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H_∞ decentralized dynamic-observer-based control design for large-scale nonlinear intercon-nected systems ; ; et al in Transaction on IoT and Cloud Computing (2014), 2(3), 46-66 Detailed reference viewed: 57 (1 UL)A model predictive approach for cyber-attack detection and mitigation in control systems Rosich, Albert ; Voos, Holger ; et al in 52nd IEEE Conference on Decision and Control CDC 2013, Florence, Italy, Dec. 2013 (2013, December 13) The paper presents a new approach for control security. Specifically, cyber-attacks on the controller are investigated by means of optimization techniques in order to determine the worst-case scenario ... [more ▼] The paper presents a new approach for control security. Specifically, cyber-attacks on the controller are investigated by means of optimization techniques in order to determine the worst-case scenario. Then, a novel attack detector based on limit checking is introduced. The particularity of this detector is that no specific controller knowledge is necessary. Hence, the vulnerability of the detector can be reduced since no reconfiguration is required (limited accessibility). Finally, the paper shows that the effect of the attacks on the system can be significantly mitigated by applying proper optimal control laws. [less ▲] Detailed reference viewed: 149 (19 UL)A model predictive approach for cyber-attack detection and mitigation in control systems Voos, Holger ; Li, Yumei ; in The 52nd IEEE Conference on Decision and Control (2013, December 10) The paper presents a new approach for control security. Speciﬁcally, cyber-attacks on the controller are in- vestigated by means of optimization techniques in order to determine the worst-case scenario ... [more ▼] The paper presents a new approach for control security. Speciﬁcally, cyber-attacks on the controller are in- vestigated by means of optimization techniques in order to determine the worst-case scenario. Then, a novel attack detector based on limit checking is introduced. The particularity of this detector is that no speciﬁc controller knowledge is necessary. Hence, the vulnerability of the detector can be reduced since no reconﬁguration is required (limited accessibility). Finally, the paper shows that the effect of the attacks on the system can be signiﬁcantly mitigated by applying proper optimal control laws [less ▲] Detailed reference viewed: 98 (6 UL)Generalized H_infinity observers design for systems with unknown inputs ; ; Voos, Holger et al in 2nd International Conference on Control and Fault-Tolerant Systems SysTol'13, Nice, France, Oct. 2013 (2013, October) A generalized H_infinity observer design is proposed for linear systems with unknown inputs. It generalizes the existing results concerning the proportional observer (PO) design and the proportional ... [more ▼] A generalized H_infinity observer design is proposed for linear systems with unknown inputs. It generalizes the existing results concerning the proportional observer (PO) design and the proportional integral observer (PIO) design. The approach is based on the solutions of the algebraic constraints obtained from the unbiasedness conditions of the estimation error. The observer design is obtained from the solutions of linear matrix inequalities (LMIs). A numerical example is given to illustrate our approach. [less ▲] Detailed reference viewed: 95 (2 UL)An Efficient Nonlinear Model-Predictive Eco-Cruise Control for Electric Vehicles Schwickart, Tim Klemens ; Voos, Holger ; Hadji-Minaglou, Jean-Régis et al in 11th IEEE International Conference on Industrial Informatics, Bochum, Germany, 29-31 July 2013 (2013, July) A nonlinear problem formulation of an energy-saving model-predictive eco-cruise controller for electric vehicles is presented. With regard to the intended application in real-world tests, the model has to ... [more ▼] A nonlinear problem formulation of an energy-saving model-predictive eco-cruise controller for electric vehicles is presented. With regard to the intended application in real-world tests, the model has to include the specific properties of a serial electric vehicle such as energy-recovery and a discontinuous accelerator input giving rise to a binary control variable. These specific features and the nonlinearity of the system dynamics make it a challenging task to formulate the optimisation problem in a way that allows a fast computation in real-time application. The challenges are addressed by using a model of the vehicle dynamics that is formulated in terms of the vehicle position instead of time and by considering the kinetic energy instead of the velocity. Furthermore, various constraints on the input and state variables are introduced for a realistic representation of the vehicle characteristics. A special focus is put on the treatment of a binary input variable in the optimisation. Here, in order to avoid a mixed-integer formulation of the problem, a continuous variable is introduced which is forced to take only discrete values by a penalty term. Finally, first simulation results underline the feasibility of this control approach. [less ▲] Detailed reference viewed: 266 (39 UL)Robust stabilization of uncertain descriptor fractional-order systems Ndoye, Ibrahima ; ; et al in Automatica (2013) This paper presents sufficient conditions for the robust asymptotical stabilization of uncertain descriptor fractional-order systems with the fractional order α satisfying 0<\alpha<2. The results are ... [more ▼] This paper presents sufficient