悬臂梁压电振子宽带低频振动能量俘获的随机共振机理研究

研究了利用系统非线性来提高悬臂梁压电振子宽带低频振动能量俘获效率的随机共振机理,通过增加一对矩形永磁铁对传统线性悬臂梁压电振子结构进行了改进,结果揭示:在外部非线性磁力作用以及合适的磁铁间距条件下,这种外加磁力悬臂梁压电振子会构成一个双稳系统,在外部宽带低频随机振动源激励下发生随机共振现象,且发生随机共振时的输出电压明显增大,从而可以扩展悬臂梁压电振子的共振频率范围、提高低频振动能量的转化输出. 关键词： 压电悬臂粱 振动能量俘获 宽带低频 随机共振

Stochastic resonance mechanism for wideband and low frequency vibration energy harvesting based on piezoelectric cantilever beams

A stochastic resonance mechanism of improving wideband and low frequency vibration energy harvesting of piezoelectric cantilever beam (PCB) is studied using the system nonlinearity. By adding a pair of rectangular permanent magnets, the structure of standard piezoelectric cantilever beam is improved. Results reveal that the improved PCB may be a bistable system under a nonlinear magnetic force and an appropriate distance between two magnets. Then a stochastic resonance phenomenon will happen by the input of wideband and low frequency stochastic vibrations. Under the condition of stochastic resonance, the electrical output of the improved PCB increases greatly. So the proposed method will be useful for extending the resonant band and improving the electrical output of a standard PCB.