Nouri ahmed said

University of Sfax | US · Department of Electronics, Electrical Engineering and Automation

The present paper deals with the design of a discrete-time integral sliding mode controller (DISMC) using only input-output measurement. The proposed strategy of control is developed and considered as a new method for voltage controller of electronic power systems, such as DC-DC buck converter. An input-output model of DC-DC buck converter is given...

This paper presents a new approach to integral sliding mode control for discrete nonlinear systems with time delay. The approach is based on an event-triggered scheme and is applied to Takagi–Sugeno fuzzy models. In the first step, a new integral sliding function is constructed, which avoids the limited assumptions of most existing fuzzy sliding mo...

This work deals with the design observer-based sliding mode control for discrete-time Takagi–Sugeno fuzzy models with time-varying delay and subject to measurement noises. The sliding surface is developed by introducing the state and input vectors to overcome the restrictive assumption in most existing sliding mode control schemes which forces the...

Discrete sliding mode control with classical sliding function for the input–output representation is not applicable in non-minimum phase systems, due to the presence of unstable zero. In fact, the presence of the unstable zero risks deteriorating or saturating the control law. In order to surmount this problem, a new discrete generalized sliding mo...

The robustness issue of uncertain nonlinear systems’ control has attracted the attention of numerous researchers. In this paper, we propose three techniques to deal with the uncertain Hammerstein nonlinear model. First, a discrete sliding mode control (SMC) is developed, which is based on converting the original nonlinear system into a linearized o...

The main challenge of sliding mode control is how to reduce chattering phenomenon. In this work, a discrete terminal neuro-sliding mode control with adaptive switching gain for a nonlinear system is presented. This new strategy blends the benefits of terminal sliding mode control and neuronal network. It guarantees a finite-time convergence of the...

The problem of sensitivity to uncertainties and disturbances is still a challenging task in the theory of discrete sliding mode controller. In this article, a discrete repetitive adaptive sliding mode control using only input-output measurements of linear time-varying system with periodic disturbances is proposed. A new indirect adaptive algorithm...

In this paper, a guaranteed cost based on novel sliding mode control (SMC) for a class uncertain nonlinear time delay systems has been proposed through the T-S (Takagi and Sugeno) models. First of all, a new sliding manifold has been developed to remove the restrictive assumptions in the most of the existing fuzzy sliding mode control approaches. I...

This paper present the esterification operation of an olive oil waste taking place in a Semi Continuous Stirred Tank Reactor (SCSTR). The plant model, presents a high level of non linearities and interconnections between states. The necessary steps required to move from differential algebraic model to a differential model is given. In this paper a...

Blocks oriented models are the most structure used to describe nonlinear systems. These models are composed with two blocks: the first is a nonlinear part and the second is a linear part. Hammerstein model is one of block oriented models. Recently, the design of sliding mode control (SMC) in discrete-time for nonlinear systems is done using this st...

This paper proposes a discrete-time neuro-sliding mode control for an uncertain nonlinear system (NL_NDSMC). The proposed technique guarantees the stability of the system and achieves zero tracking error comparing with the classical discrete sliding mode control. Although, it reduces chattering phenomenon. The selection of the neuronal sliding surf...

This thesis deals with stability and stabilization of discrete sliding mode control for linear time delay systems and nonlinear systems with delayed state represented by Takagi-Sugeno fuzzy models. The contribution of this work is reflected by the proposal of a novel structure of the sliding function which depends on both state and input vectors, i...

In this paper., we investigate the discrete sliding mode control for a class of uncertain nonlinear time-delay systems represented by T-S fuzzy models. In order to eliminate the restrictive assumptions in most previous results, a new sliding surface function is formed linearly with the system states and control inputs. In addition the delayed state...

This paper proposes a discrete-time neuro-sliding mode control for an uncertain nonlinear system (NL_NDSMC). The proposed technique guarantees the stability of the system and achieves zero tracking error comparing with the classical discrete sliding mode control. Although, it reduces chattering phenomenon. The selection of the neuronal sliding surf...

This paper shows comparison between the Predictive Sliding Mode Controller (PSMC) and the Sliding Mode Controller with Predictive Sliding Function (SMC-PSF). The proposed controllers combine the design of Sliding Mode Control (SMC) with Model Predictive Control (MPC). This combination improves the performance of these two control laws. In fact, usi...

