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closed-loop-control-systems
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Winding function model for predicting performance of 2-DOF wound rotor resolver
, Article IEEE Transactions on Transportation Electrification ; Volume 8, Issue 2 , 2022 , Pages 2062-2069 ; 23327782 (ISSN) ; Nasiri Gheidari, Z ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Two-degree-of-freedom (2-DOF) electrical machines require position sensors for their motion control. In comparison with using two independent sensors, using a 2-DOF sensor enhances the closed-loop control system's performance. However, due to the 3-D structure of the 2-DOF sensor, its performance evaluation needs 3-D analysis. Also, due to helical motion the accuracy deterioration of the sensor, under mechanical faults needs more attention. Although the finite element method (FEM) is the best way to simulate such sensors, most of the commercial packages for transient finite element simulations are not able to consider two separate motions simultaneously. Furthermore, FEM has a high...
Synthetic biology-inspired robust-perfect-adaptation-achieving control systems: model reduction and stability analysis
, Article IEEE Transactions on Control of Network Systems ; 2020 ; Tavazoei, M. S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
In addition to perfectly steering the output concentration of a process network to an exogenous set-point, a desired synthetically implemented biological controller should be able to robustly maintain this regulated output in the face of the extrinsic disturbances and inherent uncertainties due to an evervarying environment besides the imprecise modeling. Such an ability, which is called robust perfect adaptation (RPA), can be achieved by integral feedback control (IFC). Answering how IFC is (biochemically) constructible in generally unknown synthetic networks has been a research focus in the community. One of these answers, which has been well investigated previously, is to utilize a simple...
Stabilizing periodic orbits of chaotic systems using fuzzy adaptive sliding mode control
, Article Chaos, Solitons and Fractals ; Volume 37, Issue 4 , August , 2008 , Pages 1125-1135 ; 09600779 (ISSN) ; Arjmand, M. T ; Salarieh, H ; Alasty, A ; Sharif University of Technology
2008
Abstract
In this paper by using a combination of fuzzy identification and the sliding mode control a fuzzy adaptive sliding mode scheme is designed to stabilize the unstable periodic orbits of chaotic systems. The chaotic system is assumed to have an affine form x(n) = f(X) + g(X)u where f and g are unknown functions. Using only the input-output data obtained from the underlying dynamical system, two fuzzy systems are constructed for identification of f and g. Two distinct methods are utilized for fuzzy modeling, the least squares and the gradient descent techniques. Based on the estimated fuzzy models, an adaptive controller, which works through the sliding mode control, is designed to make the...
Satellite attitude control using three reaction wheels
, Article 2008 American Control Conference, ACC, Seattle, WA, 11 June 2008 through 13 June 2008 ; 2008 , Pages 4850-4855 ; 07431619 (ISSN) ; 9781424420797 (ISBN) ; Farooq, U ; Alasty, A ; Issa, J ; Sharif University of Technology
2008
Abstract
This work addresses the attitude control of a satellite by applying MIMO quantitative feedback approach. The objective is to design a set of proper controllers in presence of unknown disturbances and parametric uncertainties for a nonlinear MIMO system. The physical model of satellite utilizes three reaction wheels as actuators. The controller goal is to change the rotational speed of reaction wheels to adjust the satellite in desired course. First, the mathematical model of satellite and its actuators using angular kinematics and kinetic equations is developed. Quantitative feedback theory is then applied to synthesize a set of linear controllers that deals with both nonlinearities in the...
Robust D-stabilization analysis of fractional-order control systems with complex and linearly dependent coefficients
, Article IEEE Transactions on Systems, Man, and Cybernetics: Systems ; 2020 ; Fathi Jegarkandi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This article focuses on the robust D-stabilization analysis of fractional-order control systems where each of the system and the controller may be of fractional order. The coefficients of the system are considered as complex linear functions of interval uncertain parameters, so this article deals with fractional-order polytopic systems. First, a necessary and sufficient condition is introduced for the robust D-stabilization of the closed-loop control system based on the zero exclusion condition and the value set concept. Then, the geometric pattern of the value set of the characteristic polynomial is obtained analytically using the exposed vertices. Second, a function is presented to check...
