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Sayyaddelshad, Saleh
Alternative names
Publications (10 of 16) Show all publications
Sayyaddelshad, S., Johansson, A., Darouach, M. & Gustafsson, T. (2016). Robust state estimation and unknown inputs reconstruction for a class of nonlinear systems: multiobjective approach (ed.). Paper presented at . Automatica, 64, 1-7
Open this publication in new window or tab >>Robust state estimation and unknown inputs reconstruction for a class of nonlinear systems: multiobjective approach
2016 (English)In: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 64, p. 1-7Article in journal (Refereed) Published
Abstract [en]

We consider a novel method to design H-infinity observers for a class of uncertain nonlinear systems subject to unknown inputs. First, the main system dynamics are rewritten as an augmented system with state vector including both the state vector of the main system and the unknown inputs. Then, we design a H-infinity reduced-order observer to estimate both state variables and unknown inputs simultaneously. Based on a Lyapunov functional, we derive a sufficient condition for existence of the designed observer which requires solving a nonlinear matrix inequality. To facilitate the observer design, the achieved condition is formulated in terms of a set of linear matrix inequalities (LMI). By extending the proposed method to a multiobjective optimization problem, the maximum bound of the uncertainty and the minimum value of the disturbance attenuation level are found. Finally, the proposed observer is illustrated with an example.

Keywords
Information technology - Automatic control, Informationsteknik - Reglerteknik
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-3452 (URN)10.1016/j.automatica.2015.10.051 (DOI)000368967000001 ()2-s2.0-84951753244 (Scopus ID)14661358-2de9-42eb-87e4-fc5c24c5d160 (Local ID)14661358-2de9-42eb-87e4-fc5c24c5d160 (Archive number)14661358-2de9-42eb-87e4-fc5c24c5d160 (OAI)
Note
Validerad; 2015; Nivå 2; 20151027 (salsay)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Sayyaddelshad, S. & Gustafsson, T. (2015). H∞ observer design for uncertain nonlinear discrete-time systems with time-delay: LMI Optimization Approach (ed.). Paper presented at . International Journal of Robust and Nonlinear Control, 25(10), 1514-1527
Open this publication in new window or tab >>H∞ observer design for uncertain nonlinear discrete-time systems with time-delay: LMI Optimization Approach
2015 (English)In: International Journal of Robust and Nonlinear Control, ISSN 1049-8923, E-ISSN 1099-1239, Vol. 25, no 10, p. 1514-1527Article in journal (Refereed) Published
Abstract [en]

We present a robust H∞ observer for a class of nonlinear discrete-time systems. The class under study includes an unknown time-varying delay limited by upper and lower bounds, as well as time-varying para- metric uncertainties. We design a nonlinear H∞ observer, by using the upper and lower bounds of the delay, that guarantees asymptotic stability of the estimation error dynamics and is also robust against time-varying parametric uncertainties. The described problem is converted to a standard optimization problem, which can be solved in terms of linear matrix inequalities (LMIs). Then, we expand the problem to a multi-objective optimization problem in which the maximum admissible Lipschitz constant and the minimum disturbance attenuation level are the problem objectives. Finally, the proposed observer is illustrated with two examples.

Keywords
Information technology - Automatic control, Informationsteknik - Reglerteknik
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-11991 (URN)10.1002/rnc.3155 (DOI)000354641300006 ()2-s2.0-84929505784 (Scopus ID)b0cf01f3-be06-4f01-91cd-3841e51476a9 (Local ID)b0cf01f3-be06-4f01-91cd-3841e51476a9 (Archive number)b0cf01f3-be06-4f01-91cd-3841e51476a9 (OAI)
Note
Validerad; 2015; Nivå 2; 20140205 (tgu)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Sayyaddelshad, S., Gustafsson, T., Karimi, H. R. & Zemouche, A. (2015). Observer-based control design for a class of nonlinear systems subject to unknown inputs: LMI approach (ed.). In: (Ed.), 15th International Conference on Control, Automation and Systems (ICCAS): Busan, Korea (South), 13-16 Oct. 2015. Paper presented at International Conference on Control, Automation and Systems : 13/10/2015 - 16/10/2015 (pp. 984-989). Piscataway, NJ: IEEE Communications Society, Article ID 7364768.
Open this publication in new window or tab >>Observer-based control design for a class of nonlinear systems subject to unknown inputs: LMI approach
2015 (English)In: 15th International Conference on Control, Automation and Systems (ICCAS): Busan, Korea (South), 13-16 Oct. 2015, Piscataway, NJ: IEEE Communications Society, 2015, p. 984-989, article id 7364768Conference paper, Published paper (Refereed)
Abstract [en]

