Method and device for detecting and locating head wave of ultrasonic wave

Abstract

The invention discloses a method and a device for detecting and locating a head wave of an ultrasonic wave. The method comprises the following steps of: constructing a track array of an ultrasonic signal sequence; carrying out singular value decomposition on the track array to obtain a singular spectrum entropy of the ultrasonic signal sequence; carrying out median filtering on the singular spectrum entropy and removing signal glitches; and carrying out thresholding operation on the singular spectrum entropy subjected to the median filtering, and then judging that the failing edge of the singular spectrum entropy subjected to the thresholding operation is the head wave of the ultrasonic signal sequence. Under the condition that the track array is proper, the drop between the ultrasonic signal sequence and the singular spectrum entropy in a noise region is large, the edge is abrupt, the singular spectrum entropy has very strong robustness to the amplitude value of the ultrasonic signal sequence and cannot change a lot along with the strength of the signal to noise ratio of a certain segment in the ultrasonic signal sequence, therefore, the method for detecting and locating the head wave of the ultrasonic wave has strong capacity of resisting disturbance and can more accurately locate the very weak head wave submerged in noise.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to a method and device for detecting and locating an ultrasonic first wave. Background technique [0002] The first wave, also known as the head wave, is the beginning of a valid signal in the field of pulsed detection of ultrasound and other types of signals. Reliable detection and accurate localization of the first wave are critical to the accuracy of these measurements. The biggest difficulty in extracting the first wave is that its amplitude is generally small, and it is very easy to be confused with system noise. The existence of noise has a great impact on the accuracy of its measurement. In general, the amplitude of the first wave attenuates quickly with the increase of the signal frequency, so it is more difficult to detect the first wave in the measurement of higher frequency. [0003] At present, the commonly used first wave detection methods mainly include thr...

AI Technical Summary

Problems solved by technology

The biggest difficulty in extracting the first wave is that its amplitude is generally small, and it is very easy to be confused with system noise. The existence of noise has a great impact on the accuracy of its measurement

In general, the amplitude of the first wave attenuates quickly with the increase of the signal frequency, so it is more difficult to detect the first wave in the measurement with higher frequency.

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