mohamed L∞ Set-membership Estimation for Continuous-time Switched Linear Systems Conférence 2023. Résumé | Liens | BibTeX | Étiquettes: Bounded error context, Continous time, Continuous time systems, Continuous-time switched system, Interval observers, Linear matrix inequalities, Linear systems, Lyapunov functions, L∞ technique, matrix, Set-membership estimation, State estimation, Switched linear system, Switched system, Unknown but bounded @conference{Ethabet2023b, In this work, we focuses on the problem of designing an interval state estimation for continuous-time Switched Linear Systems (SLS) in the Unknown But Bounded Error (UBBE) context. To do so, we design a new structure of interval observers by introducing weighted matrices not only to give more degrees of design freedom but also to attenuate the conservatism caused by uncertainties. Observer gains are derived from the solution of Linear Matrix Inequalities (LMIs), based on the use of a common Lyapunov function, to ensure cooperativity and stability. An L∞ technique is then introduced to compensate the measurement noise and disturbances’ effects and to enhance the precision of interval estimation. Finally, numerical simulations are given, evaluating the proposed methodology and demonstrating its effectiveness. © 2023 IEEE. |
Ounis, Walid; Chetoui, Manel; Najar, Salheddine; Aoun, Mohamed Programmable analogue fractional controller realization Conférence 2023. Résumé | Liens | BibTeX | Étiquettes: Analog circuits, Continuous time systems, Controllers, Digital potentiometer, First order, First order low-pass filter, Fractional integrators, Fractional-order controllers, Higher order dynamics systems, Low pass filters, Low-pass filters, Operational amplifiers, Potentiometers (electric measuring instruments), Programmable analog circuit, Programmable analogs, Real- time, Signal processing, Timing circuits @conference{Ounis2023b, A fractional-order controller is an infinite-memory system. It is described by a continuous time irrational transfer function. Its realization is a delicate problem especially when its parameters are real time tunable. This paper presents a real-time programmable analogue fractional controller implementation. The controller is based on a sum of a novel real-time programmable analogue first-order low-pass filter. The signal within the circuit remains analogue and is not converted into discrete values. Real-time adjustments are made using digital potentiometers and operational amplifiers. The proposed first-order low-pass filter offers several advantages. In particular, the time constant and DC gain are independently adjusted without relying on the ohmic value of digital potentiometers. The time constant and DC gain depend on the resolution of the digital potentiometers. The high resolution of the digital potentiometer enables the circuit to achieve a wide bandwidth and allows for the use of small capacitors at lower frequencies. The proposed real-time programmable analogue fractional controller is experimented to achieve a fractional integrator. The circuit yields good similarity between theoretical simulations and experimental measurements. © 2023 IEEE. |
2022 |
Victor, S.; Mayoufi, A.; Malti, R.; Chetoui, M.; Aoun, M. System identification of MISO fractional systems: Parameter and differentiation order estimation Article de journal Dans: Automatica, vol. 141, 2022, ISSN: 00051098, (cited By 12). Résumé | Liens | BibTeX | Étiquettes: Continous time; Fractional model; Fractional systems; Instrumental variables; Multiple input single output systems; Multiple inputs single outputs; Optimization algorithms; Order estimation; Order optimizations; System-identification, Continuous time systems, Intelligent systems; Monte Carlo methods; Optimization; Parameter estimation; Religious buildings @article{Victor2022, This paper deals with continuous-time system identification of multiple-input single-output (MISO) fractional differentiation models. When differentiation orders are assumed to be known, coefficients are estimated using the simplified refined instrumental variable method for continuous-time fractional models extended to the MISO case. For unknown differentiation orders, a two-stage optimization algorithm is proposed with the developed instrumental variable for coefficient estimation and a gradient-based algorithm for differentiation order estimation. A new definition of structured-commensurability (or S-commensurability) is introduced to better cope with differentiation order estimation. Three variants of the algorithm are then proposed: (i) first, all differentiation orders are set as integer multiples of a global S-commensurate order, (ii) then, the differentiation orders are set as integer multiples of a local S-commensurate orders (one S-commensurate order for each subsystem), (iii) finally, all differentiation orders are estimated by releasing the S-commensurability constraint. The first variant has the smallest number of parameters and is used as a good initial hit for the second variant which in turn is used as a good initial hit for the third variant. Such a progressive increase of the number of parameters allows better performance of the optimization algorithm evaluated by Monte Carlo simulation analysis. © 2022 Elsevier Ltd |
Walid, Ounis; Slaheddine, Najar; Mohamed, Aoun REAL TIME TUNEABLE ANALOGUE PID CONTROLLER REALIZATION Conférence 2022, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Analog realization, Continuous time systems, Controller realization, Controllers, Discretization issue, Discretizations, Electric control equipment, PID controllers, Proportional control systems, Real- time, Three term control systems, Tunable analog PID, Tunable controller, Tunables, Voltage dividers @conference{Walid2022798, This paper proposes a real time tunable analogue PID controller realisation witch can be used as a conventional PID, an adaptative PID or an intelligent PID ‘iPID’. The integral and derivative of the PID input signal are continuous time signals and never sampled. This avoid discretization issues such as aliasing phenomena and the critical sampling period choice. The operative PID circuit part is totally analogue. Few digital potentiometers and digital switches are used. This allows to tune the parameters values of the controller and select PI, PD, PID configuration. The analogue circuit part is designed with a new original circuit architecture. A prototype of the circuit is implemented. Experimentation results show good similarity to the theoretical simulations. © 2022 IEEE. |
