基于FBG传感网络和时间反转聚焦的多源冲击成像定位技术研究

针对传统冲击监测系统存在无法定位多源冲击、组网难和精度低等问题,设计了一种基于光纤Bragg光栅(FBG)传感网络和时间反转聚焦成像冲击定位方法。在分析时间反转聚焦成像定位原理的基础上,建立由4个FBG组建的传感网络监测系统,通过窄带激光边缘滤波实现信号解调。利用Shannon小波变换提取特定频率的窄带信号,并计算信号模值及速度。通过建立时间反转聚焦模型实现多源冲击搜索定位及成像,并在监测区域为400mm×400mm的航空铝合金板结构上进行验证。结果表明,本文方法可实现冲击定位,定位误差小于15mm,为冲击监测提供了一种新的高精度方法。

Multi-impact sources localization based on FBG sensor network and time reversal focusing

In order to deal with the problem of multi-impact sources localizatio n,difficulty of networking and low accuracy of traditional impact source localization system,A impact source method is designe d based on fiber Bragg grating (FBG) sensor network and time reversal focusing imaging technology.The principle of time reversal focusi ng is analyzed in this paper.The monitoring system is established by four FBG sensors,and the narrow band laser edge filter tech nology is used to demodulate signal.The Shannon wavelet transform is used to extract narrow band signal,and the modulus value and velocity are calculated.Multi-impact sources localization is realized by establishing time reversal focusing search model,and the method is verified in impact experiment of the aviation aluminum alloy plate.The results show that this method can effectively localiz e multi-impact sources,and the localization error is less than 1.5cm.A high-accuracy method is provided for multi-impact sources detect ion and localization.