2023 |
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. |
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{Ounis2023,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 |
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. |
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. |
2020 |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed; Frej, Ghazi Bel Haj Robust sliding window observer-based controller design for Lipschitz discrete-time systems Conférence vol. 53, no. 2, 2020, (Cited by: 1; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, H ∞ criterion, Lipschitz, Lipschitz non-linearity, Observer-based, Observer-based controllers, Observer-based stabilization design, Performance, Sliding Window, Sliding window approach, Stabilization, Uncertain systems @conference{Gasmi20205970b,The aim of this paper is to develop a new observer-based stabilization strategy for a class of Lipschitz uncertain systems. This new strategy improves the performances of existing methods and ensures better convergence conditions. The observer and the controller are enriched with sliding windows of measurements and estimated states, respectively. This technique allows to increase the number of decision variables and thus get less restrictive and more general LMI conditions. The established sufficient stability conditions are in the form of Bilinear Matrix Inequality (BMI). The obtained constraint is transformed, through a useful approach, to a more suitable one easily tractable by standard software algorithms. Numerical example is given to illustrate the performances of the proposed approach. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND license |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed; Frej, Ghazi Bel Haj Robust sliding window observer-based controller design for Lipschitz discrete-time systems Conférence vol. 53, no. 2, 2020, (Cited by: 1; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, H ∞ criterion, Lipschitz, Lipschitz non-linearity, Observer-based, Observer-based controllers, Observer-based stabilization design, Performance, Sliding Window, Sliding window approach, Stabilization, Uncertain systems @conference{Gasmi20205970,The aim of this paper is to develop a new observer-based stabilization strategy for a class of Lipschitz uncertain systems. This new strategy improves the performances of existing methods and ensures better convergence conditions. The observer and the controller are enriched with sliding windows of measurements and estimated states, respectively. This technique allows to increase the number of decision variables and thus get less restrictive and more general LMI conditions. The established sufficient stability conditions are in the form of Bilinear Matrix Inequality (BMI). The obtained constraint is transformed, through a useful approach, to a more suitable one easily tractable by standard software algorithms. Numerical example is given to illustrate the performances of the proposed approach. Copyright © 2020 The Authors. This is an open access article under the CC BY-NC-ND license |
2019 |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Abrashov, Sergey; Aoun, Mohamed; Chetoui, Manel Discrete-time robust control with an anticipative action for preview systems Article de journal Dans: Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME, vol. 141, no. 3, 2019, (Cited by: 8; All Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Closed loop systems, Control methodology, Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, Feedback control, Feedback controller, Feedforward filters, Leveling (machinery), Model uncertainties, Motion control, Reference signals, Robust control, Robust controller design, Robust feedback controllers, Robustness (control systems), Signal processing, Uncertainty analysis, Water tanks @article{Achnib2019c,A discrete-time robust controller design method is proposed for optimal tracking of future references in preview systems. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system and at the same time achieves a good level of the control signal. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The feedback controller’s purpose is to assure robustness of the closed-loop system to model uncertainties. Any robust control methodology can be used (such as μ-synthesis, qft, or crone control). The focus of this paper will be on the design of the feedforward action in order to introduce the anticipative effect with respect to known future values of the reference signal without hindering the robustness achieved through the feedback controller. As such, the model uncertainties are taken into account also in the design of the feedforward anticipative filter. The proposed solution is validated in simulation and on an experimental water tank level control system. © 2019 American Society of Mechanical Engineers (ASME). All rights reserved. |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Abrashov, Sergey; Aoun, Mohamed; Chetoui, Manel Discrete-time robust control with an anticipative action for preview systems Article de journal Dans: Journal of Dynamic Systems, Measurement and Control, Transactions of the ASME, vol. 141, no. 3, 2019, (Cited by: 8; All Open Access, Green Open Access). Résumé | Liens | BibTeX | Étiquettes: Closed loop systems, Control methodology, Controllers, Digital control systems, Discrete – time systems, Discrete time control systems, Feedback control, Feedback controller, Feedforward filters, Leveling (machinery), Model uncertainties, Motion control, Reference signals, Robust control, Robust controller design, Robust feedback controllers, Robustness (control systems), Signal processing, Uncertainty analysis, Water tanks @article{Achnib2019,A discrete-time robust controller design method is proposed for optimal tracking of future references in preview systems. