Browsing by Subject "Chaos control"

Now showing 1 - 15 of 15

Open Access
Further stability results for a generalization of delayed feedback control
(Springer, 2012-08-01) Morgül, Ö.
In this paper, we consider the stabilization of unstable periodic orbits for one-dimensional and discrete time chaotic systems. Various control schemes for this problem are available and we consider a recent generalization of delayed control scheme. We prove that if a certain condition, which depends only on the period number, is satisfied then the stabilization is always possible. We will also present some simulation results.
Open Access
A model-based scheme for anticontrol of some chaotic systems
(World Scientific Publishing, 2003) Morgül, Ö.
We consider a model-based approach for the anticontrol of some continuous time systems. We assume the existence of a chaotic model in an appropriate form. By using a suitable input, we match the dynamics of the controlled system and the chaotic model. We show that controllable systems can be chaotifled with the proposed method. We give a procedure to generate such chaotic models. We also apply an observer-based synchronization scheme to compute the required input.
Open Access
A model-based scheme for anticontrol of some discrete-time chaotic systems
(World Scientific, 2004) Morgül, Ö.
We consider a model-based approach for the anticontrol of some discrete-time systems. We first assume the existence of a chaotic model in an appropriate form. Then by using an appropriate control input we try to match the controlled system with the chaotic system model. We also give a procedure to generate the model chaotic systems in arbitrary dimensions. We show that with this approach, controllable systems can always be chaotified. Moreover, if the system to be controlled is stable, control input can be chosen arbitrarily small.
Open Access
A new delayed feedback control scheme for discrete time chaotic systems
(IFAC, 2009) Morgül, Ömer
In this paper we consider the stabilization problem of unstable periodic orbits of discrete time chaotic systems. We consider both one dimensional and higher dimensional cases. We propose a novel generalization of the classical delayed feedback law and present some stability results. These results show that for period 1 all hyperbolic periodic orbits can be stabilized with the proposed method. Although for higher order periods the proposed scheme may possess some limitations, some improvement over the classical delayed feedback scheme still can be achieved with the proposed scheme. The stability proofs also give the possible feedback gains which achieve stabilization. We will also present some simulation results.
Open Access
A new generalization of delayed feedback control
(World Scientific Publishing Co. Pte. Ltd., 2009) Morgül, Ö.
In this paper, we consider the stabilization problem of unstable periodic orbits of one-dimensional discrete time chaotic systems. We propose a novel generalization of the classical delayed feedback law and present some stability results. These results show that for period 1 all hyperbolic periodic orbits can be stabilized by the proposed method; for higher order periods the proposed scheme possesses some inherent limitations. However, some more improvement over the classical delayed feedback scheme can be achieved with the proposed scheme. The stability proofs also give the possible feedback gains which achieve stabilization. We will also present some simulation results.
Open Access
A new periodic controller for discrete time chaotic systems
(IFAC, 2010) Morgül, Ömer
In this paper we consider the stabilization problem of unstable periodic orbits of discrete time chaotic systems. For simplicity we consider only one dimensional case. We propose a novel periodic feedback controller law and present some stability results. This scheme may be considered as a novel generalization of the classical delayed feedback scheme, which is also known as Pyragas scheme. The stability results show that all hyperbolic periodic orbits can be stabilized with the proposed method. The stability proofs also give the possible feedback gains which achieve stabilization. We will also present some simulation results.
Open Access
A nonlinear control scheme for discrete time chaotic systems
(The International Federation of Automatic Control, 2012-06) Morgül, Ömer
In this paper we consider the stabilization problem of unstable periodic orbits of discrete time chaotic systems. We consider both one dimensional and higher dimensional cases. We propose a nonlinear feedback law and present some stability results. These results show that for period 1 all hyperbolic periodic orbits can be stabilized with the proposed method. By restricting the gain matrix to a special form we obtain some novel stability results. The stability proofs also give the possible feedback gains which achieve stabilization. We also present some simulation results.
Open Access
On the stability of delayed feedback controllers
(Elsevier, 2003) Morgül, Ö.
