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Stability Result (stability + result)

Distribution by Scientific Domains
Engineering71%
Mathematics and Statistics28%

Selected Abstracts

Stability and H, performance of multiple-delay systems with successive delay components

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 8 2010
Ge Guo
Abstract This paper presents a new model for linear time-delay systems with multiple delayed states where each delay contains finite number of successive components with different time-varying properties, referred to as multiple-delay system with successive time-varying delay components (MDSSTDCs). General stability result and H, performance conditions, under which the MDSSTDCs are asymptotically stable with certain H, disturbance attenuation level, are derived by exploiting a general Lyapunov,Krasovskii functional and by making use of novel techniques for time-delay systems. The result is applied to two special types of time-delay systems frequently used in engineering applications and corresponding conditions for stability and H, performance are obtained. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Adaptive TS-FNN control for a class of uncertain multi-time-delay systems: The exponentially stable sliding mode-based approach

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 4 2009
Tung-Sheng Chiang
Abstract This paper presents an adaptive Takagi,Sugeno fuzzy neural network (TS-FNN) control for a class of multiple time-delay uncertain nonlinear systems. First, we develop a sliding surface guaranteed to achieve exponential stability while considering mismatched uncertainty and unknown delays. This exponential stability result based on a novel Lyapunov,Krasovskii method is an improvement when compared with traditional schemes where only asymptotic stability is achieved. The stability analysis is transformed into a linear matrix inequalities problem independent of time delays. Then, a sliding mode control-based TS-FNN control scheme is proposed to achieve asymptotic stability for the controlled system. Since the TS-FNN combines TS fuzzy rules and a neural network structure, fewer numbers of fuzzy rules and tuning parameters are used compared with the traditional pure TS fuzzy approach. Moreover, all the fuzzy membership functions are tuned on-line even in the presence of input uncertainty. Finally, simulation results show the control performance of the proposed scheme. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Robust H, filtering for switched linear discrete-time systems with polytopic uncertainties

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 6 2006
Lixian Zhang
Abstract In this paper, the problem of robust H, filtering for switched linear discrete-time systems with polytopic uncertainties is investigated. Based on the mode-switching idea and parameter-dependent stability result, a robust switched linear filter is designed such that the corresponding filtering error system achieves robust asymptotic stability and guarantees a prescribed H, performance index for all admissible uncertainties. The existence condition of such filter is derived and formulated in terms of a set of linear matrix inequalities (LMIs) by the introduction of slack variables to eliminate the cross coupling of system matrices and Lyapunov matrices among different subsystems. The desired filter can be constructed by solving the corresponding convex optimization problem, which also provides an optimal H, noise-attenuation level bound for the resultant filtering error system. A numerical example is given to show the effectiveness and the potential of the proposed techniques. Copyright © 2006 John Wiley & Sons, Ltd. [source]

A Kharitonov-like theorem for robust stability independent of delay of interval quasipolynomials

