2022 |
Najjar, A.; Dinh, T. N.; Amairi, M.; Raissi, T. Interval observer-based supervision of nonlinear networked control systems Article de journal Dans: Turkish Journal of Electrical Engineering and Computer Sciences, vol. 30, no. 4, p. 1219-1234, 2022, ISSN: 13000632, (cited By 1). Résumé | Liens | BibTeX | Étiquettes: Input-to-state stability; Interval estimation; Interval observers; Nonlinear networked control system; Observer-based; Predictor; Remote supervision; Systems’ class; Time-varying delay; Uncertain large time-varying delay, Networked control systems, Nonlinear analysis; Time delay; Time varying control systems; Time varying networks; Uncertainty analysis @article{Najjar20221219,Networked control system (NCS) is a multidisciplinary area that attracts increasing attention today. In this paper, we deal with remote supervision of a nonlinear networked control systems class subject to network imperfections. Different from many existing researches that consider only the problem of small and/or constant communication delays, we focus on large and time-varying network delays problem in both measurement and control channels. The proposed method is a set-membership estimation-based predictor approach computing a guaranteed set of admissible state values when the uncertainties (i.e. measurement noises and system disturbances) are considered unknown but bounded with a priori known bounds. The state prediction strategy is used to compensate the effect of transmission delays. Finally, the theoretical results are validated through a numerical example. © 2022 Turkiye Klinikleri. All rights reserved. |
2020 |
Najjar, A.; Amairi, M. Institute of Electrical and Electronics Engineers Inc., 2020, ISBN: 9781728188157, (cited By 0). Résumé | Liens | BibTeX | Étiquettes: Automation; Process control, Communication delays; Interval observers; Measurement channels; Networked Control Systems (NCSs); Remote supervision; Set membership; State prediction; Transmission delays, Networked control systems @conference{Najjar202071,Communication delays are one of the most challenging problems in networked control systems (NCSs). This paper deals with remote supervision of a class of discret NCSs with parameter-varying. The network induces transmission delays in the actuation and the measurement channels. These delays are assumed to be random but bounded. Under this assumption, an interval observer is developed to estimate unavailable process state. Then, a state prediction technique is required to compensate measurement channel delays. A numerical example is presented in order to demonstrate the framework efficiency. © 2020 IEEE. |
2019 |
Najjar, A.; Dinh, T. N.; Amairi, M.; Raissi, T. Supervision of Nonlinear Networked Control Systems under Network Constraints Conférence IEEE Computer Society, 2019, ISSN: 21621195, (cited By 3). Résumé | Liens | BibTeX | Étiquettes: Additive disturbance; Interval observers; Network-induced delays; Nonlinear networked control systems; Nonlinear networked control systems (NNCS); predictor; Time varying- delays; Unknown but bounded, Data acquisition; Fault tolerance; State estimation; Time delay; Time varying control systems, Networked control systems @conference{Najjar2019270,The remote supervision for a class of nonlinear systems in the presence of additive disturbances and measurement noises is considered in this paper. The communication network may introduce time delays while exchanging data among sites connected to the network medium (i.e., the data acquisition site and the remote plant site). Two different approaches are presented in this paper. The first one uses a conventional estimator-based predictor when the uncertainties are supposed to be known. In the case of unknown but bounded uncertainties by known bounds, an interval estimation-based predictor evaluating the set of admissible values for the state is investigated. The state prediction techniques are used to compensate the effect of network-induced delays. Simulation results are introduced to illustrate the efficiency of the proposed techniques. © 2019 IEEE. |
2018 |
Chabir, K.; Rhouma, T.; Keller, J. Y.; Sauter, D. State Filtering for Networked Control Systems Subject to Switching Disturbances Article de journal Dans: International Journal of Applied Mathematics and Computer Science, vol. 28, no. 3, p. 473-482, 2018, ISSN: 1641876X, (cited By 11). Résumé | Liens | BibTeX | Étiquettes: Bernoulli; Constant bias; Control signal; Discrete time linear systems; State filtering; Stochastic stability; Unknown inputs; Unreliable network, Binary sequences; Covariance matrix; Kalman filters; Linear systems; Random processes; State estimation; Stochastic systems; Switching, Networked control systems @article{Chabir2018473,State estimation of stochastic discrete-time linear systems subject to unknown inputs has been widely studied, but few works take into account disturbances switching between unknown inputs and constant biases. We show that such disturbances affect a networked control system subject to deception attacks on the control signals transmitted by the controller to the plant via unreliable networks. This paper proposes to estimate the switching disturbance from an augmented state version of the intermittent unknown input Kalman filter. The sufficient stochastic stability conditions of the obtained filter are established when the arrival binary sequence of data losses follows a Bernoulli random process. © 2018 Karim Chabir, published by Sciendo. |
