多频响应的压电振动能量采集器的性能分析与测试

为了提升压电悬臂梁采集振动能量的能力，研究了一种具有多频振动响应的振动能量采集器。在压电悬臂梁与振动激励源之间增加一个附加梁，压电悬臂梁和附加梁的末端分别安装一个质量块，压电悬臂梁和附加梁垂直连接。附加梁的末端质量被设计为远大于压电梁的末端质量，而压电梁的一阶谐振频率在附加梁的前两阶谐振频率之间。采用该设计，压电悬臂梁的振动响应是多个谐振频带的叠加。通过建立机电解析模型，描述了所提出的振动能量采集器的振动响应和发电特性，同时制作了一个振动能量采集器样机进行试验，结果表明，与传统的悬臂梁振动能量采集器相比，所提出的振动能量采集器可以在更宽的频带范围内采集更多的振动能量。

Performance Analyses and Experiments of a Piezoelectric Vibration Energy Harvested with Multifrequency Response Capability

To improve performance of vibration energy harvesting for piezoelectric cantilever, a vibration energy harvester with multifrequency responses was presented. An auxiliary beam was inserted between the piezoelectric cantilever and vibration base. Two tip masses were installed at the end of the piezoelectric beam and the auxiliary beam respectively. The two beams were connected perpendicularly. The weight of the auxiliary beam mass was designed to be much greater than that of the piezoelectric beam, and the first natural frequency of the piezoelectric beam was chosen between the first two natural frequencies of the auxiliary beam. In this way, the vibration response of the piezoelectric beam is just the sum of multiple frequency bands. An analytical electromechanical model was proposed to describe vibration response and energy harvesting feature of the proposed harvester. A prototype device was developed for testing. The results show that, compared to the conventional cantilevered piezoelectric harvester, the proposed one is capable of harvesting much energy in a broader frequency band.