Solving the problem of unpredictable transient responses and tracking reference trajectories has recently becomes one of the challenging aspects of Model Reference Adaptive Control (MRAC). In this paper, a Discrete Variable Structure Model Reference Adaptive Control using only input output measurements (D-VS-MRAC-IO) for linear non strictly positiv...

In most existing SMC, for analyzing the time delay system using the conventionnel SMC, we will transform it to its regular form, taking account a restrictive assumption. In this paper, a novel sliding surface dependent on both the state and input vector is proposed, in order to remove the restrictive assumption. Furthermore, it can be improved the...

During the reachability phase, the sliding mode control is sensitive to external disturbances and uncertainties. In this paper, we propose to determine coefficients of the sliding function using the technique of Linear Matrix Inequalities (LMIs) for single-input single-output time delay systems. This technique leads to an optimal choice of the slid...

In this chapter, we give an overview of the sliding mode control. Firstly, We are interested to the sliding mode control and different solutions for reducing the chattering phenomenon have been given. Then, we have introduced the generalized sliding mode control where the discontinuity is applied to the highest derivative of the control if the syst...

Harmonic disturbance rejection is an important field of control theory and applications. In this paper a discrete first and second order sliding mode control for multivariable systems are investigated. The necessary conditions of harmonic disturbances rejection using first and second order sliding mode control laws are elaborated. In order to impro...

The control of nonlinear systems has been the subject of extensive research. This interest is mainly due to its potential for real applications. In this paper, we investigated discrete sliding mode control for a class of nonlinear time-delay systems represented by T–S fuzzy models. In most existing fuzzy sliding mode control, a common input matrix...

In this work, we investigated the sliding mode control (SMC) for uncertain systems with both state and input varying delays. In most existing SMC, a common input and delayed input matrix are considered to apply the conventional method, which is very restrictive assumption. Therefore, we proposed a new sliding surface which takes account of the syst...

Designing an adequate controller for a plant with an arbitrary relative degree is still an active area of research. In this paper, a discrete variable structure model reference adaptive control using only input-output measurements (DVS-MRAC-IO) for not Strictly Positive Real (NSPR) system with a relative degree two is proposed. In order to show the...

The sliding mode control (SMC) has several advantages in terms of good transient performance and system robustness. However, the sensitivity of this control technique to disturbance before reaching the sliding surface and the existence of the chattering phenomenon can be considered as the major problems in its implementation. To overcome these prob...

The technique of linear matrix inequalities is a powerful method for solving optimization problems. In this paper, a sliding function vector was calculated using linear matrix inequalities approach. This technique provided optimal values of the coefficients of the sliding function vector, which led to the reduction of the reachability phase. Then,...

This paper deals with the development of two strategies of control, for multivariable systems, combining Sliding Mode Control (SMC) and Model Predictive Control (MPC). This is an extension of our previous works synthesized in the case of single input single output. The first proposed controller is the Sliding Mode Control with Predictive Sliding Fu...

The problem of the chattering phenomenon is still the main drawback of the classical sliding mode control. To resolve this problem, a discrete second order sliding mode control via input-output model is proposed in this paper. The proposed control law is synthesized for decouplable multivariable systems. A robustness analysis of the proposed discre...

In this study, we have developed a method of diagnosis based on high gain observers, for detecting faults of the actuators in a semi continuous chemical reactor. This algorithm has the advantage of detecting multiple faults simultaneously. The observer is constructed from a sub-model, one needs two observers which related to the number of actuator....

This paper shows the development of a Discrete Sliding Mode Control with Predictive Sliding Function (SMCPSF) for multivariable systems. This is an extension of our previous works synthesized in the case of single input single output. The multivariable (SMC-PSF) consists of two loops, the primary loop is a Model Predictive Control (MPC) and the sec...

In this paper, a nonlinear high gain observer is developed to reconstruct the full state of an olive oil waste esterification process. This operation is taking place in a semi-continuous stirred tank reactor. The plant model, as most of the chemical processes, presents a high level of non linearities and interconnections between states. Most of the...

In this paper, we propose two methods of discrete sliding mode control. The first is the discrete fast terminal sliding mode control (DFTSM) and the second is the discrete integral sliding mode control (DISMC). These methods are proposed in order to overcome sliding mode problems, such as chattering phenomenon, convergence speed and rejection of ex...

Designing an adequate controller for plant with uncertainties is still an open area for research. In this paper, a discrete adaptive sliding mode control is proposed for the input-output systems with uncertain parameters. It's motivated by the use of recent new variations of Recursive Least Square algorithm (M-RLS). This algorithm is combined with...

