Search for: adaptive-sliding-mode-controller
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    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) Naderi Soorki, M ; Vedadi Moghaddam, T ; Emamifard, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    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... 

    Hardware in the loop simulation and analysis of a model of fish robotic system

    , Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 203-210 ; 9780791849194 (ISBN) Zeinoddini Meymand, S ; Vosoughi, G. R ; Farshchi, M ; Nemati, A ; Sharif University of Technology
    In the present study, an adaptive sliding mode control method was employed to control a fish robotic system using hardware in the loop methodology. Up to now, few researches have focused on autonomous control of fish robot in dynamic environments which may be the result of difficulties in modeling of hydrodynamic effects on fish robot. Therefore, following the introduction of the nonlinear model for the robot, elongated body theory, suggested by Lighthill, was used to analyze fish movements. Then, kinematics control to track desired trajectories was designed for under-actuated model of robot. Adaptive sliding mode controller, capable of adapting according to changes and uncertainties, was... 

    Multivariable robust adaptive sliding mode control of an industrial boiler-turbine in the presence of modeling imprecisions and external disturbances: A comparison with type-I servo controller

    , Article ISA Transactions ; Volume 58 , September , 2015 , Pages 398-408 ; 00190578 (ISSN) Ghabraei, S ; Moradi, H ; Vossoughi, G ; Sharif University of Technology
    ISA - Instrumentation, Systems, and Automation Society  2015
    To guarantee the safety and efficient performance of the power plant, a robust controller for the boiler-turbine unit is needed. In this paper, a robust adaptive sliding mode controller (RASMC) is proposed to control a nonlinear multi-input multi-output (MIMO) model of industrial boiler-turbine unit, in the presence of unknown bounded uncertainties and external disturbances. To overcome the coupled nonlinearities and investigate the zero dynamics, input-output linearization is performed, and then the new decoupled inputs are derived. To tackle the uncertainties and external disturbances, appropriate adaption laws are introduced. For constructing the RASMC, suitable sliding surface is... 

    Nonlinear robust adaptive sliding mode control of influenza epidemic in the presence of uncertainty

    , Article Journal of Process Control ; Volume 56 , 2017 , Pages 48-57 ; 09591524 (ISSN) Sharifi, M ; Moradi, H ; Sharif University of Technology
    Elsevier Ltd  2017
    In this paper, a nonlinear robust adaptive sliding mode control strategy is presented for the influenza epidemics in the presence of model uncertainties. The nonlinear epidemiological model of influenza with five state variables (the numbers of susceptible, exposed, infected, asymptomatic and recovered individuals) and two control inputs (vaccination and antiviral treatment) is considered. The objective of the proposed controller is decreasing the number of susceptible and infected humans to zero by tracking the desired scenarios. As a result of this decreasing, the number of exposed and asymptomatic individuals is also decreased and converged to the zero. Accordingly, it is shown that the... 

    Adaptive sliding mode control of regenerative chatter and stability improvement in boring manufacturing process with model uncertainties

    , Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 234, Issue 6 , 2020 , Pages 1171-1181 Moradian, H ; Abbasi, M. H ; Moradi, H ; Sharif University of Technology
    SAGE Publications Ltd  2020
    In the machining processes, vibration suppression is crucial in order to achieve the high precision as well as high-quality surface and increase of the material removal rate. In this paper, an adaptive sliding mode control approach is presented to supress the chattering phenomenon in the boring process in the presence of model uncertainties and unmodeled dynamics. The boring bar is modeled as a cantilever Euler–Bernoulli beam, which is actuated by a piezo-actuator located at the bar's end. As a more realistic model, the cutting tool is modeled as an added mass at the bar's end. In order to derive the equations of motion, mode summation method with inclusion the first three modes of vibration... 

    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) Layeghi, H ; Arjmand, M. T ; Salarieh, H ; Alasty, A ; Sharif University of Technology
    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... 

    Adaptive attitude and position control of an insect-like flapping wing air vehicle

    , Article Nonlinear Dynamics ; Volume 85, Issue 1 , 2016 , Pages 47-66 ; 0924090X (ISSN) Banazadeh, A ; Taymourtash, N ; Sharif University of Technology
    Springer Netherlands 
    This study describes an adaptive sliding mode technique for attitude and position control of a rigid body insect-like flapping wing model in the presence of uncertainties. For this purpose, a six-degrees-of-freedom nonlinear and time-varying dynamic model of a typical hummingbird is considered for simulation studies. Based on the quasi-steady assumptions, three major aerodynamic loads including delayed stall, rotational lift and added mass are presented and analyzed, respectively. Using the averaging theory, a time-varying system is then transformed into the time-invariant system to design the adaptive controller. The controller is designed so that the closed-loop system will follow any... 

    A comparative study between linear and sliding mode adaptive controllers for a hot gas generator

    , Article Applied Thermal Engineering ; Volume 30, Issue 5 , 2010 , Pages 413-424 ; 13594311 (ISSN) Abedi, M ; Bakhtiari Nejad, F ; Saffar Avval, M ; Abedi, M ; Alasty, A ; Sharif University of Technology
    A hot gas generator is a compact heat exchanger that produces high temperature or enthalpy gases. This paper presents two methods for controlling the system. The first one is an adaptive sliding mode controller that is a Lyapunov based method and proposed to confront the dynamic modeling deficiencies and system uncertainties. The second one is a linear adaptive controller that gives a new attractive ability to the system which can track a complicated requested path. Each of the presented controllers has some capabilities that may be preferred to other. In this paper, these methods are extensively compared by several transient inputs. On the other hand, since heat exchangers are typically... 

    Robust adaptive sliding mode admittance control of exoskeleton rehabilitation robots

    , Article Scientia Iranica ; Volume 25, Issue 5B , 2018 , Pages 2628-2642 ; 10263098 (ISSN) Torabi, M ; Sharifi, M ; Vossoughi, Gh ; Sharif University of Technology
    Sharif University of Technology  2018
    A nonlinear robust adaptive sliding mode admittance controller is proposed for exoskeleton rehabilitation robots. The proposed controller has robustness against uncertainties of dynamic parameters using an adaptation law. Furthermore, an adaptive Sliding Mode Control (SMC) scheme is employed in the control law to provide robustness against disturbances (non-parametric uncertainties) with unknown bounds. For this purpose, another adaptation law is defined for the variation of the SMC gain. The proposed scheme is augmented with an admittance control method to provide the patient with compliance during interaction with the rehabilitation robot. The stability of the proposed controller and the... 

    Adaptive sliding mode control of a piezo-actuated bilateral teleoperated micromanipulation system

    , Article Precision Engineering ; Volume 35, Issue 2 , 2011 , Pages 309-317 ; 01416359 (ISSN) Motamedi, M ; Ahmadian, M. T ; Vossoughi, G ; Rezaei, S. M ; Zareinejad, M ; Sharif University of Technology
    Piezoelectric actuators are widely used in micro manipulation applications. However, hysteresis nonlinearity limits the accuracy of these actuators. This paper presents a novel approach for utilizing a piezoelectric nano-stage as the slave manipulator of a teleoperation system based on a sliding mode controller. The Prandtl-Ishlinskii (PI) model is used to model actuator hysteresis in feedforward scheme to cancel out this nonlinearity. The presented approach requires full state and force measurements at both the master and slave sides. Such a system is costly and also difficult to implement. Therefore, sliding mode unknown input observer (UIO) is proposed for full state and force...