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Z. Zhao et al.
some new localization methods are introduced to AET. Among them, AE Beamforming method is a superior localization method. Compared with TDOA method,
beamforming has some particular advantages, such as the simplified sensor arrangement, negligible channel attenuation, and localization of multiple sources. But its
localizing accuracy is affected by many variables such as wave velocity, array position and artifacts structure, and its location in the vertical array direction is relatively
sensitive, while the localizing parallel to the array direction is relatively stable [5].
So, Beamforming still needs to be improved.
Based on the localization characteristics of beamforming, this paper proposes a
improved localizing method by introduced X arrays, and verifies the localizing effect
of the presented method.
5.2 The Establishment of the Improved Beamforming
Based on X Array
Beamforming uses arrays composed of a group of sensors distributed in a fixed
position in space to measure the sound field. The acoustic emission sensor in the
arrays plays a role in collecting waveforms. Due to the large number of sensors in
use, the placement of sensors has a great impact on the accuracy of the localizing
results. This experiment adopts simulation method to study the influence of array
placement on the localizing results.
5.2.1 Linear Array
A linear array is the most direct and simplest array, the basic form of all arrays.
Placing multiple sensors on the same line creates a linear array. The position of
sensor and sound source are shown in Fig. 5.1.
As can be seen from Fig. 5.1, the projection of the sound source point on the linear
array falls within the array segment. To study the localizing range of linear array,
the location of the point source of simulation experiments should be changed for
many times. Considering the large model and time consuming of calculation, so we
fix the source location and rotate the sensors for 10° clockwise each time, the center
is the midpoint of the array, then we get 10 arrays, the result is shown in Fig. 5.2.
Calculating time is reduced and efficiency is improved. By calculating the 10 groups
of data, the localizing results are shown in the Fig. 5.3.
The deviation distance is the linear distance between the location point and the
acoustic source point, and the calculation formula is as follows:
s =
(X − x 0 )
2
− (Y − y 0 )
2
(5.1)
Z. Zhao et al.
some new localization methods are introduced to AET. Among them, AE Beamforming method is a superior localization method. Compared with TDOA method,
beamforming has some particular advantages, such as the simplified sensor arrangement, negligible channel attenuation, and localization of multiple sources. But its
localizing accuracy is affected by many variables such as wave velocity, array position and artifacts structure, and its location in the vertical array direction is relatively
sensitive, while the localizing parallel to the array direction is relatively stable [5].
So, Beamforming still needs to be improved.
Based on the localization characteristics of beamforming, this paper proposes a
improved localizing method by introduced X arrays, and verifies the localizing effect
of the presented method.
5.2 The Establishment of the Improved Beamforming
Based on X Array
Beamforming uses arrays composed of a group of sensors distributed in a fixed
position in space to measure the sound field. The acoustic emission sensor in the
arrays plays a role in collecting waveforms. Due to the large number of sensors in
use, the placement of sensors has a great impact on the accuracy of the localizing
results. This experiment adopts simulation method to study the influence of array
placement on the localizing results.
5.2.1 Linear Array
A linear array is the most direct and simplest array, the basic form of all arrays.
Placing multiple sensors on the same line creates a linear array. The position of
sensor and sound source are shown in Fig. 5.1.
As can be seen from Fig. 5.1, the projection of the sound source point on the linear
array falls within the array segment. To study the localizing range of linear array,
the location of the point source of simulation experiments should be changed for
many times. Considering the large model and time consuming of calculation, so we
fix the source location and rotate the sensors for 10° clockwise each time, the center
is the midpoint of the array, then we get 10 arrays, the result is shown in Fig. 5.2.
Calculating time is reduced and efficiency is improved. By calculating the 10 groups
of data, the localizing results are shown in the Fig. 5.3.
The deviation distance is the linear distance between the location point and the
acoustic source point, and the calculation formula is as follows:
s =
(X − x 0 )
2
− (Y − y 0 )
2
(5.1)