An Improved Matching Pursuit-Based Temperature and Load Compensation Method for Ultrasonic Guided Wave Signals

Temperature and load variations significantly affect ultrasonic guided wave propagation and therefore lead to the increasing of diagnostic uncertainty of the guided wave-based structural health monitoring system, which may cause false reports and false positives and limit the practical application of the method. Most of the existing researches focus on guided wave compensation for a single factor. Therefore it's an important challenge that how to compensate for guided waves under the influence of multiple environmental factors. This study firstly analyzes the coupled effect of temperature and load variations on the propagation characteristics of guided waves. It has been found that the two factors variations cause a highly non-linear effect on the change of guided wave signal characteristics. Based on the previous work of temperature compensation methods based on matching pursuit, this paper develops an improved matching pursuit-based temperature and load compensation method for ultrasonic guided wave signals. The developed method is featured with that the compensation performance can be improved by multiple iteration compensation of the residual signal. By improving the selection of the reference signal set, the developed environmental compensation method based on the reference signal matching is used to realize the compensation under the influence of the temperature-load coupling effect, and the experimental results verify the effectiveness of the proposed compensation method and the proposed compensation method proves to be effective under the influence of temperature and load variations.