柔性压电复合材料薄膜无线应变传感器研究

Research on wireless strain sensor using flexible piezoelectric composite film

设计了一种基于柔性压电复合材料薄膜传感器的无线测量系统。系统主要包括压电薄膜传感器、接口电路模块、AD采集模块、数据处理模块和无线传输模块。压电薄膜传感器将结构振动信息转换为压电信号,系统对压电信号进行放大、采集、无线传输和接收。提出了通过系统采集电压反解结构应变的方法,推导了压电信号的传递函数,建立了系统采集电压与应变的关系,因此可基于系统采集的电压反解出结构振动的频率和应变幅值,从而实现结构应变测量。实验结果表明,该系统对结构的振动频率和应变可实现精确测量。且该系统的无线测量距离可达40 m,因此,其能部分替代传统的有线测量系统,具有广阔的工程应用前景。

This research designs a wireless measurement system using flexible piezoelectric composite film sensor.The system mainly includes piezoelectric film sensor,interface circuit module,AD acquisition module,data processing module and wireless transmission module.The piezoelectric film sensor converts structural vibration information into Piezoelectric signal,the system amplifies,collects,wirelessly transmits and receives the piezoelectric signals.A new method to invert the structural strain by collecting voltage is proposed,The transfer function of piezoelectric signal is derived,and the relationship between acquisition voltage and strain is established,therefore,dynamic strain measurement can be achieved since the frequency and the strain amplitude of the structural vibration can be calculated inversely based on the collected piezoelectric signal.Experimental results indicate that the system can accurately measure the vibration frequency and strain of the structure,and the distance for wireless strain measurement by this system can reach 40 meters,the proposed wireless strain measurement system can partially replace the conventional wired strain measurement system so that it has great potential in engineering applications.