Controlling vibrational resonance in a delayed multistable system driven by an amplitude-modulated signal

Abstract

The phenomenon of vibrational resonance (VR) in a delayed multistable system, which is two coupled overdamped anharmonic oscillators influenced by an amplitude-modulated signal, is numerically studied. Different from traditional VR theory, in the present paper, the appearance and disappearance of the VR are made by modulating the delay parameter instead of adjusting the amplitude of the high-frequency signal. Namely, the VR is weakened or enhanced by the time delay feedback. Furthermore, the response amplitude of the system at low frequency varies periodically with respect to the delay parameter, and the period is just equal to the cycle of the high-frequency signal. With the result given by this paper, one can weaken or enhance the weak low-frequency signal in the nonlinear system by controlling the delay parameter.