直角型压电悬臂梁振动能量采集器的理论与实验研究

发布时间：2017-12-26 16:33

本文关键词：直角型压电悬臂梁振动能量采集器的理论与实验研究　出处：《浙江工商大学》2016年硕士论文　论文类型：学位论文

【摘要】：无线传感器网络的节点一般使用电池供电,有限的电池能量严重影响无线传感器网络的使用生命周期。化学电池需要定期要充电或者更换,这将会造成人力、物力资源的浪费和环境污染等各种问题。现代集成电路技术的不断发展,应用能量采集技术为传感器节点供给能量,从而实现延长它们的使用寿命,不用再频繁更换电池。能量采集技术的应用可实现持续工作、环保清洁、节省成本等特点,是解决无线传感器网络的自供电的一个关键技术。利用压电效应可以把压电材料工作环境中的振动能量转化为电能。这种新技术能够实现网络节点的自供能,摆脱了化学电池工作时间有限、污染、回收处理代价高等束缚,是一种清洁、持久的新形式能量采集技术。现在,能量采集技术已经成为中外科研的一个非常重要的研究课题。能量采集器种类繁多,其中应用前景最好的是压电振动能量采集器,原因是振动能不但是环境中普遍存在而且其输出功率密度值较大,该能量采集器有结构简单、易集成等优点。而末端固定有质量块的压电双晶悬臂梁结构是典型的压电式振动能量采集器结构,该结构缺点有工作效率低、工作频带较高、谐振响应带宽过窄等。因此,拓宽谐振响应频率带宽是提高压电式振动能量采集转换效率和最佳输出性能的关键因素。本文根据压电理论提出了一种新型的直角型压电悬臂梁振动能量采集器并制作了原型实物器件,通过在典型的压电双晶悬臂梁结构的水平梁自由端增加一个垂直悬臂梁并且垂直梁上部顶端固定有一质量块,利用这两部分的弹性耦合作用组成直角型压电悬臂梁压电振动能量采集器。根据压电效应原理,建立了该直角型压电振动能量采集器的有限元机电耦合模型和理论模型,以拓宽工作频带为目标,通过调整优化水平或者垂直压电双晶悬臂梁的结构尺寸以及材料参数,能够有效地缩小该采集器的一阶、二阶固有频率之间的间距,最终形成一个低频宽频工作带。由于该结构具有低频宽频等特点,有针对性的克服了上述缺点。论文主要研究工作有：(1)设计了直角型压电振动能量采集器的结构,应用ANSYS软件建立了直角型压电悬臂梁振动能量采集器有限元机电耦合模型,仿真分析了采集器各参数对系统谐振频率、振动特性和电输出等特性的影响,得到了其最优的结构尺寸以及设计参数。(2)结合运用压电、Euler-Bernoulli梁振动和Hamilton等理论,建立了直角型压电振动能量采集器的机电耦合动力学模型,推导了系统的谐振频率、特征方程和能量采集输出方程。运用MATLAB软件对其进行仿真,得到该采集器各参数中影响系统固有频率、幅频、电输出性能等的关键因子。(3)研制了直角型压电振动能量采集器的实验样机,搭建了实验测试平台,通过实验结果与理论模型和仿真结果的对比分析,验证了理论分析结果的正确性。(4)对本文研究进行了总结和展望,提出了下一步研究工作的重点。
[Abstract]:The nodes of wireless sensor networks usually use battery power, and the limited battery energy seriously affects the life cycle of wireless sensor networks. Chemical batteries need to be charged or replaced regularly, which will cause a variety of problems, such as the waste of human resources, material resources and environmental pollution. With the continuous development of modern integrated circuit technology, energy harvesting technology is applied to provide energy for sensor nodes, so as to extend their service life, and do not need to replace batteries more frequently. The application of energy harvesting technology can achieve continuous work, environmental protection, cleanliness, cost saving and other characteristics. It is a key technology to solve the self power supply of wireless sensor networks. By using the piezoelectric effect, the vibration energy in the working environment of the piezoelectric material can be converted into electrical energy. This new technology can realize the network node energy, get rid of the chemical battery working time is limited, pollution and recycling cost of higher bound, is a new form of energy acquisition technology of clean and durable. Now, energy acquisition technology has become a very important research topic in China and foreign countries. There are many kinds of energy harvesters. The most promising application is piezoelectric vibration energy harvester. The reason is that vibration energy is not only widespread in the environment, but also has large output power density. The energy harvester has the advantages of simple structure and easy integration. The piezoelectric bimorph cantilever structure with mass block at the end is a typical structure of piezoelectric vibration energy harvester, which has the shortcomings of low efficiency, high working frequency and narrow resonant response bandwidth. Therefore, the broadening of the frequency bandwidth of the resonant response is the key factor to improve the conversion efficiency and the optimal output performance of the piezoelectric vibration energy acquisition. Based on the piezoelectric theory proposed a new type of rectangular piezoelectric cantilever vibration energy harvester and produced a prototype by physical devices in a typical piezoelectric bimorph cantilever beam free end level adds a vertical cantilever beam and the vertical beam at the top is fixed with a mass, using the elastic coupling effect of the the two part consists of rectangular piezoelectric cantilever piezoelectric vibration energy harvester. According to the principle of piezoelectric effect, established the rectangular piezoelectric vibration energy harvester electromechanical coupling finite element model and theoretical model, to broaden the frequency band as the goal, by adjusting the horizontal or vertical structure and size of piezoelectric bimorph cantilever beam and the material parameters, can effectively reduce the spacing between the first and two. Natural frequencies, and ultimately the formation of a wide band frequency. Because the structure has the characteristics of low frequency and wide frequency and so on, it has overcome the above shortcomings. The main works of this paper are: (1) the structure design of rectangular piezoelectric vibration energy harvester, application of ANSYS software to establish a rectangular piezoelectric cantilever beam vibration energy harvester electromechanical coupling finite element model, the simulation analysis of the influence of various parameters on the collector system resonant frequency, vibration characteristics and electrical output characteristics, the the optimal structure size and design parameters. (2) combined with the theory of piezoelectricity, Euler-Bernoulli beam vibration and Hamilton, the electromechanical coupling dynamic model of the right angle piezoelectric vibration energy harvester is established, and the resonant frequency, characteristic equation and energy collection and output equation of the system are derived. The MATLAB software is used to simulate it, and the key factors that affect the natural frequency, amplitude frequency and electrical output performance of the system are obtained. (3) the experimental prototype of the right angle piezoelectric vibration energy harvester has been developed, and the experimental platform has been built. The correctness of the theoretical analysis is verified by comparing the experimental results with theoretical models and simulation results. (4) the research of this paper is summarized and prospected, and the key points of the next research work are put forward.
【学位授予单位】：浙江工商大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM619

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