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. |
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 |
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. |
2017 |
Frej, Ghazi Bel Haj; Thabet, Assem; Boutayeb, Mohamed; Aoun, Mohamed Distributed observer-based guaranteed cost control design for large scale interconnected systems Conférence vol. 2017-January, 2017, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Cost effectiveness, Cost functions, Costs, Differential mean value theorems, Guaranteed cost, Large scale systems, Large-scale interconnected systems, Linear matrix inequalities, Linear Matrix Inequalities (LMIs), Lyapunov stability, Nonlinear interconnected systems, Observer based control, Quadratic cost functions, Robustness (control systems) @conference{Frej2017306b,This paper focuses on the problem of observer-based distributed guaranteed cost control for large scale nonlinear interconnected systems with a chosen quadratic cost function. The aim is to ensures closed-loop stability and guaranteed cost for all planned parameter changes. For that, differential mean value theorem is used to introduce a general condition on the nonlinear time-varying interconnections functions. The obtained design procedures are formulated in the form of Linear matrix inequalities (LMIs) by using the Lyapunovs direct method stability analysis. Effectiveness of the proposed scheme is verified through simulation results on a power system with three interconnected machines. © 2017 IEEE. |
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. |
Achnib, Asma; Chetoui, Manel; Lanusse, Patrick; Aoun, Mohamed A comparative study of the output and the state feedback predictive control Conférence 2017, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Automation, Comparative studies, Feedback, Model predictive control, Output feedback, Predictive control, Process control, Robustness (control systems), State feedback, State feedback predictive control, System models @conference{Achnib201734b,In this paper the effectiveness of predictive control in the problems of tracking and control is studied. The principle and the implementation of the algorithm of this control are presented. In this work, two approaches using different system models are developed: The output feedback and the state feedback predictive control. The performances and the robustness of both approaches are assessed with the help of two examples. © 2016 IEEE. |
Frej, Ghazi Bel Haj; Thabet, Assem; Boutayeb, Mohamed; Aoun, Mohamed Distributed observer-based guaranteed cost control design for large scale interconnected systems Conférence vol. 2017-January, 2017, (Cited by: 1). Résumé | Liens | BibTeX | Étiquettes: Cost effectiveness, Cost functions, Costs, Differential mean value theorems, Guaranteed cost, Large scale systems, Large-scale interconnected systems, Linear matrix inequalities, Linear Matrix Inequalities (LMIs), Lyapunov stability, Nonlinear interconnected systems, Observer based control, Quadratic cost functions, Robustness (control systems) @conference{Frej2017306,This paper focuses on the problem of observer-based distributed guaranteed cost control for large scale nonlinear interconnected systems with a chosen quadratic cost function. The aim is to ensures closed-loop stability and guaranteed cost for all planned parameter changes. For that, differential mean value theorem is used to introduce a general condition on the nonlinear time-varying interconnections functions. The obtained design procedures are formulated in the form of Linear matrix inequalities (LMIs) by using the Lyapunovs direct method stability analysis. Effectiveness of the proposed scheme is verified through simulation results on a power system with three interconnected machines. © 2017 IEEE. |
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 |
Saidi, B.; Amairi, M.; Najar, S.; Aoun, M. Bode shaping-based design methods of a fractional order PID controller for uncertain systems Article de journal Dans: Nonlinear Dynamics, vol. 80, no. 4, p. 1817 – 1838, 2015, (Cited by: 66). Résumé | Liens | BibTeX | Étiquettes: Algorithms, Carbon monoxide, Constrained optimization, Damping, Design, Electric control equipment, Fractional PID, Fractional-order PID controllers, Frequency bands, Frequency domain analysis, Frequency-domain design, Iso-damping property, Numerical methods, Numerical optimization algorithms, Numerical optimizations, Optimization, Proportional control systems, Robustness (control systems), Test benches, Three term control systems, Uncertain systems, Uncertainty @article{Saidi20151817b,This paper deals with robust fractional order PID controller design via numerical