用于嵌入式传感自供电的宽带旋转运动非线性压电俘能机理与方法研究

Accurate and continuous condition signals sampling is the key of early fault detection and prediction of rotating components, where embedded sensing will be one important developing trend. However,how to power wireless sensing nodes is a bottle-neck problem of embedded sensing for rotating components. While self-powered ways based on rotating energy harvesting utilizing piezoelectric effect will be effective and promising. Thus this project aims at the significant need of self-powered embedded sensing in health monitoring of rotating components. Main focuses are paid on the problem of time-dependent and broadband rotating frequency of rotating components in many cases. By introducing nonlinear mechanisms, nonlinear piezoelectric energy harvesting of rotating motion is deeply studied. Firstly, its nonlinear mathematic model is built and the corresponding solving method is presented. Based on it, dynamic behaviors of the rotating nonlinear piezoelectric vibrator are exposed and effects of nonlinearity on the resonant bandwidth and efficiency are analyzed. Then, the mechanism of controlling nonlinearity for broadband rotating motion is explored based on chaotic dynamical theory.In the end, a new maximum power point tracking method is proposed to adapt variable rotating speeds. Thus high efficient electric energy conversion and storage can be achieved for broadband rotating motion. In summary, the proposed method in this project will provide theoretic and technical support for self-powered embedded sensing of rotating components.

持续准确获取状态信号是实现旋转部件早期故障检测和预测的关键，嵌入式传感将是重要发展趋势。而如何为无线传感节点供电是旋转部件嵌入式传感应用中亟待解决的首要瓶颈问题，利用压电效应将旋转运动能量转化为电能实现其自供电则是一种有效技术途径。为此，本项目瞄准旋转部件健康监控中嵌入式传感自供电的重大需求，针对工程应用场合中旋转部件转速往往在宽频带范围内动态变化的特性，通过引入合适的非线性机理深入开展旋转运动非线性压电俘能理论研究，建立旋转运动下非线性压电俘能的数学模型及其求解方法；揭示旋转非线性压电振子的动态行为，分析系统非线性对其共振带宽和俘能效率的影响关系；基于混沌动力学理论阐明控制非线性来适应宽带旋转运动的机制；建立自适应转速变化的最大功率点跟踪方法，实现高效的宽带旋转运动能量转换与存储，为旋转部件嵌入式传感自供电提供理论和方法支持。

如何为无线传感节点供电是旋转部件嵌入式传感应用中亟待解决的首要瓶颈问题，而利用压电效应将旋转运动能量转化为电能实现其自供电是一种有效技术途径。为此，本项目针对工程应用场合中旋转部件转速往往在宽频带范围内动态变化的特性，引入非线性磁力构建了旋转运动非线性压电振子，基于拉格朗日方程和假设模态法提出了旋转运动非线性压电振子的动力学建模方法，在此基础上建立了旋转运动非线性压电俘能系统的机电耦合模型，设计了相应的模型数值求解方法，建立了旋转运动非线性压电振子的有限元模型，仿真分析了重要结构参数对旋转运动压电俘能性能的影响特性；引入混沌动力学中的Melnikov方法，推导了旋转运动非线性压电俘能系统的Melnikov函数，揭示了非线性平面系统混沌状态下的大幅值随机跃迁运动是实现宽频带旋转运动能量俘获的理论基础、双势阱势函数是实现宽频带旋转运动能量俘获的内在机理，并依据Melnikov判决条件推导了实现宽频带旋转运动能量俘获的磁铁间距量化必要条件；提出并设计了一种基于最优电压控制的并联同步开关（COV-PSSHI）电路，推导了该电路输出功率的理论模型，建立了自供电P-SSHI电路开关时延的理论模型，分析了开关时延的主要影响因素及其对俘获功率的影响特性，并在此基础上提出了一种低时延的自供电COV-PSSHI电路；提出并建立了两类压电俘能全系统耦合模型，即压电俘能全系统电路耦合模型和压电俘能全系统有限元耦合模型；最后，搭建了宽带旋转运动非线性压电俘能实验系统，设计了自供电无线传感器节点原理样机，实验验证了所研方法的有效性。项目研究为优化设计旋转非线性压电俘能系统、高效俘获宽带旋转运动能量提供了重要理论基础，对推动实现旋转部件嵌入式传感自供电具有重要意义。