Victor, Stéphane; Mayoufi, Abir; Malti, Rachid; Chetoui, Manel; Aoun, Mohamed System identification of MISO fractional systems: Parameter and differentiation order estimation Article de journal Dans: Automatica, vol. 141, 2022, (Cited by: 10). Résumé | Liens | BibTeX | Étiquettes: Continous time, Continuous time systems, Fractional model, Fractional systems, Instrumental variables, Intelligent systems, Monte Carlo methods, Multiple input single output systems, Multiple inputs single outputs, Optimization, Optimization algorithms, Order estimation, Order optimizations, Parameter estimation, Religious buildings, System-identification @article{Victor2022b, This paper deals with continuous-time system identification of multiple-input single-output (MISO) fractional differentiation models. When differentiation orders are assumed to be known, coefficients are estimated using the simplified refined instrumental variable method for continuous-time fractional models extended to the MISO case. For unknown differentiation orders, a two-stage optimization algorithm is proposed with the developed instrumental variable for coefficient estimation and a gradient-based algorithm for differentiation order estimation. A new definition of structured-commensurability (or S-commensurability) is introduced to better cope with differentiation order estimation. Three variants of the algorithm are then proposed: (i) first, all differentiation orders are set as integer multiples of a global S-commensurate order, (ii) then, the differentiation orders are set as integer multiples of a local S-commensurate orders (one S-commensurate order for each subsystem), (iii) finally, all differentiation orders are estimated by releasing the S-commensurability constraint. The first variant has the smallest number of parameters and is used as a good initial hit for the second variant which in turn is used as a good initial hit for the third variant. Such a progressive increase of the number of parameters allows better performance of the optimization algorithm evaluated by Monte Carlo simulation analysis. © 2022 Elsevier Ltd |
Walid, Ounis; Slaheddine, Najar; Mohamed, Aoun REAL TIME TUNEABLE ANALOGUE PID CONTROLLER REALIZATION Conférence 2022, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Analog realization, Continuous time systems, Controller realization, Controllers, Discretization issue, Discretizations, Electric control equipment, PID controllers, Proportional control systems, Real- time, Three term control systems, Tunable analog PID, Tunable controller, Tunables, Voltage dividers @conference{Walid2022798b, This paper proposes a real time tunable analogue PID controller realisation witch can be used as a conventional PID, an adaptative PID or an intelligent PID ‘iPID’. The integral and derivative of the PID input signal are continuous time signals and never sampled. This avoid discretization issues such as aliasing phenomena and the critical sampling period choice. The operative PID circuit part is totally analogue. Few digital potentiometers and digital switches are used. This allows to tune the parameters values of the controller and select PI, PD, PID configuration. The analogue circuit part is designed with a new original circuit architecture. A prototype of the circuit is implemented. Experimentation results show good similarity to the theoretical simulations. © 2022 IEEE. |
2020 |
Ethabet, H.; Raissi, T.; Amairi, M.; Aoun, M. Fault Detection and Isolation for Continuous-Time Switched Linear Systems: A Set Membership Approach Conférence Institute of Electrical and Electronics Engineers Inc., 2020, ISBN: 9781728110806, (cited By 2). Résumé | Liens | BibTeX | Étiquettes: Average dwell time; Fault detection and isolation; Measurement Noise; Set membership approach; Stability condition; Switched linear system; Unknown but bounded; Unknown input observer, Continuous time systems, Fault detection; Linear matrix inequalities; Linear systems; Numerical methods @conference{Ethabet2020279, In this paper, the problem of Fault Detection and Isolation (FDI) is investigated for continuous-Time switched linear systems via a set-membership approach. Under the fulfillment of the relative degree property by all the subsystems, the proposed solution is based on the use of a bank of interval unknown input observers. Under the assumption that disturbances and measurement noise are unknown but bounded with a priori known bounds, cooperativity and stability conditions are given in terms of Linear Matrix Inequalities (LMIs) with the fulfillment of an Average Dwell Time (ADT) constraints. Then, upper and lower residuals are computed. A numerical example illustrating the validity of the method in fault detection and isolation is given. © 2020 IEEE. |
Ethabet, H.; Raïssi, T.; Amairi, M.; Combastel, C.; Aoun, M. Interval observer design for continuous-time switched systems under known switching and unknown inputs Article de journal Dans: International Journal of Control, vol. 93, no. 5, p. 1088-1101, 2020, ISSN: 00207179, (cited By 12). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Interval estimation; Lower and upper bounds; State transformation; Switched linear system; Switched system; Unknown but bounded; Unknown input estimation; Unknown inputs, Linear systems @article{Ethabet20201088, This paper deals with unknown input estimation for switched linear systems in an unknown but bounded error (UBBE) framework. Based on a known switching signal and under the fulfilment of the relative degree property by all the subsystems, a decoupling method is used to make the state partially affected by the unknown input. Assuming that the disturbances and the measurement noises are unknown but bounded with a priori known bounds, lower and upper bounds of the unmeasured state and unknown input are then computed. A numerical example illustrates the efficiency of the proposed methodology. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. |