This paper shows the development of a Discrete Predictive Sliding Mode Controller (DPSMC) for multivariable systems. This is an extension of our previous works synthesized in the case of single input single output. The multivariable DPSMC consists on two loops, the primary loop is a Sliding Mode Control (SMC) and the secondary loop is a Model Predi...

In this paper, two versions of nonlinear high gain observer are developed to reconstruct the full state of an olive oil waste esterification process. This operation is taking place in a Semi Continuous stirred Tank Reactor (SCSTR). The plant model, is one of the most important plants in chemical processes, presents a high level of non linearities a...

In this paper, we are interested to prove the performances of discrete sliding mode control for multi-variable systems with time delays. A dynamical sliding surface vector is proposed. This vector strategy is based on the a present and past values of the state. The coefficients of dynamical sliding surface vector were obtained optimally due to the...

Predictive sliding mode controller have been succefully implemented in the last 10 years overcoming the drawbacks of the traditional sliding mode control and the generalized predictive control strategies. This paper investigates the stability analysis of the new Discrete Predictive Sliding Mode Controller (DPSMC) for multivariable systems. The basi...

In this work, a robust discrete second order sliding mode control (2-DSMC) via input-output model for multivari-able systems was proposed. Firstly, a discrete second order sliding mode control for decouplable multivariable systems was presented. Then, a robust discrete second order sliding mode control for nondecouplable multivariable systems was d...

The success of the sliding mode control (SMC) is due to the simplicity of its implementation and its robustness against external disturbances via state space and input output model. In spite of this characteristic, the sliding mode control (SMC) suffers from a main drawback known as the 'chattering phenomenon'. In order to overcome this problem, a...

Owing to its potential for real applications, many researchers have studied the problem of modelling and control of time-varying delay systems. In this paper, we propose a new strategy called multi-delay approach for modelling and control of these systems. In this new strategy, the time-varying delay systems are modelled by a multi-delay model repr...

In this work, a robust discrete second order sliding mode control (2-DSMC) via input-output model for multivariable systems was proposed. Firstly, a discrete second order sliding mode control for decouplable multivariable systems was presented. Then, a robust discrete second order sliding mode control for nondecouplable multivariable systems was de...

The control of time delay systems is still an open area for research. This paper proposes an enhanced model predictive discrete-time sliding mode control with a new sliding function for a linear system with state delay. Firstly, a new sliding function including a present value and a past value of the state, called dynamic surface, is designed by me...

This paper shows the development of a Sliding Mode Controller with Predictive Sliding Function (SMC-PSF). The proposed controller blends the design of Sliding Mode Control (SMC) with Model Predictive Control (MPC). In fact, a cascade control strategy is proposed to determine the optimal linear surface parameters of the sliding mode control. The com...

In this paper, we propose a new adaptive control law with Q-parametrization for discrete multi-input multi-output systems subjected to sinusoidal disturbances with time-varying frequency. The rejection of sinusoidal disturbances with known frequency is obtained using partial state reference model control with Youla-Kucera parametrization. However,...

This paper shows the development of a Predictive Sliding Mode Controller (PSMC). The proposed controller blends the design of Sliding Mode Control (SMC) with Model Predictive Control (MPC). The combination of SMC and MPC improves the performance of these two control laws. The designed control strategy has stronger robustness and chattering reductio...

Modeling the discrete-time systems with time varying delay had several difficulties, such as, the determination of an adequate model describing the real output evolution. Also, controlling such systems is another problem to be resolved. In this paper, we propose a Multi-Structure approach for modeling and controlling discrete-time systems with time...

This paper presents a control strategy for perturbed discrete system with time delay, using Sliding Mode Control (SMC) and Model based Predictive Control (MPC). A predictive sliding mode control strategy is proposed and a discrete-time reaching law is improved. By applying a predictive sliding surface and a reference trajectory, combining with the...

A new discrete second order sliding mode control for the single input single output systems is proposed in this paper. The control law is based on an input-output model. The new control strategy is designed in order to reduce the chattering phenomenon that appears in classical sliding mode control. A numerical simulation example is presented to ill...

In this work, a discrete second order sliding mode control with a new sliding function for a linear uncertain system with state delay is proposed. The systems are assumed to have structured mismatched time varying uncertainties. Firstly, a new sliding function include a present and a past value of the state, called dynamic surface, is designed by m...

