Method and device for detecting precise arrival moment of ultrasonic wave

Abstract

The invention relates to a method and a device for detecting the precise arrival moment of an ultrasonic wave, and the method and the device are suitable for the application field of the high-precision ultrasonic detections, such as distance measurement, target tracking and positioning and flow detection. The method is based on a digital processing technology, and comprises the following steps: utilizing an A / D (analog to digital) converter to collect ultrasonic data, dynamically determining decision threshold levels reached by ultrasonic signals according to the characteristics of ultrasonic waveforms, and accurately calculating the arrival moment of the ultrasonic wave by utilizing a linear fitting method. The detection on the nanosecond stage precision can be realized through simple research and arithmetical operation at the low sampling rate. The invention provides the detection method with low calculation amount and high precision for high-precision ultrasonic detections, such as distance measurement, target tracking and positioning and flow detection.

Description

technical field [0001] The invention relates to a method and device for detecting the precise arrival time of ultrasonic waves, in particular to a method and device for detecting the arrival time of ultrasonic waves based on ultrasonic ranging, tracking and positioning, flow detection, and the like. Background technique [0002] In the measurement of distance, flow, positioning, liquid level, temperature and other parameters based on ultrasonic technology, it is usually necessary to accurately measure the transmission time of ultrasonic waves in the medium, so as to realize the measurement of the measured object directly or through engineering conversion. Transmission time is the transit time for the ultrasonic signal emitted by the transmitter to reach the receiver, and the ultrasonic emission moment can be generated by internal synchronization signal, infrared signal or radio frequency signal. The traditional fixed threshold comparison method includes single threshold meth...

AI Technical Summary

Problems solved by technology

However, in practical applications, affected by the density, temperature, flow and other factors of the transmission medium, the attenuation of the ultrasonic signal is large, and its amplitude changes greatly. Even if the automatic gain adjustment circuit is used, it is difficult to achieve high-precision detection. Therefore, based on The detection method with fixed threshold is less accurate

Based on time of flight (TOF: time of flight) estimation algorithms such as correlation function, wavelet transform and double exponential, the amount of calculation is large, and it requires high sampling rate and real-time processing capability, and the accuracy is difficult to guarantee

In practical engineering applications, there are many factors that affect the amplitude of the ultrasonic received signal, resulting in large changes in the amplitude of the ultrasonic signal. It is of practical application value to study a method and device for detecting the arrival time of ultrasonic waves that is independent of the amplitude change of the received signal.

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