误差均衡立体五基元超短基线水声定位
Ultra-short baseline positioning basing on error equalization in a five-element stereo array

采用单平面基阵进行超短基线水声定位，当声源俯仰角接近基阵平面，会导致定位误差增加。为解决该问题，提出了基于空间五基元立体基阵子阵误差均衡的定位方法。该方法将空间立体基阵划分为正交的三基元子阵，在各子阵局部坐标系中分别解算定位结果，通过坐标变换将子阵局部坐标系转化为立体阵全局坐标；最终定位数据时，根据原局部坐标系下解算结果与理论结果的误差大小进行加权，对全局坐标系下的数据加权平均。MATLAB的仿真表明：该方法可实现空间立体基阵全空间方位目标声源的定位解算，定位精度比单一基阵面提高4倍以上；并解决了声源目标俯仰角接近单基阵平面时，定位精度误差急剧增大的问题，使整个定位空间内的定位结果误差变化均衡。
Abstract：Ultra-short baseline positioning using a single-plane base array will lead to increased positioning errors when the acoustic source is close to the plane of the base array. This paper presents a method to reduce the error using different array planes which can be localized in one stereo five-element array. The stereo array can be divided into several sub-arrays having three basic elements in different orthogonal directions. The positioning data in the local coordinate system of the sub-array is first translated into the global coordinate system of the entire stereo array by a transformation matrix with a weighted average then calculated with the weighting based on the positioning error which is related to the change in the elevation angle in the local coordinate system of the sub-array. Simulations in MATLAB showed that this method can realize positioning localization of a spatially azimuthal target sound source. The positioning accuracy is more than 4 times higher than for a single array because the relative positioning error from all directions of the stereo array is smoothed due to the different elevation angles. Thus, this method significantly reduces the positioning error when the pitch angle of the sound source is close to the single base array plane.