conditions for the robust asymptotical stabilization of uncertain descriptor fractional-order systems with the fractional order α satisfying 0<\alpha<2. The results are obtained in terms of linear matrix inequalities. The parameter uncertainties are assumed to be time-invariant and norm-bounded appearing in the state matrix. A necessary and sufficient condition for the normalization of uncertain descriptor fractional-order systems is given via linear matrix inequality (LMI) formulation. The state feedback control to robustly stabilize such uncertain descriptor fractional-order systems with the fractional order \alpha belonging to 0</alpha<2 is derived. Two numerical examples are given to demonstrate the applicability of the proposed approach. [less ▲] Detailed reference viewed: 95 (5 UL)Design of Unkown Input Fractional-Order Observers for Fractional-Order Systems Ndoye, Ibrahima ; ; Voos, Holger et al in International Journal of Applied Mathematics & Computer Science (2013), 23(3), 491-500 This paper considers a method to design fractional-order observers for continuous-time linear fractional-order systems with unknown inputs. The conditions for the existence of these observers are given ... [more ▼] This paper considers a method to design fractional-order observers for continuous-time linear fractional-order systems with unknown inputs. The conditions for the existence of these observers are given. Sufficient conditions for the asymptotical stability of the fractional-order observer errors with the fractional-order \alpha satisfying 0<\alpha<2 are derived in terms of linear matrix inequalities. Two numerical examples are given to demonstrate the applicability of the proposed approach where the fractional-order \alpha belongs to 1<\alpha<2 and 0<\alpha<1 respectively. The stability analysis of the fractional-order error system is completed and it is shown that the fractional-order observers are as stable as their integer-order counterpart and guarantee better convergence of the estimation error. [less ▲] Detailed reference viewed: 105 (6 UL)Observer-Based Approach for Fractional-Order Chaotic Synchronization and Communication Ndoye, Ibrahima ; ; Voos, Holger in European Control Conference (ECC), July 17-19, 2013, Switzerland (2013) This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic ... [more ▼] This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic stability. The gains of the observer and observer-based controller are obtained in terms of linear matrix inequalities (LMIs) formulation. The proposed approach is then applied to secure communications. The method combines chaotic masking and chaotic modulation, where the information signal is injected into the transmitter and simultaneously transmitted to the receiver. Chaotic synchronization and chaotic communication are achieved simultaneously via a state observer design technique. An numerical fractional-order chaotic Lorenz system is given to demonstrate the applicability of the proposed approach. [less ▲] Detailed reference viewed: 96 (4 UL)Observer-Based Approach for Fractional-Order Chaotic Synchronization and Secure Communication Ndoye, Ibrahima ; Voos, Holger ; in IEEE Journal on Emerging and Selected Topics in Circuits and Systems (2013), 3(3), 442-450 This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic ... [more ▼] This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic stability. The gains of the observer and observer-based controller are obtained in terms of linear matrix inequalities (LMIs) formulation. The proposed approach is then applied to secure communications. The method combines chaotic masking and chaotic modulation, where the information signal is injected into the transmitter and simultaneously transmitted to the receiver. Chaotic synchronization and chaotic communication are achieved simultaneously via a state observer design technique. The fractional-order chaotic Lorenz and Lü systems are given to demonstrate the applicability of the proposed approach. [less ▲] Detailed reference viewed: 102 (5 UL)H-infinity Static Output Feedback Control for a Fractional-Order Glucose-Insulin System Ndoye, Ibrahima ; Voos, Holger ; et al in 6th Workshop on Fractional Differentiation and Its Applications. Part of 2013 IFAC Joint Conference SSSC, TDS and FDA (2013), Grenoble, February 4-6, 2013 (2013) This paper presents the H-infinity static output feedback control of nonlinear fractional-order glucose-insulin systems. In this paper, it is an attempt to incorporate fractional-order into the ... [more ▼] This paper presents the H-infinity static output feedback control of nonlinear fractional-order glucose-insulin systems. In this paper, it is an attempt to incorporate fractional-order into the mathematical minimal model of glucose-insulin system dynamics and it is still an interesting challenge to show, how the order of a fractional di erential system a ects the dynamics of system in the presence of meal disturbance. A static output feedback control is considered for the problem. Su fficient conditions are derived in terms of linear matrix inequalities (LMIs) formulation by using the fractional Lyapunov direct method where the fractional-order \alpha belongs to 0<\alpha<1. Finally, numerical simulations are carried out to illustrate our proposed results and show that the nonlinear fractional-order glucose-insulin systems are as stable as their integer-order counterpart in the presence of exogenous glucose infusion or meal disturbance. [less ▲] Detailed reference viewed: 326 (7 UL)Observer-Based Approach