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system and at the same time achieves a good level of the control signal. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The feedback controller’s purpose is to assure robustness of the closed-loop system to model uncertainties. Any robust control methodology can be used (such as μ-synthesis, qft, or crone control). The focus of this paper will be on the design of the feedforward action in order to introduce the anticipative effect with respect to known future values of the reference signal without hindering the robustness achieved through the feedback controller. As such, the model uncertainties are taken into account also in the design of the feedforward anticipative filter. The proposed solution is validated in simulation and on an experimental water tank level control system. © 2019 American Society of Mechanical Engineers (ASME). All rights reserved. |
2018 |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed Enhanced LMI conditions for observer-based H∞ stabilization of Lipschitz discrete-time systems Article de journal Dans: European Journal of Control, vol. 44, p. 80 – 89, 2018, (Cited by: 8). Résumé | Liens | BibTeX | Étiquettes: Control nonlinearities, Controller designs, Controllers, Decoding, Delayed state, Digital control systems, Discrete – time systems, Discrete time control systems, Linear matrix inequalities, Linear matrix inequality approach, Lipschitz systems, Noise analyse, Observer-based controller design, Observer-based controllers, Robustness (control systems), Sliding Window, Sliding window of measurement @article{Gasmi201880b,This paper deals with H∞ observer-based controller design for a class of discrete-time systems with Lipschitz nonlinearities. Usually, the observer-based control synthesis for the considered class of systems leads to the feasibility of a Bilinear Matrix Inequality (BMI). Since, solving a BMI constraint has been an NP-hard optimization problem, then linearizing this constraint to get a convex one is an interesting issue because Linear Matrix Inequalities (LMIs) are easily tractable by numerical softwares (LMI Toolboxes,.). Hence, the aim of this paper is to develop a new Linear Matrix Inequality (LMI) condition, ensuring the H∞ asymptotic convergence of the observer-based controller. Due to the introduction of a slack variable technique, the usual BMI problem is equivalently transformed to a more suitable one, which leads to less conservative and more general LMI condition compared to the existing methods in the literature. Conjointly to the slack variable technique, the Lipschitz property and the Young’s relation are used in a reformulated way to obtain additional decision variables in the LMI. In the aim to further relax the proposed LMI methodology, sliding windows of delayed states and measurements are included in the structures of the controller and the observer, respectively. The obtained LMI is more general and less conservative than the first one, which can be viewed as a particular solution. To show the effectiveness and superiority of the proposed methodology, some numerical examples and comparisons are provided. © 2018 European Control Association |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Guefrachi, Ayadi; Aoun, Mohamed; Chetoui, Manel Anticipative Robust Design Applied to a Water Level Control System Conférence 2018, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Controllers, Design, Digital control systems, Discrete – time systems, Discrete time control systems, Experimental test benches, Feedforward filters, Level control, Leveling (machinery), Quadratic errors, Reference signals, Reference-tracking, Robust control, Robust controller design, Robust feedback controllers, Water levels @conference{Achnib2018863b,In this paper, a discrete-time robust controller design method for optimal reference tracking in preview systems is validated on an experimental test bench. