Non-fragile Observer-based Control Research Articles

Finite-time contractive boundedness of extracorporeal blood circulation process

This paper proposes, finite-time contractive stability for a state space model of extra-corporeal blood circulation (ECC). Firstly, by virtue of an appropriately chosen Lyapunov function some sufficient inequality-based conditions for the existence of an observer-based controller has been proposed. Secondly, a non-fragile observer-based control is designed in such a way that it will withstand the impacts of uncertainties in controller and observer gains and therein guarantees H∞ finite-time contractive boundedeness of the overall dynamics of the system. The sufficient conditions derived are presented in a LMI frame work. In simulation results we address the finite-time contractive boundedness of the ECC model. The numerical simulations are conducted and discussed which validates the performance of the proposed algorithm.

Mode-dependent non-fragile observer-based controller design for fractional-order T–S fuzzy systems with Markovian jump via non-PDC scheme

In this paper, controller synthesis problem based on non-fragile observer is investigated for a class of fractional-order nonlinear systems subject to abrupt changes under the fractional-order T–S fuzzy model with Markovian jump. By utilizing non-parallel-distributed-compensation (non-PDC) scheme, the model-dependent observer and the observer-based fuzzy controller are designed under imperfect premise matching to enhance design flexibility. Moreover, the multiplicative random sensor noise over the measurement output is considered. Then, based on the matrix singular value decomposition method (SVD) and the membership-function-shape-dependent (MFSD) analysis approach, new less-conservative sufficient conditions in term of LMIs are derived to guarantee the closed-loop fractional-order fuzzy system robustly stochastically stable. Finally, two examples are provided to illustrate the effectiveness of the new design techniques for fractional-order systems.

Robust nonfragile observer-based H2/H∞ controller

A robust nonfragile observer-based controller for a linear time-invariant system with structured uncertainty is introduced. The robust stability of the closed-loop system is guaranteed by use of the Lyapunov theorem in the presence of undesirable disturbance. For the sake of addressing the fragility problem, independent sets of time-dependent gain-uncertainties are assumed to be existing for the controller and the observer elements. In order to satisfy the arbitrary H2-normed constraints for the control system and to enable automatic determination of the optimal bound of the performance functions in disturbance rejection control, additional necessary and sufficient conditions are presented in a linear matrix equality/inequality framework. The observer-based controller is then transformed into an optimization problem of coupled set of linear matrix equalities/inequality that can be solved iteratively by use of numerical software such as Scilab. Finally, concerning the evaluation of the performance of the controller, the control system is implemented in real time on a mechanical system, aiming at vibration suppression. The plant under study is a multi-input single-output clamped-free piezo-laminated smart beam. The nominal mathematical reduced-order model of the beam with piezo-actuators is used to design the proposed controller and then the control system is implemented experimentally on the full-order real-time system. The results show that the closed-loop system has a robust performance in rejecting the disturbance in the presence of the structured uncertainty and in the presence of the unmodeled dynamics.

A sliding mode approach to [formula omitted] non-fragile observer-based control design for uncertain Markovian neutral-type stochastic systems

This paper is focused on designing an H∞ sliding-mode control for a class of neutral-type stochastic systems with Markovian switching parameters and nonlinear uncertainties. An H∞ non-fragile observer subjected to the transition rates of the switching mode is firstly constructed. By some specified matrices, the connections among the designed sliding surfaces corresponding to every mode are established. Then, the state-estimation-based sliding mode control law is designed to guarantee the reachability of the sliding surface in finite time interval. Furthermore, a stochastic stability criterion is established for all admissible uncertainties, which can guarantee the error system and sliding mode dynamics to be asymptotically stochastic stable with a given disturbance attenuation level. Finally, an example is provided to illustrate the efficiency of the proposed method.

An indirect Lyapunov approach to the observer-based robust control for fractional-order complex dynamic networks

This paper concerns with the problem of the observer-based robust control for a class of fractional-order complex dynamic networks. First, by introducing a continuous frequency distributed equivalent model and using indirect Lyapunov approach, the sufficient condition for robust asymptotic stability of the closed-loop systems via state observer-based control is presented. Next, using matrix׳s singular value decomposition (SVD) and linear matrix inequality (LMI) techniques, the existence condition and method of designing a robust non-fragile observer-based controller are derived. Finally, the validity of the proposed methods are demonstrated by a numerical example.

Non-fragile observer-based robust control for a class of fractional-order nonlinear systems

The paper is concerned with the problem of the observer-based robust control for a class of fractional-order nonlinear systems. First, by introducing a continuous frequency distributed equivalent model and using indirect Lyapunov approach, the sufficient condition for robust asymptotic stability of the closed-loop system via state observer-based control is presented, which is less conservative than some existing ones in recent literature. Next, using matrix’s singular value decomposition (SVD) and linear matrix inequality (LMI) techniques, the existence condition and method of designing a robust non-fragile observer-based controller are derived. Finally, the validity of the proposed methods are demonstrated by two numerical examples.

Outer Synchronization between Fractional-Order Complex Networks: A Non-Fragile Observer-based Control Scheme

This paper addresses the global outer synchronization problem between two fractional-order complex networks coupled in a drive-response configuration. In particular, for a given fractional-order complex network composed of Lur’e systems, an observer-type response network with non-fragile output feedback controllers is constructed. Both additive and multiplicative uncertainties that perturb the control gain matrices are considered. Then, using the stability theory of fractional-order systems and eigenvalue distribution of the Kronecker sum of matrices, we establish some sufficient conditions for global outer synchronization. Interestingly, the developed results are cast in the format of linear matrix inequalities (LMIs), which can be efficiently solved via the MATLAB LMI Control Toolbox. Finally, numerical simulations on fractional-order networks with nearest-neighbor and small-world topologies are given to support the theoretical analysis.

Non-fragile observer-based controls of linear system via LMI approach

Abstract This paper investigates the non-fragile observer-based controls for continuous systems. Exponential stabilization for the systems is studied and the convergence rate is given. Two types of uncertainties which perturb the gains of control and observer are considered. Linear matrix inequality (LMI) approach is used to design the non-fragile observer-based control. The control and observer gains are given from LMI feasible solution. A numerical example is given to illustrate our method.