This paper deals with the problem of observer-based controller design for a class of nonlinear systems subject to unknown inputs. A novel method is presented to design a controller using estimated state variables which guarantees all the state variables of the closed-loop system converge to the vicinity of the origin and stay there forever. This is done via satisfying several sufficient conditions in terms of nonlinear matrix inequalities. In light of linear algebra, particularly matrix decompositions, the achieved conditions will be converted to a Linear Matrix Inequality (LMI) problem to facilitate the procedure of computing the observer and controller gains. Finally, the effectiveness of the proposed method is illustrated by implementing on a highly nonlinear chaotic system.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Communications Society, 2015
Series
International Conference on Control, Automation and Systems, ISSN 2093-7121
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-37858 (URN)10.1109/ICCAS.2015.7364768 (DOI)000382295200202 ()2-s2.0-84966270156 (Scopus ID)c02e50d5-2456-4820-90de-641afc989184 (Local ID)9788993215090 (ISBN)c02e50d5-2456-4820-90de-641afc989184 (Archive number)c02e50d5-2456-4820-90de-641afc989184 (OAI)
Conference
International Conference on Control, Automation and Systems : 13/10/2015 - 16/10/2015
Note

Validerad; 2016; Nivå 1; 2016-12-01 (andbra)

Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-07-10Bibliographically approved
Sayyaddelshad, S. (2015). Robust observer design for a class of nonlinear systems: LMI approach (ed.). (Doctoral dissertation). Paper presented at . : Luleå tekniska universitet
Open this publication in new window or tab >>Robust observer design for a class of nonlinear systems: LMI approach
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Observer design for nonlinear systems is a well-known problem in control theory that has been studied from different perspectives. Because the system state variables are generally not always available, state estimation is an essential task in many control applications, which is why this problem has attracted considerable attention from researchers and is the main focus of this thesis.Knowing that no mathematical system can exactly model a physical system, as a control engineer we must be aware of how modeling errors might adversely affect the performance of a control system. From the observer perspective, time-delays, uncertainties and unknown inputs are familiar factors that deteriorate the observer performance on the way of design, analysis and synthesis of any type of observer. Every general observer design should be able to treat all (or at least some) of these issues explicitly and provide quantitative and qualitative results about their impact on the observer performance: consequently, the concepts of robustness, robust performance and robust design have recently become common phrases in the literature and constitute an integral part of research on observer design.Compared to the typical linear systems, observer design for nonlinear systems subject to all the aformentioned deteriorative properties presents a greater challenge for control engineers and researchers. In this thesis, the problem of observer design for a class of nonlinear systems, both discrete and continuous-time, subject to time delay, structured uncertainty and unknown inputs, is investigated. The study shows that by using the upper and lower bounds of the time delay, this parameter can be excluded in the observer structure under some constraints. Moreover, a novel method for designing an Unknown Input Observer (UIO) for a class of nonlinear systems is proposed, which makes the observer capable to satisfy desired performance even inthe presence of unknown inputs. Based on the UIO structure, one step further is taken, and a multiobjective optimization approach for state estimation and unknown input reconstruction is proposed that makes the designed observer not only robust against unknown inputs but also able to reconstruct them under some provided linear matrix inequality (LMI) conditions. In light of linear algebra, note that LMI serves as an important tool in this thesis, significantly facilitating the proposed observer designs.

Place, publisher, year, edition, pages
Luleå tekniska universitet, 2015
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-18200 (URN)763169f1-ec30-451d-8cc7-21879f159ffe (Local ID)978-91-7583-386-6 (ISBN)978-91-7583-387-3 (ISBN)763169f1-ec30-451d-8cc7-21879f159ffe (Archive number)763169f1-ec30-451d-8cc7-21879f159ffe (OAI)
Note
Godkänd; 2015; 20150620 (salsay); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Saleh Sayyaddelshad Ämne: Reglerteknik/Automatic Control Avhandling: Robust observer design for a class of nonlinear systems: LMI approach Opponent: Directeur de Recherche Sophie Tarbouriech, Laboratory for Analysis and Architecture of Systems (LAAS), National Centre for Scientific Research (CNRS), Toulouse, Frankrike Ordförande: Professor Thomas Gustafsson, Avd för signaler och system, Institutionen för system- och rymdteknik, Luleå tekniska universitet, Luleå Tid: Tisdag 29 september 2015 kl 09.00 Plats: A109, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Nikolakopoulos, G., Dritsas, L. & Sayyaddelshad, S. (2014). Combined networked switching output feedback control with D-region stability for performance improvement (ed.). Paper presented at . International Journal of Control, 87(6), 1172-1180
Open this publication in new window or tab >>Combined networked switching output feedback control with D-region stability for performance improvement
2014 (English)In: International Journal of Control, ISSN 0020-7179, E-ISSN 1366-5820, Vol. 87, no 6, p. 1172-1180Article in journal (Refereed) Published
Abstract [en]

