基于复用结构的高灵敏度自取能式无线振动传感器

The demands for miniaturization, low power and even self power in wireless sensor networks are put forward in the the popularization of electric Internet of Things. For the existing magnetoelectric structure of vibration sensors, it is suitable to harvest energy, whereas, their volume is generally larger and wired transmission methods are commonly used. Therefore, a self-powered wireless vibration sensor based on the double-coil double-beam reusable structure is designed and fabricated in this paper. Firstly, the relationships among natural frequency, magnetic flux density and parameters of the device are analyzed, and the influences of double-beam structure on vibration modes are explored. Then, the dynamic, static, and impact characteristics of single/double-coil devices are tested. The results show that the device has high sensitivity and linearity in detecting vibration speed and impact. Its operating frequency is 100~1 000 Hz, with a frequency response error less than 2%, and the sensitivity of single-coil devices is 51.8 mV·s/cm, while that of double-coil devices is 91.6 mV·s/cm. Compared to existing vibration sensors, the double-coil double-beam structure is used as a measuring element and reused as an energy harvesting element, which enables the device to have higher sensitivity, and lower frequency response errors, and significantly compresses its volume. In addition, the reusable structure enables the proposed sensor to be capable of integrating output response and self power, achieving timed vibration monitoring and triggered impact detection of electrical equipment.