Robust D-stabilization analysis of fractional-order control systems with complex and linearly dependent coefficients
, Article IEEE Transactions on Systems, Man, and Cybernetics: Systems ; Volume 52, Issue 3 , 2022 , Pages 1823-1837 ; 21682216 (ISSN) ; Fathi Jegarkandi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
This article focuses on the robust D-stabilization analysis of fractional-order control systems where each of the system and the controller may be of fractional order. The coefficients of the system are considered as complex linear functions of interval uncertain parameters, so this article deals with fractional-order polytopic systems. First, a necessary and sufficient condition is introduced for the robust D-stabilization of the closed-loop control system based on the zero exclusion condition and the value set concept. Then, the geometric pattern of the value set of the characteristic polynomial is obtained analytically using the exposed vertices. Second, a function is presented to check...
Robust D-stability test of LTI general fractional order control systems
, Article IEEE/CAA Journal of Automatica Sinica ; Volume 7, Issue 3 , May , 2020 , Pages 853-864 ; Liu, X ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This work deals with the robust D-stability test of linear time-invariant ( LTI ) general fractional order control systems in a closed loop where the system and - or the controller may be of fractional order. The concept of general implies that the characteristic equation of the LTI closed loop control system may be of both commensurate and non-commensurate orders, both the coefficients and the orders of the characteristic equation may be nonlinear functions of uncertain parameters, and the coefficients may be complex numbers. Some new specific areas for the roots of the characteristic equation are found so that they reduce the computational burden of testing the robust D-stability. Based on...
Robust distributed control of spacecraft formation flying with adaptive network topology
, Article Acta Astronautica ; Volume 136 , 2017 , Pages 281-296 ; 00945765 (ISSN) ; Alasty, A ; Assadian, N ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
In this study, the distributed six degree-of-freedom (6-DOF) coordinated control of spacecraft formation flying in low earth orbit (LEO) has been investigated. For this purpose, an accurate coupled translational and attitude relative dynamics model of the spacecraft with respect to the reference orbit (virtual leader) is presented by considering the most effective perturbation acceleration forces on LEO satellites, i.e. the second zonal harmonic and the atmospheric drag. Subsequently, the 6-DOF coordinated control of spacecraft in formation is studied. During the mission, the spacecraft communicate with each other through a switching network topology in which the weights of its graph...
Robust adaptive fractional order proportional integral derivative controller design for uncertain fractional order nonlinear systems using sliding mode control
, Article Proceedings of the Institution of Mechanical Engineers. Part I: Journal of Systems and Control Engineering ; Volume 232, Issue 5 , 1 May , 2018 , Pages 550-557 ; 09596518 (ISSN) ; Salarieh, H ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
This article presents a robust adaptive fractional order proportional integral derivative controller for a class of uncertain fractional order nonlinear systems using fractional order sliding mode control. The goal is to achieve closed-loop control system robustness against the system uncertainty and external disturbance. The fractional order proportional integral derivative controller gains are adjustable and will be updated using the gradient method from a proper sliding surface. A supervisory controller is used to guarantee the stability of the closed-loop fractional order proportional integral derivative control system. Finally, fractional order Duffing–Holmes system is used to verify...
Predictive directional compensator for systems with input constraints
, Article ISA Transactions ; Volume 45, Issue 3 , 2006 , Pages 393-405 ; 00190578 (ISSN) ; Aalam, N ; Sharif University of Technology
ISA - Instrumentation, Systems, and Automation Society
2006
Abstract
Nonlinearity caused by actuator constraint plays a destructive role in the overall performance of a control system. A model predictive controller can handle the problem by implementing a constrained optimization algorithm. Due to the iterative nature of the solution, however, this requires high computation power. In the present work we propose a new method to approach the problem by separating the constraint handling from the predictive control job. The input constraint effects are dealt with in a newly defined component called a predictive directional compensator, which works based on the directionality and predictive concepts. Through implementation of the proposed method, the...
