低频压电振动系统中的力-电耦合机制研究

Piezoelectric vibration control and energy harvesting have been a research hotspot in the field of smart materials and structures. However, there still exists many unresolved issues when the piezoelectric smart structures are applied in low and ultra-low frequency vibrations, such as low efficiency of electromechanical conversion, large dielectric loss of piezoelectric materials, problem of resonant frequency matching, etc. This project will research on low and ultra-low frequency electro-mechanical coupling principle of piezoelectric smart structures based on energy conversion, including the optimization of mechanical-electro energy conversion from point of vibration energy harvesting, and the optimization of electro-mechanical energy conversion in vibration control. . The detailed research includes: (1) Frequency up-converting piezoelectric oscillators, the principle of frequency up-conversion in multi-degree-of-freedom nonlinear dynamic systems should be improved, the wideband, frequency tuning mechanisms will be also investigated; (2) nonlinear multi-shot synchronous electric charge extraction circuit, the optimized model between the multi-shot extraction strategy and the circuit power consumption should be obtained, so the energy converted efficiency of coupling systems can be enhanced from the point of circuits; (3) ultra-low frequency vibration control, the electro-mechanical coupling model of piezoelectric actuators and sensors should be firstly perfected, the consequent accurate vibration displacement signal and high efficiency of vibration suppression can be obtained. The project should summarize the accurate electromechanical energy converted principle under the condition of low and ultra-low frequency vibrations, which provides the novel approaches to optimize the energy conversion.

基于压电效应的振动控制与能量收集一直是智能材料与结构领域的研究热点。但对于常见的低频、超低频振动，压电智能结构仍存在机电耦合效率低、介质损耗大、共振频率匹配难等没有根本解决的问题。本项目将从能量转换角度研究低频、超低频压电智能结构的力-电耦合机制，包括从振动能量收集角度优化机电能量转换以及从振动控制角度研究电-机能量转换。. 具体研究内容包括：（1）升频式压电振荡器结构，完善基于多自由度非线性振动的升频转换理论，同时研究结构的宽频、调频等机制；（2）非线性分批次同步电荷提取电路，获得电路自身功耗与分批次提取策略之间的优化理论，从电路角度提高压电耦合结构机电能量转换效率；（3）超低频结构振动控制，完善压电传感/驱动器的力-电耦合模型，获得精确的振动位移信号及较高的振动抑制效率。项目最终将总结低频、超低频条件下，压电智能结构机械能-电能的精确转换机制，获得优化能量转换的新方法。

本项目针对压电材料在低频、超低频领域内的应用，从能量转化角度开展了压电智能结构的力-电耦合机制研究，包括从振动能量收集角度优化机-电能量转换以及从振动控制角度研究电-机能量转换。在项目资助期间，搭建了一套通用的实验平台和一套技术实用化验证的演示平台；发表了期刊论文7篇，其中SCI收录3篇，ESI高被引论文1篇；申请专利6件，其中已获授权4件；获创新创业大赛优胜奖1次，技术成果转化的可行性得到了现场专家的认可；（准）毕业硕士研究生3名，为祖国的“大国重器”人才贡献了微薄的力量。. 项目的代表性成果如下：（1）提出了内共振式机械升频转换方法；（2）设计实现了压电弹簧摆振子，能量收集性能达到了领先水平；（3）揭示了限位装置的新功能，拓宽了振子结构的优化途径；（4）针对无线传感器设备的工作特征提出了一般功耗模型，大大简化了设备研发过程中的功耗计算及优化工作；（5）发现了一种电路实现简单、功能强大的非线性能量操控方法。