全息声压场的加权范数外推方法

全息声压外推是Patch近场声全息技术的关键步骤.本文提出了全息声压的加权范数外推方法,该方法首先通过实测声压数据的功率谱信息构造频域加权范数,然后通过极小化频域加权范数实现全息声压外推.由于外推过程中同时利用了声压信号的波数域带宽和波数谱形状信息,因此其外推结果优于传统带限外推方法.数值仿真结果表明,该方法无论在外推精度还是计算效率上都明显优于经典的全息声压波数域外推方法.刚性箱体上的声激励固支板声压外推实验进一步验证了该方法的有效性和实用性. 关键词： 近场声全息 全息声压外推 加权范数

Hologram pressure field weighted norm extrapolation method

Hologram pressure extrapolation is a key process of Patch nearfield acoustic holography. In this paper, a pressure extrapolation method based on the weighted norm extrapolation is proposed, in which the auto-power spectrum of hologram pressure estimated by the measured data is used as a weighting function to build the weighted norm, and the hologram pressure extrapolation is realized by minimizing the weighted norm. Because both the spectrum shape and the bandwidth information about hologram pressure are utilized during the extrapolation, a more accurate extrapolated result can be achieved. The validity of the proposed method is proved by a numerical simulation and an experiment study. The simulation results show that the proposed method has obviously advantages in accurcy and computational efficiency compared with the classic wave number domain extrapolation method. Furthermore, the proposed method is used to extrapolate a pressure field generated by a camped steel plate in experiment and a satisfactory result is obtained.