双稳态三维宽频能量采集系统的实现及其理论方法研究

Vibration energy harvesting system transfers the energy from environment into electrical energy. It benefits the development of IoT (Internet of Things) technology significantly through powering the sensor nodes. And this technology further promotes the applicability and economical efficiency of sensor nodes with a bright future. In order to overcome the obstacle stemming from broadband and multi-directional environmental vibrations that hinder the advancement of vibration energy harvesting, a new approach is proposed in this project for broadband multi-directional energy harvesting. We introduce tri-directional resonant motions in bi-stable broadband energy harvesting system for arbitrary directional energy absorbing. We further couple the tri-directional resonance motions together for high efficiency energy transferring yielding broadband multi-directional energy harvesting. This project focuses on two points: firstly, we investigate the method to create and couple multiple directional motions in a bi-stable system for efficient vibration energy absorbing; secondly, we realize high-orbit motion in the bi-stable system under multi-directional excitations for efficient multi-directional broadband energy harvesting. By combining the two points, we further analyze the power output characteristics of the system with three types of electrical loads. Finally, we construct a micro energy harvesting system with capability of multi-directional and broadband energy harvesting and apply it into real-field applications. The system studied in this project can be applied to different applications in sensors with robust performance that requires harvesting broadband multi-directional vibration energy. This project yields enormous benefits to the development of vibration energy harvesting and sensor network in IoT domain in aspects of both theoretical development and applications.

振动能量采集系统将环境振动能量转换为电能，可实现物联网传感器的能量自给，极大提高了传感器的实用性和经济性，具有广阔的发展与应用前景。针对实际应用中环境振动的频率和方向多变的问题，本项目拟以宽频性能优异的双稳态能量采集系统为基础，通过构建并耦合其三维共振运动以高效吸收并传递多方向振动能量，并从三维异向共振与双稳态的动力学耦合入手，实现宽频多方向高效能量采集。主要研究：一、分析并完善双稳态系统三维运动的构造与耦合，实现高效多方向能量获取；二、实现三维激励下双稳态系统高能态运动以实现高效三维宽频能量采集。二者结合，进一步通过系统负载下能量输出特性的分析，构建具备宽频多方向能量采集能力的微能源系统并探索其应用。本项目旨在研究可推广的双稳态能量采集系统在三维空间的工作机制，推动宽频多方向能量采集的研究和实用化，对推进振动能量采集在物联网传感器节点中的实际应用具有重要的理论意义和实践价值。

项目针对宽频及多方向环境振动能量采集领域需要重点研究并解决的核心问题开展研究。基于双稳态及多自由度系统非线性动力学理论，研究双稳态势能阱二维空间拓展及其非线性特征，并研究多自由度系统频域响应特性优化机制。进一步综合利用数学模型和实验平台，分析与验证系统的宽频域与多方向响应特性，开展宽频多方向振动能量采集的研究。经过三年的努力，分别提出了基于环形稳态的多方向宽频振动能量采集机制，实现低幅值环境振动下的大幅值势阱跃迁和多方向能量采集；提出了基于内弯折悬臂梁的振动能量采集方法，实现超宽频振动能量采集；提出了基于可调电感数据增强的阻抗法结构故障诊断原理，实现高准确率结构故障的监测。共发表14篇期刊论文，其中被SCI收录9篇，EI收录论文5篇；申请发明专利11项，其中已授权1项；培养硕士生5人（已毕业1人）。项目研究成果中的环形稳态非线性谐振器的研究，不仅实现了小激励下的宽频多方向能量采集，同时亦推动了多稳态振子理论在其它工程领域中的应用。内弯折悬臂梁移动反谐振点的方法为宽频振动能量采集的研究提供了一种新的研究思路。