Mayoufi, Abir; Victor, Stéphane; Malti, Rachid; Chetoui, Manel; Aoun, Mohamed vol. 53, 2020, (Cited by: 1; All Open Access, Bronze Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Fractional model, Fractional model identification, Instrumental variables, Monte Carlo methods, Multiple input single outputs, Order estimation, Refined instrumental variables, Single input single output @conference{Mayoufi20203701b, This paper proposes an instrumental variable approach for continuous-time system identification using fractional models with multiple input single output context. This work is an extension of the simplified refined instrumental variable approach (srivcf) developed for single input-single output fractional model identification (Malti et al. (2008a); Victor et al. (2013)) to the multiple input-single output case. Monte Carlo simulation analysis is used to demonstrate the performance of the proposed approach. A study is then provided to motivate differentiation order estimation, and more specifically, commensurate order estimation. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0) |
Ethabet, H.; Raïssi, T.; Amairi, M.; Combastel, C.; Aoun, M. Interval observer design for continuous-time switched systems under known switching and unknown inputs Article de journal Dans: International Journal of Control, vol. 93, no. 5, p. 1088 – 1101, 2020, (Cited by: 12). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Interval estimation, Linear systems, Lower and upper bounds, State transformation, Switched linear system, Switched system, Unknown but bounded, Unknown input estimation, Unknown inputs @article{Ethabet20201088b, This paper deals with unknown input estimation for switched linear systems in an unknown but bounded error (UBBE) framework. Based on a known switching signal and under the fulfilment of the relative degree property by all the subsystems, a decoupling method is used to make the state partially affected by the unknown input. Assuming that the disturbances and the measurement noises are unknown but bounded with a priori known bounds, lower and upper bounds of the unmeasured state and unknown input are then computed. A numerical example illustrates the efficiency of the proposed methodology. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. |
Mayoufi, Abir; Victor, Stéphane; Malti, Rachid; Chetoui, Manel; Aoun, Mohamed vol. 53, 2020, (Cited by: 1; All Open Access, Bronze Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Fractional model, Fractional model identification, Instrumental variables, Monte Carlo methods, Multiple input single outputs, Order estimation, Refined instrumental variables, Single input single output @conference{Mayoufi20203701, This paper proposes an instrumental variable approach for continuous-time system identification using fractional models with multiple input single output context. This work is an extension of the simplified refined instrumental variable approach (srivcf) developed for single input-single output fractional model identification (Malti et al. (2008a); Victor et al. (2013)) to the multiple input-single output case. Monte Carlo simulation analysis is used to demonstrate the performance of the proposed approach. A study is then provided to motivate differentiation order estimation, and more specifically, commensurate order estimation. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0) |
Ethabet, Haifa; Raissi, Tarek; Amairi, Messaoud; Aoun, Mohamed Fault Detection and Isolation for Continuous-Time Switched Linear Systems: A Set Membership Approach Conférence 2020, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Average dwell time, Continuous time systems, Fault detection, Fault detection and isolation, Linear matrix inequalities, Linear systems, Measurement Noise, Numerical methods, Set membership approach, Stability condition, Switched linear system, Unknown but bounded, Unknown input observer @conference{Ethabet2020279b, In this paper, the problem of Fault Detection and Isolation (FDI) is investigated for continuous-Time switched linear systems via a set-membership approach. Under the fulfillment of the relative degree property by all the subsystems, the proposed solution is based on the use of a bank of interval unknown input observers. Under the assumption that disturbances and measurement noise are unknown but bounded with a priori known bounds, cooperativity and stability conditions are given in terms of Linear Matrix Inequalities (LMIs) with the fulfillment of an Average Dwell Time (ADT) constraints. Then, upper and lower residuals are computed. A numerical example illustrating the validity of the method in fault detection and isolation is given. © 2020 IEEE. |
2019 |
Ethabet, Haifa; Raïssi, Tarek; Amairi, Messaoud; Aoun, Mohamed Set-Membership Fault Detection for Continuous-time Switched Linear Systems Conférence 2019, (Cited by: 7). Résumé | Liens | BibTeX | Étiquettes: Bounded disturbances, Continuous time systems, Continuous-time, Fault detection, Linear matrix inequalities, Linear systems, Set membership, Stability criteria, Stability properties, Switched linear system, Switched system, Unknown but bounded, Upper and lower bounds @conference{Ethabet2019406b, The problem of Fault Detection (FD) for continuous-time switched linear systems subject to bounded disturbances is investigated in this paper. Based on cooperativity and stability properties, and fulfillment of an Average Dwell Time (ADT) constraint, guaranteed upper and lower bounds of the state are calculated using an interval observer. Under the assumption that disturbances and measurement noise are unknown but bounded with a priori known bounds, stability criteria is expressed in terms of Linear Matrix Inequalities (LMIs). Then, a fault detection methodology is developed to indicate the presence of faults. Finally, we demonstrate the proposed fault detection approach via an illustrative example. © 2019 IEEE. |