We consider the stability of delayed feedback control (DFC) scheme for one-dimensional discrete time systems. We first construct a map whose fixed points correspond to the periodic orbits of the uncontrolled system. Then the stability of the DFC is analyzed as the stability of the corresponding equilibrium point of the constructed map. For each periodic orbit, we construct a characteristic polynomial whose Schur stability corresponds to the stability of DFC. By using Schur-Cohn criterion, we can find bounds on the gain of DFC to ensure stability. © 2003 Elsevier B.V. All rights reserved.
Open Access
On the stability of delayed feedback controllers for discrete time systems
(Elsevier, 2005) Morgül, Ö.
We consider the stability of delayed feedback control (DFC) scheme for multi-dimensional discrete time systems. We first construct a map whose fixed points correspond to the periodic orbits of the uncontrolled system. Then the stability of the DFC is analyzed as the stability of the corresponding equilibrium point of the constructed map. For each periodic orbit, we construct a characteristic polynomial whose Schur stability corresponds to the stability of DFC scheme. © 2005 Elsevier B.V. All rights reserved.
Open Access
On the stabilization of periodic orbits for discrete time chaotic systems
(Elsevier, 2005-02) Morgül, Ö.
In this Letter we consider the stabilization problem of unstable periodic orbits of discrete time chaotic systems. We propose a novel and simple periodic delayed feedback law and present some stability results. These results show that all hyperbolic periodic orbits as well as some non-hyperbolic periodic orbits can be stabilized with the proposed method. The stability proofs also give the possible feedback gains which achieve stabilization. We will also present some simulation results.
Open Access
On the stabilization of periodic orbits for discrete time chaotic systems by using scalar feedback
(World Scientific Publishing Co. Pte. Ltd., 2007) Morgül, Ö.
In this paper we consider the stabilization problem of unstable periodic orbits of discrete time chaotic systems by using a scalar input. We use a simple periodic delayed feedback law and present some stability results. These results show that all hyperbolic periodic orbits as well as some nonhyperbolic periodic orbits can be stabilized with the proposed method by using a scalar input, provided that some controllability or observability conditions are satisfied. The stability proofs also lead to the possible feedback gains which achieve stabilization. We will present some simulation results as well.
Open Access
Stability of delayed feedback controllers for discrete time systems
(IEEE, 2003) Morgül, Ömer
We consider the delayed feedback control (DFC) scheme for one dimensional discrete time systems. To analyze the stability, we construct a map whose fixed points correspond to the periodic orbits of the system to be controlled. Then the stability of the DFC is equivalent to the stability of the corresponding equilibrium point of the constructed map.
Open Access
A stability result for delayed feedback controllers
(IEEE, 2003) Morgül, Ömer
We consider the delayed feedback control (DFC) scheme for one dimensional discrete time systems. To analyze the stability, we construct a map whose fixed points correspond to the periodic orbits of the system to be controlled. Then the stability of the DFC is equivalent to the stability of the corresponding equilibrium point of the constructed map. We obtain a formula for the characteristic polynomial of the Jacobian of this map. Then the Schur stability of this polynomial could be used to analyze the stability of DFC. We also present some simulation results.
Open Access
Stability results for some periodic feedback controllers
(IFAC, 2005) Morgül, Ömer
We propose two periodic feedback schemes for the stabilization of periodic orbits for one dimensional discrete time chaotic systems. These schemes can be generalized to higher dimensional systems in a straightforward way. We show that the proposed schemes achieve stabilization of a wide range of periodic orbits. The proposed schemes are quite simple and we show that any hyperbolic periodic orbit can be stabilized with these schemes. We also present some simulation results.
Open Access
Stabilization of unstable periodic orbits for discrete time chaotic systems by using periodic feedback
(World Scientific Publishing, 2006) Morgül, Ö.
We propose a periodic feedback scheme for the stabilization of periodic orbits for discrete time chaotic systems. We first consider one-dimensional discrete time systems and obtain some stability results. Then we extend these results to higher dimensional discrete time systems. The proposed scheme is quite simple and we show that any hyperbolic periodic orbit can be stabilized with this scheme. We also present some simulation results. © World Scientific Publishing Company.