摘要
设计了一种安装在鞋上的压电俘能器(PEH),用于收集人体行走时产生的能量。该俘能器由4根压电悬臂梁和1个弹簧-质量系统组成。弹簧-质量系统能够感知沿径骨轴的加速度激励,并通过磁耦合驱动压电梁振动从而发电。文中通过拟合实验数据获得加速度信号表达式;然后,建立仿真模型,对俘能器的发电性能进行了仿真分析。最后,加工了实验样机,并实验测试了俘能器的发电性能。结果表明,当受到沿胫骨方向的激励时,压电梁在一个步态周期内可被弹簧-质量系统激励多次从而产生多个峰值电压;受到沿胫骨和脚面两个方向激励时,压电梁的发电性能比只受到单一方向激励时好。当步行速度为2~8km/h时,每根压电梁的峰值电压可达到10V。该俘能器能够从人体行走的超低频运动中收集能量,并能够同时收集两个方向的加速度能量,提高了压电梁的发电性能。
A shoe-mounted piezoelectric energy harvester was designed to collecting energy from human walking. This energy harvester comprises of four piezoelectric cantilever beams magnetically coupled with a spring-mass system. The spring-quality system could sense the acceleration excitation along a radial bone shaft and generate electricity through the magnetic coupling driving a piezoelectric element. The expression of acceleration signals was obtained by fitting the experimental data. And then, a simulation model was established to simulate the power generation performance of the energy harvester. Finally, a prototype was also fabricated and its performance was verified by an experimental test. The results indicate that the four beams could be triggered several times by the spring-mass system within one step when the energy harvester is excited by the acceleration along the tibial axis, and several piezoelectric beam voltage outputs could be obtained. Furthermore, the power- generating capacity of the piezoelectric beam excited by the coupled accelerations is always better than that excited by the single direction acceleration. When walking speed ranges from 2 km/h to 8 km/h, the peak voltage output from each beam is as large as 10 V. The piezoelectric energy harvester collects the energy f by accelerat improved gr rom human walking in low frequency and the ions comes from two orthogonal directions, eatly. superposition of voltage outputs generated so that the power-generating capacity is improved greatly.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2017年第5期1272-1280,共9页
Optics and Precision Engineering
基金
陕西省自然科学基础研究计划资助项目(No.2015JM5193)
国家自然科学基金资助项目(No.51205302)
关键词
压电俘能器
压电效应
人体步态
能量收集
升频
双稳态结构
piezoelectric energy harvester
piezoelectric effect
human gait
energy harvesting
frequency up-conversion
bistable structure
