Loading...
Search for:
sliding-mode-control
0.012 seconds
Total 181 records
Reduced multiple model predictive control of an heating, ventilating, and air conditioning system using gap metric and stability margin
, Article Building Services Engineering Research and Technology ; Volume 43, Issue 5 , 2022 , Pages 589-603 ; 01436244 (ISSN) ; Haeri, M ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
In this paper, a reduced multiple-model predictive controller based on gap metric and stability margin is presented to control heating, ventilating, and air conditioning (HVAC) systems. To tackle the strong nonlinearity and large number of degrees of freedom in HVAC system, two approaches, called Reduced Order Model Bank-Multiple Model (ROMB-MM) and Multiple Model-Reduced Order Model (MM-ROM), are introduced. In the first approach, the order reduction is performed prior to multiple models selection and in the second one multiple models selection is implemented before the model order reduction. Furthermore, soft switching is employed to enhance the closed-loop performance as well as to gain...
Performance enhancement of an uncertain nonlinear medical robot with optimal nonlinear robust controller
, Article Computers in Biology and Medicine ; Volume 146 , 2022 ; 00104825 (ISSN) ; Soleimani, R ; Ahmadi, M ; Malekan, A ; Abualigah, L ; Dashtiahangar, F ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
So the design and control of an accurate robot for this purpose is very critical for saving the patients. Modification of the model and designing two optimized nonlinear robust controllers for the first time for the parallel manipulator medical robot and cardiopulmonary resuscitation. The main objective of the current study in order to decrease the overshoot and increase the accuracy of the position and convergence speed and robustness to destructive factors affecting the precision of the robot. In this paper firstly, the kinematics and dynamics analysis of a translational parallel manipulator robot is presented and a non-linear model in the presence of uncertainties, disturbances, and...
Comments on 'fixed-time backstepping fractional-order sliding mode excitation control for performance improvement of power system'
, Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Volume 69, Issue 8 , 2022 , Pages 3461-3462 ; 15498328 (ISSN) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
In this note, it is shown that the Lyapunov function-based analyses done in the above-titled article to design a backstepping sliding mode controller contain some drawbacks. These drawbacks include ignoring some terms in simplification of time-derivative of the considered Lyapunov functions, which do not vanish in a finite-time. Moreover, by presenting a counterexample, it is revealed that the finite-time convergence of the error signals cannot be necessarily concluded from a Lyapunov function-based inequality used in the aforementioned article. © 2004-2012 IEEE
The strong tracking innovation filter
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 58, Issue 4 , 2022 , Pages 3261-3270 ; 00189251 (ISSN) ; Ahmadvand, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Sliding innovation filter (SIF) has recently been introduced as a robust strategy for estimation of linear systems. The SIF has been extended to nonlinear systems via analytical linearization. However, as the performance of the extended SIF (ESIF) degrades in the presence of severe nonlinearities, this article has initially developed a derivative-free cubature SIF (CSIF) that uses statistical linearization for the error propagation. In addition, the SIF gain has been reformed to incorporate the innovation covariance matrix, thus reducing the estimation error. Furthermore, the adaptive fading factor has been employed to strengthen the robustness and convergence properties of the CSIF against...
Comments on 'fractional-order sliding mode approach of buck converters with mismatched disturbances'
, Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Volume 69, Issue 3 , 2022 , Pages 1381-1382 ; 15498328 (ISSN) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
In this letter, it is verified that the main result of the above article [1] on converging the voltage tracking error of a buck converter controlled by a fractional-order sliding mode controller cannot be logically justified. The root cause of this inconsistency, which is an improper use of an inequality, is discussed. © 2004-2012 IEEE
Variable speed wind turbine power control: A comparison between multiple MPPT based methods
, Article International Journal of Dynamics and Control ; Volume 10, Issue 2 , 2022 , Pages 654-667 ; 2195268X (ISSN) ; Moradi, H ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Reducing the renewable energy costs is necessary for the competition with the fossil energies and control strategies have great impact on the efficiency of wind machines. In the wind turbine industry, a practical approach is to maximize the energy capture of a wind machine by optimizing the power coefficient in the under-rated situations. In this paper, with the main objective of maximizing the energy capture in the second region, four different control strategies are compared in the presence of uncertainties. The proposed control methods are compared based on their power capture and robustness against probable uncertainties in the structural and environmental parameters. A two-mass...