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 6 2010
Onur Toker
Abstract In this paper, a Kharitonov-like theorem is proved for testing robust stability independent of delay of interval quasipolynomials, p(s)+,eqk(s), where p and qk's are interval polynomials with uncertain coefficients. It is shown that the robust stability test of the quasipolynomial basically reduces to the stability test of a set of Kharitonov-like vertex quasipolynomials, where stability is interpreted as stability independent of delay. As discovered in (IEEE Trans. Autom. Control 2008; 53:1219,1234), the well-known vertex-type robust stability result reported in (IMA J. Math. Contr. Info. 1988; 5:117,123) (See also (IEEE Trans. Circ. Syst. 1990; 37(7):969,972; Proc. 34th IEEE Conf. Decision Contr., New Orleans, LA, December 1995; 392,394) does contain a flaw. An alternative approach is proposed in (IEEE Trans. Autom. Control 2008; 53:1219,1234), and both frequency sweeping and vertex type robust stability tests are developed for quasipolynomials with polytopic coefficient uncertainties. Under a specific assumption, it is shown in (IEEE Trans. Autom. Control 2008; 53:1219,1234) that robust stability independent of delay of an interval quasipolynomial can be reduced to stability independent of delay of a set of Kharitonov-like vertex quasipolynomials. In this paper, we show that the assumption made in (IEEE Trans. Autom. Control 2008; 53:1219,1234) is redundant, and the Kharitonov-like result reported in (IEEE Trans. Autom. Control 2008; 53:1219,1234) is true without any additional assumption, and can be applied to all quasipolynomials. The key idea used in (IEEE Trans. Autom. Control 2008; 53:1219,1234) was the equivalence of Hurwitz stability and , -o -stability for interval polynomials with constant term never equal to zero. This simple observation implies that the well-known Kharitonov theorem for Hurwitz stability can be applied for , -o -stability, provided that the constant term of the interval polynomial never vanishes. However, this line of approach is based on a specific assumption, which we call the CNF-assumption. In this paper, we follow a different approach: First, robust , -o -stability problem is studied in a more general framework, including the cases where degree drop is allowed, and the constant term as well as other higher-orders terms can vanish. Then, generalized Kharitonov-like theorems are proved for , -o -stability, and inspired by the techniques used in (IEEE Trans. Autom. Control 2008; 53:1219,1234), it is shown that robust stability independent of delay of an interval quasipolynomial can be reduced to stability independent of delay of a set of Kharitonov-like vertex quasipolynomials, even if the assumption adopted in (IEEE Trans. Autom. Control 2008; 53:1219,1234) is not satisfied. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Polynomial and analytic stabilization of a wave equation coupled with an Euler,Bernoulli beam

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 5 2009
Kaïs Ammari
Abstract We consider a stabilization problem for a model arising in the control of noise. We prove that in the case where the control zone does not satisfy the geometric control condition, B.L.R. (see Bardos et al. SIAM J. Control Optim. 1992; 30:1024,1065), we have a polynomial stability result for all regular initial data. Moreover, we give a precise estimate on the analyticity of reachable functions where we have an exponential stability. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Long-term stability of dye-sensitised solar cells

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 6 2001
A. Hinsch
Accelerated ageing tests on large numbers of nanocrystalline dye-sensitised solar cells (nc-DSC) show that, to first order, separation between the effects of the stresses of visible light soaking, UV illumination and thermal treatment on long-term stability is possible. The corresponding mechanisms are electrochemical, photochemical and purely chemical in nature. It was found that visible light soaking alone is not a dominant stress factor. A dramatic improvement in UV stability has been achieved by using MgI2 as additive to the electrolyte. Thermal stress appears to be one of the most critical factors determining the long-term stability of nc-DSC and is strongly related to the chemical composition of electrolyte solvents and additives. Encouraging stability results have been obtained for cells based on pure nitrile-based solvents: (1) A minor decrease in performance of initially 5.5% solar efficient cells has been found after 2000 h at 60°C without light soaking; (2) After 900 h ageing at 85°C, a decrease of 30% in maximum power has been observed; (3) After 3400 h of combined thermal stress and continuous light soaking (45°C, 1 sun equivalent) good stability with 15% decrease in maximum power can be demonstrated. It should be noted that such good thermal stability has not been reported previously for dye-sensitised solar cells so far. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Stability of small-amplitude shock profiles of symmetric hyperbolic-parabolic systems

COMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 7 2004
C. Mascia
Combining pointwise Green's function bounds obtained in a companion paper [36] with earlier, spectral stability results obtained in [16], we establish nonlinear orbital stability of small-amplitude Lax-type viscous shock profiles for the class of dissipative symmetric hyperbolic-parabolic systems identified by Kawashima [20], notably including compressible Navier-Stokes equations and the equations of magnetohydrodynamics, obtaining sharp rates of decay in Lp with respect to small L1 , H3 perturbations, 2 , p , ,. Our analysis extends and somewhat refines the approach introduced in [35] to treat stability of relaxation profiles. © 2004 Wiley Periodicals, Inc. [source]