Stochastic resonance of multi-stable energy harvesting system with high-order stiffness from rotational environment

This paper aims to study the stochastic resonance of multi-stable energy harvesting system and enhance the performance of energy harvesting from random rotational environment. The influences of high-order stiffness terms and multi-stable characteristics are analyzed. The spectral amplification is derived to quantify the stochastic resonance for the energy harvesting system with penta-stable configuration driven by noise and periodic forcing. The non-monotonic dependence of spectral amplification on noise intensity indicates the existence of stochastic resonance. In particular, a critical high-order stiffness coefficient is revealed, for which the stochastic resonance is optimum. Meanwhile, the maximum of spectral amplification can be optimized by choosing appropriate unstable equilibrium positions. In addition, it is found that both the average input energy and the overall efficiency in power conversion can be further enhanced under conditions of stochastic resonance. Finally, the penta-stable energy harvester demonstrates a good performance in output power for different noise intensities and damping coefficients.