Abdessattar Chaari

Improved fuzzy sliding mode control for a class of MIMO nonlinear uncertain and perturbed systems

In this paper, a stable adaptive fuzzy sliding mode based tracking control is developed for a class of nonlinear MIMO systems that are represented by input output models involving system uncertainties and external disturbances. The main contribution of the proposed method is that the structure of the controller system is partially unknown and does not require the bounds of uncertainties and disturbance to be known. First, a fuzzy logic system is designed to estimate the unknown function. Secondly, in order to eliminate the chattering phenomenon brought by the conventional variable structure control, the signum function is replaced by an adaptive Proportional Derivative (PD) term in the proposed approach. All parameter adaptive laws and robustifying control terms are derived based on Lyapunov stability analysis, so that convergence to zero of tracking errors and boudedness of all signals in the closed-loop system can be guaranteed. Finally, a mass-spring-damper system is simulated to demonstrate the validity and the effectiveness of the proposed controller.

Robust Adaptive Fuzzy Sliding Mode Control Design for a class of MIMO underactuated system

Abstract In this paper, a robust adaptive fuzzy controller which combines the sliding mode control with an adaptive Proportional Integral (PI) term is developed for a class of nonlinear Multi Inputs Multi Outputs (MIMO) underactuated systems with unknown parameters and in presence of external disturbances. The main contribution of the proposed method is that underactuated systems can be controlled in their original non square form. The problem of matrix singularity for this class of systems is solved by using the property of the regularized inverse and by introducing a compensator term in the proposed control law. The free parameters of the adaptive fuzzy controller are tuned on-line based on the Lyapunov approach. The overall adaptive fuzzy scheme guarantees the boundedness of all the closed-loop signals as well as the tracking errors. The validity of the proposed approach is shown by computer simulations.

Improved observer-based adaptive fuzzy tracking control for MIMO nonlinear systems

In this paper, a stable observer-based adaptive fuzzy controller which combines a sliding mode and an adaptive Proportional Integral (PI) controllers is developed for a class of nonlinear Multiple Input Multiple Output (MIMO) systems with unknown parameters and in presence of external disturbances. The free parameters of the adaptive fuzzy controller are tuned on-line based on the Lyapunov approach. The overall adaptive fuzzy scheme guarantees the uniform ultimate boundedness of all the closed-loop signals as well as the tracking errors. The validity of the proposed approach is shown by computer simulations of a two-link robotic manipulator.

Adaptive Sliding Mode Control for a class of nonlinear MIMO systems: Application to a Turbocharged Diesel Engine

An Adaptive Sliding Mode Control (ASMC) for a class of nonlinear Multi Input Multi Output (MIMO) systems is presented in this paper. In order to reduce the chattering phenomenon without deteriorating the tracking performance, the discontinuous term of the classical sliding mode law is substituted with an adaptive Proportional Derivative (PD) term. The effect of the approximation error which arises from the PD term is reduced by adding a robust term in the proposed control law. All parameters, adaptive laws and robust control term, are derived based on the Lyapunov stability analysis. The overall adaptive sliding mode scheme guarantees the asymptotic convergence to zero of tracking errors and the boundedness of all signals in the closed-loop system. The proposed approach is applied to a Turbocharged Diesel Engine. Simulation results are presented to show the efficiency of the proposed method.

Adaptive Moving Sliding Mode Control for SISO Systems

This paper aims to propose and develop an adaptive moving sliding mode controller AMSMC that can be applied for nonlinear single-input single-output SISO systems with external disturbances. The main contribution of this framework consists to overcome the chattering phenomenon problem. The discontinuous term of the classic sliding mode control is replaced by an adaptive term. Moreover, a moving sliding surface is proposed to have better tracking and to guarantee robustness to the external disturbances. The parameters of the sliding surface and the adaptive law are deduced based on Lyapunov stability analysis. An experimental application of electropneumatic system is treated to validate the theoretical results.