Position control of ionic polymer-metal composites using fuzzy logic
, Article 2008 ASME International Mechanical Engineering Congress and Exposition, IMECE 2008, Boston, MA, 31 October 2008 through 6 November 2008 ; Volume 11 , 2009 , Pages 575-581 ; 9780791848722 (ISBN) ; Honarvar, M ; Alasty, A ; Meghdari, A ; Zohor, H ; Sharif University of Technology
2009
Abstract
The Ionic polymer-metal composites (IPMCs) form an important category of electroactive polymers which generate large deformation under a low driving voltage. In this paper an empirical model of IPMC is developed by measuring the step response of a 23 mmx3.6 mmx0.16 mm IPMC strip in a cantilever configuration. Moreover, a model-based precision position control of an IPMC base on the fuzzy logic is presented. Open-loop position responses of an IPMC are not repeatable, and hence closed-loop precision control is of critical importance to ensure proper functioning, repeatability and reliability. A CCD camera was used to observe the closed loop response of the IPMC strip in order to control this...
Performance analysis of an outer rotor variable reluctance resolver
, Article IEEE Sensors Journal ; Volume 22, Issue 18 , 2022 , Pages 17761-17768 ; 1530437X (ISSN) ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Variable reluctance resolver (VR-Resolver) is a robust electromagnetic sensor that provides position information for closed-loop control systems of permanent magnet synchronous motors (PMSMs). For specific motion control applications, an outer rotor structure is presented for the VR-Resolver in this article with a nonoverlapping tooth-coil windings configuration to simplify the manufacturing process. The study on the structure of the proposed position sensor is carried out, followed by the description of the working principle. The presented outer rotor VR-Resolver is simulated and its performance is investigated in detail with the aid of transient finite-element analysis (TFEA). Sensitivity...
Output feedback adaptive decentralized control of cooperative robots
, Article ICIECA 2005: International Conference on Industrial Electronics and Control Applications 2005, Quito, 29 November 2005 through 2 December 2005 ; Volume 2005 , 2005 ; 0780394194 (ISBN); 9780780394193 (ISBN) ; Elhamifar, E ; Sharif University of Technology
IEEE Computer Society
2005
Abstract
In this paper a decentralized control scheme for multiple cooperative manipulators is developed to achieve the desired performance in motion and force tracking, in the presence of uncertainties in dynamic equations of the robots. To eliminate the effects of uncertainties in the closed-loop performance, a new adaptive control algorithm is proposed. Based on the Lyapunov stability method, it is proved that all the error signals in the closed-loop system which is compose of a robot, an observer and a controller asymptotically converge to zero. Also to avoid the difficulties of using velocity sensors within the cooperative system, an output feedback control scheme with a linear observer is used....
Optimal phase control for equal-gain transmission in MIMO systems with scalar quantization: Complexity and algorithms
, Article IEEE Transactions on Information Theory ; Volume 56, Issue 7 , June , 2010 , Pages 3343-3355 ; 00189448 (ISSN) ; Wan Sung, C ; Khabbazian, M ; Safari, M. A ; Sharif University of Technology
2010
Abstract
The complexity of the optimal phase control problem in wireless MIMO systems with scalar feedback quantization and equal-gain transmission is studied. The problem is shown to be NP-hard when the number of receive antennas grows linearly with the number of transmit antennas. For the case where the number of receive antennas is constant, the problem can be solved in polynomial time. An optimal algorithm is explicitly constructed. For practical purposes, a low-complexity algorithm based on local search is presented. Simulation results show that its performance is nearly optimal
Observer design for a nano-positioning system using neural, fuzzy and ANFIS networks
, Article Mechatronics ; Volume 59 , 2019 , Pages 10-24 ; 09574158 (ISSN) ; Nejat Pishkenari, H ; Salarieh, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
This paper focuses on the observer design for a 2D nano-positioner. In order to position the stage with a desired accuracy, it is required to adjust the stage displacements with a closed-loop control system. Since displacement and velocity of the main stage are not measured directly in the designed nano-positioning system, some observers should be designed to estimate these state variables using data provided by measurable variables. To this end, three different observers were designed based on neural, fuzzy and adaptive neuro fuzzy inference system (ANFIS) networks. With the purpose of obtaining data for training the observer model, a reference model is required. For this reason, the...
