从宽带低频振动环境中回收能量的非线性压电结构及后续电路研究

Many vibration sources in the natural environments, industrial equipments or road traffics have wideband and low frequency, which cannot be harvested effectively by linear piezoelectric resonators. The research will investigate a new way to enhance the efficiency of piezoelectric power generation over a wideband and low frequency range. Firstly, the research will establish a coupling model of nonlinear vibration energy harvesting system, which investigates the dynamic flexibility of nonlinear piezoelectric cantilever over a wideband and low frequency range. Besides, during the design of the electrical interface between nonlinear piezoelectric cantilever and electrical storage, a new synchronized switching harvesting technique will be proposed that could handle the voltage of piezoelectric materials with a nonlinear approach using an optimized algorithm. Thus, the research will establish a theoretical foundation for effectively harvesting vibration sources over a wideband and low frequency range.Since typical frequency range of mechanical vibration in the tire is between 75Hz and 200Hz, it is a good example to investigate the way to enhance the efficiency of piezoelectric power generation over a wideband and low frequency range. Furthermore, the tire pressure monitor system will be optimized to be low-powered and then can be powered by mechanical vibration in the tire using piezoelectric energy harvesting technique. Finally, the research aim to realize a self-powered tire pressure monitor system. The research will give out a new application example of self-powered structural health monitor system using piezoelectric energy harvesting technique, which will also theoretically and practically help to provide optimization design for solving the supply power problem of other wireless sensor systems.

实际自然环境、工业设备、道路交通等诸多场合的振动源往往具有宽频带、低频率特性，对此目前线性压电振子的回收效率较低，难以满足实际供能需求。本项目研究在宽带低频振动下的提高压电能量回收效率的新方法，首先建立非线性振动能量回收的耦合模型，在此基础上研究非线性压电振子在宽带低频振动下的动态响应特性，同时分析在宽带低频振动下压电振子的电压输出特性，通过在后续接口电路设计中采用合适开关算法，对宽带振动产生的复杂压电电压进行非线性化处理，为实现宽带低频振动能量的高效回收奠定理论基础。同时，本项目将以汽车轮胎压力监测为例开展应用研究（汽车轮胎的典型振动频率在75-200Hz之间），将回收轮胎振动的能量供给胎压传感节点，真正实现自供电的汽车胎压监测系统。本课题的研究成果可以拓宽能量回收在基于压电材料的结构健康监测的应用范围，也对其他无线传感供能的系统优化设计提供理论指导和方案借鉴。

实际自然环境、工业设备、道路交通等诸多场合的振动源往往具有宽频带、低频率特性，对此目前线性压电振子的回收效率较低，难以满足实际供能需求。本项目对宽带低频振动下的非线性压电能量收集技术进行了研究，首先提出了一个多模态振动能量回收的策略，即自适应型同步开关回收技术（Adaptive Synchronized Switch Harvesting technique），其可以对宽频振动能量进行高效回收。其次利用ANSYS软件建立了双稳态压电能量回收系统仿真模型，仿真结果表明与传统的线性压电悬臂梁相比，其在宽频带内有良好的振动能量回收性能。再次设计和制作了能量自给的胎压监测系统样机。同时利用压电振动能量回收技术，分别建立了一套基于能量回收的多模态振动控制系统和一套能量自给的自感知半主动振动控制系统，这套自感知半主动振动控制系统不仅可以实现没有延时的最优开关控制，而且可以减少所需的压电片数量。最后，合作制备了一种新型压电纤维的气流传感器。