Acoustic emission positioning system and method based on FBG sensing system and second order statistic

Abstract

The invention discloses an acoustic emission positioning system and method based on an FBG sensing system and second order statistic. The positioning method comprises the steps that broadband light emitted by an ASE light source which is not flattened is transmitted to respectively corresponding FBG sensors after sequentially passing through an edge filter, a first coupler and a plurality of second couplers which are arranged in parallel; the FBG sensors reflect back light at the set wavelength, the light is transmitted to a photoelectric conversion circuit through the second couplers and is transmitted to a data collection system through an amplifier, and the data collection system records signal changes; an acoustic emission source produces high-frequency dynamic stress waves, the reflection wavelength of the FBG sensors changes, and demodulation of acoustic emission signals is achieved through the power change of the light reflected by the FBG sensors; the acoustic emission signals obtained through demodulation are subjected to Shannon wavelet transformation, and narrow-band signals are extracted; the azimuth angle and the distance of the acoustic emission source relative to a reference sensor are figured out according to the second order statistic, and then the position of the acoustic emission source is determined. The positioning method has good acoustic emission positioning accuracy and real-time performance.

Description

technical field [0001] The invention relates to an acoustic emission positioning system and method based on an FBG (Fiber Bragg Grating, fiber Bragg grating) sensing system and second-order statistics. Background technique [0002] With the rapid development of modern industry and the replacement of new products, the society has higher and higher requirements for product quality, structural safety and reliability. The structure of modern industrial equipment tends to be complex and large-scale. Moreover, if the equipment is under high load conditions for a long time, it is easy to cause damage accumulation and a decrease in the bearing capacity of the structure, and even cause structural damage. Therefore, the structural health directly affects social security and economic development. Therefore, real-time monitoring of engineering structures is of great strategic significance, especially for national defense projects, aerospace engineering, ships and civilian equipment. ...

AI Technical Summary

Problems solved by technology

Triangulation positioning method and hyperbolic positioning method need to extract accurate time difference for positioning, but due to the dispersion characteristics of acoustic emission signals, it is difficult to extract accurate time difference

Artificial intelligence algorithms include algorithms such as neural networks and support vector machines. These algorithms require a large number of training samples, but training samples are difficult to extract in practical applications, and the economy is not high.

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