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On control of spacecraft relative motion in the case of an elliptic keplerian chief
, Article Advances in the Astronautical Sciences ; Vol. 150, issue , August , 2014 , p. 1413-1432 ; 2195268X ; Butcher, E. A ; Mesbahi, A ; Sharif University of Technology
2014
Abstract
In this study, control strategies based on time-varying LQR, Lyapunov-Floquet transformation (LFT), backstepping, feedback linearization, and constant gain feedback control are implemented for the linearized time periodic equations of spacecraft relative motion when the reference orbit is elliptic. Also, natural and nonnatural leader-follower two-spacecraft formations are studied. The stability of the closed-loop response, the control effort required, and the settling time are investigated and compared for all control strategies. Furthermore, using constant gain feedback, the estimated region of attraction of the closed-loop system is obtained analytically
Fractional delayed damped Mathieu equation
, Article International Journal of Control ; Volume 88, Issue 3 , 2015 , Pages 622-630 ; 00207179 (ISSN) ; Haeri, M ; Nazari, M ; Butcher, E. A ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
This paper investigates the dynamical behaviour of the fractional delayed damped Mathieu equation. This system includes three different phenomena (fractional order, time delay, parametric resonance). The method of harmonic balance is employed to achieve approximate expressions for the transition curves in the parameter plane. The n = 0 and n = 1 transition curves (both lower and higher order approximations) are obtained. The dependencies of these curves on the system parameters and fractional orders are determined. Previous results for the transition curves reported for the damped Mathieu equation, delayed second-order oscillator, and fractional Mathieu equation are confirmed as special...
Modeling of Automatic Gas Metal Arc Welding
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
Arc welding is one of the key processes in the industry. Its vocational status in manufacturing industry comes to third place. From applicable standpoint gas metal arc welding (GMAW) has especial place between various electrode arcs. Base on the mode of transferring welding drop from electrode into welding pool the GMAW process could be categorized. The physics of metal transfer is not yet well understood, due to the facts that the arcs area is too small, the temperatures is too high and the metal transferring is at too high rate. However, physical behavior of process of each model is different from another. So equations that express each of them, need to reform toward others. The conditions...
Stable regions in the parameter space of delays for LTI fractional-order systems with two delays
, Article Signal Processing ; Volume 107 , February , 2014 , Pages 415–424 ; ISSN: 01651684 ; Haeri, M ; Sharif University of Technology
2014
Abstract
This paper studies fractional-order systems of retarded type with two independent delays, and determines the stability regions in spaces of delays. In this approach, an auxiliary polynomial is employed to calculate all purely imaginary roots of the characteristic equation of the system on the imaginary axis. Since roots of the characteristic equation are continuous with respect to delays, these purely imaginary roots determine the stability regions in delay space. Also, the necessary and sufficient condition for stability independent of delays is developed for the systems. Furthermore, a simple inequality constraint is established to obtain pure imaginary poles of the scalar systems....
Stability Analysis of Fractional Delay Systems in the Frequency Domain
, Ph.D. Dissertation Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
An algebraic method is presented for assessing the bounded input bounded output (BIBO) stability of a class of fractional delay systems with commensurate orders and multiple commensurate delays of retarded type. In the proposed method, first, by mapping the principal sheet of the Riemann surface and a pseudo-delay transformation, an auxiliary polynomial is generated. Then, this auxiliary polynomial is employed to find roots of the characteristic equation on the imaginary axis. The properties of the root path close to these roots are used to identify intervals of delay values, in which the system is stable. Moreover, a delay-independent BIBO-stability criterion is provided. Based on the...