Disturbances rejection is an important field of control theory. In this context, our paper is proposed to deal with asymptotic rejection of periodic disturbances affecting discrete multivariable systems with an interactor matrix. A multivariable repetitive sliding mode control is proposed to cancel the disturbances when the system is nondecouplable...

The design of accurate control becomes more difficult due to the complexity of industrial processes. In this paper, we are interested on the tracking of reference trajectories and the rejection of harmonic disturbances for discrete multi-input multi-output systems. A new control strategy based on the combination of partial state reference model con...

This paper presents a control strategy using Sliding Mode Control (SMC) and Model based Predictive Control (MPC) for uncertain systems. A predictive sliding mode control strategy is proposed and a discrete-time reaching law is improved. By applying a predictive sliding surface and a reference trajectory, combining with the state feedback correction...

The design of accurate control becomes more difficult due to the complexities of real systems. In this paper, a new discrete second order sliding mode control for nonlinear multivariable systems with external disturbances is proposed. The new control strategy is designed in order to reduce the chattering phenomenon that appears in classical sliding...

This paper proposes a discrete second order sliding mode control with a new sliding surface ensuring the asymptotic stability of the time-delay systems. This new surface include a present and a past value of the state, called dynamic surface, designed by means of linear matrix inequality (LMI). A robust second order sliding mode controller with thi...

The Sliding Mode Control (SMC) is well known by its robustness to parameter uncertainties or external disturbances. The repetitive control (RC) is able to track or reject periodic and multi-periodic signals. This paper presents a new control strategy as a combination of a Sliding Mode approach and Repetitive Control to reject periodic and multi-per...

This paper concerns the chattering elimination from discrete sliding mode observers. The dilemma chattering-precision, that characterizes the first order sliding mode observer in case of relatively large parameter variations and/or external disturbances, is discussed and the influence of the discontinuous term amplitude on the estimation performanc...

In this work, a second order asymptotic discrete sliding mode control with a fuzzy supervised discontinuous term is proposed. The on line variation of the discontinuous term amplitude enhances the convergence rapidity of the sliding function and reduces the chattering phenomenon. These improvements are shown by a numerical simulation and by a real...

This paper presents a control strategy using Sliding Mode Control (SMC) and Repetitive Control (RC) for linear multiinput discrete-time systems to reject periodic and multiperiodic disturbances. A new reaching law is used to steer the system trajectories into the sliding surface and then keep them on it without chattering. The repetitive control is...

Reference trajectory asymptotic tracking and disturbance re-jection are an important field of control theory. In this paper, we are interested on the tracking of reference trajectories and the rejection of periodic disturbances with unknown frequency for multivariable systems. If the frequency is known, a classical solution is to use a multivariabl...

In this paper, the chattering phenomenon that characterizes discrete sliding mode systems is analyzed and illustrated by a simulation example. In order to resolve this problem, in case of relatively large parameter variations and/or external disturbances, a second order discrete sliding mode observer (2-DSMO) is proposed. A stability analysis of th...

Temperature control of processes that involve heating and cooling of semi-batch reactors can be a real problem for conventional controllers that do not put up with relatively large model uncertainty and external disturbances. The first order sliding mode control can be a solution for this problem; however, discrete-time implementation generates the...

The esterification reaction requires a tight temperature control. As the different stages of this reaction (the heating, the reaction and the cooling) are characterised by different dynamics, a discrete second order sliding mode control using one global model of the system was not able to ensure the desired performances. We propose, in this paper,...

In this work, an asymptotic numerical second order sliding mode control (2-DSMC) is developed in order to reduce the chattering phenomenon that characterize the discrete first order sliding mode control. A comparative study with Bartolinipsilas numerical second order sliding mode control approach is realized. The obtained results in the case of the...

In this work, the multimodel approach is exploited in order to ameliorate the discrete second order sliding mode control (2-DSMC) performances in the case of highly non stationary systems. Simulation results show a notable improvement relatively to the classical 2-DSMC, especially in the reaching phase.

In order to improve the robustness of the Discrete Sliding Mode Control, essentially in the reaching phase, we propose in this paper a new version based on the multimodel and multicontrol approaches. A real time application of the Multimodel Discrete Sliding Mode Control (MM-DSMC) and of the Classical Discrete Sliding Mode Control (C-DSMC) is reali...

In this paper an essential property of sliding surface coordinate functions is exploited for proposing an experimental verification of the orders of an assumed system model. The results are applied to verify the relative degrees of actual system models, obtained by experimental identification, of a single-link robotic manipulator equipped with arti...