Complex mixed-mode oscillations based on a modified Rayleigh-Duffing oscillator driven by low-frequency excitations.

The complex mixed-mode oscillation patterns are proposed and analyzed in a modified Rayleigh-Duffing oscillator based on the bifurcation theory in this paper. Four mixed-mode oscillations, namely "Homoclinic/Homoclinic-Homoclinic/Homoclinic" intermittent type, "fold/Homoclinic-Homoclinic/supHopf" intermittent type, "fold/Homoclinic-supHopf/supHopf" intermittent type and "fold/Homoclinic" type, are discussed in detail. Considering the low frequency excitations as slow-changing state variables, a modified autonomous system is obtained. The bifurcation characteristics of the fast subsystem are presented briefly by using the bifurcation theory. Then, we investigate the generation principle of the bifurcation delay phenomenon that performs a critical role in the production of two mixed-mode oscillations. This paper presents a fact that the dynamical behaviors are sensitive to the values of the system parameters and the parameters determine different forms of the repetitive spiking states that leads to different patterns of the mixed-mode oscillations. In addition, the theoretical analysis and numerical simulations are compared to illustrate the correctness of this paper. • A route to mixed-mode oscillations named "Hopf bifurcation delay" is proposed. • A modified autonomous system is obtained by considering the low frequency excitations as slow-varying state variables. • Two Hopf-bifurcation-delay-triggered mixed-mode oscillations and two pure bifurcation-structure-induced mixed-mode oscillations are investigated. • Dynamical evolutions among different bursting patterns are studied by the two-parameter bifurcation diagram. [ABSTRACT FROM AUTHOR]