Electronic device and acoustic wave range finding method thereof

Abstract

An embodiment of the invention discloses an electronic device and an acoustic wave range finding method thereof. According to the method, first sound wave signals of first and second frequency signals, namely double acoustic multi-frequency signals, are emitted, and distance between the electronic device and a target barrier is calculated according to a time difference between the first and secondfrequency signals in a first reception signal corresponding to the first acoustic wave signal. The problem that a measurement result cannot be obtained due to overlapping of emission time and reception time of the acoustic wave signal can be overcome; The acoustic wave signal is avoided from generating POP sound (an interference signal of an audio sub system) that can be heard by people because that the first and second frequency signals do not include harmonic waves in the audio field after mutual modulation; and the user experience is improved.

Description

technical field [0001] The present application relates to the technical field of sound wave distance measurement, and in particular to an electronic device and a sound wave distance measurement method thereof. Background technique [0002] The principle of ultrasonic ranging is: transmit an ultrasonic signal, record the time at the moment of transmission, and then detect the receiving time of the reflected signal generated by the reflected signal reflected by the target obstacle after the ultrasonic signal hits the target obstacle, and subtract the two times, that is The time from emission to reflection of the ultrasonic signal can be obtained, and the speed of sound in the air is known. Therefore, the distance from the ultrasonic signal emission point to the target obstacle can be obtained by using the time from emission to reflection of the ultrasonic signal. [0003] Since the transmission and reception of sound waves requires a certain amount of time (that is, both the t...

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Problems solved by technology

[0003] Since the transmission and reception of sound waves requires a certain amount of time (that is, both the transmitted signal and the received signal have a certain rising edge and falling edge), for short-distance tests, if the rising edge and falling edge are relatively gentle, when applied to electronic equipment, It will cause the transmission time and reception time of the acoustic signal to overlap, which cannot be measured, and if the rising edge and falling edge are very steep, so that there is a clear time difference between the receiving time and the transmitting time of the ultrasonic signal, to distinguish the received In the signal, it can be distinguished whether it is the reflected signal from the target obstacle or the conducted signal from the electronic device body, and it will generate certain noises in the audio frequency band (that is, generate harmonics in the audio field), which will affect the user experience.

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