基于自适应双稳态集能器的微能源系统研究

The development of IoT (Internet of Things) technology promotes requirements on the sensors of integration, miniaturization and low power. Moreover, the abilities of scavenging environmental energy, sleep and self-start, power management etc., are also desired, especially in the field of smart transportation. Wide and bright prospective is promised for vibration energy harvesting technology. In order to solve the obstacle of the variable environmental vibrations which hinders the advancement of vibration energy harvesting, a new approach is proposed and to be studied in this project. Taking advantage of the bi-stable generator and its special bidirectional property as a typical electromechanical system, the wideband performance can be further enhanced by introducing tuning mechanism to the generator from two aspects: in the one side, low power tuning structure which can be integrated to the generator is to be developed so that the structure potential properties is capable of matching the variable excitation; in the other side, controllable mechanism is to be deployed in the interface circuit to improve the load effect. Combining the two, the dynamics of the systems can be tuned with better performance. Furthermore, analysis on the responses of the tunable generator and the energy flow inside the system is planned to determine the strategies of dynamic tuning and power management. It promises to construct a micro energy harvesting system with an adaptive bistable generator which can be applied to different applications in smart transportation with robust performance. Clearly, the researches in this project would provide enormous benefits to the development of vibration energy harvesting and wireless sensor network in IoT domain and also the advancement of clear and recyclable energy technology.

物联网技术的发展要求传感器集成化、微型化和低功耗，同时也提出了具有外部能量自收集、掉电休眠自启动等功能的需求，特别是在智能交通等领域，振动能量采集技术前景广阔。针对实际应用环境当中振动激励多变的问题，本项目拟以具备较好宽带性能的双稳态集能器为基础，利用其机电耦合系统的双端口特性，同时从结构和电路引入调节机制对集能器的动态响应进行主动控制，增强其宽带性能。一方面，研究在集能器中引入可集成的低功耗调节机构实现结构势能特性与外界激励的匹配；另一方面，在接口电路中引入可控的能量提取机制，实现最优的负载效应。二者结合，同时进一步通过动力学响应和能量流动分析的研究确定机构与动力学响应调节策略和能量管理策略，构建具备自适应能力的双稳态集能器为主题的微能源系统，探索其在各类智能交通设施场合的应用。本项目研究对于推进振动能量采集技术在物联网领域的发展，促进能源清洁可回收技术的进步，具备重要的理论和工程意义。

物联网传感器要求集成化、微型化和低功耗，在智能交通等蕴含丰富振动能量的领域，振动能量采集技术的应用前景广阔。针对实际应用环境当中振动激励多变的问题，本项目以双稳态集能器为基础，利用其机电耦合系统的双端口特性，同时从结构和电路引入调节机制对集能器的动态响应进行主动控制，增强其宽带性能。本项目的主要研究内容和成果有：.1、提出并研究了一种具有调节机构的非线性压电屈曲梁结构。为了解决非线性集能器常常受限于低能响应的问题，在屈曲梁两端分别引入压电促动器作为驱动调节机构来调整其动态响应，确定了集能器的屈曲水平和固有频率与驱动电压的对应关系。 .2、研究了一种基于屈曲水平调节的轨道跃迁简约策略。通过调整屈曲水平的方式来改变其结构特性以匹配外界激励，第一步是通过调整屈曲水平将低能轨道调节到高能轨道，第二步在高能轨道基础上继续增大屈曲水平直到获得最终的高能轨道，实验结果表明该调节策略能够实现较大频率范围内的调整。.3、研究了一种结合屈曲水平调节和短暂电压激励的轨道跃迁综合策略。为了使集能器在外界激励变化的情况下处于高能轨道，采用屈曲水平调节、短暂电压激励或二者结合的方式来调整集能器的动态响应，总结了一套系统的调节策略，有效地改善了非线性集能器在宽带振动激励下的能量回收性能。.4、基于优化的同步电荷提取电路(OSECE)的电路拓扑，运用双参数调节法，提出调频的优化同步电荷提取电路(FT-OSECE)，相对解耦地调节系统等效共振频率和电阻尼，在机电耦合系数较大时有效地提高压电式集能器的工作性能。引入衡量电路损耗的电路品质因数，分析了系统参数变化时（包括电路品质因数、机械品质因数、机电耦合系数），最大功率及其对应的最优调节参数与激励频率间存在的关系等。.通过上述研究内容的深入执行和探索，本项目在发电机结构和接口电路都提出了一种新设计和新思路，可推进振动能量采集技术以及无线传感网络技术在物联网领域的发展，较好的完成了项目的预定目标。