Vibration energy harvesters are expected to become a new source of electrical power. Piezoelectric vibration energy harvesters that employ a piezoelectric transducer, a rectifier, and a storage capacitor are being used widely as electro-mechanical harvesters. Synchronized switch harvesting on inductor enhances harvesting performance due to employing a simple additional circuit and incorporating suitable switch control functionality. Switching is usually based on the displacement of a vibrating structure; hence, sensing the vibrational states is of critical importance. Conventionally, the structural displacement is measured by displacement sensors or accelerometers attached to the target vibrating structure. Although enhancement of performance through synchronized switch harvesting on inductor equipped with sensors is important, the arrangement requirements of sensors have adverse effects on the compactness and usability of the harvesters. This study aimed to eliminate the use of sensors from switch-controlled harvesters. We developed a new state estimation method that uses the piezoelectric transducer’s voltage as an observation value. Using the proposed state estimation method, the modal state values of the vibrating structure can be determined by simply measuring the voltage of the transducer. With the switch device being controlled by the estimated modal state values, no sensors are required for ensuring effective harvesting. A comparison of the harvesting performances by the proposed self-sensing state estimation method and the conventional sensor-equipped state estimation method showed that there is little difference in harvested power between the two methods over a wide range of load resistances. The proposed method is superior to the sensor-equipped method in terms of compactness and usability as it does not require any external sensors.

中文翻译：

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开关控制能量采集器的自感知状态估计

振动能量收集器有望成为一种新的电力来源。采用压电换能器、整流器和存储电容器的压电振动能量收集器正被广泛用作机电收集器。由于采用了简单的附加电路并结合了合适的开关控制功能，电感器上的同步开关采集增强了采集性能。切换通常基于振动结构的位移；因此，感知振动状态至关重要。传统上，结构位移是通过连接到目标振动结构的位移传感器或加速度计来测量的。尽管通过配备传感器的电感器上的同步开关采集来提高性能很重要，传感器的布置要求对收割机的紧凑性和可用性产生不利影响。本研究旨在消除开关控制收割机中传感器的使用。我们开发了一种新的状态估计方法，它使用压电换能器的电压作为观察值。使用所提出的状态估计方法，可以通过简单地测量换能器的电压来确定振动结构的模态状态值。由于开关设备由估计的模态状态值控制，因此不需要传感器来确保有效的收获。通过所提出的自感应状态估计方法和传统的配备传感器的状态估计方法的采集性能的比较表明，两种方法在很宽的负载电阻范围内的采集功率几乎没有差异。所提出的方法在紧凑性和可用性方面优于配备传感器的方法，因为它不需要任何外部传感器。