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The theoretical description of this new approach is given and experimental results on a water level control system are presented. © 2018 European Control Association (EUCA). |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed H∞ Observer-Based Controller for Lipschitz Nonlinear Discrete-Time Systems Conférence 2018, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Bilinear matrix, Controllers, Design Methodology, Design problems, Digital control systems, Discrete time control systems, Linear matrix inequalities, Lipschitz property, Nonlinear discrete-time systems, Observer-based, Observer-based controllers, Robustness (control systems), Slack variables @conference{Gasmi2018771b,Within the paper, a relevant H∞observer-based controller design for a class of Lipschitz nonlinear discrete-time systems is proposed. Usually, Bilinear Matrix Inequaities (BMIs) are obtained from the resolution of the observer-based stabilization design problem for this class of systems. Since, the resolution of a BMI is a hard task, then it is interesting to search for a convenient way to linearize the obtained conditions. Therefore, the objective of this paper is to present new Linear Matrix Inequality (LMI) conditions ensuring the convergence of the observer-based controller in a noisy context. Thanks to the introduction of a slack variable the presented LMI conditions are more general and less conservative than the existence ones. Indeed, reformulations of the Lipschitz property and Young’s relation in a convenient way lead to a more relaxed new LMI. A numerical example is implemented to show high performances of the proposed design methodology with respect to some existing results. © 2018 IEEE. |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed Enhanced LMI conditions for observer-based H∞ stabilization of Lipschitz discrete-time systems Article de journal Dans: European Journal of Control, vol. 44, p. 80 – 89, 2018, (Cited by: 8). Résumé | Liens | BibTeX | Étiquettes: Control nonlinearities, Controller designs, Controllers, Decoding, Delayed state, Digital control systems, Discrete – time systems, Discrete time control systems, Linear matrix inequalities, Linear matrix inequality approach, Lipschitz systems, Noise analyse, Observer-based controller design, Observer-based controllers, Robustness (control systems), Sliding Window, Sliding window of measurement @article{Gasmi201880,This paper deals with H∞ observer-based controller design for a class of discrete-time systems with Lipschitz nonlinearities. Usually, the observer-based control synthesis for the considered class of systems leads to the feasibility of a Bilinear Matrix Inequality (BMI). Since, solving a BMI constraint has been an NP-hard optimization problem, then linearizing this constraint to get a convex one is an interesting issue because Linear Matrix Inequalities (LMIs) are easily tractable by numerical softwares (LMI Toolboxes,.). Hence, the aim of this paper is to develop a new Linear Matrix Inequality (LMI) condition, ensuring the H∞ asymptotic convergence of the observer-based controller. Due to the introduction of a slack variable technique, the usual BMI problem is equivalently transformed to a more suitable one, which leads to less conservative and more general LMI condition compared to the existing methods in the literature. Conjointly to the slack variable technique, the Lipschitz property and the Young’s relation are used in a reformulated way to obtain additional decision variables in the LMI. In the aim to further relax the proposed LMI methodology, sliding windows of delayed states and measurements are included in the structures of the controller and the observer, respectively. The obtained LMI is more general and less conservative than the first one, which can be viewed as a particular solution. To show the effectiveness and superiority of the proposed methodology, some numerical examples and comparisons are provided. © 2018 European Control Association |
Achnib, Asma; Airimitoaie, Tudor-Bogdan; Lanusse, Patrick; Guefrachi, Ayadi; Aoun, Mohamed; Chetoui, Manel Anticipative Robust Design Applied to a Water Level Control System Conférence 2018, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Controllers, Design, Digital control systems, Discrete – time systems, Discrete time control systems, Experimental test benches, Feedforward filters, Level control, Leveling (machinery), Quadratic errors, Reference signals, Reference-tracking, Robust control, Robust controller design, Robust feedback controllers, Water levels @conference{Achnib2018863,In this paper, a discrete-time robust controller design method for optimal reference tracking in preview systems is validated on an experimental test bench. In the context of preview systems, it is supposed that future values of the reference signal are available a number of time steps ahead. The objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system. The proposed solution combines a robust feedback controller with a feedforward anticipative filter. The theoretical description of this new approach is given and experimental results on a water level control system are presented. © 2018 European Control Association (EUCA). |
