scholarly journals ExponentialH∞Synchronization of Chaotic Cryptosystems Using an Improved Genetic Algorithm

2015 ◽  
Vol 2015 ◽  
pp. 1-22
Author(s):  
Feng-Hsiag Hsiao
Keyword(s):  
Genetic Algorithm ◽  
Design Methodology ◽  
Fuzzy Controller ◽  
Disturbance Attenuation ◽  
Secure Communications ◽  
Multiple Time ◽  
Systematic Design ◽  
Improved Genetic Algorithm ◽  
Attenuation Level ◽  
Disturbance Attenuation Level

This paper presents a systematic design methodology for neural-network- (NN-) based secure communications in multiple time-delay chaotic (MTDC) systems with optimalH∞performance and cryptography. On the basis of the Improved Genetic Algorithm (IGA), which is demonstrated to have better performance than that of a traditional GA, a model-based fuzzy controller is then synthesized to stabilize the MTDC systems. A fuzzy controller is synthesized to not only realize the exponential synchronization, but also achieve optimalH∞performance by minimizing the disturbance attenuation level. Furthermore, the error of the recovered message is stated by using then-shift cipher and key. Finally, a numerical example with simulations is given to demonstrate the effectiveness of our approach.

Dual-finite distributed H∞ filtering in sensor networks

2021 ◽  
pp. 095965182199758
Author(s):  
Changshuo Wang ◽  
Jiwei Wen ◽  
Xiaoli Luan
Keyword(s):  
Sensor Networks ◽  
Disturbance Attenuation ◽  
Time Interval ◽  
Frequency Range ◽  
Frequency Scale ◽  
Attenuation Level ◽  
Exogenous Noise ◽  
Disturbance Attenuation Level ◽  
Reference Input ◽  
Filtering Approach

Generally, distributed H∞ filtering approach achieves a certain disturbance attenuation level in the full frequency range. However, the energy of system noise or reference input usually limits in a specified frequency range. To reduce such a design conservatism, this article develops a distributed filtering approach based on dual scale, that is, filtering over a finite-time interval from time scale and also on a specified finite-frequency region from the frequency scale. Our target is to make the filtering error under sensor networks monitoring be relaxed into an ellipsoid bound rather than asymptotically converging to zero for exogenous noise in a specified frequency range. Finally, two illustrative examples demonstrate the strength of the developed filtering approach.

scholarly journals NonlinearL2-Gain Analysis of Hybrid Systems in the Presence of Sliding Modes and Impacts

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
T. Osuna ◽  
O. E. Montano ◽  
Y. Orlov
Keyword(s):  
Sliding Mode ◽  
Numerical Study ◽  
Sufficient Conditions ◽  
Disturbance Attenuation ◽  
Sliding Modes ◽  
Time Dynamics ◽  
Attenuation Level ◽  
Disturbance Factor ◽  
Disturbance Attenuation Level ◽  
The Impact

TheL2-gain analysis is extended towards hybrid mechanical systems, operating under unilateral constraints and admitting both sliding modes and collision phenomena. Sufficient conditions for such a system to be internally asymptotically stable and to possessL2-gain less than ana priorigiven disturbance attenuation level are derived in terms of two independent inequalities which are imposed on continuous-time dynamics and on discrete disturbance factor that occurs at the collision time instants. The former inequality may be viewed as the Hamilton-Jacobi inequality for discontinuous vector fields, and it is separately specified beyond and along sliding modes, which occur in the system between collisions. Thus interpreted, the former inequality should impose the desired integral input-to-state stability (iISS) property on the Filippov dynamics between collisions whereas the latter inequality is invoked to ensure that the impact dynamics (when the state trajectory hits the unilateral constraint) are input-to-state stable (ISS). These inequalities, being coupled together, form the constructive procedure, effectiveness of which is supported by the numerical study made for an impacting double integrator, driven by a sliding mode controller. Desired disturbance attenuation level is shown to satisfactorily be achieved under external disturbances during the collision-free phase and in the presence of uncertainties in the transition phase.