Robust non-fragile fractional order PID controller for linear time invariant fractional delay systems
, Article Journal of Process Control ; Vol. 24, issue. 9 , 2014 , pp. 1489-1494 ; Haeri, M ; Sharif University of Technology
2014
Abstract
A fractional order PID controller is designed to stabilize fractional delay systems with commensurate orders and multiple commensurate delays, where the time delays in the system may belong to several distinct intervals. Moreover, the controller parameters should belong to given intervals. In order to stabilize the system, the D-subdivision method is employed to choose the stabilizing set of the controller parameters from their available values. Furthermore, the nearest values of the obtained stabilizing set to their mean values are selected as the controller parameters so that a non-fragile controller is concluded. Two numerical examples evaluate the proposed control design method
Decomposition of the time delay systems with one delay: The simultaneous similarity of two matrices
, Article ELECO 2013 - 8th International Conference on Electrical and Electronics Engineering, Bursa ; 2013 , Pages 487-491 ; 9786050105049 (ISBN) ; Haeri, M ; Sharif University of Technology
IEEE Computer Society
2013
Abstract
The time delay equations are frequently used to model real systems since they can describe the after-effect phenomenon. It is usually difficult to analyze the properties of time delay systems. Thus it would be beneficial to make the systems as simple as possible. For this purpose, the decomposition of the systems into some separate or cascaded sub-systems with smaller dimension is introduced as the solution of the mentioned complex task. The decomposition of the time delay systems with one delay is directly related to simultaneous similarity of two matrices. In this regard, necessary and sufficient conditions are derived for the existence of a common similar block diagonal or triangular form...
The effect of fractional order on oscillatory behavior of scalar fractional delay systems of neutral type
, Article IFAC Proceedings Volumes (IFAC-PapersOnline) ; February , 2013 , Pages 480-485 ; 14746670 (ISSN); 9783902823274 (ISBN) ; Haeri, M ; Sharif University of Technology
2013
Abstract
The undamped oscillations of a scalar fractional neutral system are studied in this paper. For this purpose, it is proved that this kind of systems can have the oscillatory behavior. The necessary and sufficient condition is proposed to determine that there exists a delay value for which the system oscillates. The frequency, amplitude and required delay for the undamped oscillations depend on the fractional order. However, the behavior of dependencies is not specified. Indeed, when the system has oscillatory behavior, it is bounded-input bounded-output stable for delay less than the required delay. Moreover, when the order is approaching to an integer value, the necessary and sufficient...
Stability of linear time invariant fractional delay systems of retarded type in the space of delay parameters
, Article Automatica ; Volume 49, Issue 5 , 2013 , Pages 1287-1294 ; 00051098 (ISSN) ; Haeri, M ; Sharif University of Technology
2013
Abstract
This paper presents a new method for assessing the bounded input bounded output stability of a class of fractional delay systems with commensurate orders and multiple commensurate delays of retarded type. In the proposed method, first, by mapping the principal sheet of the Riemann surface and a pseudo-delay transformation, an auxiliary polynomial is generated. Then, this auxiliary polynomial is employed to find roots of the characteristic equation on the imaginary axis. The properties of the root path close to these roots are used to identify intervals of delay values, in which the system is stable. The obtained results are illustrated via some numerical examples
Stability of neutral type fractional delay systems and its relation with stability of timedelay and discrete systems
, Article IET Control Theory and Applications ; Volume 10, Issue 18 , 2016 , Pages 2482-2489 ; 17518644 (ISSN) ; Haeri, M ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
The bounded-input bounded-output stability of fractional delay systems of neutral type is investigated in this study. The proposed method calculates the number of unstable poles of the system for each delay value. All time-delay intervals in time-delay space where system is stable are precisely determined. The stability of systems with not only indefinitely large values of time-delay, but also with multiple poles on the imaginary axis has been studied. The proposed method is employed for investigating the stability of a fractional delay system when its fractional orders approach to the integer numbers or zero. It is proved that simple case of neutral types and time-delay systems have the...
