Resonance phenomena caused by mixed coupling in tristable systems

Abstract Coupled systems have been widely encountered and have aroused much great interest in improving the response output of the system. Scholars pay more attention to the use of vibration resonance or stochastic resonance to amplify weak signals, but few examine the role of mixed coupling on the system response. The amplifying effect of mixed coupling on signal in tristable oscillators is studied in this paper. The spectral amplification factor, which is used to measure the amplification, shows a resonance peak with the coupling strength. The optimal coupling strength can be found to achieve the maximum output of the system. Moreover, the influence of the depth and position of the potential well on the response output is also analyzed. The results show that the properties of tristable oscillators can change the coupling threshold as well as improve amplification. We speculate that, in addition to the mixed coupling, the intrinsic mechanism of this behavior may be due to the different shapes of the tristable oscillators and their modes of variation. It provides new thoughts for amplifying and detecting weak signals in coupled systems.