Ethabet, H.; Raïssi, T.; Amairi, M.; Aoun, M. Set-Membership Fault Detection for Continuous-time Switched Linear Systems Conférence Institute of Electrical and Electronics Engineers Inc., 2019, ISBN: 9781728113173, (cited By 9). Résumé | Liens | BibTeX | Étiquettes: Bounded disturbances; Continuous-time; Set membership; Stability properties; Switched linear system; Switched system; Unknown but bounded; Upper and lower bounds, Continuous time systems, Fault detection; Linear matrix inequalities; Linear systems; Stability criteria @conference{Ethabet2019406, The problem of Fault Detection (FD) for continuous-time switched linear systems subject to bounded disturbances is investigated in this paper. Based on cooperativity and stability properties, and fulfillment of an Average Dwell Time (ADT) constraint, guaranteed upper and lower bounds of the state are calculated using an interval observer. Under the assumption that disturbances and measurement noise are unknown but bounded with a priori known bounds, stability criteria is expressed in terms of Linear Matrix Inequalities (LMIs). Then, a fault detection methodology is developed to indicate the presence of faults. Finally, we demonstrate the proposed fault detection approach via an illustrative example. © 2019 IEEE. |
Chetoui, Manel; Aoun, Mohamed 2019, (Cited by: 5). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Fourth-order cumulants, Fractional differentiation, Higher order statistics, Image segmentation, Instrumental variables, Least Square, Linear systems, State-variable filters @conference{Chetoui201990b, In this paper a new instrumental variables methods based on the Higher-Order-Statistics (fourth order cumulants) are developed for continuous-time system identification with fractional models in the errors in variables context. The fractional orders are supposed known a priori and only the linear coefficients are estimated. The developed algorithms are compared to a fractional fourth order cumulants based least squares algorithm. Their performances are tested through a numerical example in two cases: white and colored noises affecting the input and the output measurements. © 2019 IEEE. |
Yakoub, Zaineb; Amairi, Messaoud; Aoun, Mohamed; Chetoui, Manel On the fractional closed-loop linear parameter varying system identification under noise corrupted scheduling and output signal measurements Article de journal Dans: Transactions of the Institute of Measurement and Control, vol. 41, no. 10, p. 2909 – 2921, 2019, (Cited by: 3). Résumé | Liens | BibTeX | Étiquettes: Accident prevention, Calculations, Continuous time systems, Differentiation (calculus), Fractional calculus, Instrumental variables, Least Square, Linear parameters, Linear systems, Non-linear optimization, Nonlinear programming, Scheduling @article{Yakoub20192909b, It is well known that, in some industrial process identification situations, measurements can be collected from closed-loop experiments for several reasons such as stability, safety, and performance constraints. In this paper, we investigate the problem of identifying continuous-time fractional closed-loop linear parameter varying systems. The simplified refined instrumental variable method is developed to estimate both coefficients and differentiation orders. This method is established to provide consistent estimates when the output and the scheduling variable are contaminated by additive measurements noise. The proposed scheme is evaluated in comparison with other approaches in terms of a simulation example. © The Author(s) 2019. |
2018 |
Ethabet, H.; Rabehi, D.; Efimov, D.; Raïssi, T. Interval estimation for continuous-time switched linear systems Article de journal Dans: Automatica, vol. 90, p. 230-238, 2018, ISSN: 00051098, (cited By 89). Résumé | Liens | BibTeX | Étiquettes: Arbitrary switching; Cooperative dynamics; Interval estimation; Interval observers; Switched linear system; Switched linear system (SLS); Switched system; Upper and lower bounds, Continuous time systems, Convergence of numerical methods; Hybrid systems; Linear systems; Numerical methods @article{Ethabet2018230, This paper deals with the design of interval observers for switched linear systems (SLS), a class of hybrid systems. Under the assumption that the disturbances and the measurement noise are bounded, upper and lower bounds for the state are calculated. New conditions of cooperativity in discrete-time instants are firstly proposed. Then, some techniques for interval estimation are developed in continuous-time. It is shown that it is possible to calculate the observer gains making the estimation error dynamics cooperative and stable via some change of coordinates under arbitrary switching sequences. The performances of the developed techniques are illustrated through numerical examples. © 2017 Elsevier Ltd |
2017 |
Raïssi, Tarek; Aoun, Mohamed On robust pseudo state estimation of fractional order systems Article de journal Dans: Lecture Notes in Control and Information Sciences, vol. 471, p. 97 – 111, 2017, (Cited by: 3). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time linear systems, Estimation errors, Fractional dynamics, Fractional systems, Fractional-order systems, Interval observers, Linear systems, Measurement Noise, Robust estimation, State estimation, State space methods, Uncertainty analysis @article{Ra\"{i}ssi201797, The goal of this chapter is to design robust observers for fractional dynamic continuous-time linear systems described by pseudo state space representation. The fractional observer is guaranteed to compute a domain enclosing all the system pseudo states that are consistent with the model, the disturbances and the measurement noise realizations. Uncertainties on the initial pseudo state and noises are propagated in a reliable way to estimate the bounds of the fractional pseudo state. Only the bounds of the uncertainties are used and no additional assumptions about their stationarity or ergodicity are taken into account. A fractional observer is firstly built for a particular case where the estimation error can be designed to be positive. Then, the general case is investigated through changes of coordinates. Some numerical simulations illustrate the proposed methodology. © Springer International Publishing AG 2017. |