Stable regions in the parameter space of delays for LTI fractional-order systems with two delays
, Article Signal Processing ; Volume 107 , February , 2015 , Pages 415-424 ; 01651684 (ISSN) ; Haeri, M ; Sharif University of Technology
Elsevier
2015
Abstract
This paper studies fractional-order systems of retarded type with two independent delays, and determines the stability regions in spaces of delays. In this approach, an auxiliary polynomial is employed to calculate all purely imaginary roots of the characteristic equation of the system on the imaginary axis. Since roots of the characteristic equation are continuous with respect to delays, these purely imaginary roots determine the stability regions in delay space. Also, the necessary and sufficient condition for stability independent of delays is developed for the systems. Furthermore, a simple inequality constraint is established to obtain pure imaginary poles of the scalar systems....
Conditions on decomposing linear systems with more than one matrix to block triangular or diagonal form
, Article IEEE Transactions on Automatic Control ; Volume 60, Issue 1 , May , 2015 , Pages 233-239 ; 00189286 (ISSN) ; Haeri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
This technical note provides necessary and sufficient conditions to determine that a linear system with more than one matrix in its state-space representation can be decomposed into cascade or separate sub-systems. In order to perform such decomposition, one needs to determine a linear transformation matrix. Furthermore, the given conditions are adapted to a simple but effective condition to derive all possible scalar sub-systems for a given linear system. Numerical examples are provided to demonstrate the applicability of the presented results
Heterogenization of Manganese Porphyrins in Zeolite Imidazolate Framework-8 and Mg–Al Layered Double Hydroxide Structures, Via Host-Guest Interactions, and Investigation of their Catalytic Activity for Olefins Epoxidation
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this work heterogenization of manganese porphyrins in ZIF-8 and Mg-Al-LDHs structures is performed, via host-guest interactions, and their catalytic activities for olefins epoxidation are also investigated.A heterogenized meso-tetrakis(2,3-dihydroxyphenyl)porphyrinatomanganese(III) acetate at zeolite imidazolate framework-8 (T(2,3-OHP)PorMn@ZIF-8) is investigated in the catalytic olefin epoxidation reactions at room temperature at the first part. Heterogenization is done through a non-classical hydrogen bond proposed between T(2,3-OHP)PorMn bearing O-H groups and C-H of the 2-methylimidazolate linkers in ZIF-8 structure. The aforementioned compound characterized by X-ray powder...
Non-fragile tuning of fractional-order PD controllers for IPD-modelled processes
, Article IFAC Proceedings Volumes (IFAC-PapersOnline) ; 2013 , Pages 361-366 ; 14746670 (ISSN) ; 9783902823274 (ISBN) ; Tavazoei, M. S ; Mesbahi, A ; Sharif University of Technology
2013
Abstract
This paper deals with introducing non-fragile algebraic tuning rules for fractional-order PD controllers where they are used in controlling processes modeled in Integral Plus Delay (IPD) forms. These tuning rules are obtained based on a recently introduced approach, named as the centroid approach, which results in non-fragile tuning methods. Based on this approach, the centroids of two-dimensional admissible regions or the center of gravity of three-dimensional admissible regions in controller parameter space give non-fragile options for choosing controller parameters. © 2013 IFAC
BIBO stability of fractional delay systems in the parametric space of delays
, Article International Conference on Control, Automation and Systems ; 2011 , Pages 1841-1845 ; 15987833 (ISSN) ; 9781457708350 (ISBN) ; Haeri, M ; Nasiri, H. R ; Sharif University of Technology
2011
Abstract
In this work, a novel method is proposed to study the BIBO stability of a fractional delay system. The characteristic equation of a fractional delay system with some transcendental terms has infinitely many roots. Applying D-subdivision method and the Rekasius substitution divide one-dimensional parametric space of the time delay to infinite intervals with finite unstable roots. The number of unstable roots in each interval is calculated with the definition of root tendency on the boundary of each interval. Two illustrative examples are presented to confirm the proposed method results
On the structural and strong structural controllability of undirected networks
, Article IEEE Transactions on Automatic Control ; Volume 63, Issue 7 , July , 2018 , Pages 2234-2241 ; 00189286 (ISSN) ; Haeri, M ; Mesbahi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Characterization of network controllability through its topology has recently gained a lot of attention in the systems and control community. Using the notion of balancing sets, in this note, such a network-centric approach for the controllability of certain families of undirected networks is investigated. Moreover, by introducing the notion of a generalized zero forcing set, the structural controllability of undirected networks is discussed; in this direction, lower bounds on the dimension of the controllable subspace are derived. In addition, a method is proposed that facilitates synthesis of structural and strong structural controllable networks as well as examining preservation of...