Gasmi, Noussaiba; Boutayeb, Mohamed; Thabet, Assem; Aoun, Mohamed H∞ Observer-Based Controller for Lipschitz Nonlinear Discrete-Time Systems Conférence 2018, (Cited by: 0). Résumé | Liens | BibTeX | Étiquettes: Bilinear matrix, Controllers, Design Methodology, Design problems, Digital control systems, Discrete time control systems, Linear matrix inequalities, Lipschitz property, Nonlinear discrete-time systems, Observer-based, Observer-based controllers, Robustness (control systems), Slack variables @conference{Gasmi2018771,Within the paper, a relevant H∞observer-based controller design for a class of Lipschitz nonlinear discrete-time systems is proposed. Usually, Bilinear Matrix Inequaities (BMIs) are obtained from the resolution of the observer-based stabilization design problem for this class of systems. Since, the resolution of a BMI is a hard task, then it is interesting to search for a convenient way to linearize the obtained conditions. Therefore, the objective of this paper is to present new Linear Matrix Inequality (LMI) conditions ensuring the convergence of the observer-based controller in a noisy context. Thanks to the introduction of a slack variable the presented LMI conditions are more general and less conservative than the existence ones. Indeed, reformulations of the Lipschitz property and Young’s relation in a convenient way lead to a more relaxed new LMI. A numerical example is implemented to show high performances of the proposed design methodology with respect to some existing results. © 2018 IEEE. |
2017 |
Guefrachi, Ayadi; Najar, Slaheddine; Amairi, Messaoud; Aoun, Mohamed Tuning of Fractional Complex Order PID Controller Conférence vol. 50, no. 1, 2017, (Cited by: 22; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Calculations, Complex order controllers, Controlled system robustness, Controllers, Delay control systems, Design, Electric control equipment, Fractional calculus, Frequency and time domains, Frequency domain analysis, Gain variations, Numeric optimization, Numerical methods, Numerical optimizations, Optimization, PID controllers, Proportional control systems, Robust control, Three term control systems, Time domain analysis @conference{Guefrachi201714563b,This paper deals with a new structure of Fractional Complex Order Controller (FCOC) with the form PIDx+iy, in which x and y are the real and imaginary parts of the derivative complex order, respectively. A tuning method for the Controller based on numerical optimization is presented to ensure the controlled system robustness toward gain variations and noise. This can be obtained by fulfilling five design requirements. The proposed design method is applied for the control of a Second Order Plus Time Delay resonant system. The effectiveness of the FCOC design method is checked through frequency and time domain analysis. © 2017 |
Yakoub, Z.; Amairi, M.; Chetoui, M.; Saidi, B.; Aoun, M. Model-free adaptive fractional order control of stable linear time-varying systems Article de journal Dans: ISA Transactions, vol. 67, p. 193 – 207, 2017, (Cited by: 22). Résumé | Liens | BibTeX | Étiquettes: Adaptive control systems, Calculations, Controllers, Fractional calculus, Fractional order control, Fractional pid controllers, Frequency characteristic, Frequency domain analysis, Linear time-varying systems, Model-free adaptive control, Numerical methods, Numerical optimizations, Optimization, Robustness (control systems), Selective filtering, Three term control systems, Time varying control systems @article{Yakoub2017193b,This paper presents a new model-free adaptive fractional order control approach for linear time-varying systems. An online algorithm is proposed to determine some frequency characteristics using a selective filtering and to design a fractional PID controller based on the numerical optimization of the frequency-domain criterion. When the system parameters are time-varying, the controller is updated to keep the same desired performances. The main advantage of the proposed approach is that the controller design depends only on the measured input and output signals of the process. The effectiveness of the proposed method is assessed through a numerical example. © 2017 ISA |
Hmed, Amina Ben; Amairi, Messaoud; Aoun, Mohamed Robust stabilization and control using fractional order integrator Article de journal Dans: Transactions of the Institute of Measurement and Control, vol. 39, no. 10, p. 1559 – 1576, 2017, (Cited by: 8). Résumé | Liens | BibTeX | Étiquettes: Calculations, Control design, Controllers, Delay control systems, Fractional calculus, Fractional-order integrator, Robust stability, Robustness (control systems), Smith predictors, Stabilization, Uncertain systems @article{BenHmed20171559b,This paper addresses the robust stabilization problem of first-order uncertain systems. To treat the robust stabilization problem, an interval-based stabilization method using stability conditions of the non-commensurate elementary fractional transfer function of the second kind is developed. Some analytic expressions are determined to compute the set of all stabilizing controller parameters and plot the stability boundary. A robust performance control is also developed to fulfil some desired time-domain performances as the iso-overshoot property. The fractional controller can be used combined with the Smith predictor to control a first-order system with time delay and achieve desired specifications. Numerical examples are presented to illustrate the obtained results. © 2017, © The Author(s) 2017. |
