摘要
低频振动在环境中广泛存在,针对目前低频振动能量收集效率低的问题,提出将外界低频振动转化成摩擦系统的自激振动,实现低频振动到高频振动的升频转换,以达到提高低频能量收集效率的目的。为此,首先建立了集总参数模型,从理论上阐明低频振动能量收集方法的可行性,并分析模拟了该模型压电电压与功率的输出特性;其次分别设计了往复摩擦自激振动能量收集试验和压电悬臂梁碰撞能量收集试验,对比分析将低频振动转化为摩擦振动能否提高压电输出功率。试验与仿真结果表明,利用摩擦自激振动能够显著提升振动频率。摩擦自激振动电压幅值随着激励频率的增大而增大,与碰撞电压相比,其电压幅值较低,但是频率得到了大幅提升。由于频率的提升,压电振子的能量输出大幅提升,使得超低频振动能量收集性能明显提高。
Low-frequency vibration energy is ubiquitous in surroundings.However,it is a consensus that obtaining a satisfactory efficient of energy harvesting at ultra-low ambient frequencies remains challenging.Therefore,a solution to this problem is proposed,which is to increase the working frequency by converting the low-frequency excitation into self-excited vibration of friction systems.Inspired by the idea,a lumped parameter model is developed to confirm the feasibility theoretically,and the characteristics of the output voltage and power is analyzed and simulated based on the numerical model.An energy harvesting experiment where the excitation comes from the vibration induced by reciprocating sliding friction is performed,for comparison,an impact-driven energy harvesting experiment is also conducted,to confirm the efficacy of improving the output power by converting the ultra-low-frequency excitation into friction-induced vibration of friction systems.Both the experimental and numerical results indicate that the working frequency can be tremendously improved via friction-induced vibration,and the amplitude of the voltage generated by the friction-induced vibration is positively correlated with the excitation frequency.Compared with the voltage generated by the impact,the voltage generated by the friction-induced vibration owns lower amplitude but much higher frequency.Thanks to the frequency-up-conversion effect,the output power of the energy harvester is improved significantly,which enhances the performance of the energy harvester at ultra-low ambient frequencies.
作者
陈伟
项载毓
钱泓桦
莫继良
CHEN Wei;XIANG Zaiyu;QIAN Honghua;MO Jiliang(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031;Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province,Southwest Jiaotong University,Chengdu 610031)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2021年第15期160-167,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(51822508)
四川省科技计划(2020JDTD0012)资助项目。
关键词
能量回收
升频转换
超低频振动
摩擦自激振动
energy harvesting
frequency-up-conversion
ultra-low frequency vibration
friction-induced vibration