Adaptive Fuzzy Sliding Mode Tracking Control of Uncertain Underactuated Nonlinear Systems

The trajectory tracking of underactuated nonlinear system with two degrees of freedom is tackled by an adaptive fuzzy hierarchical sliding mode controller. The proposed control law solves the problem of coupling using a hierarchical structure of the sliding surfaces and chattering by adopting different reaching laws. The unknown system functions are approximated by fuzzy logic systems and free parameters can be updated online by adaptive laws based on Lyapunov theory. Two comparative studies are made in this paper. The first comparison is between three different expressions of reaching laws to compare their abilities to reduce the chattering phenomenon. The second comparison is made between the proposed adaptive fuzzy hierarchical sliding mode controller and two other control laws which keep the coupling in the underactuated system. The tracking performances of each control law are evaluated. Simulation examples including different amplitudes of external disturbances are made.

Generalized fuzzy sliding mode control for MIMO nonlinear uncertain and perturbed systems

In this paper, a stable adaptive fuzzy sliding mode based tracking control is developed for a class of non-square nonlinear systems that are represented by input output models involving system uncertainties and external disturbances. The main contribution of the proposed method is that non-square systems are be controlled in their original non-square form instead of squaring them by adding or eliminating variables. First, a fuzzy logic system is designed to estimate the unknown function. Secondly, in order to eliminate the chattering phenomenon brought by the conventional variable structure control, the signum function is replaced by an adaptive Proportional Derivative (PD) term in the proposed approach. All parameter adaptive laws and robustifying control terms are derived based on Lyapunov stability analysis, so that the convergence to zero of tracking errors and the boudedness of all signals in the closed-loop system can be guaranteed. The efficiency of the proposed approach is shown by computer simulations.

Fuzzy Sliding Mode Control for Turbocharged Diesel Engine

In this work, Fuzzy Second Order and Adaptive Sliding Mode Control are developed for a Turbocharged Diesel Engine (TDE). In control design the TDE is represented by Multi-Output Multi-Input (MIMO) nonlinear model with partially unknown dynamics. To regulate the intake manifold pressure, the exhaust manifold pressure, the compressor flow and to estimate the unknown functions, a Sliding Mode Control (SMC) combined with Fuzzy Logic are firstly developed. Secondly to reduce the chattering phenomenon without deteriorating the tracking performance, two approaches are investigated. A special case of the Second Order Sliding Mode Controller (2-SMC): the super twisting sliding mode controller is developed. The results obtained using the Adaptive Sliding Mode Control (ASMC) are also presented to compare the performances of both methods. All parameter adaptive laws and robustifying control terms are derived based on Lyapunov stability analysis, so that convergence to zero of tracking errors and boudedness of all signals in the closed-loop system are guaranteed. Simulation results are given to show the efficiency of the proposed approaches.

Adaptive Type-2 Fuzzy Sliding Mode Control for MIMO nonlinear systems: Application to a Turbocharged Diesel Engine

In this paper, an Adaptive Type-2 Fuzzy Sliding Mode Control is designed for a class of nonlinear Multi-Input Multi-Output (MIMO) systems with unknown partially dynamics and in presence of external disturbances. To estimate the unknown functions, a Sliding Mode Control (SMC) combined with Type-2 Fuzzy Logic are developed. The discontinuous term of the classical sliding mode law is substituted with an adaptive Proportional Derivative term to reduce the chattering phenomenon. All parameters, adaptive laws and robustifying control terms are derived based on Lyapunov stability analysis, so that convergence to zero of tracking errors and boudedness of all signals in the closed-loop system are guaranteed. The proposed approach is applied to a Turbocharged Diesel Engine (TDE) and simulation results are presented to show the efficiency of the proposed method.

Modeling and sliding mode control of an electropneumatic system

This paper present a sliding mode controller of an electropneumatic system. In order to obtain a good position and pressure tracking and to reduce the chattering phenomenon, a proportional derivative PD sliding surface is used with an integral law. Finally, simulation results are presented to test the effectiveness of this proposed controller comparing with a classic sliding mode controller.