for Fractional-Order Chaotic Synchronization and Communication Ndoye, Ibrahima ; ; Voos, Holger in European Control Conference (ECC), Switzerland, July 17-19, 2013 (2013) This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic ... [more ▼] This paper presents a method based on the state observer design for constructing a chaotically synchronized systems. Fractional-order direct Lyapunov theorem is used to derive the closed-loop asymptotic stability. The gains of the observer and observer-based controller are obtained in terms of linear matrix inequalities (LMIs) formulation. The proposed approach is then applied to secure communications. The method combines chaotic masking and chaotic modulation, where the information signal is injected into the transmitter and simultaneously transmitted to the receiver. Chaotic synchronization and chaotic communication are achieved simultaneously via a state observer design technique. An numerical fractional-order chaotic Lorenz system is given to demonstrate the applicability of the proposed approach. [less ▲] Detailed reference viewed: 103 (9 UL)Static Output Feedback Stabilization of Nonlinear Fractional-Order Glucose-Insulin System Ndoye, Ibrahima ; Voos, Holger ; et al in IEEE EMBS Conference on Biomedical Engineering and Sciences, Malaysia, 17th - 19th December, 2012 (2012) Diabetes is a long-term disease during which the body's production and use of the insulin are impaired, causing glucose concentration level to increase in the bloodstream. The blood glucose dynamics is ... [more ▼] Diabetes is a long-term disease during which the body's production and use of the insulin are impaired, causing glucose concentration level to increase in the bloodstream. The blood glucose dynamics is described using the generalized minimal model structure for the intravenously infused insulin blood glucose, which can represent a wide variety of diabetic patients. In this paper, it is an attempt to incorporate fractional-order derivative into the mathematical minimal model of glucose-insulin system dynamics and it is still an interesting challenge to determine, mathematically, how the order of a fractional differential system affects the dynamics of system. The paper presents the asymptotical stabilization problem of nonlinear fractional-order glucose insulin systems. A static output feedback control is considered for the problem. Sufficient conditions for the asymptotical stabilization of the nonlinear fractional-order glucose-insulin system are derived in terms of linear matrix inequalities (LMIs) formulation by using the fractional Lyapunov direct method where the fractional-order \alpha belonging to 0<\alpha<1. Finally, numerical simulations are carried out to illustrate our proposed results. These numerical simulations show that the nonlinear fractional-order glucose-insulin systems are, at least, as stable as their integer-order counterpart. [less ▲] Detailed reference viewed: 194 (5 UL)An Unknown Input Fractional-Order Observer Design for Fractional-Order Glucose-Insulin System Ndoye, Ibrahima ; Voos, Holger ; et al in IEEE EMBS Conference on Biomedical Engineering and Sciences, Malaysia, 17th - 19th December, 2012 (2012) In this paper, we introduce fractional-order derivatives into a generalized minimal model of glucose-insulin. A fractional-order state observer is designed for estimating the structure of a blood glucose ... [more ▼] In this paper, we introduce fractional-order derivatives into a generalized minimal model of glucose-insulin. A fractional-order state observer is designed for estimating the structure of a blood glucose-insulin with glucose rate disturbance to show the complete dynamics of the glucose-insulin system where the fractional-order \alpha belonging to 0<\alpha<1. A nonlinear fractional-order unknown input observer strategy is used where the glucose rate disturbance is considered as an unknown input to the perspective dynamical system. The developed method provides the observer estimation algorithm for a glucose-insulin system with unknown time-varying glucose rate disturbance. The stability analysis of the fractional-order error system is completed and showed that the fractional-order observer design is as stable as their integer-order counterpart and guarantees the best convergence of the estimation error. Finally, numerical simulations are given to illustrate the effectiveness of the proposed method. [less ▲] Detailed reference viewed: 126 (5 UL)Fractional-Order Observers Design for Fractional-Order Systems with Unknown Inputs Ndoye, Ibrahima ; ; in 2nd International Conference on Systems and Control, Morocco, June 20-22, 2012 (2012) This paper considers a method to design the functional observers for continuous-time linear fractional-order systems with unknown inputs. The conditions for the existence of these observers are given ... [more ▼] This paper considers a method to design the functional observers for continuous-time linear fractional-order systems with unknown inputs. The conditions for the existence of these observers are given. Sufficient conditions for the asymptotical stability of observers with the fractional-order satisfying 0<\alpha<2 are derived in terms of linear matrix inequalities formulation. Two numerical examples are given to demonstrate the applicability of the proposed approach where the fractional-order belonging to 1<\alpha<2 and 0<\alpha<1 respectively. [less ▲] Detailed reference viewed: 126 (1 UL)Regularization and Robust Stabilization of Singular Uncertain Fractional-Order Systems