Raïssi, Tarek; Aoun, Mohamed On robust pseudo state estimation of fractional order systems Article de journal Dans: Lecture Notes in Control and Information Sciences, vol. 471, p. 97 – 111, 2017, (Cited by: 3). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time linear systems, Estimation errors, Fractional dynamics, Fractional systems, Fractional-order systems, Interval observers, Linear systems, Measurement Noise, Robust estimation, State estimation, State space methods, Uncertainty analysis @article{Ra\"{i}ssi201797b, The goal of this chapter is to design robust observers for fractional dynamic continuous-time linear systems described by pseudo state space representation. The fractional observer is guaranteed to compute a domain enclosing all the system pseudo states that are consistent with the model, the disturbances and the measurement noise realizations. Uncertainties on the initial pseudo state and noises are propagated in a reliable way to estimate the bounds of the fractional pseudo state. Only the bounds of the uncertainties are used and no additional assumptions about their stationarity or ergodicity are taken into account. A fractional observer is firstly built for a particular case where the estimation error can be designed to be positive. Then, the general case is investigated through changes of coordinates. Some numerical simulations illustrate the proposed methodology. © Springer International Publishing AG 2017. |
Ethabet, Haifa; Raissi, Tarek; Amairi, Messaoud; Aoun, Mohamed Interval observers design for continuous-time linear switched systems Conférence vol. 50, no. 1, 2017, (Cited by: 30; All Open Access, Bronze Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time linear switched systems, Convergence of numerical methods, Cooperativity, Estimation errors, Hybrid systems, Interval observers, Linear switched systems, Numerical methods, Observer gain, Switched system, Unknown but bounded @conference{Ethabet20176259b, This paper is devoted to investigate interval observers design for linear switched systems. The considered systems are subject to disturbances which are assumed to be unknown but bounded. First, observer gains are computed to ensure the stability of the estimation error. Then, under some changes of coordinates an interval observer is designed. Efficiency of the proposed method is demonstrated through a numerical example. © 2017 |
Ethabet, H.; Raissi, T.; Amairi, M.; Aoun, M. Interval observers design for continuous-time linear switched systems Conférence vol. 50, no. 1, Elsevier B.V., 2017, ISSN: 24058963, (cited By 33). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time linear switched systems; Cooperativity; Estimation errors; Interval observers; Linear switched systems; Observer gain; Switched system; Unknown but bounded, Convergence of numerical methods; Hybrid systems; Numerical methods @conference{Ethabet20176259, This paper is devoted to investigate interval observers design for linear switched systems. The considered systems are subject to disturbances which are assumed to be unknown but bounded. First, observer gains are computed to ensure the stability of the estimation error. Then, under some changes of coordinates an interval observer is designed. Efficiency of the proposed method is demonstrated through a numerical example. © 2017 |
2016 |
Salem, Thouraya; Chetoui, Manel; Aoun, Mohamed 2016, (Cited by: 9). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Differential equations, Estimation, Fractional differential equations, Fractional differentiation, Identification (control systems), Instrumental variables, Intelligent systems, Linear parameter varying models, Linear parameter varying systems, Linear systems, LPV systems, Monte Carlo methods, Parameter estimation, Refined instrumental variables, Religious buildings @conference{Salem2016640b, This paper deals with continuous-time linear parameter varying (LPV) system identification with fractional models. Two variants of instrumental variables based techniques are proposed to estimate continuous-time parameters of a fractional differential equation linear parameter varying model when all fractional orders are assumed known a priori: the first one is the instrumental variables estimator based in an auxiliary model. The second one is the simplified refined instrumental variables estimator. A comparison study between the developed estimators is done via a numerical example. A Monte Carlo simulation analysis results are presented to illustrate the performances of the proposed methods in the presence of an additive output noise. © 2016 IEEE. |
2015 |
Yakoub, Z.; Chetoui, M.; Amairi, M.; Aoun, M. A bias correction method for fractional closed-loop system identification Article de journal Dans: Journal of Process Control, vol. 33, p. 25 – 36, 2015, (Cited by: 21). Résumé | Liens | BibTeX | Étiquettes: Active filters, Algorithms, Bias-correction methods, Bias-eliminated least squares methods, Closed loop systems, Commensurate-order, Continuous time systems, Electromagnetic wave attenuation, Fractional differentiation, Identification (control systems), Intelligent systems, Least Square, Least squares approximations, Least-squares estimator, Monte Carlo methods, Non-linear optimization algorithms, Nonlinear programming, Numerical methods, Optimization, Religious buildings, State-variable filters @article{Yakoub201525b, Abstract In this paper, the fractional closed-loop system identification using the indirect approach is presented. A bias correction method is developed to deal with the bias problem in the continuous-time fractional closed-loop system identification. This method is based on the least squares estimator combined with the state variable filter approach. The basic idea is to eliminate the estimation bias by adding a correction term in the least squares estimates. The proposed algorithm is extended, using a nonlinear optimization algorithm, to estimate both coefficients and commensurate-order of the process. Numerical example shows the performances of the fractional order bias eliminated least squares method via Monte Carlo simulations. © 2015 Elsevier Ltd. |
Yakoub, Z.; Chetoui, M.; Amairi, M.; Aoun, M. 2015, (Cited by: 2). Résumé | Liens | BibTeX | Étiquettes: Algorithms, Closed loop systems, Closed loops, Continuous time systems, Continuous-time, Direct approach, Fractional differentiation, Identification (control systems), Least Square, Least squares approximations, Nonlinear programming, Numerical methods, Optimization, Religious buildings, State-variable filters @conference{Yakoub2015e, The paper deals with the continuous-time fractional closed-loop system identification in a noisy output context. Both coefficients and fractional orders of the process are estimated using the direct approach. The proposed method is based on the least squares technique and the state variable filter. It is an extension of the bias eliminated least squares method to the fractional systems. It is combined to a nonlinear optimization algorithm in order to estimate both coefficients and fractional orders of the fractional process. A numerical example is presented to illustrate the performances of the proposed methods. © 2015 IEEE. |
