Original data feature extraction and identification method based on multi-channel ultrasonic flaw detection

Abstract

The invention discloses an original data feature extraction and identification method based on multi-channel ultrasonic flaw detection, and particularly relates to an extraction and identification method for ultrasonic flaw detection original data acquired by a steel rail. Non-blind area detection is carried out on the rail head and the rail waist of a steel rail by adopting a 10-channel compositeserial probe, and broadband ultrasonic waves are reflected by the steel rail and are received by a receiving probe of an array probe. The method mainly comprises the following steps: firstly, using awavelet transform algorithm based on an improved threshold function for denoising a collected steel rail ultrasonic echo A-display data signal; then extracting features of the ultrasonic echo A-display data signals by adopting a wavelet modulus maximum feature extraction method, finally, normalizing the extracted features, converting all feature data into [0, 1] data, and displaying the processed echo in a B-type display mode. The method can extract effective pulse signals, improves the flaw judgment accuracy, and can be widely applied to the field of steel rail ultrasonic flaw detection.

Description

technical field [0001] The invention belongs to the technical field of non-destructive testing, is mainly applied in the field of rail flaw detection, and relates to a feature extraction and recognition method based on multi-channel ultrasonic flaw detection raw data. Background technique [0002] The rapid development of my country's high-speed railways has brought challenges to the state maintenance and safety assurance of railway rail infrastructure, especially the multiple speed increases have also put forward higher requirements for the quality of the rails. Rails are prone to cracks and other damages that affect and limit the performance of rails during use, and under the action of wheel load and temperature force, rail damage will be more serious. Rail fractures caused by rail stress, fatigue, and defect failures can lead to major accidents such as train derailment and overturning, resulting in casualties and huge property losses. [0003] Ultrasonic flaw detection i...

AI Technical Summary

Problems solved by technology

Although this method can completely decompose the signal in the frequency domain and realize the vision of removing noise by smoothing the signal, it will also cause a serious loss of effective information, and the Fourier transform lacks time-domain analysis capabilities. Once the time axis changes suddenly , will affect the entire frequency spectrum, resulting in wrong judgment results

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