Ultrasonic wave ranging method

Abstract

The invention belongs to the ultrasonic wave ranging field and especially relates to an ultrasonic wave ranging method. The method comprises the following steps that on an ultrasonic wave transmitting terminal, a pulse signal is coded, a coded signal is used to modulate a carrier wave, and a modulated pulse excitation sequence to excite an ultrasonic wave sensor; an emitted signal is spread in air and is reflected after encountering a barrier, and an echo signal enters into an ultrasonic wave receiving end; and on the receiving end, the echo signal and a reference signal which is stored in advance are used to carry out correlation operation, time delay is continuously performed on the reference signal so as to acquire a cross-correlation function peak value and then acquire transit time, and then a distance is acquired. In the method, under the condition that a signal to noise ratio is small, the transit time can be still accurately estimated so that a problem that a first wave of threshold of a detection echo signal is difficult to set is solved; and a crosstalk problem generated when ranging is performed on a plurality of ultrasonic waves simultaneously can be solved too.

Description

technical field [0001] The field of ultrasonic distance measurement of the present invention is specifically an ultrasonic distance measurement method. Background technique [0002] Sound waves are divided according to the ability of the human ear to distinguish sound, and can be divided into infrasonic waves, sound waves, and ultrasonic waves according to frequency differences. According to the vibration theory, it can be defined that ultrasonic wave is an elastic vibration with a frequency higher than 20KHz, which belongs to the category of mechanical waves. [0003] In the field of ultrasonic testing, ultrasonic waves can be divided into longitudinal waves, transverse waves, surface waves and Lamb waves, which are divided according to the different directions of ultrasonic propagation and vibration [38]. Since the ultrasonic ranging is mainly carried out in the air medium, the air medium cannot transmit the transverse shear stress, so the waves used by most ultrasonic ra...

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Problems solved by technology

[0029] The technical problem to be solved by the present invention is to provide a method of ultrasonic distance measurement, which solves the problems of difficult setting of the first wave threshold of the detection echo signal and ultrasonic crosstalk

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