optimization. Three new frequency-domain design methods are proposed. They achieve good robustness to the variation of some parameters by maintaining the open-loop phase quasi-constant in a pre-specified frequency band, i.e., maintaining the iso-damping property of the controlled system. The two first methods are extensions of the well-known Monje-Vinagre et al. method for uncertain systems. They ameliorate the numerical optimization algorithm by imposing the open-loop phase to be flat in a frequency band not only around a single frequency. The third method is an interval-based design approach that simplifies the algorithm by reducing the constraints number and offers a more large frequency band with an iso-damping property. Several numerical examples are presented to show the efficiency of each proposed method and discuss the obtained results. Also, an application to the liquid carbon monoxide level control is presented. © 2014, Springer Science+Business Media Dordrecht. |
Saidi, B.; Amairi, M.; Najar, S.; Aoun, M. Multi-objective optimization based design of fractional PID controller Conférence 2015, (Cited by: 9). Résumé | Liens | BibTeX | Étiquettes: Closed loop systems, Closed-loop behavior, Design, Electric control equipment, Fractional PID, Fractional pid controllers, Fractional-order PID controllers, Frequency bands, Frequency domain analysis, Frequency domains, Frequency specifications, Iso-damping property, Multiobjective optimization, Numerical methods, Phase margins, Proportional control systems, Robustness (control systems), Specifications, Three term control systems @conference{Saidi2015d,This paper deals with robust fractional order PID controller design via numerical multi-objective optimization. The proposed interval-based design scheme uses frequency-domain specifications to ensure a desired closed-loop behavior. By maintaining the desired phase margin quasi-constant in a pre-specified frequency band, it guarantees more robustness to gain uncertainties. This leads to a closed-loop system with an interesting iso-damping property in a more large frequency band than other design methods. A numerical example is presented to show the efficiency of the proposed method and to discuss about the obtained results. © 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. |
Saidi, B.; Amairi, M.; Najar, S.; Aoun, M. Min-Max optimization-based design of fractional PID controller Conférence 2014, (Cited by: 3). Résumé | Liens | BibTeX | Étiquettes: Algorithms, Automation, Calculations, Constrained optimization, Convergence of numerical methods, Design method, Disturbance rejection, Electric control equipment, Fractional calculus, Fractional pid controllers, Load disturbance rejection capabilities, Min-max optimization, Numerical methods, Optimization, Proportional control systems, Robustness (control systems), Simulation example, Stability margins, Three term control systems @conference{Saidi2014468b,This paper deals with a new design method of a fractional PID controller. The proposed method is based on a numerical constrained Min-Max optimization algorithm. Its main objective is the improvement of the transient response, the stability margin, the robustness and the load disturbance rejection capability. All these performances are tested through a simulation example. © 2014 IEEE. |
Publications
2019 |
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). |
2018 |
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). |
H∞ Observer-Based Controller for Lipschitz Nonlinear Discrete-Time Systems Conférence 2018, (Cited by: 0). |
2017 |
Distributed observer-based guaranteed cost control design for large scale interconnected systems Conférence vol. 2017-January, 2017, (Cited by: 1). |
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). |
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). |
A comparative study of the output and the state feedback predictive control Conférence 2017, (Cited by: 1). |
Distributed observer-based guaranteed cost control design for large scale interconnected systems Conférence vol. 2017-January, 2017, (Cited by: 1). |
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). |
2015 |
Bode shaping-based design methods of a fractional order PID controller for uncertain systems Article de journal Dans: Nonlinear Dynamics, vol. 80, no. 4, p. 1817 – 1838, 2015, (Cited by: 66). |
Multi-objective optimization based design of fractional PID controller Conférence 2015, (Cited by: 9). |
2014 |
Design of robust fractional order PI for FOPDT systems via set inversion Conférence 2014, (Cited by: 4). |
Min-Max optimization-based design of fractional PID controller Conférence 2014, (Cited by: 3). |