Yakoub, Z.; Chetoui, M.; Amairi, M.; Aoun, M. Model-based fractional order controller design Conférence vol. 50, no. 1, 2017, (Cited by: 3; All Open Access, Bronze Open Access). Résumé | Liens | BibTeX | Étiquettes: Bias elimination, Closed loops, Controllers, Fractional differentiation, Frequency domain analysis, Identification for control, Least squares approximations, Optimization, Process control, Recursive least square (RLS) @conference{Yakoub201710431b,This paper deals with model-based fractional order controller design. The objective is identification for controller design in order to achieve the desired closed-loop performances. Firstly, the fractional order closed-loop bias-eliminated least squares method is used to identify the process model. Then, based on the numerical optimization of a frequency-domain criterion, the fractional controller is designed. If the proposed algorithm detects any changes in the process parameters, the controller is updated to keep the same performances. A numerical example is presented to show the efficiency of the proposed scheme. © 2017 |
Hmed, Amina Ben; Amairi, Messaoud; Aoun, Mohamed Robust stabilization and control using fractional order integrator Article de journal Dans: Transactions of the Institute of Measurement and Control, vol. 39, no. 10, p. 1559 – 1576, 2017, (Cited by: 8). Résumé | Liens | BibTeX | Étiquettes: Calculations, Control design, Controllers, Delay control systems, Fractional calculus, Fractional-order integrator, Robust stability, Robustness (control systems), Smith predictors, Stabilization, Uncertain systems @article{BenHmed20171559c,This paper addresses the robust stabilization problem of first-order uncertain systems. To treat the robust stabilization problem, an interval-based stabilization method using stability conditions of the non-commensurate elementary fractional transfer function of the second kind is developed. Some analytic expressions are determined to compute the set of all stabilizing controller parameters and plot the stability boundary. A robust performance control is also developed to fulfil some desired time-domain performances as the iso-overshoot property. The fractional controller can be used combined with the Smith predictor to control a first-order system with time delay and achieve desired specifications. Numerical examples are presented to illustrate the obtained results. © 2017, © The Author(s) 2017. |
2015 |
Hmed, A. Ben; Amairi, M.; Aoun, M. Stabilizing fractional order controller design for first and second order systems Conférence 2015, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Analytic expressions, Calculations, Closed loop systems, Control, Controllers, DC motors, Electric machine control, Fractional calculus, Fractional-order controllers, Invariance, Linear systems, Linear time invariant systems, Numerical methods, Resonance, Second-order systemss, Stability regions, Stabilization, Stabilization problems, Time domain analysis, Time varying control systems, Time-domain specifications @conference{BenHmed2015c,The paper deals with the stabilization problem of the Linear Time Invariant system. In this work, we present a new method of stabilization addressed to the first and second order unstable system in order to guarantee the stability and the time domain performances. Analytic expressions are developed in the purpose of setting the stabilizing parameters of the controller by describing the stability region. Moreover, the time domain-curves of the desired closed-loop system are used to show time domain specifications. Finally, some numerical examples and a control of DC motor are proposed in order to show the benefits and the reliability of the new technique. © 2015 IEEE. |
Azaiez, Wiem; Chetoui, Manel; Aoun, Mohamed Analytic approach to design PID controller for stabilizing fractional systems with time delay Conférence 2015, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Controllers, dual-locus diagram, Electric control equipment, Fractional differentiation, Fractional systems, Graphical criteria, Optimal controller, PID controller design, PID controllers, Proportional control systems, Stability regions, Three term control systems, Time delay @conference{Azaiez2015b,The paper considers the problem of PID controller design for stabilizing fractional systems with time delay. An analytic approach developed for rational systems with time delay is extended for fractional systems with time delay. It consists in determining the stability regions in the PID controller parameters planes and choosing the optimal controller by analyzing the stability of the closed-loop corrected system using a graphical criterion, like the dual-locus diagram. The performances of the proposed approach are illustrated using two numerical examples. © 2015 IEEE. |
