Transit-time difference ultrasonic flow velocity measurement method using frequency hopping signal

Abstract

The invention discloses a time-difference ultrasonic flow velocity measurement method using a frequency hopping signal. The second transducer receives the ultrasonic signal emitted by the first transducer, detects the demarcation point of different signal segments, that is, the frequency hopping point, and determines the receiving time of the ultrasonic signal according to the time of the frequency hopping point and the duration of each signal segment; The transducer receives the ultrasonic signal emitted by the second transducer, detects the demarcation point of different signal segments, that is, the frequency hopping point, and determines the receiving time of the ultrasonic signal according to the time of the frequency hopping point and the duration of each signal segment; compares the receiving time of the ultrasonic signal time, calculate the time difference; use the time difference method to calculate the flow velocity of the fluid according to the time difference. The method of the invention has high measurement accuracy, high flow velocity measurement stability, strong anti-interference ability and good environmental adaptability.

Description

technical field [0001] The invention belongs to the field of fluid flow velocity measurement, and in particular relates to a time difference ultrasonic flow velocity measurement method using frequency hopping signals. Background technique [0002] The time-difference method is used to measure the average velocity of the river (canal) end surface, which is to use the characteristics of different propagation speeds due to different fluid flow directions when the sound wave propagates in the fluid, and measure the difference between the forward-flow propagation time and the upstream-flow propagation time of the sound signal, thereby calculating The speed of fluid flow, the principle is as attached figure 1 shown. [0003] Existing ultrasonic current meters mainly use the method of single-frequency pulse signal amplitude detection to measure the sound wave propagation time. The detection method is shown in the attached figure 2 shown. The receiving circuit at both ends of th...

AI Technical Summary

Problems solved by technology

Acoustic propagation time measurement accuracy is greatly affected by the amplitude consistency of the two received signals, which requires high transducer parameter consistency and equipment matching, which reduces production efficiency and increases production costs

The amplitude of the underwater acoustic signal is greatly affected by factors such as water surface, underwater reflection, and foreign object occlusion. It has high requirements for the equipment installation environment, which increases the difficulty of installation and reduces the environmental adaptability of the equipment.

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