2014 |
Chetoui, Manel; Thomassin, Magalie; Malti, Rachid; Aoun, Mohamed; Abdelkrim, Mohamed Naceur 2014, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Additive noise, Additives, commensurate order, Continuous time systems, Continuous-time, Differential equations, Electronic systems, Errors in variables, Fourth-order cumulants, Fractional differentiation, Higher order statistics, Identification (control systems), Nonlinear programming, Religious buildings, Signal processing @conference{Chetoui2014, This paper considers the problem of identifying continuous-time fractional systems from noisy input/output measurements. Firstly, the differentiation orders are fixed and the differential equation coefficients are estimated using an estimator based on Higher-Order Statistics: fractional fourth-order cumulants based least squares (ffocls). Then, the commensurate order is estimated along with the differential equation coefficients using a non linear optimization technique combined to the ffocls algorithm (co-ffocls). Under some assumptions on the distributional properties of additive noises and the noise-free input signals, the developed estimators give consistent results. Hence, the noise-free input signal is assumed to be non gaussian, whereas the additive noises are assumed to be gaussian. The performances of the developed algorithms are assessed through a practical application for modeling a real electronic system. © 2014 IEEE. |
Yakoub, Z.; Amairi, M.; Chetoui, M.; Aoun, M. 2014, (Cited by: 5). Résumé | Liens | BibTeX | Étiquettes: Closed loop systems, Closed loops, Continuous time systems, Continuous-time, Fractional differentiation, Identification (control systems), Least Square, Least squares approximations, Numerical methods, Religious buildings, State-variable filters @conference{Yakoub2014128b, This paper deals with continuous-time fractional closed-loop system identification in a noisy output context. A bias correction method called the bias-eliminated least squares is extended for indirect approach identification of closed-loop system with fractional models. This method is based on the least squares method combined with the state variable filter and assumes that the regulator order can not be lower than the process order. The performances of the proposed method are assessed through a numerical example. © 2014 IEEE. |
Chetoui, Manel; Thomassin, Magalie; Malti, Rachid; Aoun, Mohamed; Abdelkrim, Mohamed Naceur 2014, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Additive noise, Additives, commensurate order, Continuous time systems, Continuous-time, Differential equations, Electronic systems, Errors in variables, Fourth-order cumulants, Fractional differentiation, Higher order statistics, Identification (control systems), Nonlinear programming, Religious buildings, Signal processing @conference{Chetoui2014b, This paper considers the problem of identifying continuous-time fractional systems from noisy input/output measurements. Firstly, the differentiation orders are fixed and the differential equation coefficients are estimated using an estimator based on Higher-Order Statistics: fractional fourth-order cumulants based least squares (ffocls). Then, the commensurate order is estimated along with the differential equation coefficients using a non linear optimization technique combined to the ffocls algorithm (co-ffocls). Under some assumptions on the distributional properties of additive noises and the noise-free input signals, the developed estimators give consistent results. Hence, the noise-free input signal is assumed to be non gaussian, whereas the additive noises are assumed to be gaussian. The performances of the developed algorithms are assessed through a practical application for modeling a real electronic system. © 2014 IEEE. |
2013 |
Chetoui, Manel; Malti, Rachid; Thomassin, Magalie; Najar, Slaheddine; Aoun, Mohamed; Abdelkrim, Mohamed Naceur; Oustaloup, Alain Fourth-order cumulants based method for continuous-time EIV fractional model identification Conférence 2013, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Continuous-time system identification, Distributional property, Errors, Errors in variables, Fourth-order cumulants, Fractional differentiation, Fractional model identification, Higher order statistics, Identification (control systems), System identification problems @conference{Chetoui2013c, The errors-in-variables (EIV) system identification problem concerns the dynamic systems whose discrete input and output are corrupted by additive noises, that can be white, colored and/or mutually correlated. In this paper, a new estimator based on Higher-Order Statistics (fourth-order cumulants) is proposed for continuous-time system identification with fractional models. Under some assumptions on the distributional properties of the noise and noise-free signals, the fractional fourth-order cumulants based least squares (ffocls) estimator gives consistent results. A numerical example illustrates the performance of the proposed method. © 2013 IEEE. |
Chetoui, Manel; Malti, Rachid; Thomassin, Magalie; Najar, Slaheddine; Aoun, Mohamed; Abdelkrim, Mohamed Naceur; Oustaloup, Alain Fourth-order cumulants based method for continuous-time EIV fractional model identification Conférence 2013, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Continuous-time system identification, Distributional property, Errors, Errors in variables, Fourth-order cumulants, Fractional differentiation, Fractional model identification, Higher order statistics, Identification (control systems), System identification problems @conference{Chetoui2013, The errors-in-variables (EIV) system identification problem concerns the dynamic systems whose discrete input and output are corrupted by additive noises, that can be white, colored and/or mutually correlated. In this paper, a new estimator based on Higher-Order Statistics (fourth-order cumulants) is proposed for continuous-time system identification with fractional models. Under some assumptions on the distributional properties of the noise and noise-free signals, the fractional fourth-order cumulants based least squares (ffocls) estimator gives consistent results. A numerical example illustrates the performance of the proposed method. © 2013 IEEE. |
