面向人体运动能的二次升频压电俘能机理与方法研究

Piezoelectric energy harvesting technology that can convert human motion energy into electrical energy is the current research hotspot. However, it is one of the bottlenecks that the energy density and energy conversion efficiency of the piezoelectric energy harvester are poor in the low-frequency random human motion environment. Accordingly, this project aims to improve the energy density and efficiency by constructing bistable and multistable impact-based frequency up-converting configurations, so as to meet the power supply demand of the wearable electronic products. The collision force model and mechanics-magnet-electricity coupled distributed parameter model of these harvesters are established. The research on mechanism and method of these novel piezoelectric energy harvesters is carried out based on the human motion. The characteristics and innovations of this project lie in: (1) a dual frequency up-converting piezoelectric energy harvesting method is proposed to harvest human motion energy by using impact and magnetic interaction; (2) the influence mechanism of sub-impact on the vibration and power generation characteristics of the piezoelectric element is revealed; (3) the mechanism of dual frequency up-converting piezoelectric energy harvesting is illuminated. Through the mathematical modelling, simulation, experimental verification and comparative study, the method and configuration of the broadband piezoelectric energy harvesting with high efficiency are obtained, and the advantages and application conditions of the bistable and multistable configurations are clarified, respectively. The successful implementation of this project will significantly improve the collection and conversion of human motion energy, supply the effective theoretical and technical support, and provide a novel efficient, environmentally friendly and long-term power supply for the wearable electronic products with a wide range of applications.

将人体运动能转换为电能的压电俘能技术是当前研究热点，然而，人体低频随机运动环境下压电俘能器能量密度和俘能效率低是瓶颈问题之一。为此，本项目瞄准可穿戴电子产品供电需求，以提高能量密度和俘能效率为目标，构建双稳态、多稳态碰撞升频式压电俘能器，建立碰撞力模型和力-磁-电耦合分布参数数学模型，开展人体运动环境下新型压电俘能机理与方法研究。本项目的特色与创新点在于：（1）耦合碰撞升频和磁力升频，提出面向人体运动能的二次升频压电俘能方法；（2）揭示次碰撞对压电俘能单元振动和发电特性的影响机制；（3）阐明二次升频压电俘能机理。结合数学建模、仿真分析、实验验证和对比研究，获得宽频带、高效压电俘能方法及构型，明确双稳态、多稳态构型的俘能优势和适用条件。本项目的成功实施将显著提升人体运动能收集和转换效率，为之提供有效的理论和技术支持，为可穿戴电子产品提供一种高效、环保、长久的新供电方案，具有广泛的应用前景。

将人体运动能转换为电能的压电俘能技术是当前研究热点，然而，人体低频随机运动环境下压电俘能器能量密度和俘能效率低是瓶颈问题之一。为此，本项目瞄准可穿戴电子产品供电需求，以提高俘能器能量密度和俘能效率为目标，开展低频振动环境下高效宽频压电俘能方法研究，通过耦合碰撞升频和磁力升频，提出了二次升频压电俘能方法，构建了双稳态碰撞升频式压电俘能器结构，建立了含碰撞力模型的力-磁-电耦合分布参数数学模型和多物理场耦合有限元仿真模型，研制了样机并进行实验测试，研究了限位器类型、刚度、间隙对发电性能的影响规律，通过对比明确了双稳态结构的俘能优势和适用条件。研究表明，在低频激励下，二次升频策略是提高能量转换效率和拓宽俘能频带的有效途径；为了进一步提高俘能器在不同振动环境下的发电性能，探索了新型俘能机制和方法，分别对磁力耦合多频压电电磁复合俘能器、风致振动俘能器、非线性两自由度电磁俘能器和Galfenol俘能器进行了理论和实验研究，在结构设计、参数优化、俘能机理等方面取得了有益成果，为今后开展工程应用提供了参考。本项目的成功实施为人体运动能收集提供了有效的理论和技术支持，为可穿戴电子产品提供了一种高效、环保、长久的新供电方案，具有广泛的应用前景。