This paper constructs a three-dimensional (3D) memristor-based system for creating multiwing chaotic attractors. A second-degree polynomial memristance function and a sixth-order exponent internal state memristor function with one parameter are employed, and the complexity of attractors is increased. A detailed analysis on dynamical behaviors of the proposed system are described, such as the bifurcation diagrams, finite-time local Lyapunov exponents, time series, phase portraits, and Poincaré maps. By adjusting the design parameters, the system displays two-to-eight-wing chaotic attractors, especially the five-wing and seven-wing attractors, which have never been found in the known systems. Further, we provide the calculation formula of the number of wings in the system, discuss the distribution of the involving inner holes on the plane, and design an electronic circuit to realize the proposed system. The experimental results of the circuit implementation agree with the numerical simulations on Matlab well. It indicates the potential engineering applications for various chaos-based information systems.
KEYWORDSchaotic system, circuit implementation, Lyapunov exponents, memristor, the number of the wings
INTRODUCTIONAfter the first solid state realization of a memristor was successfully fabricated in 2008 by researchers at HP, 1 memristor, the new two-terminal circuit element postulated by Chua 2 in 1971 and classified by Chua and Kang 3 in 1976, has been well known and studied thanks to its potential applications in neural networks, novel storage medium, artificial intelligence, and a wide range of other chaotic circuit. 4-12 Since the mathematical model involving chaos was first suggested by Lorenz 13 in 1963 and the term chaos was first used by Li and Yorke 14 in 1975, the design of new chaotic systems with complex topological structures are attracting more and more interest in the research. [15][16][17][18][19][20][21][22][23][24][25][26] In 1993, Stone and Miranda observed first multiwing chaotic attractor from a proto-Lorenz system. 27 Since then, people has found that a wide variety of memristor-based systems can exhibit the complicated dynamics, particularly in birth of multiwing attractors. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] This problem is interesting, especially in the case of a simple, low-dimensional system with less equilibrium points, more wings, and more coexisting attractors. The multiwing or multiscroll 45-53 chaotic attractors with more complex is of the meaningful applications in many fields, particularly, including chaotic broad band radio, encryption, and secure communication. 54 In the reported multiwing systems, most memristor models are based on 686