第十三届数学中国数学建模网络挑战赛
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英文摘要
Three methods of using microphone array to locate sound source are currently studied m
ore highresolution spectral positioning method, controllable beam positioning method, time d
elay positioning method, considering that our sound source signal is an artificially generated s
ound source signal, with realtime , Discontinuity, transient stability, so we use the time delay
positioning method as the main method.
Considering the reverberation and noise interference in the indoor environment, we use
MATLAB to simulate the real signal received by the microphone and use the generalized cros
s-correlation method to find the time delay to reduce the impact of the reverberation signal.
For problem one, since the room size is known, the solution to the position of the footste
p sound source is the two dimensional plane. The height of the twodimensional plane is negl
igible, so the lower the height of the microphone array, the better. It can be obtained from theo
ry that at least three microphones are needed for the two dimensional plane. Since the placem
ent and rotation angle of the microphone array cannot be accurately known, we use the linea
r equalspace structure and the method of placing it in the corner of the room to easily determi
ne the position and rotation angle. Then continue to increase the spacing step by step, and dete
rmine the appropriate spacing according to the accuracy of the required results and the cost o
f control, and finally get the proper spacing of 20cm. Problem 1 The final microphone array i
s a ternary linear equal spacing array with a spacing of 20cm .
For problem two, the room size needs to be solved, so we convert the two-dimensional pl
ane into a three-dimensional plane. Since the position of the three-dimensional plane is more c
omplicated, we introduce the spherical interpolation method to solve the position of the soun
d source. The number of microphones has also been increased from three to four. Through exp
erimental comparison, we have found that the microphone array with a regular tetrahedral stru
cture has the highest accuracy, and then the method of gradually increasing the spacing is use
d to find the most suitable when the spacing is 25cm. Since R of the cross-correlation functio
n has multiple peaks, we can estimate the delay of the signal of the path other than the direct p
ath according to different peaks, Assuming that the wall reflects only once, find the position
s of the sound source and the mirrored sound source.Finally, according to the coordinates of th
e sound source and the mirror sound source, the geometrical principle is used to obtain the siz
e of the room.Problem 2: The final microphone array is a regular tetrahedron structure, eac
h microphone is located at each vertex of the tetrahedron, with a spacing of 25cm.
