高斯白噪声激励下压电振动能量采集系统的随机共振OA

A bistable piezoelectric vibration energy harvesting system driven by Gaussian white noise and harmonic excitation is introduced to study the energy harvesting capability of rotating automotive tire.Firstly,the generalized harmonic transform method is applied to equivalently decompose the coupled voltage terms in the piezoelectric vibration energy harvesting system.Secondly,the stochastic averaging method is used to derive the stationary probability density of the equivalently decoupled system,based on which the average output power is computed.Thirdly,the signal-to-noise ratio expression is obtained based on two-state model theory.Lastly,the effects of Gaussian white noise and other parameters on the stochastic resonance of the system are investigated in detail.The results show that the non-monotonic evolution trend of the signal-to-noise ratio curve indicates the occurrence of stochastic resonance phenomena.With the increase of noise intensity and coupling coefficient,the stochastic resonance behavior is enhanced apparently.It is also found that the evolution of average output power with parameter variation demonstrates a consistent trend to that of the signal-to-noise ratio curves.In particular,when the additive noise intensity is increased from 0.005 to 0.02 to induce the emergence of stochastic resonance,the power conversion efficiency is increased by 50%and the average output power is increased by 10-3 mW,and when the time-constant ratio is increased from 0.018 to 0.022,the power conversion efficiency is increased by 35%and the average output power is increased by 8×10-3 mW.