Method and device for precisely measuring ultrasonic wave transmission time

Abstract

The invention relates to a method and a device for precisely measuring ultrasonic wave transmission time. The method adopts two ultrasonic wave transducers A and B, a hardware circuit and a software subdivision algorithm. The hardware circuit mainly comprises an ultrasonic wave transducer drive circuit, an ultrasonic wave return signal filter circuit, an amplification circuit and a signal processing circuit. The signal processing circuit comprises an analog-to-digital (A / D) converter, an FPGA and a CPU. The CUP control the FPGA to start the ultrasonic wave transducer drive circuit to drive the transducer A to send an ultrasonic wave signal; the filter circuit filters and amplifies an ultrasonic wave return signal received by the ultrasonic wave transducer B; the A / D converter samples the wave return signal and stores the sampled data in a storage region constructed in the FPGA; and after the sampling is completed, the CPU reads the sampled data from the FPGA and accurately calculates the transmission time of the ultrasonic wave between the two transducers A and B by adopting the software subdivision algorithm. As the FPGA-based hardware circuit and the special software subdivisionalgorithm are adopted, the method and the device can realize the measurement of the ultrasonic wave transmission time with nanosecond precision and ensure good real-time.

Description

technical field [0001] The invention belongs to the technical field of precision sensors and detection, and in particular relates to a precision measurement technology of ultrasonic transmission time. Background technique [0002] The salient features of ultrasonic waves are high frequency, thus short wavelength, small diffraction phenomenon, good directionality, and directional propagation. In liquids and solids, the attenuation is small and the penetrating ability is strong. When encountering impurities or interfaces, there will be significant reflection. With the development of electronic technology, ultrasonic technology is more and more used in the precise measurement of distance and flow. [0003] When the ultrasonic wave propagates in the fluid, the time difference between the forward flow direction and the reverse flow direction is different. For example, the propagation speed of ultrasonic waves in clean water is about 1450m / s. Under the conditions of pipe diamete...

AI Technical Summary

Problems solved by technology

If a conventional timing and counting circuit is used, the frequency of the clock circuit must reach at least 1G, which is obviously difficult to achieve for instrument development.

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