Strong structural controllability of signed networks
, Article 58th IEEE Conference on Decision and Control, CDC 2019, 11 December 2019 through 13 December 2019 ; Volume 2019-December , 2019 , Pages 4557-4562 ; 07431546 (ISSN); 9781728113982 (ISBN) ; Haeri, M ; Mesbahi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, we discuss the controllability of a family of linear time-invariant (LTI) networks defined on a signed graph. In this direction, we introduce the notion of positive and negative signed zero forcing sets for the controllability analysis of positive and negative eigenvalues of system matrices with the same sign pattern. A sufficient combinatorial condition that ensures the strong structural controllability of signed networks is then proposed. Moreover, an upper bound on the maximum multiplicity of positive and negative eigenvalues associated with a signed graph is provided. © 2019 IEEE
Strong structural controllability of networks under time-invariant and time-varying topological perturbations
, Article IEEE Transactions on Automatic Control ; Volume 66, Issue 3 , 2021 , Pages 1375-1382 ; 00189286 (ISSN) ; Haeri, M ; Mesbahi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
This article investigates the robustness of strong structural controllability for linear time-invariant and linear time-varying directed networks with respect to structural perturbations, including edge deletions and additions. In this direction, we introduce a new construct referred to as a perfect graph associated with a network with a given set of control nodes. The tight upper bounds on the number of edges that can be added to, or removed from a network, while ensuring strong structural controllability, are then derived. Moreover, we obtain a characterization of critical edge sets, the maximal sets of edges whose any subset can be respectively added to or removed from a network while...
Laplacian dynamics on cographs: controllability analysis through joins and unions
, Article IEEE Transactions on Automatic Control ; Volume 66, Issue 3 , 2021 , Pages 1383-1390 ; 00189286 (ISSN) ; Haeri, M ; Mesbahi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
In this article, we examine the controllability of Laplacian dynamic networks on cographs. Cographs appear in modeling a wide range of networks and include as special instances, the threshold graphs. In this article, we present necessary and sufficient conditions for the controllability of cographs, and provide an efficient method for selecting a minimal set of input nodes from which the network is controllable. In particular, we define a sibling partition in a cograph and show that the network is controllable if all nodes of any cell of this partition except one are chosen as control nodes. The key ingredient for such characterizations is the intricate connection between the modularity of...
A high-throughput approach for the determination of pesticide residues in cucumber samples using solid-phase microextraction on 96-well plate
, Article Analytica Chimica Acta ; Volume 740 , 2012 , Pages 36-42 ; 00032670 (ISSN) ; Es'haghi, A ; Eshaghi, A ; Mesbahi, N ; Sharif University of Technology
2012
Abstract
A high-throughput solid-phase microextraction (SPME) on 96-well plate together with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of some selected pesticides in cucumber samples. Pieces with the length of 1.0cm of silicon tubing were precisely prepared and then coated on the end part of stainless steel wires. The prepared fibers were positioned in a home-made polytetrafluoroethylene (PTFE)-based constructed ninety-six holes block to have the possibility of simultaneous immersion of the SPME fibers into the center of individual wells. Pesticides such as diazinon, penconazol, tebuconazol, bitertanol, malathion, phosalone and chlorpyrifos-methyl were selected...