Robust adaptive synchronization of dynamic networks with varying time delay coupling using varible structure control

The synchronization problem for a class of delayed complex dynamical networks via employing variable structure control has been explored and a solution proposed. The synchronization controller guarantees the state of the dynamical network is globally asymptotically synchronized to arbitrary state. The switching surface has been designed via the left eigenvector function of the system, and assures the synchronization sliding mode possesses stability. The hitting condition and the adaptive law for estimating the unknown network parameters have been used for designing the controller hence the network state hits the switching manifold in finite time. Two illustrative examples along with the respective simulation results are given, which employ the designed variable structure controllers

Superior performance of switched fuzzy control systems: An overview and simulation experiments

Dimirovski, Georgi M. (Dogus Author)This article gives a brief overview of the basic notions of switched fuzzy systems, their model construction and stability analysis, followed by the proposed concepts for building simulation algorithms for this type of systems. Using these concepts we have shown the whole process of modelling, stability analysis and design of stabilizing switching fuzzy logic controllers for the hovercraftvehicle as a typical nonholonomic system. MATLAB Simulator (Simulink model) and special MATLAB functions for the switching fuzzy controller of the hovercraft vehicle, along with the numerous simulation results, verify the correctness of the proposed concepts. Using this typical nonholonomic system we have also explored the good performance of switched fuzzy systems in comparison to the ordinary T-S fuzzy systems

Recent advances in analysis and control design for switched fuzzy systems: A review

Dimirovski, Georgi M. (Dogus Author) -- Conference full title: 2012 6th IEEE International Conference Intelligent Systems, Sofia, Bulgaria, September 6-8.This paper overviews recent advances in the field of switched fuzzy systems, switched systems whose subsystems are fuzzy systems, followed by the comparative study for this kind of systems. Starting with the basic ideas of switched fuzzy systems, the comparative study is aimed in introducing the diverse approaches in their model construction, as well as the challenges related with the stability analysis and stabilization of such systems. The last includes the issue of stability analysis and finding conditions for existence of switched fuzzy controllers which will stabilize the nonlinear system.The Ss Cyril and Methodius Universit

Synergy of switched-fuzzy and fuzzy-neural nonlinear systems enhances complexity and potential

Dimirovski, G. M. (Dogus Author) -- Conference full title: 2016 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2016; Budapest; Hungary; 9 October 2016 through 12 October.In this paper we present concepts for synergy of switched fuzzy and fuzzy-neural systems. First, an algorithm/procedure for neural network identification of switched fuzzy models, out of input-output data pairs is given. In order to use the existing stability and stabilization results in the field of switched fuzzy systems to the identified switched fuzzyneural models, an extension of the switched fuzzy model with levels of structure is presented. The proposed concepts are used for identification of discrete switched fuzzy models. To confirm the proposed algorithm/procedure, and the new extended model, a fuzzy-neural identification of the discrete switched fuzzy model for the nonholonomic WMR vehicle is presented. Based on the identified discrete switched fuzzy model for the WMR vehicle, design of discrete switched fuzzy controller is made. The simulation results show the effectiveness of the proposed concepts

Switched fuzzy control systems: Exploring the performance in applications

Dimirovski, Georgi M. (Dogus Author) -- Conference full title: EMS 2010 : proceedings : UKSim Fourth European Modelling Symposium on Computer Modelling and Simulation : 17-19 November 2010, Pisa, ItalyIn this paper we propose a concept for building simulation algorithms for switched fuzzy control systems. Using these concepts we have shown the whole process of modeling, stability analysis and design of stabilizing switched fuzzy logic controllers for the hovercraft-vehicle, as a typical nonholonomic system. Using this typical nonholonomic system (the system is subject to constraints involving both, the position and velocity, whereupon it can not be stabilized by any continuous feedback control law) we have also explored the good performance of switched fuzzy systems in comparison to the ordinary T-S fuzzy systems. MATLAB Simulator (Simulink model) and special MATLAB functions for the switched fuzzy controller of the hovercraft vehicle, along with the numerous simulation results, verify the correctness of the proposed concepts.UKSim, USM, Scuola Superiore Sant'Anna, Asia Modelling and Simulation Society (AMSS), Nottingham Trent University

FMS intelligent supervision and control 2: Communications among machines under FPSC

