宽带压电振动能量收集器结构设计与实验验证

为了收集环境中随机振动的能量，提出谐振频率和带宽皆可调的压电振动能量收集方法.通过调节止挡块的高度，振动能量收集器可以达到自由、碰撞和预紧3种工作状态.根据3种工作状态，建立振动数学模型，利用有限元和MATLAB软件仿真振动能量收集器的输出性能.加工L型四悬臂结构的大尺寸原理样机，在1g激励加速度下，测试自由、碰撞和预紧3种结构下的电压输出与频率的关系.实验结果与建模仿真结果表明，碰撞振动模式比自由和预紧模式有更好的能量收集效果，结构的非线性刚度对能量收集器的谐振频率和带宽有显著影响.
Abstract: A piezoelectric vibration energy harvesting method with tunable frequency and wideband was proposed in order to harvest the energy of random vibration from ambient. The vibration energy harvester (VEH) can work at free, impact, and preload vibration mode by adjusting the height of mechanical stopper, respectively. The mathematical model was established corresponding to the three work modes of the VEH. The output characteristics of VEH was simulated using finite element analysis software and MATLAB. Large size of prototype with four L-shape cantilevers was fabricated through experiments. The relationships between voltage output and frequency were measured under free, impact, and preload work modes, respectively, with external excitation of a=1.0g. Experimental results and modeling results show that the impact mode has better energy harvesting effect than the free and preload mode. The nonlinear stiffness of the structure has a significant effect on the resonant frequency and bandwidth of VEH.