Rhouma, T.; Chabir, K.; Abdelkrim, M. N. Resilient Control for Networked Control Systems Subject to Cyber/Physical Attacks Article de journal Dans: International Journal of Automation and Computing, vol. 15, no. 3, p. 345-354, 2018, ISSN: 14768186, (cited By 15). Résumé | Liens | BibTeX | Étiquettes: Anomaly detector; Cyber physicals; Kalman-filtering; Networked Control Systems (NCSs); Resilient control, Closed loop systems; Computer crime; Fault detection; Kalman filters; Network architecture, Networked control systems @article{Rhouma2018345,In this paper, we investigate a resilient control strategy for networked control systems (NCSs) subject to zero dynamic attacks which are stealthy false-data injection attacks that are designed so that they cannot be detected based on control input and measurement data. Cyber resilience represents the ability of systems or network architectures to continue providing their intended behavior during attack and recovery. When a cyber attack on the control signal of a networked control system is computed to remain undetectable from passive model-based fault detection and isolation schemes, we show that the consequence of a zero dynamic attack on the state variable of the plant is undetectable during attack but it becomes apparent after the end of the attack. A resilient linear quadratic Gaussian controller, having the ability to quickly recover the nominal behavior of the closed-loop system after the attack end, is designed by updating online the Kalman filter from information given by an active version of the generalized likelihood ratio detector. © 2017, Institute of Automation, Chinese Academy of Sciences and Springer-Verlag GmbH Germany, part of Springer Nature. |
2015 |
Rhouma, T.; Keller, J. Y.; Sauter, D.; Chabir, K.; Abdelkrim, M. N. Active GLR detector for resilient LQG controller in networked control systems Conférence vol. 28, no. 21, 2015, ISSN: 24058963, (cited By 9). Résumé | Liens | BibTeX | Étiquettes: Anomaly detector; Computing science; Generalized Likelihood Ratio Test; Linear quadratic Gaussian control; Linear Quadratic Gaussian controllers; Model-based fault detection; Normal operations; Tracking ability, Controllers; Fault detection; Kalman filters; Network architecture; Network security; Plant management; Robustness (control systems); Control systems, Networked control systems @conference{Rhouma2015754,In computing science, resilience is the ability of system or network architecture to recover normal operation after a brutal crash. When malicious cyber act on control signals of a Networked Control System (NCS) is designed to remain undetectable from passive modelbased Fault Detection and Isolation (FDI) schemes, we show that the unobservable consequence on the state variable of the plant becomes brutally observable after the disappearance of the damaging action. In order to quickly recover the nominal behavior of the Linear Quadratic Gaussian (LQG) controller, a resilient LQG controller is obtained from an active version of the Generalized Likelihood Ratio (GLR) test designed to detect the disappearance of the malicious act and to increase the tracking ability of the Kalman filter at detection time. © 2015, IF AC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved. |
2014 |
Naoui, A.; Ali, S. Bel Hadj; Afilal, L. -E.; Abdelkrim, M. N. Institute of Electrical and Electronics Engineers Inc., 2014, ISBN: 9781479959075, (cited By 0). Résumé | Liens | BibTeX | Étiquettes: Actuators; Automation; Computer system recovery; Control system analysis; Control systems; Controllers; Hierarchical systems; Networks (circuits); Safety engineering; Sensors; Specifications, AEEL; AMDE; Conventional methods; Functional specification; Operational safety; Qualitative analysis; SA/RT; System decomposition, Networked control systems @conference{Naoui201444,Networked control system functional analysis makes it possible to define studied system material limits, to carry out various functions and operations and to study various configurations of exploitation. This stage which makes it possible to carry out hierarchical system decomposition in material elements and/or software does not bring information on modes of failure, their effect, their occurrence and their criticality. It is thus necessary to supplement it by a second analysis taking of account dysfunctions. These two types of analyzes which constitute qualitative analysis, are complementary, and make it possible to model more accurately a networked control system. The goal of this paper is to apply various traditional methods employed in functional specification and operational safety in order to make a relevant qualitative analysis of a networked control system. © 2014 IEEE. |
Publications
2022 |
Interval observer-based supervision of nonlinear networked control systems Article de journal Dans: Turkish Journal of Electrical Engineering and Computer Sciences, vol. 30, no. 4, p. 1219-1234, 2022, ISSN: 13000632, (cited By 1). |
2020 |
Institute of Electrical and Electronics Engineers Inc., 2020, ISBN: 9781728188157, (cited By 0). |
2019 |
Supervision of Nonlinear Networked Control Systems under Network Constraints Conférence IEEE Computer Society, 2019, ISSN: 21621195, (cited By 3). |
2018 |
State Filtering for Networked Control Systems Subject to Switching Disturbances Article de journal Dans: International Journal of Applied Mathematics and Computer Science, vol. 28, no. 3, p. 473-482, 2018, ISSN: 1641876X, (cited By 11). |
Resilient Control for Networked Control Systems Subject to Cyber/Physical Attacks Article de journal Dans: International Journal of Automation and Computing, vol. 15, no. 3, p. 345-354, 2018, ISSN: 14768186, (cited By 15). |
2015 |
Active GLR detector for resilient LQG controller in networked control systems Conférence vol. 28, no. 21, 2015, ISSN: 24058963, (cited By 9). |
2014 |
Institute of Electrical and Electronics Engineers Inc., 2014, ISBN: 9781479959075, (cited By 0). |