Laboratory for Robotics and Engineering Systems, University of Algarve, 8005-139 Faro, Portugal.
Algarve Technological Research Center, University of Algarve, 8005-139 Faro, Portugal.
Sensors (Basel). 2023 May 20;23(10):4931. doi: 10.3390/s23104931.
Underwater acoustic spiral sources can generate spiral acoustic fields where the phase depends on the bearing angle. This allows estimating the bearing angle of a single hydrophone relative to a single source and implementing localization equipment, e.g., for target detection or unmanned underwater vehicle navigation, without requiring an array of hydrophones and/or projectors. A spiral acoustic source prototype made out of a single standard piezoceramic cylinder, which is able to generate both spiral and circular fields, is presented. This paper reports the prototyping process and the multi-frequency acoustic tests performed in a water tank where the spiral source was characterized in terms of the transmitting voltage response, phase, and horizontal and vertical directivity patterns. A receiving calibration method for the spiral source is proposed and showed a maximum angle error of 3° when the calibration and the operation were carried out in the same conditions and a mean angle error of up to 6° for frequencies above 25 kHz when the same conditions were not fulfilled.
水下螺旋声源可以产生相位取决于方位角的螺旋声场。这使得能够估算相对于单个声源的单个水听器的方位角，并实现定位设备，例如用于目标检测或无人水下航行器导航，而无需使用水听器和/或投影仪阵列。本文介绍了一种由单个标准压电陶瓷圆柱制成的螺旋声源原型，该圆柱能够产生螺旋场和圆形场。本文报道了原型制作过程和在水箱中进行的多频声测试，其中根据发射电压响应、相位以及水平和垂直指向性图案对螺旋声源进行了表征。提出了一种用于螺旋声源的接收校准方法，当在相同条件下进行校准和操作时，最大角度误差为 3°，而当不满足相同条件时，频率高于 25 kHz 时的平均角度误差高达 6°。
