针对气象观测、煤矿/隧道/通风管道运行状况监测等的需求,设计了一个由带谐振腔的风能采集器供电的无线风速传感器,该无线传感器包括两个带谐振腔的风能采集器,其中一个用于风能采集,另一个用于风速测量。当风速在特定区间变化时,采集器将发生强烈振动,将风能转换为电能。由于采集器的振动频率随风速单调递减,因此在建立采集器振动频率与风速的关系后,通过测量振动频率就可以实现对风速的测量。实验结果表明,自供能无线风速传感器在8.5~12.1m/s风速范围内可以正常工作,灵敏度为1.45Hz·s/m,当风速为12.1m/s时,自供能无线风速传感器每隔30s可以测量并发送一次风速信息,基本可以满足通风管道运行状况监测的要求。
According to the requirements of the meteorological observation and running state monitoring of coal mines, tunnels, ventilating ducts and etc., a self-powered wireless air flow sensor was developed. The self-powered wireless sensor includes two piezoelectric wind energy harvesters similar to harmonicas. A harvester is used to scavenge wind energy and the other is used to measure the wind speed. When wind speed is in a specified range, the reeds of the harvesters vibrate dramatically and convert the wind energy into electrical energy. As the vibration frequencies of the reeds decrease monotonically with the wind speed, the wind speed can be obtained by measuring the vibration frequencies of the reeds after the relationship between the wind speed and the vibration frequencies of the harvesters has been established. The experimental results show that the selfpowered wireless air flow sensor worked normally with the sensitivity of about 1.45 Hz ·s /m when wind speed was between 8.5 m/s and 12.1 m/s. The sensor measured and transmitted the wind speed signal every 30 s when wind speed was 12 m/s. It satisfies the requirements for air flow sensors in many environments such as in ventilating ducts.