2012 |
Chetoui, Manel; Malti, Rachid; Thomassin, Magalie; Aoun, Mohamed; Najar, Slaheddine; Oustaloup, Alain; Abdelkrim, Mohamed Naceur EIV methods for system identification with fractional models Conférence vol. 16, no. PART 1, 2012, (Cited by: 14). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Continuous-time, Cumulants, Differential equations, Errors in variables, Fractional SVF, Higher order statistics, Identification (control systems), Iterative, Iterative methods, Least Square, Monte Carlo methods, Religious buildings @conference{Chetoui20121641b, This paper deals with continuous-time system identification with fractional models in Errors-In-Variables context. Two estimators based on Higher-Order Statistics (third-order cumulants) are proposed. A State Variable Filter approach is extended to fractional orders to compute fractional derivatives of third-order cumulants estimates. The performance of the proposed algorithms is illustrated in a numerical example. Firstly, differentiation orders are fixed and differential equation coefficients are estimated. The consistency of the proposed estimators is evaluated through a study of the tuning parameter and Monte Carlo simulations. Then, the commensurate differentiation order is optimized along with the differential equation coefficients. © 2012 IFAC. |
2011 |
Chetoui, M.; Malti, R.; Thomassin, M.; Aoun, M.; Najar, S.; Abdelkrim, M. N. IEEE Computer Society, 2011, ISBN: 9781457704130, (cited By 3). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Cumulants; Errors in variables; Fractional derivatives; Fractional SVF; High order statistics, Identification (control systems); Indium compounds; Least squares approximations; Numerical methods; Religious buildings; Signal to noise ratio @conference{Chetoui2011, This paper deals with continuous-time system identification using fractional models in a noisy input/output context. The third-order cumulants based least squares method (tocls) is extended here to fractional models. The derivatives of the third-order cumulants are computed using a new fractional state variable filter. A numerical example is used to demonstrate the performance of the proposed method called ftocls (fractional third-order cumulants based least squares). The effect of the signal-to-noise ratio and the hyperparameter is studied. © 2011 IEEE. |
Chetoui, M.; Malti, R.; Thomassin, M.; Aoun, M.; Najar, S.; Abdelkrim, M. N. 2011, (Cited by: 3). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Cumulants, Errors in variables, Fractional derivatives, Fractional SVF, High order statistics, Identification (control systems), Indium compounds, Least squares approximations, Numerical methods, Religious buildings, Signal to noise ratio @conference{Chetoui2011b, This paper deals with continuous-time system identification using fractional models in a noisy input/output context. The third-order cumulants based least squares method (tocls) is extended here to fractional models. The derivatives of the third-order cumulants are computed using a new fractional state variable filter. A numerical example is used to demonstrate the performance of the proposed method called ftocls (fractional third-order cumulants based least squares). The effect of the signal-to-noise ratio and the hyperparameter is studied. © 2011 IEEE. |
2003 |
Aoun, Mohamed; Malti, Rachid; Levron, Francois; Oustaloup, Alain Orthonormal basis functions for modeling continuous-time fractional systems Conférence vol. 36, no. 16, 2003, (Cited by: 11; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Fourier analysis, Fourier coefficients, Fractional differentiation, Fractional systems, Identification (control systems), Laguerre filter, Laguerre functions, Least squares approximations, Least squares errors, Least squares methods, Orthogonal functions, Orthonormal basis functions, Poles, Religious buildings @conference{Aoun20031333, The classical Laguerre functions are known to be divergent as soon as their differentiation order is non-integer. They are hence inappropriate for representing fractional differentiation systems. A complete orthogonal basis, having fractional differentiation orders and a single pole, is synthesized. It extends the well-known definition of Laguerre functions to fractional systems. Hence a new class of fixed denominator models is provided for system identification. Fourier coefficients are computed using a least squares method. The least squares error is plotted versus the differentiation order and the pole, in an example, and shows that an optimal differentiation order may be located away from an integer number. Hence, the use of the synthesized basis is fully justitied. © 2003 International Federation of Automatic Control. |
Aoun, Mohamed; Malti, Rachid; Levron, Francois; Oustaloup, Alain Orthonormal basis functions for modeling continuous-time fractional systems Conférence vol. 36, no. 16, 2003, (Cited by: 11; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Continuous time systems, Fourier analysis, Fourier coefficients, Fractional differentiation, Fractional systems, Identification (control systems), Laguerre filter, Laguerre functions, Least squares approximations, Least squares errors, Least squares methods, Orthogonal functions, Orthonormal basis functions, Poles, Religious buildings @conference{Aoun20031333b, The classical Laguerre functions are known to be divergent as soon as their differentiation order is non-integer. They are hence inappropriate for representing fractional differentiation systems. A complete orthogonal basis, having fractional differentiation orders and a single pole, is synthesized. It extends the well-known definition of Laguerre functions to fractional systems. Hence a new class of fixed denominator models is provided for system identification. Fourier coefficients are computed using a least squares method. The least squares error is plotted versus the differentiation order and the pole, in an example, and shows that an optimal differentiation order may be located away from an integer number. Hence, the use of the synthesized basis is fully justitied. © 2003 International Federation of Automatic Control. |
2002 |
