System and method for measuring distance using acoustic signal

An electronic apparatus comprising:

• a plurality of sound sources comprising a first sound source and a second sound source spaced apart from each other, the first sound source and the second sound source being configured to generate a plurality of acoustic signals;
• an acoustic sensor interposed between the first sound source and the second sound source, the acoustic sensor comprising a first directional acoustic sensor and a second directional acoustic sensor arranged symmetrically with respect to each other relative to a front direction of the acoustic sensor and to be inclined at a certain angle with respect to the front direction of the acoustic sensor, wherein the first directional acoustic sensor and the second directional acoustic sensor are configured to generate output signals by sensing the plurality of acoustic signals generated by the first sound source and the second sound source, and the acoustic sensor has a bi-directionality in a particular direction based on directionalities of the first directional acoustic sensor and the second directional acoustic sensor;
• a controller configured to control a phase difference between the plurality of acoustic signals generated by the plurality of sound sources by adjusting a delay time between the plurality of acoustic signals, wherein the plurality of acoustic signals have a directionality in a desired direction based on the controlled phase difference;
• and
• at least one processor configured to:
• adjust the acoustic sensor to have a directional characteristic in the desired direction, that is different from the particular direction, based on at least one of an addition of the output signals of the first directional acoustic sensor and the second directional acoustic sensor or a subtraction between the output signals of the first directional acoustic sensor and the second directional acoustic sensor, the at least one of the addition or the subtraction being based on applying a weight to at least one of the output signals, wherein a value of the weight is adjusted to obtain the directional characteristic of the acoustic sensor in the desired direction, and
• determine a distance between the acoustic sensor and a reflection surface based on a time for an acoustic signal to arrive at the acoustic sensor in the desired direction after being generated and then reflected from the reflection surface,
• wherein a distance between the first sound source and the second sound source corresponds to one half of a wavelength of each of the first sound source and the second sound source.

A distance measurement method, comprising:

• generating a plurality of acoustic signals in a plurality of sound sources comprising a first sound source and a second sound source spaced apart from each other;
• receiving an acoustic signal by an acoustic sensor, the acoustic sensor being interposed between the first sound source and the second sound source, the acoustic sensor comprising a first directional acoustic sensor and a second directional acoustic sensor arranged symmetrically with respect to each other relative to a front direction of the acoustic sensor and to be inclined at a certain angle with respect to the front direction of the acoustic sensor, wherein the first directional acoustic sensor and the second directional acoustic sensor are configured to generate output signals by sensing the plurality of acoustic signals generated by the first sound source and the second sound source, and the acoustic sensor has a bi-directionality in a particular direction based on directionalities of the first directional acoustic sensor and the second directional acoustic sensor;
• controlling a phase difference between the plurality of acoustic signals generated by the plurality of sound sources by adjusting a delay time between the plurality of acoustic signals, wherein the plurality of acoustic signals have a directionality in a desired direction based on the controlled phase difference;
• adjusting the acoustic sensor to have a directional characteristic in the desired direction, that is different from the particular direction, based on at least one of an addition of the output signals of the first directional acoustic sensor and the second directional acoustic sensor or a subtraction between the output signals of the first directional acoustic sensor and the second directional acoustic sensor, the at least one of the addition or the subtraction being based on applying a weight to at least one of the output signals, wherein a value of the weight is adjusted to obtain the directional characteristic of the acoustic sensor in the desired direction;
• and
• determining a distance between the acoustic sensor and a reflection surface based on a time for the acoustic signal to arrive at the acoustic sensor in the desired direction after being generated and then reflected from the reflection surface,
• wherein a distance between the first sound source and the second sound source corresponds to one half of a wavelength of each of the first sound source and the second sound source.