研究了一种新型的空速测量方法。通过引入大气声学中的有效声速概念,建立了稳定气流作用下声矢量传感器阵列的近场输出模型,模型的阵列流形矢量中包含了待估计的空速信息。在此基础上提出了一种基于多重信号分类(multiple signal classi...研究了一种新型的空速测量方法。通过引入大气声学中的有效声速概念,建立了稳定气流作用下声矢量传感器阵列的近场输出模型,模型的阵列流形矢量中包含了待估计的空速信息。在此基础上提出了一种基于多重信号分类(multiple signal classification,MUSIC)的空速估计(airspeed estimation,ASE)算法,该算法可用于对空速的高精度估计。为了降低计算复杂度,进一步提出了一种快速的空速估计(fast airspeed estimation,FASE)算法,该算法虽然在ASE的精度上不如MUSIC-ASE算法,但无需谱搜索,具有更强的实时性。最后,对算法的估计性能进行分析,推导了ASE的克拉美-罗界表达式。仿真实验验证了算法的有效性。展开更多
研究如何利用信号的非圆性提高声矢量阵列信号波达方向(Directon of arrival,DOA)估计的精度。提出通过广义相位平滑预处理提高多重信号分类(Multiple signal classification,MUSIC)DOA估计方法特征子空间对数据协方差矩阵扰动的鲁棒性...研究如何利用信号的非圆性提高声矢量阵列信号波达方向(Directon of arrival,DOA)估计的精度。提出通过广义相位平滑预处理提高多重信号分类(Multiple signal classification,MUSIC)DOA估计方法特征子空间对数据协方差矩阵扰动的鲁棒性。该法适用于任意中心对称声矢量阵列,且无需子阵划分,不存在孔径损失,并可完成两个多径信号的解相干。仿真结果表明,广义相位平滑处理可明显改善恶劣条件下(低信噪比,小快拍数)基于MUSIC的非圆信号DOA估计精度。展开更多
One-step patch near-field acoustical holography(PNAH) is a powerful tool for identifying noise sources from the partially known sound pressure field.The acoustical property to be reconstructed on the surface of intere...One-step patch near-field acoustical holography(PNAH) is a powerful tool for identifying noise sources from the partially known sound pressure field.The acoustical property to be reconstructed on the surface of interest is related to the partially measured pressure on the hologram surface in terms of sampling and bandlimiting matrices,which cost more in computation.A one-step procedure based on measuring of the normal component of the particle velocity is described,including the mathematical formulation.The numerical simulation shows that one-step PNAH based on particle velocity can obtain more accurately reconstructed results and it is also less sensitive to noise than the method based on pressure.These findings are confirmed by an underwater near-field acoustical holography experiment conducted with a vector hydrophone array.The experimental results have illustrated the high performance of one-step PNAH based on particle velocity in the reconstruction of sound field and the advantages of a vector hydrophone array in an underwater near-field measurement.展开更多
文摘研究如何利用信号的非圆性提高声矢量阵列信号波达方向(Directon of arrival,DOA)估计的精度。提出通过广义相位平滑预处理提高多重信号分类(Multiple signal classification,MUSIC)DOA估计方法特征子空间对数据协方差矩阵扰动的鲁棒性。该法适用于任意中心对称声矢量阵列,且无需子阵划分,不存在孔径损失,并可完成两个多径信号的解相干。仿真结果表明,广义相位平滑处理可明显改善恶劣条件下(低信噪比,小快拍数)基于MUSIC的非圆信号DOA估计精度。
基金supported by the National Natural Science Foundation of China(Grant No.11204049)the National Defence Research Funds (Grant No.7131107 and 51310040202)the Fundamental Research Funds For the Central Universities(Grant No.HEUCFR1013 and HEUCF120504)
文摘One-step patch near-field acoustical holography(PNAH) is a powerful tool for identifying noise sources from the partially known sound pressure field.The acoustical property to be reconstructed on the surface of interest is related to the partially measured pressure on the hologram surface in terms of sampling and bandlimiting matrices,which cost more in computation.A one-step procedure based on measuring of the normal component of the particle velocity is described,including the mathematical formulation.The numerical simulation shows that one-step PNAH based on particle velocity can obtain more accurately reconstructed results and it is also less sensitive to noise than the method based on pressure.These findings are confirmed by an underwater near-field acoustical holography experiment conducted with a vector hydrophone array.The experimental results have illustrated the high performance of one-step PNAH based on particle velocity in the reconstruction of sound field and the advantages of a vector hydrophone array in an underwater near-field measurement.