Aoun, Mohamed; Malti, Rachid; Cois, Olivier; Oustaloup, Alain System identification using fractional hammerstein models Conférence vol. 15, no. 1, 2002, (Cited by: 23). Résumé | Liens | BibTeX | Étiquettes: Automation, Continuous time systems, Fractional differentiation, Fractional model, Fractional order, Hammerstein model, Hammerstein-type models, Identification (control systems), Identification method, Linear systems, Non-linear modelling, Nonlinear systems, Riemann-liouville definitions @conference{Aoun2002265, Identification of continuous-time non-linear systems characterised by fractional order dynamics is studied. The Riemann-Liouville definition of fractional differentiation is used. A new identification method is proposed through the extension of Hammerstein-type models by allowing their linear part to belong to the class of fractional models. Fractional models are compact and so are used here to model complex dynamics with few parameters. Copyright © 2002 IFAC. |
Aoun, Mohamed; Malti, Rachid; Cois, Olivier; Oustaloup, Alain System identification using fractional hammerstein models Conférence vol. 15, no. 1, 2002, (Cited by: 23). Résumé | Liens | BibTeX | Étiquettes: Automation, Continuous time systems, Fractional differentiation, Fractional model, Fractional order, Hammerstein model, Hammerstein-type models, Identification (control systems), Identification method, Linear systems, Non-linear modelling, Nonlinear systems, Riemann-liouville definitions @conference{Aoun2002265b, Identification of continuous-time non-linear systems characterised by fractional order dynamics is studied. The Riemann-Liouville definition of fractional differentiation is used. A new identification method is proposed through the extension of Hammerstein-type models by allowing their linear part to belong to the class of fractional models. Fractional models are compact and so are used here to model complex dynamics with few parameters. Copyright © 2002 IFAC. |
Publications
2023 |
L∞ Set-membership Estimation for Continuous-time Switched Linear Systems Conférence 2023. |
Programmable analogue fractional controller realization Conférence 2023. |
2022 |
System identification of MISO fractional systems: Parameter and differentiation order estimation Article de journal Dans: Automatica, vol. 141, 2022, ISSN: 00051098, (cited By 12). |
REAL TIME TUNEABLE ANALOGUE PID CONTROLLER REALIZATION Conférence 2022, (Cited by: 0). |
System identification of MISO fractional systems: Parameter and differentiation order estimation Article de journal Dans: Automatica, vol. 141, 2022, (Cited by: 10). |
REAL TIME TUNEABLE ANALOGUE PID CONTROLLER REALIZATION Conférence 2022, (Cited by: 0). |
2020 |
Fault Detection and Isolation for Continuous-Time Switched Linear Systems: A Set Membership Approach Conférence Institute of Electrical and Electronics Engineers Inc., 2020, ISBN: 9781728110806, (cited By 2). |
Interval observer design for continuous-time switched systems under known switching and unknown inputs Article de journal Dans: International Journal of Control, vol. 93, no. 5, p. 1088-1101, 2020, ISSN: 00207179, (cited By 12). |
vol. 53, 2020, (Cited by: 1; All Open Access, Bronze Open Access, Green Open Access). |
Interval observer design for continuous-time switched systems under known switching and unknown inputs Article de journal Dans: International Journal of Control, vol. 93, no. 5, p. 1088 – 1101, 2020, (Cited by: 12). |
vol. 53, 2020, (Cited by: 1; All Open Access, Bronze Open Access, Green Open Access). |
Fault Detection and Isolation for Continuous-Time Switched Linear Systems: A Set Membership Approach Conférence 2020, (Cited by: 1). |
2019 |
Set-Membership Fault Detection for Continuous-time Switched Linear Systems Conférence 2019, (Cited by: 7). |
Set-Membership Fault Detection for Continuous-time Switched Linear Systems Conférence Institute of Electrical and Electronics Engineers Inc., 2019, ISBN: 9781728113173, (cited By 9). |
2019, (Cited by: 5). |
On the fractional closed-loop linear parameter varying system identification under noise corrupted scheduling and output signal measurements Article de journal Dans: Transactions of the Institute of Measurement and Control, vol. 41, no. 10, p. 2909 – 2921, 2019, (Cited by: 3). |
2018 |
Interval estimation for continuous-time switched linear systems Article de journal Dans: Automatica, vol. 90, p. 230-238, 2018, ISSN: 00051098, (cited By 89). |
2017 |
On robust pseudo state estimation of fractional order systems Article de journal Dans: Lecture Notes in Control and Information Sciences, vol. 471, p. 97 – 111, 2017, (Cited by: 3). |
On robust pseudo state estimation of fractional order systems Article de journal Dans: Lecture Notes in Control and Information Sciences, vol. 471, p. 97 – 111, 2017, (Cited by: 3). |
Interval observers design for continuous-time linear switched systems Conférence vol. 50, no. 1, 2017, (Cited by: 30; All Open Access, Bronze Open Access, Green Open Access). |
Interval observers design for continuous-time linear switched systems Conférence vol. 50, no. 1, Elsevier B.V., 2017, ISSN: 24058963, (cited By 33). |
2016 |
2016, (Cited by: 9). |
2015 |
A bias correction method for fractional closed-loop system identification Article de journal Dans: Journal of Process Control, vol. 33, p. 25 – 36, 2015, (Cited by: 21). |
2015, (Cited by: 2). |
2014 |
2014, (Cited by: 0). |
2014, (Cited by: 5). |
2014, (Cited by: 0). |
2013 |
Fourth-order cumulants based method for continuous-time EIV fractional model identification Conférence 2013, (Cited by: 4). |
Fourth-order cumulants based method for continuous-time EIV fractional model identification Conférence 2013, (Cited by: 4). |
2012 |
EIV methods for system identification with fractional models Conférence vol. 16, no. PART 1, 2012, (Cited by: 14). |
2011 |
IEEE Computer Society, 2011, ISBN: 9781457704130, (cited By 3). |
2011, (Cited by: 3). |
2003 |
Orthonormal basis functions for modeling continuous-time fractional systems Conférence vol. 36, no. 16, 2003, (Cited by: 11; All Open Access, Bronze Open Access). |
Orthonormal basis functions for modeling continuous-time fractional systems Conférence vol. 36, no. 16, 2003, (Cited by: 11; All Open Access, Bronze Open Access). |
2002 |
System identification using fractional hammerstein models Conférence vol. 15, no. 1, 2002, (Cited by: 23). |
System identification using fractional hammerstein models Conférence vol. 15, no. 1, 2002, (Cited by: 23). |