Navegando por Autor "Torricos, Rene Orlando Medrano"

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An inductor-free realization of the Chua’s circuit based on electronic analogy.
(2009) Rocha, Ronilson; Torricos, Rene Orlando Medrano
Although literature presents several alternatives, an approach based on the electronic analogy was still not considered for the implementation of an inductor-free realization of the double scroll Chua’s circuit. This paper presents a new inductor-free configuration of the Chua’s circuit based on the electronic analogy. This proposal results in a versatile and functional inductorless implementation of the Chua’s circuit that offers new and interesting features for several applications. The analogous circuit is implemented and used to perform an experimental mapping of a large variety of attractors.
Chua circuit based on the exponential characteristics of semiconductor devices.
(2022) Rocha, Ronilson; Torricos, Rene Orlando Medrano
The use of non-ideal features of semiconductor devices is an interesting option for implementations of nonlinear electronic systems. This paper analyzes the Chua circuit with nonlinearity based on the expo- nential hyperbolic characteristics of semiconductor devices. The stability analysis using describing func- tions predicts the dynamics of this nonlinear system, which is corroborated by numerical investigations and experimental results. The dynamic behaviors and bifurcations of this nonlinear system are mapped in parameter space in order to create a base for studies, analyses, and designs. The dynamic behavior of the experimental high speed implementation of this version of Chua circuit differs from the expected dynamics for a conventional Chua circuit due to effects of unmodelled non-idealities of the real semicon- ductor devices, displaying that new and different dynamics for the Chua circuit can be obtained exploring different nonlinearities.
Experimental characterization of nonlinear systems : a real-time evaluation of the analogous Chua’s circuit behavior.
(2010) Rocha, Ronilson; Andrucioli, Guilherme Lucio Damião; Torricos, Rene Orlando Medrano
This paper presents an experimental characterization of the behavior of an analogous version of the Chua’s circuit. The electronic circuit signals are captured using a data acquisition board (DAQ) and processed using LabVIEW environment. The following aspects of the time series analysis are analyzed: time waveforms, phase portraits, frequency spectra, Poincaré sections, and bifurcation diagram. The circuit behavior is experimentally mapped with the parameter variations, where are identified equilibrium points, periodic and chaotic attractors, and bifurcations. These analysis techniques are performed in real-time and can be applied to characterize, with precision, several nonlinear systems.
Finding hidden oscillations in the operation of nonlinear electronic circuits.
(2016) Rocha, R.; Torricos, Rene Orlando Medrano
Several dynamic behaviours can simultaneously coexist in the operation of a nonlinear electronic circuit. However, some of these dynamics are difficult to be observed due to their sensibility to initial conditions. The use of describing functions to determine the coexistence of multiple dynamics in the operation of an electronic circuit with nonlinear feedback is proposed.
Self-similarities of periodic structures for a discrete model of a two-gene system.
(2012) Souza, Silvio Luiz Thomaz de; Lima, Angélica Alves; Caldas, Iberê Luiz; Torricos, Rene Orlando Medrano; Guimarães Filho, Zwinglio de Oliveira
We report self-similar properties of periodic structures remarkably organized in the two-parameter space for a two-gene system, described by two-dimensional symmetric map. The map consists of difference equations derived from the chemical reactions for gene expression and regulation. We characterize the system by using Lyapunov exponents and isoperiodic diagrams identifying periodic windows, denominated Arnold tongues and shrimp-shaped structures. Period-adding sequences are observed for both periodic windows. We also identify Fibonacci-type series and Golden ratio for Arnold tongues, and period multiple-of-three windows for shrimps.
Stability analysis and mapping of multiple dynamics of Chua’s circuit in full four-parameter SpacesV.
(2015) Rocha, Ronilson; Torricos, Rene Orlando Medrano
The stability analysis is used in order to identify and to map different dynamics of Chua’s circuit in full four-parameter spaces. The study is performed using describing functions that allow to identify fixed point, periodic orbit, and unstable states with relative accuracy, as well as to predict route to chaos and hidden dynamics that conventional computational methods do not detect. Numerical investigations based on the computation of eigenvalues and Lyapunov exponents partially support the predictions obtained from the theoretical analysis since they do not capture the multiple dynamics that can coexist in the operation of Chua’s circuit. Attractors obtained from initial conditions outside of neighborhoods of the equilibrium points confirm the multiplicity of dynamics in the operation of Chua’s circuit and corroborate the theoretical analysis.
The negative side of Chua’s circuit parameter space : stability analysis, period-adding, basin of attraction metamorphoses, and experimental investigation.
(2014) Torricos, Rene Orlando Medrano; Rocha, Ronilson
Although Chua’s circuit is one of the most studied nonlinear dynamical systems, its version with negative parameters remains practically untouched. This work reports an interesting and rich dynamic scenery that was hidden in this almost unexplored region. The study is focused on 2D parameter space and presents an analysis of stability based on describing functions. Numerical investigations present a gallery of period-adding cascades and a strong presence of basin boundary metamorphoses. The key to this new scenario is that for negative parameters, Chua’s system does not satisfy the Shilnikov condition and it is shown that the homoclinic orbit organizes the parameter space completely different from as known. The obtained experimental results corroborate with the numerical and theoretical investigations.