Load frequency control (LFC) strategies in renewable energy‐based hybrid power systems: a review
, Article Energies ; Volume 15, Issue 10 , 2022 ; 19961073 (ISSN) ; Iqbal, M ; Shahzad, S ; Muqeet, H. A ; Shahzad, M ; Hussain, M. M ; Sharif University of Technology
MDPI
2022
Abstract
The hybrid power system is a combination of renewable energy power plants and conventional energy power plants. This integration causes power quality issues including poor settling times and higher transient contents. The main issue of such interconnection is the frequency variations caused in the hybrid power system. Load Frequency Controller (LFC) design ensures the reliable and efficient operation of the power system. The main function of LFC is to maintain the system frequency within safe limits, hence keeping power at a specific range. An LFC should be supported with modern and intelligent control structures for providing the adequate power to the system. This paper presents a...
Fault-tolerant control of flexible satellite with magnetic actuation and reaction wheel
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 236, Issue 6 , 2022 , Pages 1222-1238 ; 09544100 (ISSN) ; Assadian, N ; Sharif University of Technology
SAGE Publications Ltd
2022
Abstract
The attitude fault-tolerant control of a flexible satellite actuated by reaction wheels and magnetic torquer bars is investigated in this article. A low earth orbit is considered for moment perturbations such as drag and gravity gradient. Furthermore, the flexible panels attached to a rigid central body are modeled through the assumed mode approach by a finite set of bending modal motion. The ordinary differential equations of their generalized coordinates are found using Lagrange’s equation, and the resulting dynamical model is validated by comparing its simulation results to the NX Siemens software results. Finally, a fault-tolerant controller based on sliding mode control is suggested and...
Robust independent and simultaneous position control of multiple magnetic microrobots by sliding mode controller
, Article Mechatronics ; Volume 84 , 2022 ; 09574158 (ISSN) ; Yousefi, M ; Nejat Pishkenari, H ; Vossoughi, G ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Recent development in technology and improvement of manufacturing tools have accelerated the use of microrobots (MRs) in numerous areas such as micro sensing and medical applications. The ability to control multiple MRs simultaneously and independently could lead to higher performance, and even make new applications possible. In this paper, we have proposed a system for simultaneous and independent control of the position of multiple MRs in a plane. The system consists of 2N permanent magnets (PMs) with a circular arrangement in the plane around the workspace and a pair of Helmholtz coil to control N MRs. PMs are rotated by servomotors, and the coil aligns the orientation of the MRs normal...
Comment on S. Ahmed, H. Wang, and Y. Tian, “Robust adaptive fractional-order terminal sliding mode control for lower-limb exoskeleton,” Asian J. Control, vol. 21, no. 1, pp. 1–10 (2019)
, Article Asian Journal of Control ; 2022 ; 15618625 (ISSN) ; Sheikh Ahmadi, S ; Naderi Soorki, M ; Amini, S. S ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
In this comment, it is shown that there are some non-negligible big mistakes in the analyses and stability proof of the proposed controller in the quoted paper, which makes the main results of this paper to be incorrect. The main unavoidable mistakes in the stability analysis of the main theorem (Theorem 1) are stated and some remarks are also mentioned to fix some of them. © 2022 Chinese Automatic Control Society and John Wiley & Sons Australia, Ltd
Modeling and exponential reaching law sliding mode control of the lower limb in cycling
, Article 8th International Conference on Control, Instrumentation and Automation, ICCIA 2022, 2 March 2022 through 3 March 2022 ; 2022 ; 9781665495691 (ISBN) ; Zolfaghari, S. E ; Mahzoon, M ; Eqra, N ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
In this study, a 3-DOF dynamic model is developed for the lower limb in the cycling activity using Lagrangian mechanics. An exponential reaching law sliding mode controller is then applied to the system in order to imitate the joints' real motion. The kinematic data of the joints are obtained through conducting experiments with an ergometer bike. Results show acceptable tracking performance for the control system. The study's outcome can be used by rehabilitation experts in their work. It is also useful for the engineers in designing rehabilitation devices or developing muscular models. © 2022 IEEE
Identification of the dynamics of the drivetrain and estimating its unknown parts in a large scale wind turbine
, Article Mathematics and Computers in Simulation ; Volume 192 , 2022 , Pages 50-69 ; 03784754 (ISSN) ; Moradi, H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this paper, the drivetrain identification problem of a horizontal axis gear-driven wind turbine has been considered. The identification problem leads to a precise model of the drivetrain of the wind turbines which plays a key role in the production and transmission of electrical energy. This process consists of two stages: First, offline identification which needs the input–output data from the drivetrain system. These data are obtained from the FAST code. FAST (Fatigue, Aerodynamics, Structures, and Turbulence) is a valid aeroelastic code in the simulation aeroelastic field of offshore and onshore wind turbines. In region 2 (wind velocity is between the cut-in and rated velocities), the...
