An Adaptive Ultrasonic Echo Signal Detection Circuit

Abstract

The invention discloses an adaptive ultrasonic echo signal detection circuit. The echo signal connected by the front channel circuit is amplified and filtered, and the main channel circuit is re-amplified and zero-crossing compared to generate interference pulses. The main channel signal; the auxiliary channel circuit performs peak detection on the pre-received signal and attenuates it according to a certain ratio to obtain a comparison level. The gate signal is generated to perform an AND operation with the main channel signal, and the second pulse train signal is output to trigger the timing module to stop timing to obtain the time difference. The invention adopts the peak detection circuit and cooperates with the working mode of transmitting and receiving signals twice in a row, dynamically tracks the pre-received signal and flexibly adjusts the comparison level, and solves the problem of pulse train wave skipping; in addition, the function of the gating signal avoids the noise of the main channel The impact of pulses on time measurement, the main channel uses a zero-crossing comparator to solve the problem that the phase of the pulse train is leading or lagging within a quarter of the cycle.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic gas flow measurement, and more specifically relates to an adaptive ultrasonic echo signal detection circuit. Background technique [0002] In recent years, the ultrasonic gas flow measurement technology has developed rapidly, which has driven the rapid development of the ultrasonic gas flow meter industry. Compared with traditional flowmeters, ultrasonic gas flowmeters have many advantages such as wide measurement range, high precision, and strong stability, and are very suitable for industrial and civil gas measurement. [0003] The accuracy of the instantaneous flow rate of the ultrasonic gas flowmeter based on the time difference method mainly depends on the accuracy of measuring the time of the echo signal. In ultrasonic gas flow measurement, with the continuous increase of gas flow velocity and the uneven flow field of pipelines and other factors, the received echo signal will be attenuat...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an adaptive ultrasonic echo signal detection circuit, which solves the problem of burst wave skipping by using the auxiliary channel circuit and the main channel circuit to process the received echo signal and the issue of the pulse train being phase-leading or lagging within a quarter of a cycle

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