Robust Delay-Dependent H∞ Control for Uncertain Structural Systems With Actuator Delay

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Hakan Yazici ◽  
Rahmi Guclu ◽  
Ibrahim B. Kucukdemiral ◽  
M. N. Alpaslan Parlakci
Keyword(s):  
Optimization Technique ◽  
Time History ◽  
Disturbance Attenuation ◽  
Structural Systems ◽  
Attenuation Level ◽  
Uncertainty Bound ◽  
Disturbance Attenuation Level ◽  
Delay Dependent ◽  
Bounded Uncertainties ◽  
Norm Bounded Uncertainties

This paper is concerned with the design of a robust, state-feedback, delay-dependent H∞ controller for an active vibration control of seismic-excited structural systems having actuator delay, norm bounded uncertainties, and L2 disturbances. The norm bounded uncertainties are assumed to exist in variations of structural stiffness and damping coefficients. Based on the selection of Lyapunov–Krasovskii functional, first a bounded real lemma (BRL) is obtained in terms of linear matrix inequalities (LMIs) such that the nominal, time-delay system is guaranteed to be globally asymptotically stable with minimum allowable disturbance attenuation level. Extending BRL, sufficient delay-dependent criteria are developed for a stabilizing H∞ controller synthesis involving a matrix inequality for which a nonlinear optimization algorithm with LMIs is proposed to get feasible solution to the problem. Moreover, for the case of existence of norm-bounded uncertainties, both the BRL and H∞ stabilization criteria are easily extended by employing a well-known bounding technique. Then, a cone complementary algorithm is also utilized to solve the nonconvex optimization problem. By use of the proposed method, a suboptimal controller with maximum allowable delay bound, uncertainty bound and minimum allowable disturbance attenuation level can be easily obtained by solving the proposed convex optimization technique. A four-degree-of-freedom uncertain structural system subject to seismic excitations is used to illustrate the effectiveness of the approach through simulations. Simulation results, obtained by using real time-history data of Kobe and Kocaeli earthquakes show that the proposed controller is very effective in reducing vibration amplitudes of storeys and guarantees stability at maximum actuator delay and parametric uncertainty bound.

scholarly journals Multicriteria Adaptive Observers for Singular Systems with Unknown Time-Varying Parameters

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wookyong Kwon ◽  
Jaepil Ban ◽  
Soohee Han ◽  
Chong Soo Lee ◽  
Sangchul Won
Keyword(s):  
Singular Systems ◽  
Disturbance Attenuation ◽  
Estimation Accuracy ◽  
Time Varying ◽  
Varying Parameters ◽  
Integral Action ◽  
Attenuation Level ◽  
Adaptive Observers ◽  
Time Varying Parameters ◽  
Disturbance Attenuation Level

This paper proposes multicriteria adaptive observers for a class of singular systems with unknown time-varying parameters. Two criteria for theH∞disturbance attenuation level and the upper bound of an ultimate invariant set are scalarized into a single cost function and then it is minimized by varying the weight parameter, which creates the optimal trade-off curve or Pareto optimal points. The proposed multicriteria adaptive observers are shown to be able to easily include integral action for better robust performance. It is demonstrated with numerical simulations that the proposed multicriteria adaptive observers provide the good estimation accuracy and allow effective and compromising design by considering two different cost functions simultaneously.

scholarly journals H∞Filtering for Networked Markovian Jump Systems with Multiple Stochastic Communication Delays

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Hui Dong ◽  
Juntong Chen
Keyword(s):  
Filter Design ◽  
Design Method ◽  
Disturbance Attenuation ◽  
Markovian Jump Systems ◽  
Communication Delays ◽  
Markovian Jump ◽  
Attenuation Level ◽  
Measurement Signal ◽  
Disturbance Attenuation Level ◽  
Jump Systems

This paper is concerned with theH∞filtering for a class of networked Markovian jump systems with multiple communication delays. Due to the existence of communication constraints, the measurement signal cannot arrive at the filter completely on time, and the stochastic communication delays are considered in the filter design. Firstly, a set of stochastic variables is introduced to model the occurrence probabilities of the delays. Then based on the stochastic system approach, a sufficient condition is obtained such that the filtering error system is stable in the mean-square sense and with a prescribedH∞disturbance attenuation level. The optimal filter gain parameters can be determined by solving a convex optimization problem. Finally, a simulation example is given to show the effectiveness of the proposed filter design method.