Ndoye, Ibrahima ; ; et al in 18th IFAC World Congress, Milano, Italy, 2011 (2011) In this paper, robust asymptotical stabilization problem via a predictive and memoryless static feedbacks for uncertain singular fractional-order systems for the fractional-order belonging to 0<\alpha<2 ... [more ▼] In this paper, robust asymptotical stabilization problem via a predictive and memoryless static feedbacks for uncertain singular fractional-order systems for the fractional-order belonging to 0<\alpha<2 is investigated. The parameter uncertainty is assumed to be time-invariant and norm-bounded appearing in the state matrix. Suffcient linear matrix inequalities (LMIs) conditions for regularization of uncertain singular fractional-order systems are given. Then, the predictive controller aims to regularizing the uncertain singular fractional-order systems while the memoryless state feedback is designed to stabilize the resulting regularized system. A numerical example is given to demonstrate the applicability of the proposed approach. [less ▲] Detailed reference viewed: 36 (4 UL)Observers for Singular Fractional-Order Systems Ndoye, Ibrahima ; ; et al in 50th IEEE Conference on Decision and Control and European Control Conference (CDC-ECC), Orlando, FL, USA, December 12-15, 2011 (2011) This paper considers the observers design for continuous-time singular fractional-order systems. The approach is based on the generalized Sylvester equations solutions. The conditions for the existence of ... [more ▼] This paper considers the observers design for continuous-time singular fractional-order systems. The approach is based on the generalized Sylvester equations solutions. The conditions for the existence of these observers are given and sufficient conditions for their stability are derived in terms of linear matrix inequalities formulation. [less ▲] Detailed reference viewed: 65 (0 UL)Exponential Stabilization of a Class of Nonlinear Systems : A Generalized Gronwall-Bellman Lemma Approach Ndoye, Ibrahima ; ; et al in Nonlinear Analysis: Theory, Methods & Applications (2011), 74 In this paper, stabilizing control design for a class of nonlinear affine systems is presented by using a new generalized Gronwall-Bellman lemma approach. The nonlinear systems under consideration can be ... [more ▼] In this paper, stabilizing control design for a class of nonlinear affine systems is presented by using a new generalized Gronwall-Bellman lemma approach. The nonlinear systems under consideration can be non Lipschitz. Two cases are treated for the exponential stabilization: the static state feedback and the static output feedback. The robustness of the proposed control laws with regards to parameter uncertainties is also studied. A numerical example is given to show the effectiveness of the proposed method. [less ▲] Detailed reference viewed: 100 (8 UL)Stabilisation des systèmes bilinéaires fractionnaires Ndoye, Ibrahima ; ; et al in Sixième Conférence Internationale Francophone d'Automatique, CIFA 2010, Nancy, France (2010) Cet article traite de la stabilisation des systèmes bilinéaires fractionnaires par l'approche de la nouvelle généralisation du lemme de Gronwall-Bellman. L'utilisation de cette nouvelle approche permet de ... [more ▼] Cet article traite de la stabilisation des systèmes bilinéaires fractionnaires par l'approche de la nouvelle généralisation du lemme de Gronwall-Bellman. L'utilisation de cette nouvelle approche permet de montrer sous certaines hypothèses adéquates, qu'on peut garantir une stabilisation asymptotique par retour d'état statique et par retour de sortie statique des systèmes bilinéaires fractionnaires. La méthodologie est illustrée par l'intermédiaire d'un exemple numérique. [less ▲] Detailed reference viewed: 89 (1 UL)Stabilization of Singular Fractional-Order Systems : An LMI Approach Ndoye, Ibrahima ; ; et al in 18th IEEE Mediterranean Conference on Control & Automation, Morocco, June 23-25, 2010 (2010) This paper presents the asymptotical stabilization problem of linear singular fractional-order systems. The results are obtained in terms of linear matrix inequalities, which are derived using the ... [more ▼] This paper presents the asymptotical stabilization problem of linear singular fractional-order systems. The results are obtained in terms of linear matrix inequalities, which are derived using the decomposition on the matrices of the original system. An illustrative example is provided to illustrate the proposed [less ▲] Detailed reference viewed: 128 (3 UL)Robust Stabilization of Linear and Nonlinear Fractional-Order Systems with Nonlinear Uncertain Parameters Ndoye, Ibrahima ; ; et al in 49th IEEE Conference on Decision and Control (CDC), Hilton Atlanta Hotel, Atlanta, December 15-17, 2010 (2010) The paper presents the robust stabilization problem of linear and nonlinear fractional-order systems with nonlinear uncertain parameters. The uncertainty in the model appears in the form of combination of ... [more ▼] The paper presents the robust stabilization problem of linear and nonlinear fractional-order systems with nonlinear uncertain parameters. The uncertainty in the model appears in the form of combination of additive perturbation and multiplicative perturbation. Sufficient conditions for robust stabilization of such linear and nonlinear fractional-order systems are presented in terms of linear matrix inequalities and using the new generalization of Gronwall-Bellman approach. [less ▲] Detailed reference viewed: 90 (3 UL) |
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