High-order moment-based coded ultrasonic signal pulse flow forming method and circuit

Abstract

The invention discloses a high-order moment-based coded ultrasonic signal pulse flow forming method and circuit, and the method comprises the following steps: generating a coded excitation signal c (t), exciting an ultrasonic transducer to transmit a coded ultrasonic signal e (t) after power amplification, and obtaining a coded ultrasonic echo signal r (t) through an echo receiving circuit; extracting a second moment s (t) of the coded ultrasonic echo signal r (t); converting the second-order moment signal s (t) into a high-order moment signal h (t); performing gain adjustment on the high-order moment signal h (t) to obtain a coded ultrasonic echo signal pulse flow p (t). The implementation circuit of the method comprises a code generation and excitation circuit, an echo receiving circuit,a second-order moment extraction circuit, a high-order moment conversion circuit and a gain adjustment circuit. According to the method disclosed in the invention, an analog circuit is adopted to obtain a high-order moment pulse flow of the coded ultrasonic echo signal in real time, the signal has the characteristics of high signal-to-noise ratio and low sidelobe, and a detection range can be effectively expanded anddistance resolution can be effectively improved during defect detection.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic detection, and relates to a high-order moment-based coded ultrasonic signal pulse flow forming method and a circuit. Background technique [0002] Ultrasonic testing is an important means of non-destructive testing. The current excitation forms of ultrasonic signals can be divided into pulse excitation form and code excitation form. The pulse excitation generation method is simple and easy to adjust, but the amplitude of the excitation pulse determines the peak acoustic power of the initial wave, and in the detection of medical and acoustic high-attenuation materials, the emission energy cannot be increased without limit, so it often causes peak The sound power is close to the upper limit and the average sound power is still low. The average acoustic power is determined by the pulse width, increasing the average acoustic power requires increasing the pulse width, which leads to a decrease in d...

AI Technical Summary

Problems solved by technology

However, the encoded ultrasonic signal does not belong to the FRI signal, does not have the characteristics of the FRI signal, and does not meet the conditions for direct FRI sparse sampling

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