Design of a continuous fractional-order nonsingular terminal sliding mode control with time delay estimation for fes control of human knee joint
, Article 7th International Conference on Control, Instrumentation and Automation, ICCIA 2021, 23 February 2021 through 24 February 2021 ; 2021 ; 9780738124056 (ISBN) ; Abbasi, M ; Vossoughi, G ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
The design of a novel Continuous Fractional-Order Nonsingular Terminal Sliding Mode controller is the focus of this study. Time Delay Estimation technique is incorporated into the controller. The proposed method is responsible for controlling the human knee joint neuromusculoskeletal model via Functional Electrical Stimulation. A second-order nonlinear model with time-varying coefficients is used for characterizing the FES-stimulated neuromusculoskeletal model. The presence of time-varying coefficients often complicates precise control of knee joint through FES and impairs the performance of conventional methods. To this end, the TDECFONTSM has been proposed consisting of three components, a...
Variable speed wind turbine power control: A comparison between multiple MPPT based methods
, Article International Journal of Dynamics and Control ; 2021 ; 2195268X (ISSN) ; Moradi, H ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
Reducing the renewable energy costs is necessary for the competition with the fossil energies and control strategies have great impact on the efficiency of wind machines. In the wind turbine industry, a practical approach is to maximize the energy capture of a wind machine by optimizing the power coefficient in the under-rated situations. In this paper, with the main objective of maximizing the energy capture in the second region, four different control strategies are compared in the presence of uncertainties. The proposed control methods are compared based on their power capture and robustness against probable uncertainties in the structural and environmental parameters. A two-mass...
A new fast finite time fractional order adaptive sliding-mode control for a quadrotor
, Article 7th International Conference on Control, Instrumentation and Automation, ICCIA 2021, 23 February 2021 through 24 February 2021 ; 2021 ; 9780738124056 (ISBN) ; Vedadi Moghaddam, T ; Emamifard, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Fast finite time adaptive sliding mode control of a quadrotor in the presence of uncertainties and unbounded external disturbances is dealt in this paper. To this end, a fractional order sliding surface is first defined and then, an adaptive sliding mode controller is designed to guarantee finite time stability with fast convergence of quadrotor states to the desired trajectory. In this controller, it is assumed that the upper bound of the model uncertainties and external disturbances is a nonlinear function with unknown coefficients. These coefficients are estimated via stable adaptive laws. Finite time stability of the closed-loop system is analyzed using Lyapunov theorem. Simulation...