Hmed, A. Ben; Amairi, M.; Aoun, M. Stabilizing fractional order controller design for first and second order systems Conférence 2015, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Analytic expressions, Calculations, Closed loop systems, Control, Controllers, DC motors, Electric machine control, Fractional calculus, Fractional-order controllers, Invariance, Linear systems, Linear time invariant systems, Numerical methods, Resonance, Second-order systemss, Stability regions, Stabilization, Stabilization problems, Time domain analysis, Time varying control systems, Time-domain specifications @conference{BenHmed2015e,The paper deals with the stabilization problem of the Linear Time Invariant system. In this work, we present a new method of stabilization addressed to the first and second order unstable system in order to guarantee the stability and the time domain performances. Analytic expressions are developed in the purpose of setting the stabilizing parameters of the controller by describing the stability region. Moreover, the time domain-curves of the desired closed-loop system are used to show time domain specifications. Finally, some numerical examples and a control of DC motor are proposed in order to show the benefits and the reliability of the new technique. © 2015 IEEE. |
Azaiez, Wiem; Chetoui, Manel; Aoun, Mohamed Analytic approach to design PID controller for stabilizing fractional systems with time delay Conférence 2015, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Controllers, dual-locus diagram, Electric control equipment, Fractional differentiation, Fractional systems, Graphical criteria, Optimal controller, PID controller design, PID controllers, Proportional control systems, Stability regions, Three term control systems, Time delay @conference{Azaiez2015,The paper considers the problem of PID controller design for stabilizing fractional systems with time delay. An analytic approach developed for rational systems with time delay is extended for fractional systems with time delay. It consists in determining the stability regions in the PID controller parameters planes and choosing the optimal controller by analyzing the stability of the closed-loop corrected system using a graphical criterion, like the dual-locus diagram. The performances of the proposed approach are illustrated using two numerical examples. © 2015 IEEE. |
2014 |
Amairi, M.; Aoun, M.; Saidi, B. Design of robust fractional order PI for FOPDT systems via set inversion Conférence 2014, (Cited by: 4). Résumé | Liens | BibTeX | Étiquettes: Controllers, Design approaches, Different frequency, First order plus dead time, Fractional controllers, Fractional order pI, Interval analysis, Robustness (control systems), Set inversion via interval analysis, Time delay, Uncertainty, Uncertainty analysis @conference{Amairi20141166b,This paper presents a new design approach of a fractional order PI controller for uncertain system with delay. The method uses the set inversion via interval analysis approach to determine the three parameters of the controller in accordance with different frequency specifications. When applied to uncertain delay system, the method computes the interval of each parameter providing the desired performances. Some numerical examples illustrate the effectiveness of the proposed approach in the case of an uncertain first order plus dead time system. © 2014 IEEE. |
Hmed, A. Ben; Amairi, M.; Aoun, M. Fractional order controller design using time-domain specifications Conférence 2014, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Automation, Closed loop systems, Closed-loop behavior, Control design, Controller designs, Controllers, Convergence of numerical methods, Design, Fractional controllers, Fractional systems, Fractional-order controllers, Numerical methods, Resonance, Time domain, Time domain analysis, Time-domain specifications @conference{BenHmed2014462b,This paper deals with the design of a fractional controller to achieve a desired closed loop system. Based on the resonance and time-domain studies of the desired closed-loop behavior, the controller design is carried out by a pole-compensator method. Numerical examples are proposed to show the efficiency of the proposed technique. © 2014 IEEE. |
Hmed, A. Ben; Amairi, M.; Aoun, M. Fractional order controller design using time-domain specifications Conférence 2014, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Automation, Closed loop systems, Closed-loop behavior, Control design, Controller designs, Controllers, Convergence of numerical methods, Design, Fractional controllers, Fractional systems, Fractional-order controllers, Numerical methods, Resonance, Time domain, Time domain analysis, Time-domain specifications @conference{BenHmed2014462c,This paper deals with the design of a fractional controller to achieve a desired closed loop system. Based on the resonance and time-domain studies of the desired closed-loop behavior, the controller design is carried out by a pole-compensator method. Numerical examples are proposed to show the efficiency of the proposed technique. © 2014 IEEE. |