EEMD–Wavelet Adaptive Threshold Function Denoising and Its Application in Damage Monitoring of Aviation Connection Structure

Considering the problem of noise in the damage monitoring signal of the aviation connection structure, a new denoising algorithm based on the combination of EEMD and wavelet adaptive threshold function is proposed, which can effectively solve the shortcomings of a single de-noising algorithm. In this algorithm, a new threshold function is designed, which can effectively solve the poor continuity and constant deviation problem of the traditional threshold function. At the same time, a variable adjustment factor is further adopted to realize the adaptive adjustment of the new threshold function to different decomposition scales. The simulation is compared to the EEMD algorithm and traditional soft and hard threshold function de-noising algorithms in terms of signal-to-noise ratio and root mean square error of the de-noised signal, and verified its effectiveness and superiority. The bolt damage signal in the aviation connecting structure damage monitoring system is taken as an example to perform noise reduction processing.