Some novel results on a organizing supervisory control, employing fuzzy Petri-net reasoning, along with intelligent communication protocols tailored for flexible manufacturing systems are proposed. Stochastic Petri-net supervisor has been derived via a synergy of fuzzy set and Petri net theories while intelligent communication protocols via object oriented emulation modeling and corresponding programming. These innovative technologies were tested through their application in parallel simulation of medium-size FMS model. Developed representation models have been derived by compatible usage of math-analytical queue, fuzzy Petri-net, and appropriate object-oriented models. Some simulations are presented to illustrate these novel developments

Uticaj podele prostora stanja na regıone prilikom projektovanja prebacivačkih fazi kontrolera

Dimirovski, Georgi M. (Dogus Author)In this paper we explore the influence of the state-space partitioning into specific regions, when designing switched fuzzy controllers, to the stability performance of the system. For examination purposes we have designed switched fuzzy model and appropriate switched fuzzy controller for a hovercraft vehicle, as a typical nonholonomic system. The design is made for four different ways of state-space partitioning. The simulation results verify the influence of the different partitioning of the state space to the control performance of the system.U ovom radu istražuje se uticaj podele prostora stanja u određenim regionima, prilikom projektovanja prebacivačkih fazi upravljača, na performanse stabilnosti sistema. Za svrhe ispitivanja projektovali smo prebacivački fazi model i odgovarajući prebacivački fazi upravljač za hovercraft vozila, kao tipični neholonomni sistem. Dizajn je napravljen za četiri različita načina podele prostora stanja. Rezultati simulacije verifikuju uticaj različitih podela prostora stanja na performanse upravljanja sistema

Fuzzy matrix game perspective for problems of cooperation, non-cooperation, and conflicts

Dimirovski, Georgi M. (Dogus Author) -- This article belongs to a special issue-12th IFAC Workshop on Supplementary Ways for Improving International StabilityIn societal applications of systems science where competition under conflicting interests is pertinent to, the decision making faces situations in which one must decide whether to cooperate or not with a competitor or opponent. Each of the opponents (‘players’) has as well as carries own missions within the society out. At least two if not more parties need to make decisions under fully or partially conflicting objectives when involved in a dispute or open conflict. By and large decisions must be made under risk, uncertainty, and incomplete or fuzzy information implying large amounts of linguistic and probabilistic information. For cases of two opponents, the synergy of fuzzy control approach and matrix games seems rather effective to represent and find solutions for such multi-criteria conflicting situations. The fuzzy procedure is used to take into account some of the subjective attitudes of the decision makers that are difficult to model using classical game theory

Enhanced control of electrical power system oscillations by GA optimized damping controller

Dimirovski, Georgi M. (Dogus Author) -- Conference full title: 2010 14th International Power Electronics and Motion Control Conference (EPE/PEMC 2010) : Ohrid, Macedonia, 6 - 8 September 2010A genetic algorithm based optimization technique for optimum design of power system damping controller in a multi-machine power system has been developed. In this technique, the genetic algorithm involves an objective function that is based on the integral of squared-time- squared-error criterion. Parameters of the power system stabilizers are tuned via simulation experiments based on a non-linear model of the system. The dynamic performance has been investigated under both small and large disturbance perturbation, and compared with the case of conventional optimization using phase compensation. Simulation experiments have demonstrated the proposed genetic-algorithm optimized power system stabilizers do enhance quality dynamic performance over a wide range of operating conditions by effectively damping both local and inter-area oscillation modes.ELEM, Repub. Macedonia Chamb. Certif. Archit. Certif. Eng

Domain of attraction estimation for SIRS epidemic models via sum-of-square optimization

Dimirovski, Georgi M. (Dogus Author)Estimation of the domain of attraction of a class of susceptible infectious removed susceptible (SIRS) epidemic models for varying-size population with constant immigration is investigated. On assumption that the disease-free equilibrium and the endemic equilibrium exist, the domain of attraction of epidemic model is estimated by using sum-of-squares optimization approach. An invariant subset of domain of attraction is computed and an enlargement obtained. Simulation results, given in a comparison presentation, demonstrate feasibility and validity of the proposed technique as well as reveal that this algorithm outperforms other ones in applications to the epidemic model.This work is supported by the National Natural Science Foundation of China (grant 60774097) and Fundamental Research Funds for the Central Universities of P.R. China (grant N100604019), by Ministry of Education and Science of the R. Macedonia (grant 14-3154/1- 17.12.2007), and by Dogus University Fund for Science