Directional acoustic sensor, and methods of adjusting directional characteristics and attenuating acoustic signal in specific direction using the same
Disclosed are a directional acoustic sensor, a method of adjusting directional characteristics using the directional acoustic sensor, and a method of attenuating an acoustic signal in a specific direction using the directional acoustic sensor. The directional acoustic sensor includes a plurality of resonance units arranged to have different directionalities and a signal processor configured to adjust directional characteristics by calculating at least one of a sum of and a difference between outputs of the resonance units. In this state, the signal processor attenuates an acoustic signal in a specific direction by using a plurality of directional characteristics obtained by calculating at least one of the sum of and the difference between the outputs of the resonance units at a certain ratio.
1. A directional acoustic sensor comprising:
a plurality of resonance units arranged to have different directionalities, the plurality of resonance units comprising a first resonance unit and a second resonance unit that are arranged to have an angle less than 180 degrees with respect to each other; and
a signal processor configured to adjust directional characteristics of a first output signal and a second output signal that are received from the first resonance unit and the second resonance unit,
wherein the signal processor attenuates an acoustic noise signal by calculating at least one of a sum of the first output signal and the second output signal and a difference between the first output signal and the second output signal at a predetermined ratio.
2. The directional acoustic sensor of claim 1 , wherein
each of the first resonance unit and the second resonance unit comprises:
a substrate having an aperture; and
at least one resonator provided on the substrate.
3. The directional acoustic sensor of claim 1 , wherein
the signal processor is further configured to acquire a first directional signal corresponding to a first direction by calculating the sum of the first output signal and the second output signal, and acquire a second directional signal corresponding to a second direction by calculating the difference between the first output signal and the second output signal.
4. The directional acoustic sensor of claim 1 , wherein
the signal processor is further configured to adjust at least one of output levels of the first output signal and the second output signal, and calculate the sum or the difference based on the adjusted at least one of the output levels.
5. The directional acoustic sensor of claim 1 , wherein
the signal processor is further configured to attenuate the acoustic noise signal generated in a second direction by processing a first signal that is obtained from the first resonance unit and the second resonance unit and is oriented in a first direction, and processing a second signal that is obtained from the first resonance unit and the second resonance unit and is oriented in the second direction perpendicular to the first direction.
6. The directional acoustic sensor of claim 5 , wherein
each of the first signal and the second signal is obtained by summing the first output signal and the second output signal generated in the first direction and the first output signal and the second output signal generated in the second direction at the predetermined ratio.
7. A method of adjusting directional characteristics of a directional acoustic sensor, the method comprising:
receiving a first output signal and a second output signal from a first resonance unit and a second resonance unit arranged to have different directionalities, and
attenuating an acoustic noise signal by adjusting directional characteristics of the first output signal and the second output signals,
wherein the acoustic noise signal is attenuated by calculating at least one of a sum of the first output signal and the second output signal and a difference between the first output signal and the second output signal at a predetermined ratio.
8. The method of claim 7 , wherein the adjusting the directional characteristics of the first output signal and the second output signal comprises:
acquiring first directional characteristics of a first direction by calculating the sum of the first output signal and the second output signal; and
acquiring second directional characteristics of a second direction that is perpendicular to the first direction by calculating the difference between the first output signal and the second output signal.
9. The method of claim 7 , wherein the adjusting the directional characteristics of the first output signal and the second output signal comprises:
adjusting at least one of output levels of the first output signal and the second output signal, and
calculating the sum or the difference based on the adjusted at least one of the output levels.
10. The method of claim 7 , wherein
each of the first resonance unit and the second resonance unit comprise:
a substrate having an aperture; and
at least one resonator provided in the substrate,
wherein the first resonance unit and the second resonance unit are arranged to form an angle less than 180 degrees with each other.
11. The method of claim 7 , wherein the attenuating the acoustic noise signal comprises:
attenuating the acoustic noise signal in a second direction by processing a first signal that is obtained from the first resonance unit and the second resonance unit oriented in a first direction, and processing a second signal that is obtained from the first resonance unit and the second resonance unit oriented in the second direction, the second direction being perpendicular to the first direction.
12. The method of claim 11 , wherein the processing the first signal and the processing the second signal comprises:
summing the first and the second output signals generated in the first direction and the first and the second output signals generated in the second direction at the predetermined ratio.