PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 11

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Model reduction problem of linear discrete systems: Admissibles initial states
Abdelhak A., Rachik M.
Archives of Control Sciences
|
2019
|
Vol. 29, No. 1
41--55
EN
Given a linear discrete system with initial state x0 and output function yi , we investigate a low dimensional linear system that produces, with a tolerance index ϵ, the same output function when the initial state belongs to a specified set, called ϵ-admissible set, that we characterize by a finite number of inequalities. We also give an algorithm which allows us to determine an ϵ-admissible set.
2
Content available Ideal observability for bilinear discrete-time systems with and without delays in observation
Lhous M., Rachik M., Magri E. M.
Archives of Control Sciences
|
2018
|
Vol. 28, No. 4
601--616
EN
An ideal observability subspace expression is stated for bilinear abstract system with bounded operator in Hilbert spaces. The case of finite dimentional space is also treated. However, it’s noticed that the state ideal observability can never be fulfilled within an infinite dimensional phase space in the case of scalar output. The case of bilinear discrete-time system with delays in observation is also described. To illustrate this work some examples are presented.
3
Content available An observer-based control of linear systems with uncertain parameters
Rachik M., Lhous M.
Archives of Control Sciences
|
2016
|
Vol. 26, no. 4
565--576
EN
In this paper, the observer-based control for a class of uncertain linear systems is considered. Exponential stabilizability for the system is studied and reduced-order observer is discussed. Numerical examples are given to illustrate obtained results.
4
Content available remote A quadratic optimal control problem for a class of linear discrete distributed systems
Rachik M., Lhous M., El Kahlaoui O., Labriji E., Jourhmane H.
International Journal of Applied Mathematics and Computer Science
|
2006
|
Vol. 16, no 4
431-440
EN
A linear quadratic optimal control problem for a class of discrete distributed systems is analyzed. To solve this problem, we introduce an adequate topology and establish that optimal control can be determined though an inversion of the appropriate isomorphism. An example and a numerical approach are given.
5
Content available remote Admissible disturbances for perturbed nonlinear discrete systems
Rachik M., Tridane A., Lhous M., Tridane Z.
Archives of Control Sciences
|
2006
|
Vol. 16, no. 3
297-314
EN
Consider the discrete perturbed controlled nonlinear system given by { xe (i+1)=Axe(i) + f(ζiui+ωi), i≥0 xe(0)=γx0+ψ The disturbance e is said to be ε-admissible if IIye(i) - y(i)II ≤ε, ∀≥0. The set of all ε-admissible disturbances is the admissible set σ(ε). The characterization of σ(ε) is investigated and practical algorithms with numerical simulation are given. The admissible set σd(ε) for discrete delayed systems is also considered.
6
Content available remote Optimizing the Linear Quadratic Minimum-Time Problem for Discrete Distributed Systems
Rachik M., Abdelhak A.
International Journal of Applied Mathematics and Computer Science
|
2002
|
Vol. 12, no 2
153-160
EN
With reference to the work of Verriest and Lewis (1991) on continuous finite-dimensional systems, the linear quadratic minimum-time problem is considered for discrete distributed systems and discrete distributed time delay systems. We treat the problem in two variants, with fixed and free end points. We consider a cost functional J which includes time, energy and precision terms, and then we investigate the optimal pair (N,u) which minimizes J.
7
Content available remote On the admissible perturbations for discrete systems
Rachik M., Abdelhak A.
Archives of Control Sciences
|
2002
|
Vol. 12, no. 3
301-313
EN
We consider a discrete system described by xi+1=Axi, i>0 with the output function yi=Cxi, i>0 which is subject to the constraints (...). Then we investigate the admissible nonlinear perturbations (Ni)i, i.e., the ones such that the corresponding perturbed output function (...) remains in the constraints set omega for all i>0.
8
Content available remote Admissible Disturbance Sets for Discrete Perturbed Systems
Bouyaghroumni J., El Jai A., Rachik M.
International Journal of Applied Mathematics and Computer Science
|
2001
|
Vol. 11, no 2
349-367
EN
We consider a discrete disturbed system given by the difference bilinear equation x^{w}_{i+1} =Ax^{w}_{i} + De_{i} + sum_{j=1}^{q}f^{j}_{i}B_{j}x^{w}_{i}, i geq 0, where w=((e_{i})_{i geq 0}, (f_{i})_{i geq 0}) are disturbances which excite the system in a linear and a bilinear form. We assume that the system is augmented with the output function y^{w}_{i}=Cx^{w}_{i}, i geq 0. Let varepsilon be a tolerance index on the output. The disturbance w is said to be varepsilon-admissible if ||y^{w}_{i}-y_{i}|| leq varepsilon, forall i geq 0, where (y_{i})_{i geq 0} is the output signal associated with the case of an uninfected system. The set of all varepsilon-admissible disturbances is the admissible set {cal W}(varepsilon). The characterization of {cal W}(varepsilon) is investigated and numerical simulations are given.
9
Content available remote Optimal control for bilinear systems with delay on control
Eljai A., Karrakchou J., Rachik M., Lhous M.
Archives of Control Sciences
|
2001
|
Vol. 11, no. 1/2
23-55
EN
The quadratic optimal control for bilinear distributed systems with delays in the control is considered. A semigroup model which involves no explicit delays in control is introduced. In the case of continuous delay, the control operator is bounded and the classical results can be applied. The case of general delays can be considered as a distributed system with boundary control. With the aid of a family of approximating systems, it is shown that the optimal control is obtained as a limit of sequence which is solution of classical control problems.
10
Content available remote Linear Quadratic Control Problem With Fixed Final State for Discrete-Time Distributed Systems
Chraibi L., Karrakchou J., Ouansafi A., Rachik M.
International Journal of Applied Mathematics and Computer Science
|
2000
|
Vol. 10, no 3
517-535
EN
The problem considered is that of minimizing a quadratic cost functional for a discrete distributed system with fixed initial and final states. It is shown that under suitable controllability assumptions, there is a close relationship between this problem and that of exact controllability with minimization of a time-varying energy criterion. The HUM technique is then extended to treat the exact controllability problem in the time-varying case and applied to provide an explicit form for the optimal control and the optimal cost.
11
Content available remote On the asymptotic stability of nonlinear discrete systems
Rachik M., Lhous M., Tridane A.
Archives of Control Sciences
|
2000
|
Vol. 10, no. 3/4
125-140
EN
Discrete nonlinear systems are considered. Inspired by what was done in (Banks et al., 1996) and (Hong et al., 1994), we develop some sufficient conditions which assure the stability of discrete-time nonlinear varying systems. The problem for discrete delayed systems is also considered.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.