Nonsingular terminal sliding mode control with ultra-local model and single input interval type-2 fuzzy logic control for pitch control of wind turbines
, Article IEEE/CAA Journal of Automatica Sinica ; Volume 8, Issue 3 , 2021 , Pages 690-700 ; 23299266 (ISSN) ; Parvaresh, A ; Mohseni, S. R ; Jahanshahi Zeitouni, M ; Gheisarnejad, M ; Khooban, M. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
As wind energy is becoming one of the fastest-growing renewable energy resources, controlling large-scale wind turbines remains a challenging task due to its system model nonlinearities and high external uncertainties. The main goal of the current work is to propose an intelligent control of the wind turbine system without the need for model identification. For this purpose, a novel model-independent nonsingular terminal sliding-mode control (MINTSMC) using the basic principles of the ultra-local model (ULM) and combined with the single input interval type-2 fuzzy logic control (SIT2-FLC) is developed for non-linear wind turbine pitch angle control. In the suggested control framework, the...
Nonsingular terminal sliding mode control with ultra-local model and single input interval type-2 fuzzy logic control for pitch control of wind turbines
, Article IEEE/CAA Journal of Automatica Sinica ; Volume 8, Issue 3 , 2021 , Pages 690-700 ; 23299266 (ISSN) ; Parvaresh, A ; Mohseni, S. R ; Zeitouni, M. J ; Gheisarnejad, M ; Khooban, M. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
As wind energy is becoming one of the fastest-growing renewable energy resources, controlling large-scale wind turbines remains a challenging task due to its system model nonlinearities and high external uncertainties. The main goal of the current work is to propose an intelligent control of the wind turbine system without the need for model identification. For this purpose, a novel model-independent nonsingular terminal sliding-mode control (MINTSMC) using the basic principles of the ultra-local model (ULM) and combined with the single input interval type-2 fuzzy logic control (SIT2-FLC) is developed for non-linear wind turbine pitch angle control. In the suggested control framework, the...
Novel sensorless fault-tolerant pitch control of a horizontal axis wind turbine with a new hybrid approach for effective wind velocity estimation
, Article Renewable Energy ; Volume 179 , December , 2021 , Pages 1291-1315 ; 09601481 (ISSN) ; Tse, K. T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this research, the fault-tolerant pitch angle control of a horizontal axis wind turbine in region 3 (where the wind velocity is greater than rated wind speed) is investigated. The effective wind velocity (EWV) is one of the necessary information for each control system. Wind speed is measured by the anemometers on the top of the nacelle however, the measurement is not precise and is only applicable for one point in the rotor. To address this issue, we have developed a novel hybrid approach. The approach is based on a sliding mode observer to estimate the aerodynamic torque and an adaptive neuro-fuzzy inference system (ANFIS) is introduced for obtaining the EWV. The estimated aerodynamic...
Nonlinear pitch angle control of an onshore wind turbine by considering the aerodynamic nonlinearities and deriving an aeroelastic model
, Article Energy Systems ; 2021 ; 18683967 (ISSN) ; Moradi, H ; Tse, K. T ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In this paper, the control problem of a wind turbine in region 3 (where the wind velocity is between the rated wind velocity and cut out wind velocity) has been investigated by considering the aerodynamic nonlinear behavior of the wind-structure interaction. The model has been developed by using the blade element momentum (BEM) theory to obtain the aerodynamic torque and aerodynamic loads in edgewise and flapwise directions. For validation, the aerodynamic behavior of the onshore NREL 5 MW turbine has been compared with the Fatigue, Aerodynamics, Structures, and Turbulence (FAST) aeroelastic code in terms of the power coefficient. Wind speed is modelled as a three-dimensional profile with...
Fault-tolerant control of flexible satellite with magnetic actuation and reaction wheel
, Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; 2021 ; 09544100 (ISSN) ; Assadian, N ; Sharif University of Technology
SAGE Publications Ltd
2021
Abstract
The attitude fault-tolerant control of a flexible satellite actuated by reaction wheels and magnetic torquer bars is investigated in this article. A low earth orbit is considered for moment perturbations such as drag and gravity gradient. Furthermore, the flexible panels attached to a rigid central body are modeled through the assumed mode approach by a finite set of bending modal motion. The ordinary differential equations of their generalized coordinates are found using Lagrange’s equation, and the resulting dynamical model is validated by comparing its simulation results to the NX Siemens software results. Finally, a fault-tolerant controller based on sliding mode control is suggested and...