DESIGNING CNN GENES

2003 ◽  
Vol 13 (10) ◽  
pp. 2739-2824 ◽  
Author(s):  
MAKOTO ITOH ◽  
LEON O. CHUA
Keyword(s):  
Genetic Algorithm ◽  
Design Methodology ◽  
Signal Propagation ◽  
Systematic Design ◽  
Stable States ◽  
Propagation Property ◽  
Gene Design

A systematic design methodology for finding CNN parameters with prescribed functions is proposed. A given function (task) is translated into several local operations, and they are realized as stable states of the CNN system. Many CNN parameters (CNN genes) with the same functions can be easily derived by using this design methodology. A genetic algorithm based CNN gene design methodology is also proposed. Two new genetic "activation and inactivation" operations are introduced to generate CNN genes effectively. Many useful CNN genes can be obtained systematically from known genes by using these genetic operations. Furthermore, the signal propagation property for activated and inactivated CNN genes is studied.

Optimal H∞ Fuzzy Control for Nonlinear Interconnected Systems via Genetic Algorithm

2013 ◽  
Vol 459 ◽  
pp. 256-261
Author(s):  
Feng Hsiag Hsiao ◽  
Chien Yu Liu
Keyword(s):  
Genetic Algorithm ◽  
Fuzzy Control ◽  
Direct Method ◽  
Random Search ◽  
Disturbance Attenuation ◽  
Interconnected Systems ◽  
Space Representation ◽  
Multiple Time ◽  
Interconnected System ◽  
Fuzzy Controllers

This paper presents an effective approach for stabilizing nonlinear multiple time-delay (NMTD) interconnected systems via a composite of genetic algorithm (GA) and fuzzy controllers. First, a neural-network (NN) model is employed to approximate each subsystem with multiple time delays. Then, the dynamics of the NN model is converted into a linear differential inclusion (LDI) state-space representation. Next, in terms of Lyapunov's direct method, a delay-dependent stability criterion is derived to guarantee the exponential stability of the NMTD interconnected system. Subsequently, the stability condition of this criterion is reformulated into a linear matrix inequality (LMI). Due to the capability of GA in a random search for global optimization, the lower and upper bounds of the search space can be set so that the GA will seek better feedback gains of fuzzy controllers in order to stabilize more quickly the NMTD interconnected system based on the feedback gains via LMI-based approach. According to the Improved genetic algorithm (IGA), which is demonstrated to have better performance than that of a traditional GA, a robustness design of fuzzy control is synthesized not only to stabilize the NMTD interconnected system but also to achieve optimal H performance by minimizing the disturbance attenuation level.

scholarly journals Control for Networked Control Systems with Time Delays and Packet Dropouts

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Yilin Wang ◽  
Hamid Reza Karimi ◽  
Zhengrong Xiang
Keyword(s):  
Control Systems ◽  
Networked Control Systems ◽  
Average Dwell Time ◽  
Networked Control ◽  
Disturbance Attenuation ◽  
Linear Matrix ◽  
Packet Dropouts ◽  
Attenuation Level ◽  
Mean Square Exponential Stability ◽  
Disturbance Attenuation Level

This paper is concerned with the control issue for a class of networked control systems (NCSs) with packet dropouts and time-varying delays. Firstly, the addressed NCS is modeled as a Markovian discrete-time switched system with two subsystems; by using the average dwell time method, a sufficient condition is obtained for the mean square exponential stability of the closed-loop NCS with a desired disturbance attenuation level. Then, the desired controller is obtained by solving a set of linear matrix inequalities (LMIs). Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

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