Class Of Uncertain Discrete Systems Research Articles

Design and Implementation of Novel LMI-Based Iterative Learning Robust Nonlinear Controller

An iterative learning robust fault-tolerant control algorithm is proposed for a class of uncertain discrete systems with repeated action with nonlinear and actuator faults. First, by defining an actuator fault coefficient matrix, we convert the iterative learning control system into an equivalent unknown nonlinear repetitive process model. Then, based on the mixed Lyapunov function approach, we describe the stability of the nonlinear repetitive mechanism on time and trial indices and have appropriate conditions for the repeated control system’s stability in terms of linear matrix inequality theory. Through LMI techniques, we have obtained satisfactory results and controller stability, and robustness against fault tolerance is also discussed in detail. Finally, the simulation results of the output tracking control of the two exemplary models verify the effectiveness of the proposed algorithm.

Robust stability of 2-D discrete systems employing generalized overflow nonlinearities: An LMI approach

This paper deals with the problem of global asymptotic stability of a class of uncertain discrete systems described by the Fornasini–Marchesini second local state-space (FMSLSS) model using generalized overflow nonlinearities. The systems under investigation involve parameter uncertainties that are assumed to be deterministic and norm bounded. An LMI-based criterion for the global asymptotic stability of such systems is proposed. The proposed criterion is compared with previously reported criteria.

An A[r, R) instability criteria for a class of uncertain discrete systems

In this paper, simple criteria for the instability of a class of uncertain discrete systems are derived. Such criteria can be easily checked by estimating the largest nonnegative zero of two specific polynomials. A numerical example is also provided to illustrate the main results.

Simple instability criterion for a class of uncertain discrete systems

In this note, the instability of a class of uncertain discrete systems is investigated. Simple instability criterion is derived to guarantee the instability of such systems. Finally, a numerical example is provided to illustrate the main result.

D-Stability Analysis for a Class of Uncertain Discrete Systems with Multiple Time Delays.

In this paper, the robust D-stability problem for a class of nominally stable linear uncertain discrete systems with multiple time delays is considered. A delay-dependent criterion is first proposed to guarantee the D-stability of the uncertain system subject to structured perturbations. A criterion deduced from the robust D-stability criterion is then proposed to ensure the robust asymptotic stability of the uncertain system. It is shown that our results are less conservative than some other results in recent literature.

Comments on ‘Uncertain discrete systems: uniform ultimate bounded stabilization’

Bahnasawi and Mahmoud (1989) give a two-pan (linear plus non-linear) control law to guarantee global uniform ultimate boundedness of a class of uncertain discrete systems. These results are applicable to naturally discrete systems, but require care in applying lo sampled-data systems. Some observations on the application by Bahnasawi and Mahmoud (1989) of these discrete system results to a discretized model of a Ward-Leonard speed controller arc indicated, and several interesting comments arc offered.