In this article, a combined networked switching output feedback control scheme, with a (Formula presented.)-region stability performance improvement module is presented. The network induced time delays, that are considered to be time varying and integer multiples of the sampling period, are being embedded in the system model, by state augmentation. The resulting model of the overall networked closed-loop system is switching, with the current measured round-trip time delay acting as the switching rule. Based on this modelling approach, a Linear Matrix Inequality (LMI) tuned switching output feedback controller is designed. The proposed approach establishes robustness against time delays and is able to guarantee the overall stability of the switching closed-loop system. Integrated in the controlled synthesis phase, an LMI tuned performance improvement module is being introduced, based on (Formula presented.)-region stability. Multiple simulation results are being presented that prove the efficacy of the proposed scheme.

Keywords
Information technology - Automatic control, region stability, LMI, networked controlled systems, switching output feedback, Informationsteknik - Reglerteknik
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-3605 (URN)10.1080/00207179.2013.868932 (DOI)000333996000007 ()2-s2.0-84896392488 (Scopus ID)16d4f660-7025-4eef-841e-d5288928a2fc (Local ID)16d4f660-7025-4eef-841e-d5288928a2fc (Archive number)16d4f660-7025-4eef-841e-d5288928a2fc (OAI)
Note
Validerad; 2014; 20140317 (johsod)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Sayyaddelshad, S., Johansson, A., Darouach, M. & Gustafsson, T. (2014). H∞ filter design for state estimation and unknown inputs reconstruction of a class of nonlinear systems (ed.). In: (Ed.), (Ed.), 19th IFAC World Congress on International Federation of Automatic Control: IFAC 2014, Cape Town, South Africa 24 - 29 August 2014. Paper presented at IFAC World Congress : 25/08/2014 - 29/08/2014 (pp. 61-66).
Open this publication in new window or tab >>H∞ filter design for state estimation and unknown inputs reconstruction of a class of nonlinear systems
2014 (English)In: 19th IFAC World Congress on International Federation of Automatic Control: IFAC 2014, Cape Town, South Africa 24 - 29 August 2014, 2014, p. 61-66Conference paper, Published paper (Refereed)
Abstract [en]

We consider a novel method to design a H∞ filter for a class of nonlinear systems subject to unknown inputs. First, we rewrite the system dynamics as a descriptor system. Then, we design a robust H∞ reduced-order filter to estimate both state variables and unknown inputs at the same time. Based on a Lyapunov functional, we derive a sufficient condition for existence of the designed filter which requires solving a nonlinear matrix inequality. The achieved condition is further formulated in terms of a linear matrix inequality (LMI) that is straightforward to solve by popular methods. Finally, the proposed filter is illustrated with an example.

