Gur Berke
Department of Mechatronics Engineering, Bahcesehir University, Istanbul, Turkey.
J Acoust Soc Am. 2014 Jun;135(6):3463-73. doi: 10.1121/1.4876180.
In this paper, a subtractive beamforming algorithm for short linear arrays of two-dimensional particle velocity sensors is described. The proposed method extracts the highly directional acoustic modes from the spatial gradients of the particle velocity field measured at closely spaced sensors along the array. The number of sensors in the array limits the highest order of modes that can be extracted. Theoretical analysis and numerical simulations indicate that the acoustic mode beamformer achieves directivity comparable to the maximum directivity that can be obtained with differential microphone arrays of equivalent aperture. When compared to conventional delay-and-sum beamformers for pressure sensor arrays, the proposed method achieves comparable directivity with 70%-85% shorter apertures. Moreover, the proposed method has additional capabilities such as high front-back (port-starboard) discrimination, frequency and steer direction independent response, and robustness to correlated ambient noise. Small inter-sensor spacing that results in very compact apertures makes the proposed beamformer suitable for space constrained applications such as hearing aids and short towed arrays for autonomous underwater platforms.
本文描述了一种用于二维粒子速度传感器短线性阵列的减法波束形成算法。该方法从沿阵列紧密排列的传感器所测量的粒子速度场的空间梯度中提取高指向性声学模式。阵列中的传感器数量限制了可提取的最高模式阶数。理论分析和数值模拟表明，声学模式波束形成器实现的指向性与等效孔径的差分传声器阵列所能获得的最大指向性相当。与传统的压力传感器阵列延迟求和波束形成器相比，该方法在孔径缩短70%-85%的情况下实现了相当的指向性。此外，该方法还具有其他能力，如高前后（左-右）分辨力、频率和转向方向无关响应以及对相关环境噪声的鲁棒性。传感器间间距小导致孔径非常紧凑，使得所提出的波束形成器适用于空间受限的应用，如助听器和用于自主水下平台的短拖曳阵列。