Non-linear feedback optimal control law for minimum-time injection problem using fuzzy system
, Article Aircraft Engineering and Aerospace Technology ; Volume 77, Issue 5 , 2005 , Pages 376-383 ; 00022667 (ISSN) ; Rahbar, N ; Novinzadeh, A. B ; Sharif University of Technology
2005
Abstract
Purpose - To devise a new technique to synthesise optimal feedback control law for non-linear dynamic systems through fuzzy logic. Design/methodology/approach - The proposed methodology utilizes the open-loop optimal control solutions (OCSs) of the non-linear systems for the training of the fuzzy system in the process of developing closed-loop fuzzy logic guidance (FLG). This is achieved through defining a set of non-dimensionalised variables related to the system states. Findings - FLG is capable of generating closed-loop control law for the non-linear problem investigated. Since the proposed fuzzy structure is independent of the system equations, the approach is potentially applicable to...
Model reference adaptive control of SUT building energy management system
, Article 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, FL, 5 November 2005 through 11 November 2005 ; Volume 10 , 2006 , Pages 25-28 ; 0791842274 (ISBN) ; Selk Ghafari, A ; Hannani, S. K ; Sharif University of Technology
2006
Abstract
Model Reference Adaptive Controller (MRAC) design, for Sharif University of Technology (SUT) Building Energy Management System (BEMS) is addressed in this paper. A reference model with fuzzy adaptive control rules was employed to design the controller for a system with time delay and model parameter uncertainties. Simulation study shows good performance of the closed loop system with optimum energy consumption for this system under external load disturbance. Copyright © 2005 by ASME
Maestro: A high performance AES encryption/decryption system
, Article Proceedings - 17th CSI International Symposium on Computer Architecture and Digital Systems, CADS 2013 ; October , 2013 , Pages 145-148 ; 9781479905621 (ISBN) ; Qasemi, E ; Pourmohseni, B ; Computer Society of Iran; IPM ; Sharif University of Technology
IEEE Computer Society
2013
Abstract
High throughput AES encryption/decryption is a necessity for many of modern embedded systems. This article presents a high performance yet cost efficient AES system. Maestro can be used in a wide range of embedded applications with various requirements and limitations. Maestro is about one million times faster than the pure software implementation. The Maestro architecture is composed of two major components; the soft processor aimed at system initialization and control, and the hardware AES engine for high performance AES encryption/decryption. A ten stage implicit pipelined architecture is considered for the AES engine. Two novel techniques are proposed in design of AES engine which enable...
Intelligent trajectory tracking of an aircraft in the presence of internal and external disturbances
, Article International Journal of Robust and Nonlinear Control ; Volume 29, Issue 16 , 2019 , Pages 5820-5844 ; 10498923 (ISSN) ; Banazadeh, A ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
This research deals with developing an intelligent trajectory tracking control approach for an aircraft in the presence of internal and external disturbances. Internal disturbances including actuators faults, unmodeled dynamics, and model uncertainties as well as the external disturbances such as wind turbulence significantly affect the performance of the common trajectory tracking control approaches. There are several fault-tolerant control approaches in the literature to overcome the effects of specific actuator or sensor faults during the flight. However, trajectory tracking control of an air vehicle in the presence of unexpected faults and simultaneous presence of wind turbulence is...
Hybrid modeling and control of a DC-DC boost converter via Extended Mixed Logical Dynamical systems (EMLDs)
, Article PEDSTC 2014 - 5th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2014 , pp. 373-378 ; Mokhtari, H ; Sharif University of Technology
Abstract
The objective of this paper is to expand the concept of hybrid modeling and control in power electronics area. A new precise and non-averaged model of a DC-DC boost converter is developed on the basis of Mixed Logical Dynamical (MLD) systems, and the approach is extended by a new version of such systems which is called as Extended Mixed Logical Dynamical (EMLD) systems in this paper. A Model Predictive Controller (MPC) based on the Mixed Integer Quadratic Programming (MIQP) is designed for the MLD and EMLD models of the DC-DC boost converter considering all possible dynamics in Continuous and Discontinuous Conduction Modes of operations (CCM-DCM). The simulation results show the satisfactory...