The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
One crucial aspect in building engineering is to accomplish the trade-off between reduction of energy consumption and high level thermal comfort for the occupants. To this aim, advanced control algorithms are fundamental to guarantee a certain optimality of the system performance in working conditions that can be quite different from the nominal ones due to the presence, for example, of variable external...
We consider linear continuous-time systems with multiplicative noise and polytopic type parameter uncertainty and we address the problems of H∞ state-feedback control and filtering of these systems. These problems are solved by applying a vertex dependent Lyapunov function that considerably reduces the over-design associated with the classical “quadratic” design that is based on a single Lyapunov...
In this paper, a sliding mode control based on backstepping (BSMC) and feedback linearization (FLSMC) are proposed to solve disturbances, nonlinearity and chattering problems for a class of uncertain systems in strict feedback form. Based on backstepping technique, the proposed control strategy has fast response and good disturbance rejection capability. The stability analysis of the closed-loop system...
In this paper, some of the now well established results from the area of parametric robust control are combined with the describing function method to analyze the stability problem of uncertain discrete time systems with separable nonlinearities. Numerical examples are given to illustrate application of the proposed method.
In this paper we present an efficient algorithm to compute exact value set contours of affine uncertain transfer functions. This algorithm is based on a generalization of line-sweep algorithms developed for computational geometric applications and preserves the geometric parametrization of value set contours.
This paper studies the problem of Η∞ detection filter design for state delayed linear continuous-time systems with parameter uncertainty, in which the effects of faults and disturbances cannot be de-coupled from each other. The detection filter gains are designed so that, if the fault of the system is absent, the filter is convergent for the admissible uncertainty conditions. The transfer function...
The paper deals with the problem of robust absolute stability of systems with parametric uncertainties. By using a 2q-convex parpolygonal value set of a family of polynomials of the form P(s, q) = a0(q) + a1(q)s +………+ an(q)sn whose coefficients depend linearly on q = [q1, q2,…, qq]T and the uncertainty box is Q = {q : qi ∊ [qi, qi], i = 1,2,….q}, an extremal boundary result for a transfer function,...
The problem of composite regulation for shape and gauge of Φ300 mm 4-high reversible cold strip mill with the aid of backup roll and work roll bending is discussed in this paper. A composite regulation model with parameter uncertainties is developed. Then the paper deals with the problem of guaranteed cost control synthesis for uncertain systems. Necessary and sufficient conditions as well as controller...
This paper deals with a new filtering problem for linear uncertain discrete-time stochastic systems with randomly varying sensor delay. The system measurements are subject to randomly varying sensor delays, which often occur in information transmissions through networks. The problem addressed is the design of a linear filter such that, for all admissible parameter uncertainties and all probabilistic...
For any two n-th order polynomials a(s) and b(s), the Hurwitz stability of their convex combination is necessary and sufficient for the existence of a polynomial c(s) such that c(s)/a(s) and c(s)/b(s) are both strictly positive real.
When the process uncertainty size increases, even linear minimum phase systems must sacrifice desirable aggressive feedback control benefits to avoid an excessive ‘cost of feedback’, while preserving the robust stability. With a suitable uncertainty division and a QFT controller-prefilter to command each uncertainty subset inside a controller-scheduler structure, it is possible to enhance the feedback...
The paper considers a class of control systems, described by a finite set of linear systems with the transition between them determined by a homogeneous Markov chain. Every state of this chain correspond to some mode of the system. When the mode is fixed, the plant state evolves according to the corresponding individual dynamic. At the moment of discontinuous mode change the plant state vector can...
The robustness features versus unmatched uncertainties of a hybrid variable structure control strategy for a class of second order systems are analyzed in this paper. The hybrid control relies on a subdivision of the system state space into nested regions, and on an event-driven switching among the control laws associated with each region. By componing globally stabilizing variable structure laws,...
Most of the existent linear matrix inequality based conditions for robust stability of time-delay systems in polytopic domains are expressed in terms of constant Lyapunov-Krasovskii functions. This note presents a simple way to extend these conditions in order to construct parameter-dependent functions that provide less conservative results, in both delay-independent and delay-dependent situations.
In this paper design of switching controllers for linear systems with analog uncertainty is considered. The controllers are LQ controllers and switching sequence is determined by minimization of suitable defined priority function. The priority function includes switching penalty term which introduces cautiousness in switching discrete state. First in the paper are finded conditions for weighting matrices...
The stability robustness analysis for a class of nonlinear systems with bounded structured uncertainties is characterized by Nonlinear Matrix Inequalities (NLMI). By introducing scaling to reduce conservatism arising from the uncertainty structure, the problem turns out to be still convex. However, it is shown that it is as hard as Lyapunov stability analysis. In this paper, it is proposed a new way...
This paper deals with the combination of sliding mode control (SMC) and fuzzy logic system (FLS) for a class of non-linear multi-input multi-output (MIMO) uncertain systems. An adaptive scheme for the fuzzy control is developed to approximate the unknown system functions. A SMC is then applied to reduce the effects of both approximation errors and external disturbances. Thanks to Lyapunov's theory,...
The robust linear H∞ FIR filter, which guarantees a prescribed H∞ performance, is designed for continuous time-varying systems subject to unknown initial state, real norm-bounded parameter uncertainty and unknown cone-bounded nonlinearity. The infinite horizon filtering for time-varying systems is investigated in terms of two Riccati equations by the finite moving horizon.
The controller synthesis problem of uncertain negative-imaginary systems has important engineering applications in, for example, lightly damped flexible structures with colocated position sensors and force actuators. This paper provides a systematic controller synthesis procedure via an LMI approach to construct a state-feedback internally stabilizing controller such that the nominal closed-loop system...
A new method is proposed for the solution of linear matrix inequalities over a finite horizon for linear discrete time varying systems with or without uncertainties. The method is used to solve a variety of problems beginning with the standard H∞ discrete-time bounded real lemma and extending through to robust H∞ general-filtering and output-feedback control design of uncertain systems. In the latter...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.