Series
IFAC proceedings series, ISSN 0741-1146 ; 47:3
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-35562 (URN)10.3182/20140824-6-ZA-1003.02363 (DOI)a22bed4f-a498-4c94-affa-9ae1ac1fb551 (Local ID)a22bed4f-a498-4c94-affa-9ae1ac1fb551 (Archive number)a22bed4f-a498-4c94-affa-9ae1ac1fb551 (OAI)
Conference
IFAC World Congress : 25/08/2014 - 29/08/2014
Note
Godkänd; 2014; 20140401 (tgu)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-12-15Bibliographically approved
Sayyaddelshad, S. & Gustafsson, T. (2014). Observer Design for a Class of Nonlinear Systems Subject to Unknown Inputs (ed.). Paper presented at Reglermöte 2014 : 03/06/2014 - 04/06/2014. Paper presented at Reglermöte 2014 : 03/06/2014 - 04/06/2014.
Open this publication in new window or tab >>Observer Design for a Class of Nonlinear Systems Subject to Unknown Inputs
2014 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-32230 (URN)6a843dcf-0286-49d8-a189-a1ab542b02ee (Local ID)6a843dcf-0286-49d8-a189-a1ab542b02ee (Archive number)6a843dcf-0286-49d8-a189-a1ab542b02ee (OAI)
Conference
Reglermöte 2014 : 03/06/2014 - 04/06/2014
Note
Godkänd; 2014; 20141124 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Sayyaddelshad, S. & Gustafsson, T. (2014). Observer Design for a Class of Nonlinear Systems Subject to Unknown Inputs (ed.). Paper presented at Reglermöte 2014 : 03/06/2014 - 04/06/2014. Paper presented at Reglermöte 2014 : 03/06/2014 - 04/06/2014.
Open this publication in new window or tab >>Observer Design for a Class of Nonlinear Systems Subject to Unknown Inputs
2014 (English)Conference paper, Oral presentation only (Other academic)
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-27413 (URN)0dada63c-9fb3-4656-b92b-1259939a1159 (Local ID)0dada63c-9fb3-4656-b92b-1259939a1159 (Archive number)0dada63c-9fb3-4656-b92b-1259939a1159 (OAI)
Conference
Reglermöte 2014 : 03/06/2014 - 04/06/2014
Note
Godkänd; 2014; 20141124 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Sayyaddelshad, S. & Gustafsson, T. (2014). Observer design for a class of nonlinear systems subject to unknown inputs (ed.). In: (Ed.), (Ed.), 2014 European Control Conference (ECC), June 24-27, 2014. Strasbourg, France: . Paper presented at European Control Conference : 24/06/2014 - 27/06/2014 (pp. 970-974). Piscataway, NJ: IEEE Communications Society, Article ID 6862555.
Open this publication in new window or tab >>Observer design for a class of nonlinear systems subject to unknown inputs
2014 (English)In: 2014 European Control Conference (ECC), June 24-27, 2014. Strasbourg, France, Piscataway, NJ: IEEE Communications Society, 2014, p. 970-974, article id 6862555Conference paper, Published paper (Refereed)
Abstract [en]

We consider a novel method to design an observer for a class of nonlinear discrete-time systems with unknown inputs. Based on Lyapunov functional, we derive a sufficient condition for existence of the designed observer which requires solving a nonlinear matrix inequality. In light of linear algebra, the achieved condition will be formulated in terms of linear matrix inequality (LMI) that can be solved by popular methods easily. Compared to recent researches, the developed approach shows a significant better performance than other techniques previously published in literature and is less conservative in terms of Lipschitz constant. Finally, the proposed observer is illustrated by implementing the proposed method on a single- link flexible manipulator and the results are compared to some recent similar researches in terms of performance and conservativeness.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE Communications Society, 2014
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-39356 (URN)10.1109/ECC.2014.6862555 (DOI)2-s2.0-84911464359 (Scopus ID)e1089c23-0c06-46cd-8369-0e697e82062f (Local ID)9783952426913 (ISBN)e1089c23-0c06-46cd-8369-0e697e82062f (Archive number)e1089c23-0c06-46cd-8369-0e697e82062f (OAI)
Conference
European Control Conference : 24/06/2014 - 27/06/2014
Note
Godkänd; 2014; 20140401 (tgu)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-07-10Bibliographically approved
Asheghan, M. M., Sayyaddelshad, S., Beheshti, M. T. & Tavazoeid, M. S. (2013). Non-fragile control and synchronization of a new fractional order chaotic system (ed.). Paper presented at . Applied Mathematics and Computation, 222, 712-721
Open this publication in new window or tab >>Non-fragile control and synchronization of a new fractional order chaotic system
2013 (English)In: Applied Mathematics and Computation, ISSN 0096-3003, E-ISSN 1873-5649, Vol. 222, p. 712-721Article in journal (Refereed) Published
Abstract [en]

In this paper, we address global non-fragile control and synchronization of a new fractional order chaotic system. First we inspect the chaotic behavior of the fractional order system under study and also find the lowest order (2.49) for the introduced dynamics to remain chaotic. Then, a necessary and sufficient condition which can be easily extended to other fractional-order systems is proposed in terms of Linear Matrix Inequality (LMI) to check whether the candidate state feedback controller with parameter uncertainty can guarantee zero convergence of error or not. In addition, the proposed method provides a global zero attraction of error that guarantees stability around all existing equilibrium points. Finally, numerical simulation are employed to verify the validity of the proposed algorithm.

National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-9010 (URN)10.1016/j.amc.2013.07.045 (DOI)000326877300061 ()2-s2.0-84884899669 (Scopus ID)79193f82-e911-4dea-8c88-ad2f99361827 (Local ID)79193f82-e911-4dea-8c88-ad2f99361827 (Archive number)79193f82-e911-4dea-8c88-ad2f99361827 (OAI)
Note
Validerad; 2013; 20130906 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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